DISECCION AÓRTICA

La disección aórtica se caracteriza por la creación de una falsa luz en la capa media de la pared aórtica.

La forma típica de inicio sería un desgarro en la íntima a través del cual la sangre, impulsada por la presión con la que circula penetraría en la capa media disecando la pared aórtica.

Este nuevo trayecto de la sangre a través de la pared de la Aorta es la “Falsa Luz”.La parte interna de la pared disecada de la aorta es lo que en la literatura en inglés se denomina “Intimal Flap”.A medida que progresa la disección pueden crearse nuevos orificios en la capa íntima de la Aorta, tanto de salida de la sangre procedente de la falsa luz como de reentrada de sangre procedente de la luz verdadera.Aunque lo habitual es que la sangre progrese de forma anterógrada a lo largo de la falsa luz, también puede progresar hacia detrás, extendiéndose proximalmente.La distensión de la luz falsa puede hacer que la luz verdadera se vea constreñida, disminuyendo el calibre previo de la aorta.También puede suceder que la disección se inicie por la ruptura de los vasa vasorum dentro de la capa media de la Aorta, dando lugar a un “Hematoma Intramural”, que puede progresar hasta perforar la capa íntima y comunicar así la falsa luz con la

verdadera. De hecho, en un 13% de las autopsias de pacientes con diagnóstico previo de DA no se encuentra ninguna falta de continuidad en la íntima.

Clasificación

► Por la localización:Aproximadamente el 65% de las Disecciones se inician en la Aorta Ascendente (a <5cm de la Válvula Aórtica), 10% en el arco aórtico, 20% en la Aorta Torácica (justo después de la subclavia izq.), y un 5% en la Aorta abdominal.a) De Bakey:

I: inicio: Aorta Ascendente + Arco aórtico ó incluso Aorta descendente,II: inicio: Aorta Ascendente exclusivamente, sin afectar al arco aórtico.III: inicio: Aorta Descendente progresando distalmente, aunque puede

extenderse de forma retrógrada al arco aórtico y a la Aorta ascendente.

b) Stanford: A: todas las que afecten a la Aorta ascendente, independientemente del lugar en

el que se inicien,B: las demás. (Las de arco aórtico no quedan bien definidas: en general son “A”)

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c) -Proximal (DeBakey types I and II or Stanford type A), (hasta subclavia izq) -Distal (DeBakey type III or Stanford type B)Khan (2002) recomienda esta clasificación porque las otras dejan la duda en casos en que solo esté afectado el arco (y no la Ao Asc)

► Por el Tiempo de presentación:a) Aguda: Menos de dos semanasb) Crónica: dos semanas o más.

► Nueva clasificación (Svensson 1999) (Erbel 2001) (adoptada por la Task Force of the European Society of Cardiology)

Clase 1 : Disección clásica con Luz Verdadera y Falsa, con/sin comunicación.

Clase 2 : Hemorragia o Hematoma intramuralClase 3 : Pequeña Disección solo con abombamiento de la

pared aórticaClase 4 : Ulceración de una placa aórtica, siguiendo a la

ruptura de la placa.Clase 5 : Disección aórtica traumática o iatrogénica.

Recuerdo anatómico de la Aorta abdominal ylos troncos supraaórticos.

Etiología y Patogénesis

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El factor clave parece ser la degeneración de la media.La HTA (70-80% de los casos) y la Edad avanzada son dos de rasgos más típicos. El pico de incidencia está en la 6ª y 7ª décadas (55 en proximal, 65 en distal), y afecta el doble o triple a los hombres que a las mujeres.Son factores predisponentes la Arteriosclerosis y algunas enfermedades hereditarias del tejido conectivo como los Síndromes de Marfan (5 a 9% de la Disecciones, y la mayoría de las que se dan en <40 años) y el S. de Ehlers Danlos. También las E. autoinmunes, Anuloectasia, Predisposición familiar, Artritis Reumatoide, LES…

Otros factores de riesgo son la Válvula Aórtica Bicúspide (en 7-14%) de las disecciones y la Coartación Aórtica. Otros: Embarazo (la mitad de las disecciones en mujeres <40 años se presenta en embarazadas, a veces con S de Marfan asociado), S de Noonan y Turner, Arteritis (sobretodo la arteritis de células gigantes, el abuso de cocaína (Eagle 2002)...Los Traumatismos , la Cirugía Cardiac), el Cateterismo, o el BCPA también pueden actuar como causa etiológica. La Disección post Cirugía cardiaca ocurre a veces al de varios meses o años (Stanger 2002), sobre todo de reemplazamiento valvular aórtico y mas si se trataba de IAo con Aorta de paredes delgadas. En el registro del IRAD no parece conllevar una mayor mortalidad (Collins 2004, IRAD).

Clínica

Dolor: (96%) de los casos. Las Disecciones crónicas pueden no presentar dolor en el momento del diagnóstico. Típicamente es súbito y severo desde el principio. Puede ser migratorio (17%) siguiendo el camino de la disección. La localización es importante ya que se ha visto que en los casos de dolor anterior está afectada la Aorta ascendente en un 90 % de los casos (Spittell), y en caso de dolor interescapular está afectada la Ao descendente también en un 90%. Así mismo el dolor en el cuello, mandíbulas, etc. se asocia a la Disección de Aorta ascendente, y el dolor abdominal, de espalda o piernas a la afectación de aorta descendente. En algunos casos (raros) es de características pleuro-pericárdicas por hemorragia y pericarditis en la cavidad pericárdica, pudiendo dar lugar a un diagnóstico erróneo. El Taponamiento cardiaco conlleva una mortalidad del 25% en las primeras 24 horas.

Otros síntomas: Insuficiencia cardiaca congestiva (casi siempre por IAo) en un 7%, Síncope (9%), ACV(5%), Neuropatía isquémica periférica, Paraplejia, PCR, Muerte súbita. El síncope suele ser un signo de gravedad, a menudo producido por hemopericardio o mas raramente hemotórax (Brahmajee,2002) .

Exploración

- HTA: en el 70% de las distales y en el 36% de las proximales.

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- Hipotensión : se da en el 25% de las proximales (frecuentemente por taponamiento cardiaco), y en el 4% de las distales. La afectación de las arterias braquiocefálicas puede inducir a error (pseudo-hipotensión). - Pulsos disminuidos o asimétricos (se cen en 50% de las proximales y en 15% de las distales) por obliteración o estrechamiento de la luz.- Soplo de I Ao: (en 35-50% de las proximales). Con frecuencia previo a la disección, por afectación crónica del aparato valvular aórtico. La Regurgitación aórtica puede producirse en la disección proximal por dilatación de la raíz aórtica, por despegamiento de una de las valvas aórticas, o por prolapso de la íntima hacia el ventrículo izq.

Izq: íntima intacta comprimiendo la luz verdadera y causando malperfusión de una rama de la aorta.dcha. : La ruptura de la íntima puede o no devolver el flujo a la rama afectada.

La sangre contenida en la falsa luz puede actuar comprimiendo la salida de un de las ramas de la aorta. Por eso a veces la ruptura de la falsa luz puede mejorar la isquemia.

- Manifestaciones neurológicas: 6-19%. ACV (3-6%. Paraplejia. Coma. Por afectación carotídea, espinal…- Infarto renal, Fracaso renal e HTA severa por compromiso de la arteria renal (5-8%).- Isquemia e infarto mesentérico (3-5%).- Déficit de pulsos femorales (12%) por compromiso de las arterias ilíacas, con dolor torácico mínimo que nos puedeconfundir con embolismo periférico.

- IAM: es poco frecuente : 1-2% por afectación del ostium coronario (más el derecho). Puede confundir el diagnóstico, lo que en caso de trombolísis puede ser catastrófico. . .

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- Otras manifestaciones clínicas pueden ser hemotórax, hemoptisis y hematemesis por roturas en el espacio pleural, bronquios o esófago. Ocasionalmente se han descrito roturas en la aurícula derecha o izquierda, en el ventrículo derecho con fallo cardíaco. También, Síndrome de vena cava superior, pulsación esternoclavicular, masa pulsátil cervical y síndrome de Horner. La mortalidad sube un 1-2%/h (>40% al de 1 semana, >50% al de un mes) (Khan, 2002 70% en la 1ª semana y 80% a las 2 s. Sin cirugía 90% fallecen al de 3 meses. En 1995 Fann, de Stanford, reportaba una mortalidad por encima del 25% en pacientes intervenidos entre 1963 y 1992 por disección A o B, aguda o crónica: en 360 pacientes). Apaydin (2002) también señala una mortalidad del 25%. Ehrlich (2000) del Mount Sinai del 15,4% (19/124). Mészáros (2000) de Hungría 68% en las primeras 48 horas.Nienaber (2004) señala una mayor mortalidad en mujeres 832% vs 22% (IRAD)En 1996 se creó un Registro Internacional de Disección Aórtica : IRAD: International Registry of Aortic Dissection (18 centros en 6 países) (Hagan 2000), cuyos datos en cuanto a la clínica resumimos a continuación (Trimarchi 2005).

Variable Total (n = 526) Sobrev. (n = 394)

Exitus (n = 132) (25%) P

Dolor (cualquier) 470 (89.4) 354 (89.8) 116 (87.9) .53

Inicio brusco 426 (85.5) 322 (85.4) 104 (86.0) .88

Dolor en el pecho 416 (81.6) 316 (82.7) 100 (78.1) .25

Dolor abdominal 110 (22.0) 82 (21.9) 28 (22.2) .94

Severidad: dolor severo, o máximo 378 (91.3) 278 (89.4) 100 (97.1) .02

Dolor migratorio 69 (14.2) 44 (12.1) 25 (20.5) .02

Síncope 98 (19.4) 69 (18.2) 29 (23.2) .22

Déficit de pulso (cualquier) 139 (31.0) 90 (26.9) 49 (43.0) .001

Fallo cardiaco congestivo 27 (5.4) 25 (6.7) 2 (1.6) .03

Déficit neurológico (nuevo) 68 (13.6) 45 (11.8) 23 (19.5) .03

ECG normal 153 (31.0) 127 (33.9) 26 (22.0) .02

ECG con HTVI 101 (21.6) 79 (22.2) 22 (19.8) .60

ECG con Isquemia miocárdica 94 (19.9) 64 (17.8) 30 (26.8) .04

ECG con IAM, Q nuevas, o alt. ST 28 (6.0) 16 (4.5) 12 (10.9) .01

Isquemia mioc. Preoperatoria 52 (10.4) 35 (9.3) 17 (13.9) .14

IAM preoperatorio 18 (3.6) 10 (2.7) 8 (6.6) .06

Isquemia-infarto mesentérico 10 (2.0) 8 (2.1) 2 (1.6) >.99

Isquemia EE 48 (9.7) 29 (7.8) 19 (15.8) .009

FRA 22 (4.4) 16 (4.3) 6 (5.0) .75

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Variable Total (n = 526) Sobrev. (n = 394)

Exitus (n = 132) (25%) P

Taponamiento cardiaco 78 (15.7) 44 (11.8) 34 (27.6) <.0001

Estado hemodinámico preoperatorio en pacientes con Disección tipo “A” (IRAD)

Variable Total (n = 526) Sobrev (n = 394) Exit (n = 132) P

TA al ingreso

TA S >150 mm Hg 160 (32.4) 128 (34.2) 32 (26.7) .12

TA S 100-149 mm Hg 213 (42.9) 176 (46.9) 37 (30.6) .002

TA S <100 mm Hg 88 (17.6) 50 (13.3) 38 (30.4) <.0001

Shock o TC (TAS ≤80 mm Hg) 82 (16.1) 47 (12.3) 35 (27.6) <.0001

Hemodinámica peroperatoria

TA S <100 mm Hg 153 (31.0) 79 (21.4) 74 (59.2) <.001

TA S 100-149 mm Hg 262 (53.9) 219 (60.5) 43 (34.7) <.001

Disfunción VI 63 (13.0) 34 (9.3) 29 (24.2) <.001

Disfunción VD 31 (6.4) 10 (2.8) 21 (17.5) <.001

Datos demográficos y antecedentes de los pacientes con Disección “A” quirúrgicos

Variable Total (n = 526) Sobrev (n = 394) Exit (n = 132) P

n (%) 526 (100.0) 394 (74.9) 132 (25.1) —

Edad 59.7 ± 13.6 58.7 ± 13.2 62.5 ± 14.2 .005

Edad ≥70 a 139 (26.5) 91 (23.2) 48 (36.4) .003

Mujeres 158 (30.1) 108 (27.5) 50 (37.9) .02

Marfan 31 (6.0) 25 (6.4) 6 (4.8) .51

Hipertensión 354 (68.9) 268 (69.3) 86 (67.7) .75

Aterosclerosis 138 (26.9) 100 (25.8) 38 (30.2) .34

Aneurisma aórtico conocido 51 (10.0) 39 (10.1) 12 (9.7) .90

Disección aórtica previa 14 (2.7) 14 (3.6) 0 (0.0) .03

Diabetes mellitus 16 (3.2) 13 (3.4) 3 (2.4) .77

Cirugía cardiaca previa 76 (17.2) 53 (15.9) 23 (21.1) .21

Prótesis Aórtica previa 22 (4.4) 13 (3.5) 9 (7.4) .07

Disecc o Aneur intervenido 25 (5.0) 18 (4.8) 7 (5.8) .66

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Variable Total (n = 526) Sobrev (n = 394) Exit (n = 132) P

BP AoCo previo 31 (6.3) 21 (5.6) 10 (8.1) .32

Cirugía mitral previa 2 (0.4) 2 (0.5) 0 (0.0) >.99

Iatrogénico 28 (5.8) 19 (5.2) 9 (7.8) .30

Válvula aórtica bicúspide 15 (4.9) 12 (5.2) 3 (3.9) >.99

EXPLORACIONES

Exploración física:

El paciente suele impresionar de gravedad y estar bastante ansioso. En los aneurismas crónicos a veces el dolor no es tan lacerante. Hay que buscar signos de hipoperfusión de las extremidades, del cerebro, o de otras vísceras. Es importante, ante la sospecha de Disección, explorar los pulsos femorales, radiales y carotídeos y tomar la TA en ambos brazos. También se debe prestar especial atención a la función renal. Sospechar isquemia intestinal (dolor, acidosis…). La presencia de síncope o ACV incrementa la gravedad. La pérdida de perfusión a nivel de las intercostales y lumbares puede llevar a isquemia medular y paraplejia. Es relativamente fácil confundir el cuadro con otros como IAM, TEP. Pericarditis, Dolor músculo-esquelético, etc. Los síntomas pueden variar en el tiempo a medida que la disección progresa o se producen reentradas en la verdadera luz. Como ya hemos dicho, puede haber taquicardia e HTA, pero también Hipotensión por taponamiento (muy mal pronóstico, Bayegan 2001), IAo, Rotura aórtica, IAM asociado, etc. A la Auscultación puede oírse soplo de IAo, roce pericárdico, S3, o disminución de la ventilación por derrame o hemotórax.… Puede haber ingurgitación yugular por TC. También S de V Cava S, S de Horner, Hemoptisis, y compresión de vías aéreas o parálisis de cuerdas vocales. .

Radiografía de Tórax:

A menudo es la primera exploración encaminada a establecer el diagnóstico. El signo característico es la distorsión de la silueta aórtica y el ensanchamiento mediastínico. En caso de calcificación aórtica puede a veces verse la calcificación de la íntima separada del borde externo de la silueta ( ±1 cm ). Sin embargo hay que tener muy en cuenta que un mediastino ensanchado o una aorta tortuosa (frecuente en los ancianos) no confirma ni descarta per se la existencia de una disección aórtica.

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En ocasiones el principal valor de la RX puede ser el ayudar a diagnosticar otras posibles causas del dolor o la insuficiencia cardiaca (neumotórax, atelectasia, neoplasia, EAP…).Si es posible se debe comparar con RX previas.Es relativamente frecuente el derrame pleural (+ izq) sobretodo en disección de Aorta torácica descendente.

ECG:

Puede servir para descartar IAM. Hay que tener en cuenta que la afectación coronaria en la Disección proximal puede afectar a las coronarias y producir IAM.Otros hallazgos frecuentes son la HTFVI secundaria a cardiopatía hipertensiva.En sí mismo tiene escaso valor para diagnosticar la presencia de Disección.

Laboratorio:

Puede haber alteraciones derivadas de las complicaciones de la Disección (Crp↑, etc.).Recientemente se ha publicado la posible utilidad de la detección de miosina (Suzuki 2000), pero no suele ser una prueba disponible. La disección al dañar la media liberaría proteínas estructurales como la miosina de cadena pesada, a la circulación, que podrían ser detectadas por inmunoensayo. Los niveles se elevan significativamente en las 6 primeras horas de la disección. Niveles > 2.5 µg/L serían sugestivos, pero también puede aumentar en el IAM. Con >10 µg/L la especificidad es del 100%.D-dímeros: parece que están generalmente elevados (en torno a 9,4 µg/mL 0,6-55) [normal 0.5 µg/mL], pero hace falta mas estudios. (Perez, 2004)(Weber. D-dimer in Acute Aortic Dissection. Volume 123 • Number 5 • May 2003)

Técnicas diagnósticas de confirmación (Imagen)

Los objetivos son: 1) Confirmar el diagnóstico, 2) determinar si la Aorta ascendente está afectada (A) o solo la descendente (B), 3) Identificar todos los datos

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posibles de la disección: punto de origen y salida (s), extensión, reentradas, calibre de la luz verdadera y falsa, ramas da la aorta afectadas, presencia de trombos en la falsa luz, afectación de las coronarias, regurgitación valvular aórtica, hemopericardio, u ocupación pleural…. Las técnicas mas utilizadas son: la Aortografía, la TAC, la Resonancia Magnética, y la Ecografía (Transtorácica y Transesofágica).Deben ser interpretadas por un experto ya que puede haber imágenes que simulen disección sin serlo. (Batra 2000. Radiographics.20:309-320. Pitfalls in the Diagnosis of Thoracic Aortic Dissection at CT )

Aortografía

El diagnóstico se basa en la presencia de signos directos (visualización de la luz falsa y verdadera, o del Flap de la íntima) o indirectos (deformidad de la aorta, engrosamiento de la pared aórtica, anormalidades en las ramas arteriales, y regurgitación aórtica. La luz falsa se visualiza en el 87%, el Flap en 70%, y el punto de origen en 56% (Earnest).

►Izq: Dilatación de la raíz aórtica, T=luz verdadera, F: falsa luz, I: Flap de la íntima.LV: ventrículo izq: la abundancia de contraste en su interior es indicativa de

regurgitación.►Centro: La luz verdadera está mas opacificada que la falsa. Flechas: se aprecian dos planos del

Flap. CA: estrechamiento de la carótida derecha. (Isselbache, NEJM 328:35.►Dcha.: Ruptura traumática del istmo aórtico con pseudoaneurisma (substracción digital)

La angiografía se practica desde hace mas de 40 años y era el procedimiento estándarhasta la llegada de técnicas alternativas. Suele ser bien tolerada. Su sensibilidad y especificidad estarían en torno a 88 y 94% respectivamente (Erbel), aunque su sensibilidad sería solo del 77% en caso de hematoma intramural (Bansal). Son ventajas la posibilidad de delinear con precisión la extensión de la disección y las ramas afectadas, así como la presencia de regurgitación aórtica o de afectación coronaria. Inconvenientes: que es un procedimiento invasivo, que no siempre está disponible, que lleva tiempo, y que su sensibilidad y especifidad puede ser menor que con otras técnicas.

TAC con contraste

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Lo característico es encontrar dos Luces separadas por el Flap, o diferenciadas por la distinta captación de contraste. Tiene una sensibilidad y una especificidad que pueden llegar con la TAC helicoidal al 96 y 100% respectivamente.Es rápido y suele estar disponible. También precisa contraste y tiene el inconveniente de que el orificio de entrada puede no verse y que tampoco permite ver claramente si hay o no regurgitación aórtica. Puede haber confusiones diagnósticas (Thoongsuwan, 2002)

Disección B Disección B + Hemotórax

AngioTAC

Disección de Aorta descendente.

I= Flap de la íntima

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T= Luz verdadera

F= Luz falsa

En LePage, 2001 pueden verse numerosas figuras.

RMN

Proporciona una información muy completa, tan buena o mejor que la de cualquiera de las otras técnicas y además no es invasiva ni requiere contraste. Tiene una sensibilidad y especificidad del 98 % (Nienaber). Es el método más completo.El mayor inconveniente suele ser la escasa disponibilidad, el tiempo necesario y la dificultad de obtenerla en pacientes inestables (shock ,IOT, etc.).Está contraindicado en pacientes con MP y con modelos antiguos de prótesis valvulares.

(A) Plano oblicuo sagital mostrando una disección distal al origen de la subclavia izq,

(B) reconstrucción axial

(C) reconstrucción sagital

(Vogt. MR angiography of the chest. Radiologic Clinics of North America. Volume 41: 1 • January 2003)

Ecocardiografía

Es un método rápido y que suele estar disponible. Aquí también el diagnóstico lo da la imagen del Flap ondulando y separando la luz verdadera de la falsa. En el Doppler los flujos de la luz verdadera y falsa tienen un patrón de color diferente.

a) Transtorácico:Tiene una sensibilidad del 59 al 85%, y una especificidad del 63 al 96%. b) Transesofágico Puede ser necesario sedar y puede ser mal tolerado (HTA, bradicardia,

broncoespasmo, etc.), pero no es frecuente. La parte distal de la Aorta ascendente puede no visualizarse bien por la interposición de la Traquea o los Bronquios. La sensibilidad diagnóstica es de cerca del 100% (para diagnosticar el punto de origen 73%, trombos 68%, regurgitación aórtica y derrame pericárdico100%). La especificidad estaría en 97 % para Erbel y en 77% para Nienaber.

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Puede servir también para diagnosticar si hay afectación coronaria (aunque no sustituye a la coronariografía).

Fig. izq: Se observa una aorta dilatada en la que: T= Luz verdaderaI= Flap. F= Luz Falsa. /// Fig. dcha.: L=Luz aórtica. H= hematoma (no se ve Flap)

ECO Doppler transesofágico de la aorta descendente disecada, en que se muestra el lugar de desgarro de la íntima: Se evidencia el flujo sistólico en naranja, por la luz verdadera, y un jet azul de flujo de alta velocidad que cruza hacia la luz falsa a través de un orificio en al Flap de la íntima.

Eco transesofágico de la Aorta ascendente proximal.

LA: aurícula izq.

AV: válvula aórtica

I: Flap

T: Luz verdadera

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F: Falsa luz

Misma vista con Doppler

T: Luz verdadera (azul)

F: Luz falsa naranja con flujo retrógrado

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Top: Biplane TEE in the longitudinal plane left ventricular outflow tract view demonstrating an aortic dissection beginning at the sinotubular junction with the intimal flap (curved arrow) separating the true and false lumens.

Bottom: Biplane TEE in the horizontal plane of the aortic root demonstrating the intimal flap (curved arrow) separating the true and false lumens and a patent left main coronary artery. AO = aorta; AV = aortic valve; FL = false lumen; LA = left atrium; LM = left main coronary artery; MV = mitral valve

(Willens. Transesophageal Echocardiography in the Diagnosis of Diseases of the Thoracic Aorta. Chest.;116:1772-1779. 1999 )

Ultrasonografía intravascular (catéter por arteria femoral)

Tiene la ventaja de que se visualiza bien la aorta abdominal que es inasequible para la ECO transesofágica y es particularmente útil para guiar la colocación de endoprótesis.Permite analizar la disección en toda su extensión y detectar las entradas y reentradas y parece que puede ser el mejor método para visualizar la afectación de las ramas de la aorta y el Hematoma intramural, así como as placas ulceradas. Se ha utilizado para guiar la fenestración y la colocación de stent (endoprótesis). Los nuevos transductores permiten además la incorporación del Doppler.

Elección de la técnica.Braunwald considera que el método inicial preferente es el ETE y que hay hospitales donde el paciente va a quirófano únicamente con dicha exploración. Si no está disponible entonces se debe practicar primero una TAC con contraste y quizá mas adelante, incluso con el paciente ya en quirófano se puede evaluar con ETE. En la revisión de Moore (2002) se analizan los métodos utilizados en el IRAD.

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La RMN es un método excelente para situaciones menos urgentes y para seguimiento evolutivo. La aortografía puede ser de especial utilidad cuando es preciso evaluar la afectación de las ramas de la Aorta. Es controvertida la indicación de Coronariografía (tanto en la afectación coronaria por la disección, como en la cardiopatía isquémica previa, que puede complicar el procedimiento quirúrgico y la evolución posterior, aunque parece que la incidencia de IAM postoperatorio es bastante baja.

Sensibilidad Especificidad TAC helicoidal 83–100% 87–100%

ETE 95–100% 85–96%

RMR 96–100% 98–100%

Aortografía 86–89% 75–94%

HEMATOMA INTRAMURAL

(Nienaber2002.. Intramural Hematoma in Acute Aortic Syndrome. Circulation.;106:284. Evangelista. Acute Intramural Hematoma of the Aorta: A Mystery. Circulation 111(8) 1 March 2005; 1063-1070 ).

Se diagnosticó en 5,7% de pacientes del IRAD. 60% tienen afectación del arco distal. Los pacientes suelen ser algo mayores que en la disección (69 vs 62 años).El dolor es incluso mas intenso, pero tienen menos isquemia periférica o IAo.El 16% (30-50% según otros) progresaron a Disección y/o ruptura.Mortalidad similar pero algo menor tanto en el grupo proximal como distal.Regresión en 10%. Actitud quirúrgica similar a la de las otras disecciones (A=quirúrgico, B : conservador). Song (2002) encuentra una tasa de resolución bastante apreciable sin cirugía. Kodolitsch (2003) encuentra que el HIM en Aorta ascendente requiere cirugía urgente independientemente de su diámetro.

Arteriograma mostrando un HIM de aorta descendente.

Evolución de un HIM de Aorta descendente, con formación de un aneurisma, y su posterior resolución con una endoprótesis.

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ÚLCERA AÓRTICA ATEROSCLERÓTICA PENETRANTE

La UP, como su nombre indica, sería una ulceración de una lesión arteriosclerótica aórtica que penetra en la lámina elástica interna, formando un hematoma en la capa media de la aorta torácica descendente, permaneciendo localizado o extendiéndose unos centímetros, sin formar una segunda luz.

Frecuentemente originan aneurismas aórticos saculares o fusiformes. En el 25% de los casos causan pseudoaneurisma aórtico y en un 8% conducen a rotura aórtica. La progresión a una DAo extensa es rara.

En Hayashi 2000 pueden verse numerosas figuras.

Izq: Sagittal contrast-enhanced MRI of penetrating atherosclerotic ulcer of the ascending aorta (arrowhead).

Dcha: TEE view of the descending thoracic aorta in the longitudinal plane. An atherosclerotic aortic ulcer (U) is manifested by the presence of a crater with overhanging borders in the atherosclerotic plaque. An intramural hematoma originates from the ulcer with propagation into the aortic wall. From: Khan: Chest, Volume 122(1).July 2002.311-328

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IRAD

Variable Total (n = 526) Sobrev (n = 394) Exit (n = 132) P

ECO Transesofágico 417 (79.3) 313 (79.4) 104 (78.8) .87

TAC 358 (68.1) 274 (69.5) 84 (63.6) .21

Aortografía 100 (19.0) 83 (21.1) 17 (12.9) .04

RMN 25 (4.8) 22 (5.6) 3 (2.3) .12

RX normal (disección) 65 (14.3) 55 (16.0) 10 (8.9) .06

Mediastino ensanchado (RX) 279 (61.5) 199 (58.2) 80 (71.4) .01

Hematoma Intramural 28 (5.4) 19 (4.9) 9 (6.9) .37

Regurgitación aórtica 300 (62.6) 227 (63.2) 73 (60.8) .64

Derrame pericárdico 228 (46.3) 170 (45.7) 58 (48.3) .62

Afectación coronaria 57 (14.2) 44 (14.3) 13 (13.8) .90

Desgarro íntima en Ao Asc 186 (41.6) 145 (43.2) 41 (36.9) .25

Desgarro íntima en arco aórtico 26 (5.8) 18 (5.4) 8 (7.2) .47

Origen en raíz aórtica 193 (39.0) 137 (36.8) 56 (45.5) .09

Origen en aorta ascendente 271 (54.7) 214 (57.5) 57 (46.3) .03

Origen en arco aórtico 19 (3.8) 12 (3.2) 7 (5.7) .28

AppendixScore=Age · 0.5331 + Sex · 0.3244 + Abrupt Onset Chest Pain at Presentation · 0.9569 + Pulse Deficit at Presentation · 0.7089 + Abnormal ECG at Presentation · 0.5714 · Renal Failure at Presentation or Before Surgery · 1.5616 + Hypotension/Shock/Tamponade at Presentation · 1.0876, with Age an indicator for Age 70; Sex an indicator with female=1, male=0; and the other variables being indicators for respective conditions. Note logit (probability of in-hospital death)=Score + (-2.94), where -2.94 is the intercept.

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TRATAMIENTO DE LA DISECCION AORTICA

En la disección tipo A, el tratamiento es quirúrgico. En algunos pacientes el riesgo quirúrgico puede ser tan elevado que desaconseje

la cirugía (patología concomitante severa: paciente en muy mala situación, infarto cerebral, renal, miocárdico o intestinal extensos, etc.). Las disecciones crónicas también son quirúrgicas. Con frecuencia evolucionan a aneurisma.

En la disección tipo B, en principio el tratamiento es médico, salvo complicaciones (dolor persistente, HTA incontrolable, evidencia de expansión o amenaza de ruptura del aneurisma, y compromiso visceral, renal o de EEII).

Algunos centros con experiencia en cirugía de aorta torácica están operando con excelentes resultados quirúrgicos disecciones agudas tipo B de bajo riesgo. Las disecciones B crónicas deben operarse cuando el diámetro llega a 6-6,5 cm.

Los pacientes con S de Marfan, un gran falso aneurisma, afectación retrógrada, o complicaciones, son con más frecuencia candidatos a cirugía. El objetivo en los casos quirúrgicos es evitar la ruptura y la afectación visceral. Suele afectar más al lado izquierdo (arteria renal izq o los vasos iliacos izq).

En el Hematoma intramural y la Úlcera penetrante el grupo de Yale recomienda cirugía precoz cuando afectan a la aorta ascendente, y tratamiento médico, pero con menor “umbral” para decidir cirugía, haciendo controles de imagen a los 3-5 días de tratamiento médico.

Tratamiento Médico

Inicialmente el objetivo es controlar el dolor y estabilizar hemodinámicamente.

Analgesia:Incluso antes de proceder a administrar hipotensores se debe tratar el dolor, lo que por sí mismo ayuda al control de la TA.

Morfina 10 mg/1mL Bolos 2-10 mg ( 0,1 mg/Kg sbc.im.iv) Perfusión ± 3-6 Amp/d

Otros analgésicos (Toradol, Paracetamol, etc.)también pueden utilizarse, según la intensidad y las circunstancias de cada paciente. (P.ej: Mórfico+Toradol+Primperán en PC) En cualquier caso se atenderá a la intensidad del dolor, al estado de conciencia, a la capacidad respiratoria, tolerancia hemodinámica, etc.,

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Estabilización hemodinámica:

Ante la sospecha de disección se debe proceder a control hemodinámico estricto de la TA.En caso de Hipertensión se debe procurar mantener TA máxima en torno a 110 mmHg y FC 60-80 X´, teniendo en cuenta que es esencial también disminuir la fuerza de eyección (dp/dt), Para ello se utiliza NTP + β-bloqueante, o β-bloqueante solo. Pueden utilizarse también Solinitrina, Nicardipina, o IECA, Verapamilo, Diltiazem en caso de contraindicación para betabloqueantes.

- Nitroprusiato , (Nipride ) Puede dar taquicardia refleja y aumentar la contractilidad y el dp/dt, por lo que debe asociarse con β-B. Puede, además, aumentar la isquemia miocárdica al derivar flujo sanguíneo a otras zonas vasodilatadas, y disminuir la TA diastólica. Puede dar hipoxemia, por inhibición de la vasoconstricción refleja producida por la hipoxia. A dosis altas puede producir toxicidad por cianidas.

NTP 50 mg/5mL 50/250Gl 1mL= 200 μg 0,2-2-8µg/Kg/min 60 Kg: 2-36-146 mL/h

- Trandate, (Labetalol )Es α y β bloqueante (7 veces + beta que alfa por vía iv, y 3:1 por vía oral). Efecto cronotrópico e inotrópico negativo. El efecto α-bloqueante inhibe la vasoconstricción refleja. Su acción dura 6 horas. Muy utilizado en disección aórtica tanto pre- como post- operatoriamente. En Bolos: 15-20 mg en 2´, luego 20-80 mg/15´, hasta un máximo de 300 mg. En Disecciones algunos señalan la conveniencia de no administrar dosis de carga por el peligro de hipotensión.

LAB 100mg/20mL 200/200 Gl 1mL=1mg 1-4 mg X´ hasta ≈300 mg, o respuesta adecuada

- Esmolol (Brevibloc), ESM : 1Amp=2,5 gr (para dilución), 1 vial= 100 mg. 250-500 μg /kg/min en 1 min + 50 μg /kg/min durante 4 minutos. Repetir la secuencia cada 5 min hasta 4 veces, aumentando 50 μg /kg/min, hasta que se consiga el efecto deseado, luego suele bastar con 50-25 μg /kg/min, o menos, para mantenimiento. Retirar también lentamente (posible crisis hipertiroidea)Cardioselectivo de acción ultracorta (comienza a actuar en 2 minutos, alcanza nivel terapéutico en 5 y revierte en 10-20). Inotrópico negativo: baja el gasto. Puede usarse en pacientes con broncoespasmo. Baja mas la TA que la FC.Es una de las drogas más utilizadas.

ESM 1Amp: 2,5 g 2,5 gr/250G 1mL=10mg 25-50-300 µg/Kg/min 18-80 mL/h

La presencia de Hipotensión/Shock en caso de disección, suele constituir una urgencia quirúrgica. Puede ser por hemorragia, taponamiento cardiaco, regurgitación aórtica, etc.Puede ser muy peligroso tratar de drenar un hemopericardio por punción, fuera del ámbito del quirófano. Tanto el shock como el déficit neurológico severo o el TC se asocian a malos resultados (Long 2003).

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Tratamiento Quirúrgico

El objetivo inicial es evitar la ruptura hacia el saco pericárdico o hacia la Pleura, y el compromiso de las arterias coronarias o de la válvula aórtica.Los pacientes en coma, con severa afectación neurológica por la disección tienen un pésimo pronóstico.

Son intervenciones que propician el sangrado por lo que resultan útiles los antifibrinolíticos (Aprotinina, EACA, etc). También es habitual precisar Plasma, plaquetas, crioprecipitado…

► Tratamiento de la Disección Aórtica tipo A

Se hace con CEC, anulando clásicamente la A Femoral, o la Aorta ascendente. Los procedimientos a utilizar son diversos (Kallenbach, 2004).

Si hay regurgitación aórtica se hace resuspensión o reemplazamiento de la Válvula Aórtica (según el grado de distorsión), resección de la disección, e interposición de un tubo de Dacron. En S de Marfan se prefiere la sustitución completa. Si es posible es aconsejable conservar la válvula nativa. (Harringer 1999), (Graeter 2000), aunque las técnicas de remodelación no en todas las series han dado buenos resultados (Leyh 2002) .Puede usarse Teflon para reforzar las zonas de sutura y cola biológica (Bio Glue) para mejorar la integridad tisular para recibir los injertos. El uso de BioGlue (Raanani 2004) consigue el cierre de la falsa luz en >50% de los pacientes, y ha reducido el número de reemplazamientos valvulares, así como la incidencia de complicaciones postoperatorias, aunque tiene cierto riesgo de redisección y de necrosis de pared aórtica (Kazui (2001). Si la raíz aórtica está muy deteriorada y no se puede reconstruir se puede colocar un tubo valvulado (Bentall) (Prifti 2000). (Frecuente en S de Marfan con ectasia previa).

El desarrollo de injertos impermeables como el Dacron, los injertos impregnados de colágeno (Hemashield), los injertos aórticos de anatomía variada, los injertos recubiertos de Gel (gel-coated Carbo-Seal Ascending Aortic Prothesis) y la utilización de parada circulatoria en hipotermia profunda, con perfusión cerebral retrógrada o anterógrada, han mejorado notablemente los resultados quirúrgicos, aunque la mortalidad sigue siendo considerable (20-35%).

Si está afectado el arco aórtico suele ser preciso utilizar Hipotermia profunda y Parada circulatoria. No lo es en los casos limitados a la aorta ascendente.

Válvula nativa resuspendida dentro de una prótesis tubular. Simon, 1995

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A: Resuspensión con preservación de la válvula aórtica nativa. Las capas disecadas son aproximadas en cada comisura con suturas dobles reforzadas con “almohadillas”.

B: Resuspensión completada.

C: Se colocan unas finas tiras de teflon (de 8–10 mm de ancho ) por dentro y por fuera de la circunferencia de la Aorta (los ostium coronarios no estarían aquí afectados).

D: la pared aórtica quedaría en “ sandwich” entre las tiras de teflon con las suturas dobles englobadas. (Fleck, 2003)

E: sutura del tubo de Dacron a la aorta proximal reconstruida.

Refuerzo de la aorta distal con tiras de teflon, interna y externa, previo a la sutura del extremo distal del tubo de Dacron.

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► Tras haber completado la sutura distal, el tubo es canulado para reestablecer el flujo anterógrado.

► La sutura proximal es estabilizada inyectando BioGlue, y se procede a anastomosar el cabo proximal del injerto.

-------------------------

Sutura de un tubo valvulado de St Jude al anillo aórtico. (Bentall)

Bentall.

Coronarias implantadas

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La cirugía sobre el arco aórtico, cuando es precisa, es muy delicada y compleja. El arco es la porción de la aorta que se extiende entre el origen del tronco braquiocefálico (o art.Innominada) y el origen de la arteria subclavia izquierda.

Las intervenciones en esta zona requieren habitualmente bypass cardiopulmonar con hipotermia, y un periodo de parada circulatoria, que puede llegar hasta unos 30-40 minutos a 15-18 grados. Puede haber déficit neurológico difuso o focal postoperatorio en 3-18% de los pacientes intervenidos, aunque raramente hay déficit severo permanente.

En los aneurismas de arco aórtico, la cirugía se reserva para casos en que la dilatación es de >5,5-6 cm, hay síntomas neurológicos, o el tamaño va aumentando. En la disección es indicación quirúrgica cuando hay desgarro de la íntima en el arco, el arco está roto, la parte externa del arco está adelgazada y hemorrágica, y cuando la parte interna está fragmentada

Reemplazamiento de aorta ascendente y hemiarco aórtico.

Reemplazamiento de Aorta Ascendente y Arco aórtico

Implantación en bloque de los troncos supraaórticos, no afectados, y resecados previamente, en el tubo de Dacron.

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Cuando está además afectada la Aorta descendente se puede colocar una “trompa de elefante” (Hanafusa, 2002) (Safi 2000 y 2004), realizando en un segundo tiempo el tratamiento de la zona distal disecada (anastomosis a la aorta, a otro tubo, o fijación de stent sobre la trompa).

Reemplazamiento de aorta ascendente y arco aórtico + Trompa de elefante.

A, Reconstructed 3D MRI after percutaneous use of a customized stent-graft to connect a surgically inserted elephant trunk with the upper abdominal aorta in order to exclude an aneurysm that had formed at the distal end of the elephant trunk (B);

after placement of the customized stent-graft, the thoracic aneurysm was successfully excluded from circulation with thrombus formation around the stent-graft protheses (C).

Resultados:

Trimarchi-2 (IRAD 2005) (18 hospitales en 8 países) reseña los resultados quirúrgicos en 529 pacientes con Disección Tipo A: Se reemplazó la Aorta ascendente en el 92% de los pacientes intervenidos, y el arco aórtico en el 31.5% (en 23 % se hizo sustitución parcial y en 12% completa).En 14% se reemplazó válvula + raíz + Aorta Ascendente con injerto valvulado.

En 91% se hizo parada circulatoria hipotérmica, con perfusión cerebral anterógrada en 52%. Se reemplazó la válvula aórtica en 23%, y precisaron CABG simultáneo 16%.

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La mortalidad intrahospitalaria fue del 25% /31% en los inestables y 17% en los estables). El 13% precisó reintervención.

El intervalo entre los síntomas y la intervención fue de 79 horas (38 en los fallecidos y 93 en los sobrevivientes) . Entre el diagnóstico y la intervención transcurrieron 4 horas. En el 21% la cirugía se demoró mas de 24 horas (por necesidad de nuevas pruebas diagnósticas, estabilización, disponibilidad, etc), de los que sobrevivieron 85%.

Tratamiento y Complicaciones en Diseccion tipo “A” (Trimarchi)

Variable Total Sobrev. Exitus P Cirugía 436 (79.7) 320 (73.4) 116 (26.6) *<0.0001 Tto Médico. 111 (20.3) 49 (44.1) 62 (55.9)

----------- Complicaciones ---------- Déficit Neurológico 97 (17.8) 55 (14.9) 42 (23.9) 0.01 Coma/Alt concienc. 80 (15.3) 34 (9.7) 46 (27.1) <0.0001 Isquemia Miocárdica 57 (11.2) 33 (9.5) 24 (14.9) 0.07 Isquemia mesentérica 16 (3.2) 7 (2.0) 9 (5.6) 0.03 FRA 28 (5.6) 10 (2.9) 18 (11.3) 0.0002 Hipotensión 137 (27.0) 59 (17.0) 78 (48.8) <0.0001 Taponamiento C. 84 (16.5) 34 (9.9) 50 (31.1) <0.0001 Isquemia EE. 48 (9.5) 25 (7.3) 23 (14.5) 0.01

En series de pocos pacientes Hirotani (2000,) refiere sustitución total del arco con mortalidad del 11%, Kato (2002) del 5,3%).

Factores predictivos asociados a mortalidad:

Variables at presentationOverall type A

%

Percent among

survivors

Percent among deaths

Model P

value

Mortality, odds ratio (95% CI)

History of aortic valve replacement 4.4 3.5 7.4 .02 3.12 (1.16-8.40)

Migrating chest pain 14.2 12.1 20.5 .001 2.77 (1.49-5.15)

Presenting hypotension as sign of AAD 17.6 13.3 30.4 .02 1.95 (1.08-3.52)

Presenting shock or tamponade 24.7 19.5 40.7 .002 2.69 (1.41-5.11)

Preoperative cardiac tamponade 15.7 11.8 27.6 .01 2.22 (1.17-4.22)

Preoperative limb ischemia 9.7 7.8 15.8 .04 2.10 (1.00-4.38)

En relación a la edad, Mehta (2002), en un análisis de los pacientes del IRAD encuentra que solamente el 64% de los pacientes mayores de 70 años (que eran un 32% del total) fueron intervenidos, (frente al 86% de los menores de 70). Su mortalidad fue del 43%.

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Cuando analiza los pacientes con Disección “B” del IRAD (383) encuentra un 41% >70 años, con una mortalidad del 16% vs el 10% en los <70 años. La malperfusión visceral y el shock se asocian a la mayor mortalidad (28 y 56% respectivamente). Mehta (2004).

► Tratamiento de la Disección aórtica tipo B:

En principio el tratamiento suele ser preferentemente médico, para control del dolor y la HTA, salvo complicaciones, aunque es un tema recientemente cuestionado. (Umaña (Stanford). Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? . J Thorac Cardiovasc Surg;124:896-910. 2002).

El objetivo de la cirugía es evitar la ruptura y la afectación visceral. Entre el 70 y el 80% de los pacientes sobreviven a la fase aguda, y la fase subaguda, solo con tratamiento médico.

La cirugía aquí, tiene una mortalidad por encima del 30% y la incidencia de paraplejia postoperatoria también está próxima a esos niveles. (Lansman, 2002, del Mount Sinai refiere una mortalidad del 0%, aunque con un 47% de complicaciones importantes en 34 pacientes con disección B aguda que requirieron cirugía). Roseborough 2004, del Jhons Hopkins refiere una mortalidad del 13% (12/92) con tratamiento médico, y del 18% (4/22) en los que requirieron intervención.

Pueden constituir indicación quirúrgica, la ruptura, el dolor incoercible, la progresión de la disección a pesar de tratamiento médico enérgico, los síndromes de malperfusión orgánica o la imposibilidad de controlar la TA.

La presencia de S de Marfan, o de grandes falsos aneurismas, el desarrollo de hematomas periaórticos o mediastínicos que amenacen romperse, o la afectación retrógrada del arco aórtico (Kaji, 2003), son factores que pueden aconsejar una cirugía mas temprana La parálisis aguda no solo no contraindica la cirugía sino que la puede hacer el único medio de recuperación al lograr la revascularización.

El tipo de cirugía a realizar es diverso (Sustitución parcial de la aorta, Bypass extraanatómico, etc) . (Hsu, 2005)

Sin embargo, incluso en presencia de complicaciones hay un interés creciente y preferente en el tratamiento endovascular con stent, manteniendo una actitud conservadora (tratamiento médico) en casos no complicados.

Bell (2003), señala que el tto. endovascular de una disección complicada tipo B incluiría: cubrir el punto de entrada con la endoprótesis + fenestración de la íntima + stents en las ramas aórticas obstruidas. El tto. endovascular también puede ser útil en el tto de las complicaciones no cardiacas de la cirugía de la disección (Beregui 2003)

♦ Fenestración: El objetivo es crear una comunicación entre la luz verdadera y la falsa, cuando la

verdadera está comprimida por la falsa, y ello crea un compromiso isquémico de las ramas aórticas viscerales o de los miembros. Se hace introduciendo una aguja (Brockenborough) que perfora la íntima desde la luz menor a la mayor (generalmente desde la verdadera a la falsa luz), dilatando después el orificio con un balón de 12-15 mm de diámetro y 20-40 mm de largo. Indicada en presencia de isquemia intestinal o de los miembros o en FRA.

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La reparación quirúrgica de la aorta torácica disecada consigue una recuperación de pulsos periféricos en 90%. Sin embargo los pacientes con isquemia renal pueden tener una mortalidad del 50-70%, y del 87% en isquemia mesentérica o isquemias periféricas. Con Fenestración quirúrgica la mortalidad varia entre el 20 y 60%, lo que ha hecho acrecentar el interés por la utilización de la Fenestración con balón endovascular percutáneo.

El cierre de la puerta de entrada parece esencial para que se reconstruya la verdadera luz y se trombose la falsa, y también aquí las técnicas percutáneas (incluso en el arco) pueden ser eficaces.

La obstrucción estática de una rama arterial de la aorta pudiera ser vencida con la colocación de un stent en el vaso original. Los stent a diversos niveles de la luz verdadera aórtica pueden así mismo mejorar el flujo a las diversas ramas de la aorta, con o sin la utilización, además, de la fenestración con balón.

♦ Endoprótesis: (Excelente Revisión en Lee 2004 de Stanford)

Se utiliza para corregir la compresión de la verdadera luz y mejorar así el flujo distal. El objetivo es taponar la puerta o puertas de entrada, con lo que la comunicación proximal entre las dos luces queda sellada. Esto favorece la trombosis y obliteración de la falsa luz.

Se debe evitar ocluir el origen del tronco celíaco, mesentérica superior y arterias renales. En base a cuidadosas mediciones obtenidas en los procedimientos de imagen se coloca una (o mas) endoprótesis de hasta 18 cm y 25-35 mm de diámetro, mediante técnica de Seldinger, por femoral.

Durante el procedimiento (que suele requerir anestesia general) se intenta mantener una TA de 50-60 con NTP, durante corto tiempo. En Stanford utilizan de rutina ECO intravascular.Tras desplegar el injerto puede utilizarse un balón de látex intraluminal para “pegar” el injerto a la pared aórtica. Pueden colocarse stent en el ostium de las ramas de la aorta afectadas por obstrucción.

Aortograma antes y después de colocar un Stent sobre la puerta de entrada.

Izq: la flecha señala el paso de contraste desde la luz verdadera (T) a la falsa (F) a través del desgarro.Dcha: solo se ve la luz verdadera.

Dake. N Eng J Med 340 (20): 1546, Figure 1 May 20, 1999

Tras la colocación del stent puede haber una reacción febril, con elevación de la Proteína C Reactiva, que desaparece espontáneamente o se trata con antiinflamatorios no esteroideos.Una complicación temible es el daño neurológico espinal con paraplejia. Algunos propugnan el drenaje profiláctico del LCR o la monitorización de potenciales evocados . También se ha utilizado con buenos resultados el drenaje de LCR como tratamiento (5 de 13 recuperaron).

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Acute type B aortic dissection in a 44-year-old man; note the communications between the true and false lumen at the thoracic and abdominal level. After stent-graft placement across the proximal thoracic entry, the entire aorta including the abdominal segment is reconstructed with time, with complete "healing" of the dissected aortic wall and closure of distal communication.

Intravascular ultrasound image of leaking pseudoaneurysm of previously repaired ruptured thoracic aortic aneurysm. Note the color flow of the obvious breakdown of the proximal anastamosis. This patient was treated with a stent graft that covered the entry site, and the patient's symptoms of pain and hemothorax resolved.

Intravascular ultrasound images of type B aortic dissection extending down to the abdominal aorta with catheter within true lumen (t). Note that the left renal artery (L) comes off the true lumen, while the right renal artery (R) comes off the false lumen (f).

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Criteria for endovascular repair of thoracic aortic disease at Harbor-UCLA Medical Center. Lee 2004.Thoracic aortic aneurysm Type B aortic dissectionDescending thoracic aneurysm >5.5 cm Acute dissection with intractable pain,

uncontrollable hypertension, progression of dissection, or end-organ ischemia

Aneurysm 4.5–5.5 cm with increase in size by 0.5 cm in last 6 months or twice size normal

Chronic dissection with aneurysmal dilatation of proximal descending aorta

Saccular aneurysm or penetrating ulcer Chronic dissection with acute symptomsNonaneurysmal proximal and distal aortic neck measures between 22 and 40 mm (dependent on device availability)

Entry tear at least 1 cm from left subclavian orifice (potentially 2 cm if plan to cover subclavian)

No extension of aneurysm into abdominal aorta (distal neck at least 2 cm above celiac)

No entry site of dissection that is proximal to subclavian or involves arch or ascending portion of aorta

Devices available that are suitable for patient's anatomyPatent iliac or femoral arteries that allow introduction of 22–25 F delivery sheath (device dependent)Life expectancy at least 6 monthsAble to consent for appropriate trials and follow-up protocols

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Consideraciones para elección del tratamiento en la Disección aórtica.

► Cirugía Es el tratamiento de lección el la Disección tipo A Indicada en Disección tipo B, complicada con: Extensión retrógrada a la aorta ascendente Disección en S de Marfan Ruptura o amenaza inminente de ruptura (ej.: formación de aneurisma sacular (¿endoprótesis?) Progresión con compromiso de órganos vitales (¿stent?)

► Tratamiento médico Es el tratamiento de elección Disección tipo B no complicada Disección estable, aislada, del arco Disección estable tipo B (crónica, 2 semanas desde el inicio)

► Tratamiento endovascular intervencionista Stent-grafts para sellar la puerta de entrada a la falsa luz y aumentar el diámetro de la verdadera luz, comprimida por la falsa. Disección tipo B inestable. S de Malperfusión (proximal aortic stent-graft and/or distal fenestration/stenting of branch arteries) Disección tipo B estable (en estudio)

Nienaber, Aortic Dissection: New Frontiers in Diagnosis and Management Part II: Therapeutic Management and Follow-Up. Circulation. 2003;108:772.)

Bavaria (2002) señala las siguientes medidas que han mejorado el pronóstico quirúrgico:1. Admisión directa a quirófano para diagnóstico (ETE) y tratamiento, sin pasar por Cardiología.2. ETE intraoperatoria.3. Monitorización Neurocerebral (60% de los pac.): EEG, Potenciales evocados. Enfriando a 3ºC por debajo del silencio eléctrico (usualmente a Tª nasofaringea 15-20ºC). Si no tenían monitorización enfriaban al menos durante 45 minutos antes de la intervención abierta del arco aórtico. Administran además1 g de Solumedrol, 1 g de magnesio, y 2.5 mg/kg de Lidocaina tras iniciar la CEC.4. Reconstrucción abierta del arco aórtico (mejor hemiarco) con perfusión cerebral retrógrada o anterógrada. (vía femoral, axilar dcha, o subclavia). 5. Perfusión anterógrada del injerto de arco aórtico tras la finalización de la reconstrucción del arco. 6. Resuspensión valvular en la mayoría de los pacientes sin patología de las valvas o la raíz aórtica previas. 7. Creación de una capa "neo-media" usando teflon o Bioglue para reforzar las paredes de los senos y la aorta y obliterar la falsa luz

Aneurisma Aórtico Torácico y Abdominal

(Isselbacher: Circulation, Volume 111(6).February 15, 2005.816-828) (http://www.eurostar-online.org/)

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Son dilataciones localizadas de la Aorta. Puede ocurrir a cualquier nivel. La prevalencia se considera que ha aumentado 40 veces en los últimos 50 años. Es 4 veces mas frecuente en varones (5-10% de los mayores de 60 años tienen un aneurisma aórtico, la mayoría de ellos asintomáticos).

Pueden afectar a uno o varios segmentos de la aorta.El 60% afectan a la raíz aórtica y/o la Aorta ascendente y el 40% a la aorta descendente. El 10% afectan al arco, y el 10% a la aorta torácica y abdominal. Son frecuentes por debajo de las renales.Se producen, en general, por la degeneración de la media, favorecida por la edad y por la Hipertensión.

► Etiología: S. Marfan, S. familiar de Aneurisma aórtico, Válvula aórtica bicúspide, Ateroesclerosis

/ sobretodo en los de aorta descendente), Sífilis (raro actualmente), S. de Turner, Arteritis aórtica, Disección aórtica crónica, Traumatismo…► Clínica : La mayoría son asintomáticos. Otras producen signos por compresión de estructuras vecinas (tos, disnea, neumonitis, disfagia…) o Insuficiencia

aórtica, por regurgitación. La complicación mayor es la Ruptura o la Disección. Crecen ≈ 0,1 cm /año. Con menos de 5 cm se el peligro de ruptura es de un 2% anual, y del 3% para los que miden 5-6 cm. Por encima de 6 cm el riesgo aumenta más del doble. Ruptura, shock y malperfusión son signos de mal pronóstico (Genoni, 2002).

► Clasificación de los aneurismas toraco-abdominales (Crawford).

► Diagnóstico: Al igual que en las disecciones los RX, la Ecografía, la

TAC , la RMN y la angiografía son los métodos mas usuales.

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◄ Standard axial image from a contrast-enhanced CT scan showing what appears to be an oval-shaped descending thoracic aortic aneurysm, appearing to measure as much as 8.0×5.2 cm in diameter (arrows).

B

◄ Three-dimensional reconstruction in a left anterior oblique view of same CT scan demonstrating that the descending aorta is tortuous and was consequently cut off-axis (dotted arrow) on axial CT image. The true maximal diameter of this aortic segment was only 5.6 cm (solid arrow)

►Contrast-enhanced CT scan demonstrating a 7.5×8.3-cm ascending thoracic aortic aneurysm.

A indicates ascending; D, descending.

A transthoracic echocardiogram, in a parasternal long-axis view, demonstrating a dilated aortic root (4.4 cm) and ascending aorta (4.2 cm). Whereas the aortic root is well visualized, the ascending aorta is less so, as is often the case with transthoracic imaging.

RV indicates right ventricle; LV, left ventricle; and LA, left atrium.

►Angioresonancia mostrando un aneurisma de aorta torácica de 4,7 cm

► Tratamiento: En los de Aorta ascendente la cirugía está indicada a partir de 5,5 cm. Los

Marfan o los casos de válvula bicúspide se operan antes (a partir de 5 cm). En intervención de un aneurisma que afecte al arco se debe practicar coronariografía en >40 años. Es aconsejable también TAC craneal y Doppler de TSA previos a la cirugía.Los de Aorta torácica descendente se operan a partir de 6 cm. (Mitsumasa 2003)

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Abdominal: El riesgo es la ruptura, fundamentalmente a partir de 50-55 mm (“grandes”) en que sería del 10% en 12 meses, entre 30-39 mm (“muy pequeños”) el riesgo de ruptura es escaso (0,4% en 12 meses) (Aneurysm Detection and Management Veteran Affairs Cooperative Study (ADAM study). (Shakibaie 2004)

La cirugía electiva convencional consiste en la inserción de un tubo de Dacron, que puede estar bifurcado, y que es suturado dentro del saco aórtico, para “excluir” el segmento afectado. La mortalidad quirúrgica (en electiva) es del 5-10%, y el periodo de recuperación se alarga varios meses. La mortalidad del aneurisma abdominal roto está alrededor del 80% (Shakibaie, 2004).

Reparación endovascular: Efectuada por primera vez en Argentina en 1991 (Juan Parodi). Se introduce un

injerto “compactado”, bifurcado o no, a través de la arteria femoral con control RX. Se despliega la “endoprótesis” y se fija con resortes de alambre o stents algunos de los cuales tienen ganchos o lengüetas que penetran en la pared del vaso. Las mediciones previas deben ser muy cuidadosas. Dake (2) (1999) refiere el tto con endoprótesis en Disección A y B.

Aunque las ventajas son obvias, los resultados a largo plazo no están claros (en cuanto a la durabilidad y la seguridad de las endoprótesis no suturadas), y es problemática su utilización en caso de buenos candidatos para cirugía.

La incidencia de pacientes que requieren reintervención es escasa (Grabenwoger,2004)Es necesaria la colaboración interdisciplinar (RX, Cardiología, Cirugía, etc) para optimizar los resultados (Herold 2002).

Imágenes en : (Therasse. Stent-Graft Placement for the Treatment of Thoracic Aortic Diseases. RadioGraphics;25:157-173. 2005)

Leurs (2005) recoge los resultados en 443 pacientes del Eurostar y de UK.Nienaber (2005) dice que es necesario precisar mejor a que pacientes beneficia realmente.Doss (2005) compara el tratamiento quirúrgico (28p) o con endoprótesis (32p), en 60 pacientes agudos con lesión de aorta torácica (27 rupturas de aneurisma, 15 disecciones B perforadas, y 18 rupturas traumáticas). Aunque la mortalidad perioperatoria fue de 5 (18%) vs 1 (3%), favorable a la endoprótesis, pasado un año hubo 4 fallecimientos en el grupo de endoprótesis (3 relacionadas con el procedimiento) y 1 en el grupo quirúrgico (no relacionada con la cirugía). También la morbilidad fue mayor, a largo plazo, en el

grupo de endoprótesis.Bortone (2004) refiere buenos resultados a corto y medio plazo en 110 pacientes con patología de aorta descendente, incluida disección B aguda.

Marin (2003) revisa los resultados en 817 pacientes en 10 años.

Martín (2005) de Asturias, reporta sus resultados en 15 pacientes y revisa el tema (en español).

A: reconstrucción de la tomografía computarizada previa a la intervención en un paciente con aneurisma de aorta

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torácica que englobaba el origen de la subclavia izquierda. Diámetro proximal (34,1 mm) y diámetro distal (31,1 mm), aneurisma (73,2 mm) relleno con un gran trombo mural. Flecha grande: trombo mural. Doble flecha: bypass desde la aorta ascendente al tronco supraaórtico. B: el mismo caso, una vez implantada la endoprótesis

Martín.Tratamiento percutáneo de las afecciones de la aorta torácica. Una labor multidisciplinaria. REC 58;1:27-33. 2005

► Complicaciones : a) Inmediatas: FRA, Infarto intestinal, Embolismo EEII, Ruptura de la falsa luz, paraplejia, S. postimplantación (fiebre,↑Prot C Reactiva, y leucocitosis)b) Tardías: fractura, migración o prolapso, erosión a esófago, infección, leak endovascular, embolización distal, isquemia intestinal, expansión y ruptura del aneurisma tratado. (Gowda, 2003).

En 1996 se estableció el Proyecto Eurostar que es un registro europeo de pacientes a los que se ha efectuado reparación endovascular de un aneurisma aórtico. http://www.eurostar-online.org/

Con mas de 7000 pacientes, de 66 Hospitales, es la mayor base de datos al respecto. De 6264 pacientes con aneurisma abdominal (En/05), 5887 son varones y 377 mujeres. Edad media = 72,3 años. La Estancia media hospitalaria fue 5,8 días. Hubo complicaciones intraoperatorias relacionadas con el procedimiento en 299 (+ 168 posteriormente), y no se pudo completar el procedimiento en 99. Complicaciones de otro tipo (sistémicas) en 703. Anestesia general en 4371 pac. Duración del procedimiento 131 minutos.La mortalidad precoz fue del 2,4%, y a 30 días cerca del 10%. La incidencia de endoleak en los meses posteriores está en torno al 10%.

De 522 pacientes (Feb 05), de 53 hospitales, con aneurisma torácico, el 78% fueron varones, y la edad media fue de 63 años. Etiología: arteriosclerótica 268, Traumática 62, Postdisección 163. En 74 hubo disección + aneurisma y en 94 disección sin aneurisma, aneurisma solo en 352. En 491 se utilizó anestesia general. En casi la mitad se implantó mas de un Stent. El procedimiento duró una media de 132 minutos. En 50 hubo complicaciones relacionadas con el Stent, en 53 complicaciones arteriales, en 5 no se consiguió realizar el procedimiento. Secuelas neurológicas en 52 y

complicaciones sistémicas en 122. La estancia media en UCI fue de 5 día, y la hospitalaria de 15. Murieron en periodo precoz 61 pacientes, y 94 en el primer mes.

◄ Composite aortic graft repair of aneurysm involving the aortic root and

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ascending thoracic aorta. The coronary arteries are excised as buttons, and the aneurysm is resected to the level of the aortic annulus, with sacrifice of the native aortic valve. A prosthetic valve is attached directly to a Dacron graft, and this composite graft is sewn directly to the annulus. The native coronary buttons are then reimplanted into the graft. (©Massachusetts General Hospital Thoracic Aortic Center.) From: Isselbacher: Circulation, Volume 111(6).February 15, 2005.816-828

◄Valve-sparing procedure to repair an aneurysm involving the aortic root and ascending thoracic aorta. The aortic sinuses are excised, but the valve leaflets are not. The leaflets are then placed within the lumen of a Dacron graft that is then sewn directly to the aortic annulus. The valve leaflets are then reimplanted within the base of the graft to restore competency.

◄Repair of an aneurysm involving ascending thoracic aorta and arch by using a multilimbed prosthetic graft

Reparación de un Aneurisma de Aorta descendente

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Reparación con endoprótesis. Se avanza hasta el lugar de anclaje y se expande el cabo proximal y luego se ancla el distal (respecto a la aorta). El saco aneurismático alrededor del stent acaba trombosándose.

(A) Computed tomography scan and drawing of a patient with mega aorta–fusiform aneurysmal disease involving the ascending, arch, and all of the thoracoabdominal aorta. (B) First stage of repair including resection and replacement of the ascending aorta and transverse aortic arch using the elephant-trunk technique and coronary artery bypass grafting with vein grafts for coronary artery occlusive disease. (C) Drawing and aortogram following completion of repair including ascending, transverse aortic arch, all of thoracoabdominal aorta, and reattachment of intercostal, visceral, and renal vessels.

Coselli. Descending and Thoracoabdominal Aneurysm. Cap. 48. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill, 2003.

► Lugar de canulación: El lugar habitual de canulación para la CEC es la aorta ascendente, pero en caso de disección aneurisma, o severa arteriosclerosis se utilizan otros lugares, entre los cuales el mas usado ha sido la arteria femoral, con perfusión retrógrada. Con frecuencia creciente se utilizan otros accesos como la arteria axilar (Neri 1999), el tronco braquiocefálico, o incluso el ápex cardiaco.La perfusión retrógrada con canulación femoral o iliaca produce una distribución del flujo similar a la de la perfusión anterógrada, pero puede dar lugar a múltiples complicaciones (desgarros, disección, estenosis tardías, trombosis, sangrado, fístula linfática, infección, ateroembolismo coronario o cerebra, isquemia distal en EEII….) ,. La complicación mas peligrosa es la disección retrógrada (0,2-1,3% de incidencia), que conlleva una mortalidad de cerca del 50%. Fusco (2004) de Yale, la continúa recomendando.

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Es más recomendable (Cohn), sobretodo en la cirugía del arco aórtico, usar preferentemente la arteria axilar derecha que suele estar poco o nada afectada en la arteriosclerosis. Strauch (2004), del Mount Sinai, refiere su utilización en 284 pacientes con cirugía de aorta ascendente o sustitución del arco, entre 1999 y 2003, con una mortalidad hospitalaria del 4,6% y ACV permanente en 4,6% (morbimortalidad combinada:6,6%).Se evita así la perfusión retrógrada a través de una aorta abdominal y torácica frecuentemente enfermas, así como las turbulencias que se crean en la canulación de aorta ascendente. Además es muy útil para la perfusión cerebral anterógrada durante la reconstrucción del arco. La circulación del brazo derecho está bastante bien suplida por colaterales o puede mantenerse con “flush” retrógrados. Como complicaciones puede dar trombosis o lesión del plexo braquial, y otros problemas (Schachner 2005).

Se ha descrito la canulación directa de la aorta ascendente en caso de disección, con control ecográfico, en un lugar libre de disección, en caso de dificultad para la canulación axilar o subclavia (japonesas pequeñitas) . (Yamada 2003). (Noiseux 2003)Además de la monitorización convencional, es muy útil la ecografía TE intraoperatoria. Algunos utilizan monitorización EEG continua. No se recomienda la protección con barbitúricos por su efecto sobre la función cardiaca. Se administran Corticoides. Spielvogel (2003) utiliza 2 gr de Solumoderín al inicio si se prevé parada circulatoria. Si la parada es > de 30 minutos se administran 125 mg/6h durante 24 h postoperatorias y 125mg/12 horas otras 12 horas.

Protección CerebralEn las operaciones que afectan al arco aórtico es esencial conseguir una

adecuada protección cerebral, es decir proteger al cerebro mientras se accede quirúrgicamente a los vasos que lo irrigan. El objetivo es minimizar el daño isquémico originado por la parada circulatoria y evitar embolizaciones (aéreas, o de material ateromatoso). Se han utilizado varias técnicas (Souza, 2003 http://perfline.com/ ):

- Hipotermia profunda con Parada Circulatoria. La temperatura se baja a menos de 20ºC, perfundiendo una solución fría (en torno a 10º-15º), lo que disminuye el consumo de Oxígeno cerebral y atenúa la liberación de neurotransmisores y oxidantes, durante los periodos de isquemia y reperfusión. La Tª puede medirse a varios niveles: en la vejiga, en la arteria pulmonar, en el esófago, en el recto, en la nasofaringe, o en la membrana timpánica. Para estimar la adecuación de la respuesta a la hipotermia pueden utilizarse parámetros como el silencio EEG, una saturación venosa yugular del 95%, o simplemente esperar a tener una Tª < 20º en nasofaringe o membrana timpánica al menos 30 minutos antes de parar la circulación. (Stecker 2001).Con esta técnica, si se sobrepasan los 40 minutos, la incidencia de ACV aumenta mucho, y a partir de 65 minutos se disparan las cifras de mortalidad. Si la intervención lo permite pueden intercalarse periodos de parada circulatoria de 10-20 minutos, con periodos de perfusión de 10-15.La cabeza puede ser envuelta en hielo como protección adicional. Tanto el enfriamiento como el recalentamiento deben hacerse lentamente. (Prêtre 2003)Algunos como Lai (2002), de Stanford, cuestionan su utilidad real.

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- Perfusión cerebral selectiva anterógrada parcial o bilateral. Puede utilizarse “en lugar de” la Hipotermia + PC, o “además de”. Se usó ya en los años 60 (De Bakey). Si se trata de cirugía programada se debe evaluar antes, si hay estenosis carotídea (>70% de estenosis) y el funcionalismo del Polígono de Willis (con Doppler, angiografía, EEG, etc.). Los vasos cerebrales son perfundidos individualmente en conjunto, a menudo a través de injertos con múltiples salidas, por las que se efectúa perfusión de forma secuencial. Se perfunde a 10-18ºC, a un flujo de 10-20 mL/Kg/min, limitando la presión de perfusión a 30-70 mmHg. La perfusión unilateral (cánula en art subclavia derecha) tiene algunas ventajas en cuanto al riesgo de disección o el correcto posicionamiento de la cánula. El hemisferio izquierdo se perfundiría a través del polígono de Willis y en menor medida a través de colaterales cervicofaciales. Es importante que la carótida y la subclavia izquierdas estén ocluidas para evitar pérdidas. Con PA (P anterógrada) Hagl (2001) del Mount Sinai encuentra menor incidencia de complicaciones neurológicas en 717 pacientes sobrevivientes de cirugía aórtica con parada hipotérmica:145 con reemplazamiento total del arco y 25 con trompa de elefante (588 pacientes con solo Hipotermia profunda, 43 con PR asociada y 86 con PA) .Mortalidad total 10%. Daño neurológico permanente 5,7%, transitorio 3,3%).Dossche (1999)(2000), refiere una mortalidad del 8,5% en cirugía de aorta torácica proximal (60 aneurismas, 26 aneurismas postdisección, 16 disección A), utilizando perfusión anterógrada. Lo mismo Okita 2001.Di Eusanio (2003) compara la perfusión anterógrada con la hipotermia , con resultados algo mejores con PA.Küçüker 2005 refiere un 2,2% de complicaciones neurológicas con perfusión anterógrada canulando arteria braquial derecha.(Veeragandham. Experience with antegrade bihemispheric cerebral perfusion in aortic arch operations . Ann Thorac Surg;66:493-499. 1998)

- Perfusión cerebral retrógrada: perfundiendo a través de la Vena Cava Superior a 8-18ºC, a 25-40 mmHg de presión de perfusión, y a flujos de 250-400 mL/min. Se comenzó a utilizar en 1980.La incidencia de complicaciones es similar a la de la técnica anterior. Bavaria (1995). La perfusión efectiva (en cuanto a nutrición cerebral) es muy escasa (≈5%) y de distribución poco homogénea. (Tanoue. 1999)

Inicialmente varios autores encontraron mejoría significativa en sus resultados usando la perfusión retrógrada:(Brux 1995).(Deeb 1995). Ehrlich (1999). Esmailian (1999)El empleo de una u otra técnica es controvertido. Barnard (2004) estudiando 408 artículos al respecto, concluye que la perfusión anterógrada como complementaria de la hipotermia profunda con PC, es superior a la perfusión retrógrada o la hipotermia + PC solas, aunque señala que el nivel de evidencia es pequeño. Parecido, Sinatra 2001. Fleck (2003) no encuentra mejoría al añadir PR a la Parada circulatoria. Safi de Houston en 1997 reportaba una mortalidad del 6% con hipotermia y perfusión retrógrada.Se pueden utilizar diversos medios de monitorización neurofisiológica (Ganzel, 1997)

Izq: Perfusión anterógrada bilateral, obtenida por canulación selectiva del TBC y de la A. Carótida izq.

Dcha (arriba): Perfusión cerebral retrógrada vía Vena Cava superior.

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Dcha (abajo): Perfusión anterógrada unilateral vía arteria Subclavia derecha.

Prevención de Paraplejia Debe prevenirse fundamentalmente en las intervenciones que afectan a la aorta

torácica o toracoabdominal. La médula espinal está parcialmente protegida por la hipotermia sistémica, pero se necesita protección adicional. Se pueden monitorizar los potenciales evocados somato-sensitivos o motores. Los vasos intercostales son clampados de uno en uno, antes de iniciar el BP cardiopulmonar, y solo son sacrificados si los potenciales evocados están conservados a los 10 minutos del clampaje. Algunos aconsejan continuar la monitorización de los potenciales evocados hasta que el paciente despierte, y luego explorar la funcionalidad de las EE horariamente durante 72h. Si hay una alteración de los PE o se deteriora la función motora se procede a aumentar la TA y disminuir la presión intratecal mediante drenaje del LCR.

Uso de Cola biológica Se ha utilizado sobretodo en Europa, para reforzar los tejidos aórticos tras la

Disección.

Perfusión cerebral anterógrada del TBC y de la carótida izquierda (10 mL/Kg/min)(40 mm Hg). (La circulación sistémica se establece por otra cánula en aorta ascendente)La subclavia izq. está clampada.

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Injerto de 4 ramas de “Intervascular”

C: sutura del extremo distal a la aorta descendente, (parte inferior del cuerpo sin perfusión). D: Se clampa el cabo proximal y se hace perfusión sistémica anterógrada a través de la 4ª rama. Se sutura la 3ª rama a la subclavia izq. y se desclampa. E: El cabo proximal se sutura a la aorta ascendente y se inicia perfusión a las coronarias. F y G: Se anastomosan el TBC y la Carótida izq. H se retira la

4ª rama utilizada para perfusión anterógrada sistémica.

(T Total bomba: 166 minutos, T Perfusión selectiva: 94 minutos, T parada circulatoria para la anastomosis distal: 55 minutos. Mortalidad en 120 pacientes: 2,5%, 16% en emergencia. Daño neurológico permanente 2,5%.

Kazui 1996, 2000. Use of aortic arch branched graft in the treatment of aortic arch aneurysm or aortic dissection. http://www.intervascular.com/us/clinicalarticles_4.html

H agl C,. Neurologic outcome after ascending aorta-aortic arch operations: effect of brain protection technique in high-risk patients J Thorac Cardiovasc Surg 2001;121(6):1107-1121. Mount SinaiAll 717 patients who survived ascending aorta–aortic arch operations through a median sternotomy since 1986 were examined for factors influencing stroke. 17 of the 734 patients died in the operating room or shortly thereafter before adequate assessment of neurologic function was possible. Fifty-six of the operative survivors died before discharge from the hospital, resulting in an overall mortality of 10%. 24 ACV transitorio, 22 ACV permanente.

Hagl (2001) . The simplified technique for selective ACP used at Mount Sinai, showing incorporation of the cerebral vessel graft into the arch repair. A, The cap of cerebral vessels, dissected from the native arch, is sutured to an appropriately shaped 14- to 16-mm Hemashield graft by using a running 3-0 polypropylene suture reinforced with Teflon felt. B, An arterial inflow cannula has been inserted, the proximal end of the graft has been clamped, and selective ACP

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has been initiated with blood at 15°C to 20°C to achieve pressure of 50 to 60 mm Hg in either radial artery (flow rate, 800-1200 mL/min). A second Hemashield graft is shown after the reinforced distal anastomosis has been completed and the proximal anastomosis is being constructed. C, The arch reconstruction is being completed by means of a graft-to-graft anastomosis of the proximal-distal arch and cerebral vessel grafts during a brief (5-10 minute) interval of HCA. D, The completed repair. This technique can be combined with axillary artery cannulation to minimize risk of embolization.

Bachet Antegrade cerebral perfusion with cold blood: a 13-year experience. Ann Thorac Surg 1999;67:1874-1878.

The perfusion circuit of the brain and the coronary arteries with cold blood. Ox = oxygenator; P1 = roller pump for the cold blood perfusion; P2 = roller pump for the main circuit; E1 = extra heat exchanger for the cerebral circuit (10–12°C); E2 = heat exchanger of the main circuit (28°C).

Otro método usando un injerto “trifurcado”. Perfusión selectiva anterógrada a través de la arteria axilar derecha.Spielvogel. Aortic arch replacement using a trifurcated graft and selective cerebral antegrade perfusion

Ann Thorac Surg 2002;74:S1810-S1814

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Steps in attaching the grafts. A) Ascending aortic replacement is completed; the intimal tear is seen to originate between the orifices of the innominate artery and the left carotid artery. B) The innominate artery is dissected free and a 10-mm Dacron graft is anastomosed to it in an end-to-end fashion during circulatory arrest. Antegrade selective cerebral perfusion is begun through the innominate artery graft. C) A 14-mm Dacron graft is anastomosed to the button containing the left carotid and left subclavian arteries. Both grafts are used for antegrade cerebral perfusion. D) A 22-mm tubular graft with an elephant trunk is anastomosed to the descending aorta. This graft is then sewn to the proximal aortic graft in an end-to-end fashion. E) After attachment of the left carotid/subclavian button graft to the new aortic arch, perfusion of the lower body and of the left carotid and left subclavian arteries is initiated via the femoral artery

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cannula. The arch graft is cross-clamped proximal to the left carotid/subclavian anastomosis. The graft to the innominate artery is sewn to the ascending aortic graft during warming. Apaydin.2001. Tex Heart Inst J. 2001; 28(4): 288–291.

A continuación se reseña la bibliografía por orden alfabético. En primer lugar se citan las Revisiones, Capítulos de Libros, etc, que solo ocasionalmente son citados en el texto. Luego los artículos referentes a ensayos clínicos, resultados, etc, que sí van referenciados en el texto.

Haciendo click en el nombre correspondiente en el texto previo se accede a la referencia bibliográfica, y desde ella al artículo completo en Word (más fácil de leer) o en PDF (mejor para imprimir o escuchar).

BIBLIOGRAFÍA

REVISIONES

Anderson. Ascending Aortic Aneurysms. Chapter 46. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill,:11231148. 2003. Word

Ankel. Aortic Dissection. Marx: Rosen's Emergency Medicine: Concepts and Clinical Practice, 5th ed., Copyright © Mosby, Inc. 2002. Word

Bowlby. Aortic Dissection (PTG). Ferri: Ferri's Clinical Advisor: Instant Diagnosis and Treatment, 2005 ed., Copyright © Mosby, Inc. 2005. Word

Braunwald: Disección. Heart Disease: A Textbook of Cardiovascular Medicine, 6th ed. , Copyright © W. B. Saunders Company. 2001. Word (volver)Braunwald:Aneurisma. Heart Disease: A Textbook of Cardiovascular Medicine, 6th ed. , Copyright © W. B. Saunders Company. 2001. Word

Cheng-Zaas: The Osler Medical Handbook, 1st ed., Copyright © Johns Hopkins University. Aortic Dissection. 2003. Word

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Coselli. Descending and Thoracoabdominal Aneurysm. Cap. 48. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill, 2003. Word (volver)

Creager. Atherosclerotic Vascular Disease Conference. Writing Group V: Medical Decision Making and Therapy. Circulation.;109:2634-2642. 2004. Word REVISION

Eurostar: http://www.eurostar-online.org/

Evangelista. Historia natural y tratamiento del síndrome aórtico agudo. R Esp Card 57:667-679. 2004. REVISIÓN EN ESPAÑOL. Word PDF

Gleason. Trauma to Great Vessels. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill,:12291250. 2003. Word

Gomez. E-medicine: Diseccióon aortica. 2005. Word

Hals. PC Textbook - Management of Abdominal Aortic Aneurysm. Word

Isselbacher. Thoracic and Abdominal Aortic Aneurysms . Circulation; 111: 816-828, 2005. PDF

Khan . Clinical, Diagnostic, and Management Perspectives of Aortic Dissection. Chest;122:311-328. 2002. REVISIÓN. Word PDF (volver)

Knaut. Aortic emergencies. Emergency Medicine Clinics of North America. Volume 21 • Number 4 • November 2003. Word PDF REVISIÓN

Kouchoukos. Surgery of the thoracic aorta. N Engl J Med. Jun 26;336(26):1876-88. 1997. Word PDF REVISION.

Lee. Stanford. Current status of thoracic aortic endograft repair. Surgical Clinics of North AmericaVolume 84 • Number 5 • October 2004. Word PDF (volver) REVISIÓN

Levine. Thoracoabdominal Aneurysm Repair: Anesthetic Management. International Anesthesiology Clinics. Care of the Vascular Patient. 43(1):39-60, Winter 2005. Word PDF REVISIÓN

Miller: Thoracoabdominal aortic aneurysm surgery. Miller's Anesthesia, 6th ed.,. 2005. Word

Nelson. Aneurysm Thoracic. E-medicine. 2005. Word

Nienaber and Eagle. Aortic Dissection: New Frontiers in Diagnosis and Management: Part I: From Etiology to Diagnostic Strategies. Circulation;108:628-635. 2003. REVISIÓN Word PDF

Nienaber and Eagle. Aortic Dissection: New Frontiers in Diagnosis and Management: Part II: Therapeutic Management and Follow-Up. Circulation;108:772-778. 2003. REVISIÓN Word . (volver)

Prêtre. Deep Hypothermic Circulatory Arrest. Cap. 13. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill, 2003. Word (volver)

Randall. Aortic Dissection .Chap 45. Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult . McGraw-Hill, 2003. Word

Riddell, Endovascular Abdominal Aortic Aneurysm Repair. International Anesth Clin 43(1). 79-91.Winter 2005 . REVISIÓN. Word PDF Riambau. Tratamiento endovascular de las lesiones de la aorta torácica: estado actual. Rev Esp Cardiol; 58: 1 – 5. 2005. REVISIÓN Word

Rogers. Aortic Disasters.Emergency Medicine Clinics of North America.Volume 22 • Number 4 • November 2004. REVISIÓN Word PDF

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Sawhney. Aortic Intramural Hematoma. An Increasingly Recognized and Potentially Fatal Entity. Chest.;120:1340-1346. 2001. REVISIÓN Word PDF

Souza. Antegrade cerebral perfusion during surgical management of aortic arch lesions. The Handbook of Cardiovascular Perfusion Word (volver)Dossche and associates have used the technique popularized by Kazui since 1995, for bilateral antegrade selective cerebral perfusion. In short, the technique consisted of the following. Patients were cooled down to nasopharingeal temperature of 220C to 250C. Systemic circulation was then arrested and the aortic arch was opened in continuity with the rest of the aneurysm. Under visual control and with the patient in Trendelenburg position, the cannulas for antegrade cerebral perfusion were inserted into the innominate and left common carotid artery; for the innominate artery usually a 15F-18F retrograde coronary sinus perfusion cannula with manual-inflating cuff and silicone body was used, for the left common carotid artery, a 13F-14F cannula was inserted. In addition, the left subclavian artery was either clamped or occluded with a Fogarty catheter. Blood was then perfused into both arteries at a rate of 10 ml/kg/min using a single roller pump separated from the systemic circulation. The cerebral perfusion pressure was adjusted to maintain a right radial pressure of 40 to 70 mmHg. During the period of body circulation arrest, nasopharingeal temperatures and blood temperatures are kept at 250C; occasionally, the EEG disappeared during cooling of the patient, but was usually restored within a few minutes when the brain became perfused with blood at 250C. If available, transcranial Doppler measurements of blood velocity of the middle cerebral artery (MCA) confirmed the proper placement and function of both cannulas. Open distal aortic anastomosis was made in all procedures. While performing the distal aortic anastomosis, blood perfusion to the lower half of the body was arrested. After completion of the distal anastomosis CPB is restarted and rewarming begins. After rewarming up to about 360C, the patient was weaned off the CPB. Dossche, Kazui and several other authors have found the described technique superior to DHCA alone or in combination with retrograde cerebral perfusion. More recently, Aebert and associates described a similar technique with cannulation of the right subclavian artery.

Spielvogel. Aneurysms of the Aortic Arch .Chapter 47. In: Cohn LH, Edmunds LH Jr, eds. Cardiac Surgery in the Adult. New York: McGraw-Hill,:11491168. 2003. Word (volver)

THE MERCK MANUAL, Sec_ 16, Ch_ 211, Diseases Of The Aorta. Word

Townsend. Thoracic aortic aneurysms. Sabiston Textbook of Surgery, 17th ed., 2004. Word

Zappa. Thoracic Aortic Aneurysms. Word

Zamorano. Guías de práctica clínica de la Sociedad Española de Cardiología en enfermedades de la aorta. Rev Esp Cardiol; 53: 531 – 541. 2000. Word PDF

ARTÍCULOS

Apaydin. Perioperative risk factors for mortality in patients with acute type a aortic dissection. Ann Thorac Surg 2002;74:2034-2039. 2002. Word (volver)Between 1993 and 2001, 108 consecutive patients (86 men; mean age, 53 years) underwent emergent operations for AADA. All patients but 2 underwent replacement of the ascending aorta with an open distal anastomosis during a period of hypothermic circulatory arrest. In addition, 22 patients had hemiarch and 5 had total arch replacement. Aortic root was replaced in 20 and repaired with gelatin-resorcinol-formaldehyde glue in 39 patients; aortic valve was separately replaced in 3, resuspended in 24, and remained untouched in 22 patients. RESULTS: Overall in-hospital mortality was 25%. Mortality rate was significantly higher in patients with preoperative dissection complications than in those without (21/36 [58%] vs 6/72 [8%], p < 0.001). In multivariate analysis, predictors of mortality were presence of rupture, renal failure, and intestinal malperfusion, duration of cardiopulmonary bypass 200 minutes, blood loss 500 mL, and transfusion of blood 4 units

Apaydin.Cerebral Perfusion through Separate Grafts for Repair of Acute Aortic Dissection with Torn Arch. Tex Heart Inst J. ; 28(4): 288–291. 2001. Word (volver)We have modified the technique of cerebral perfusion through anastomosed grafts for repair of acute arch dissections that require total arch replacement. We have performed this operation on a 71-year-old man

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with an acute type-A dissection and an arch tear between the orifices of the brachiocephalic arteries. We used 2 separate grafts for the brachiocephalic arteries and minimized brain ischemia by initiating antegrade selective cerebral perfusion after the 1st anastomosis. The patient had an excellent outcome. This method is simple and provides effective protection. Cerebral ischemic time can be kept under 30 minutes without need of a sophisticated pump setup or a multibranched graft.

Barnard. In aortic arch surgery is there any benefit in using antegrade cerebral perfusion or retrograde cerebral perfusion as an adjunct to hypothermic circulatory arrest? . Interactive Cardiovascular and Thoracic Surgery 3:621-630. (2004). Word. PDF. (volver)Altogether 408 papers were found using the reported search, of which 16 presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that antegrade cerebral perfusion is superior as an adjunct to hypothermic circulatory arrest when compared to retrograde cerebral perfusion or hypothermic circulatory arrest alone, although clinical evidence for this from prospective clinical trials is weak.

Batra. Radiographics.20:309-320. Pitfalls in the Diagnosis of Thoracic Aortic Dissection at CT. Two hundred seventy-five computed tomographic (CT) angiograms of the thoracic aorta were obtained over a period of approximately 4 years in patients with suspected or known aortic dissection. A variety of pitfalls were encountered that mimicked aortic dissection. (Muchas figuras: libre acceso en Internet). 2000. Word PDF (volver)

Bavaria. Retrograde Cerebral and Distal Aortic Perfusion During Ascending and Thoracoabdominal Aortic Operations. Ann Thorac Surg;60:345-352. 1995. Word (volver)For proximal aortic procedures, the stroke rate was 12% using cardiopulmonary bypass and 48% using hypothermic circulatory arrest. The addition of retrograde cerebral perfusion decreased the stroke rate to 0% (p < 0.01) and the mortality rate to 7.1% compared with 37% for hypothermic circulatory arrest (p < 0.05). For thoracic and thoracoabdominal aortic operations, straight cross-clamping resulted in a 27% rate of spinal cord injury and a 24% rate of renal failure, whereas the addition of distal aortic bypass resulted in a statistically significant reduction (p < 0.01) in neurologic injury to 7% and a notable, but not statistically significant, decrease in renal failure to 13%. Distal aortic bypass also reduced the mortality rate from 22% to 7% (p < 0.05). Conclusions. Retrograde cerebral perfusion decreases the stroke rate and mortality rate in proximal aortic operations and distal aortic perfusion decreases the rates of neurologic injury, renal failure, and mortality in thoracoabdominal aortic operations.

Bavaria. Advances in the treatment of acute type A dissection: an integrated approach. Ann Thorac Surg;74:S1848-S1852. 2002. Word PDF (volver)

Bayegan. Acute type A aortic dissection: the prognostic impact of preoperative cardiac tamponade. Eur J Cardiothorac Surg;20:1194-1198. 2001. Word (volver)Conclusion: Patients with acute type A aortic dissection and signs of preoperative cardiac tamponade without palpable pulses had a 16-fold increased risk for poor outcome, particularly preoperative death. In contrast, cardiac tamponade with palpable pulses was not associated with increased frequency of MOF/in-hospital mortality.

Bell. Endovascular treatment of thoracic aortic disease. Heart;89:82 2003. Word PDF (volver)Endovascular treatment of complicated type B dissection includes covering the primary entry tear with a stent graft, percutaneous fenestration of the intimal flap, and stenting of obstructed aortic side branches. The most common complication of endoluminal repair is damage to the access artery. As with open surgery, paraplegia is the most devastating complication of endoluminal repair of thoracic aortic disease. The incidence of paraplegia following endoluminal repair for thoracic aneurysmal disease is comparable to open surgery (2–5%). CSF drainage for open surgery is used to reduce raised CSF pressure, which occurs on aortic cross clamping and consequently improves spinal cord perfusion. There have also been reports of successful reversal of delayed onset paraplegia with CSF drainage for both open surgery and endoluminal repair. There have been a total of 13 reported cases of paraplegia following endoluminal repair, of which 5/13 (38%) recovered with CSF drainage.

Beregi. Endovascular treatment of acute complications associated with aortic dissection: midterm results from a multicenter study. J Endovasc Ther. Jun;10(3):486-93. 2003. Word

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CONCLUSIONS: Endovascular treatment of noncardiac acute complications associated with aortic dissection has favorable early and midterm outcomes.

Bortone. Endovascular Treatment of Thoracic Aortic Disease. Circulation.;110:II-262 – II-267. 2004. Word PDF (volver)From March 1999 to October 2003, 132 patients (113 male and 19 female, mean age 62±14 years) were enrolled. They were divided into 4 groups: aneurysms (43, group A), post-traumatic lesions (24, group B), and complicated type B dissections (43, group C). Twenty-two further patients, with chronic type B dissection and not suitable for endovascular or surgical or hybrid techniques because of multiple entry tears without difference between the true and false lumen and poor clinical conditions, were obliged to receive medical management only (group D). An optimal deployment with exclusion of the aneurysm and/or closure of the entry tear in dissection was achieved in 96.4% (106/110) of the patients that were discharged in good conditions within 6 days. No spinal cord injuries were observed. Conclusions— Endovascular treatment of thoracic aortic diseases, even in the acute phase, may represent a valid option with a low mortality rate. Moreover, the efficacy is proved in the middle-term whereas the long-term follow-up is still pending.

Brahmajee. Syncope in acute aortic dissection: Diagnostic, prognostic, and clinical implications. American Journal of Medicine Volume 113 • Number 6 • October 15, 2002. Word (volver)

Brux. Retrograde Cerebral Perfusion: Anatomic Study of the Distribution of Blood to the Brain. Ann Thorac Surg;60:1294-1298. 1995. Word (volver)Despite apparently good clinical results with retrograde cerebral perfusion during operation on the aortic arch, there is still concern about the real distribution of the blood injected in the superior vena cava to the brain, especially when the internal jugular vein is valvulated (88% of the cases).

Castañer. CT in Nontraumatic Acute Thoracic Aortic Disease: Typical and Atypical Features and Complications. Radiographics.;23:S93-S110. 2003. Word

Chiappini. Surgery for acute type a aortic dissection: is advanced age a contraindication?. Ann Thorac Surg;78:585-590: cardiovascular. 2004. WordBetween 1976 and 2001, 315 patients underwent emergency operation for acute type A dissection: 245 were younger than 70 years (group 1) and 70 patients were 70 years of age and older (group 2). Early and late outcomes of both groups were compared. RESULTS: The hospital mortality rates were 20.5% in group 1 and 17.6% in group 2 (p = 0.751). The mean extracorporeal circulation time was 192.6 ± 65.2 minutes and 185.7 ± 58.4 minutes in groups 1 and 2, respectively (p = 0.42). The mean cross-clamp time was 116.3 ± 45.8 minutes and 100 ± 36.7 minutes in groups 1 and 2, respectively (p = 0.009). Actuarial survival rates were 77.1% after a mean follow-up time of 259 ± 9 months for patients of group 1 and 80% after 77 ± 5 months for patients of group 2, without any statistically significant difference (p = 0.619).

Chiappini. Early and late outcomes of acute type A aortic dissection: analysis of risk factors in 487 consecutive patients. Eur Heart J 26:2; 180-186. En 2005. Word PDFFrom 1976 to 2003, 487 patients with acute type A aortic dissection treated surgically were enrolled. Twenty-five pre-operative and intra-operative variables were analysed to identify conditions influencing early and late morbidity and early mortality. The in-hospital mortality rate including operative death was 22% (107 patients). Multivariable analysis indicated that pre-existing cardiac disease (RR=3.7, 95% CI=1.8–7.4) and cardiopulmonary resuscitation (RR=6.8, 95% CI=2.3–20.2) were independent predictors of in-hospital death. The causes of in-hospital mortality were low cardiac output in 32 patients (6.6%), major brain damage in 24 patients (5.9%), haemorrhage in 11 patients (2.2%), sepsis in nine patients (1.8%), visceral ischaemia in eight patients (1.6%), multiple organ failure in seven patients (1.4%), rupture of the thoracic aorta in six patients (1.2%), respiratory failure in six patients (1.2%), and four intra-operative deaths. The follow-up was 100% complete. The actuarial survival was 94.9±1.2% and 88.1±2.6%, at 5 and 10 years, respectively.

Collins. Differences in Clinical Presentation, Management, and Outcomes of Acute Type A Aortic Dissection in Patients With and Without Previous Cardiac Surgery. Circulation.;110:II-237 – II-242. 2004. Word (volver)

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Our study highlights differences in clinical characteristics, management, and outcomes of AAD patients with PCS. Importantly, PCS, with the exception of previous AVR, does not adversely influence early outcomes of AAD patients, including those undergoing surgical repair

Dake, Endovascular stent-graft placement for the treatment of acute aortic dissection. N Engl J Med 340,1546-1552. 1999. Word PDF (volver) (volver-2)Placement of endovascular stent–grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months.

Dangenais. Changing trends in management of thoracic aortic disease: Where do we stand with thoracic endovascular stent grafts?. Can J Cardiol. Feb;21(2):173-8. 2005. WordData on long-term outcomes are required before applying thoracic endovascular stent grafts to patients with a lower operative risk..

David. Surgery for acute type A aortic dissection. Ann Thorac Surg;67:1999-2001. 1999. WordThere were 109 patients: 81 men and 28 women, with a mean age of 57 years, range 23 to 80. Most patients were acutely ill and 15 were in shock at the time of surgery. Operations were performed under cardiopulmonary bypass with femoral artery and right atrial cannulation. In 55 patients, the aorta was clamped and retrograde femoral perfusion was used throughout the procedure (group I). In 54 patients, no clamp was used; under circulatory arrest the primary tear was resected whether in the ascending aorta or transverse arch, and antegrade cardiopulmonary bypass was started after completion of the distal anastomosis (group II). Postoperative computed tomographic or magnetic resonance scans were completed annually. Results. There were 16 operative deaths (15%): 11 (20%) in group I, and 5 (9.2%) in group II (p = 0.10). There were 10 strokes: 8 (14.5%) in group I and 2 (3.7%) in group II (p = 0.05). After a mean follow-up time of 59 ± 45 months for group I, 31 (56%) patients were alive, and after a mean follow-up time of 45 ± 26 months for group II, 44 (81%) patients were alive. The actuarial survival of group II was higher than group I, but the difference was not significant (p = 0.09). Postoperatively, a patent false lumen was found in 91% of group I patients and in 59% of group II (p = 0.01). Conclusions. This study suggests that avoidance of aortic clamping, resection of the primary tear in the ascending aorta or transverse arch, and antegrade perfusion after completion of the distal anastomosis improve the early and late outcomes of surgery for acute type A aortic dissection.

Deeb. Retrograde cerebral perfusion during hypothermic circulatory arrest reduces neurologic morbidity. J Thorac Cardiovasc Surg;109:259-268. 1995. Word (volver)

Di Eusianio. Deep hypothermic circulatory arrest and antegrade selective cerebral perfusion during ascending aorta-hemiarch replacement: a retrospective comparative study. J Thorac Cardiovasc Surg;125(4):849-854. 2003. Word PDF (volver)Between January 1995 and September 2001, 289 patients (mean age, 62.2 ± 13.2 years; urgent status, 122/289 [42.2%]) underwent ascending aorta-hemiarch replacement with the aid of antegrade selective cerebral perfusion (161 patients) or deep hypothermic circulatory arrest (128 patients). Results: Overall hospital mortality was 11.4% (deep hypothermic circulatory arrest group, 13.3%; antegrade selective cerebral perfusion group, 9.9%; P = .375). A logistic regression analysis revealed acute type A dissection (P = .001; odds ratio, 4.3) and age of greater than 70 years (P = .019; odds ratio, 2.5) to be independent predictors of hospital mortality. The permanent neurologic dysfunction rate was 9.3% (deep hypothermic circulatory arrest group, 12.5%; antegrade selective cerebral perfusion group, 7.6%; P = .075). Renal dysfunction (postoperative creatinine level of >250 µmol/L; deep hypothermic circulatory arrest, 10 [7.8%]; antegrade selective cerebral perfusion, 6 [3.7%]; P = .030), as well as prolonged intubation time (deep hypothermic circulatory arrest, 3.8 ± 6.3 days; antegrade selective cerebral perfusion, 2.2 ± 2.5 days; P = .005) were more common in the deep hypothermic circulatory arrest group. Conclusion: The use of antegrade selective cerebral perfusion and deep hypothermic circulatory arrest during ascending aorta-hemiarch replacement resulted in acceptable hospital mortality and neurologic outcome. Reduced postoperative intubation time and better renal function preservation were observed in the antegrade selective cerebral perfusion group.

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Doss. Emergency endovascular interventions for acute thoracic aortic rupture: Four-year follow-up Read at the Thirtieth Annual Meeting of The Western Thoracic Surgical Association, Maui, Hawaii, June 23-26, 2004. Journal of Thoracic and Cardiovascular Surgery. 2005. Word (volver)Sixty patients aged 28 to 83 years were admitted to our institution with an acute rupture of the thoracic aorta (27 ruptured aneurysms, 15 perforated type B dissections, 18 traumatic ruptures). Twenty-eight patients were treated surgically with cardiopulmonary bypass, and 32 patients were acutely treated with an endovascular stent graft. Perioperatively, there were 1 death (3.1%) among the 32 patients in the endovascular group and 5 deaths (17.8%) among the 28 patients in the surgical group. There were 4 late deaths in the endovascular group and 1 in the surgical group. There were 2 access failures in the endovascular group. There were 1 stroke in the endovascular group and 1 case of paraplegia in the surgical group. Three patients in the endovascular group had endovascular leaks develop that required reintervention. Two patients in the endovascular group had late thrombosis of the left subclavian artery. Conclusion : Despite encouraging early outcomes, midterm results suggest a trend toward increased reintervention and late complication rates in the endovascular group.

Dossche. Bilateral antegrade selective cerebral perfusion during surgery on the proximal thoracic aorta. Eur J Cardiothorac Surg;17:462-467. 2000. Word. (volver)

Dossche. Antegrade selective cerebral perfusion in operations on the proximal thoracic aorta. Ann Thorac Surg;67:1904-1910. 1999. Word (volver)From May 1989 through April 1997, 106 patients underwent surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. Mean age was 64.0 ± 11.5 years. Unilateral antegrade cerebral perfusion was used in 37 patients (35%), bihemispheric antegrade cerebral perfusion in 69 patients (65%). Mean antegrade cerebral perfusion time was 50.5 ± 20.5 minutes. Indication for surgery was atherosclerotic aneurysm in 60 (56.5%) patients, postdissection aneurysm in 26 (24.4%), acute type A dissection in 16 (15.1%), other in 4 (4.0%). Results. Hospital mortality was 8.5%

Eagle. Cocaine-Related Aortic Dissection in Perspective. Circulation.;105:1529. 2002. Word. PDFIn the present issue of Circulation, Hsue and colleagues1 report on their 20-year experience with acute aortic dissection at an inner-city hospital. Remarkably, their findings indicate that 14 (37%) of 38 patients treated for acute dissection reported having used cocaine in the minutes or hours preceding their presentation. Cocaine, particularly crack cocaine, seemed to have played a significant role in precipitating aortic dissection among this cohort of young (age 41±8.8 years), predominantly black (11 of 14; 79%), and hypertensive (11 of 14; 79%) individuals. This study represents the largest cohort of cocaine-related dissection ever reported.

Eggebrecht. Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome. Eur Heart Journal;26:489-497. 2005. Word PDFA total of 38 patients (62±10 years, 32 male) with acute (n=10) and chronic (n=28) type B-AD were treated with endovascular stent-grafts. The implantation procedure was successful in all patients. Peri-procedural non-fatal complications occurred in four (11%) patients. Overall, 4/38 (11%) patients died during the in-hospital period. Patients undergoing stent-graft placement for acute AD had a significantly higher in-hospital mortality than patients with chronic AD (40 vs. 0%, P=0.001). During a median follow-up of 18 (1–57) months, there were six additional deaths. Overall survival rates were 97.4±2.6% at 30 days, 80.4±6.7% at 1 year, 73.2±7.8% at 2 years, and 54.9±16.9% at 4 years. Patients with a poor clinical health status (ASA class > 3) had a significantly reduced life expectancy compared with patients with only moderate co-morbidities (ASA class 3) (1-year survival rate 28.6±17.1 vs. 92.6±6.7%, P=0.0001). Multivariable analysis revealed that a poor clinical health status (ASA>3) pre-operatively (HR=29.5, 95% CI 1.5–581.9, P=0.026) and increased age (HR=1.1, 95% CI 0.9–1.2, P=0.084) were independent determinants of post-interventional mortality. Conclusion Endovascular stent-graft treatment is a safe alternative for patients with AD. The pre-operative clinical health status of the patient is the most important determinant of post-interventional outcome. Careful patient selection is thus of particular importance.

Ehrlich. (Mount Sinai). Predictors of Adverse Outcome and Transient Neurological Dysfuntion Following Surgical Treatment of Acute Type A Dissections. Circulation.;108:II-318. 2003. PDF

Ehrlich. Surgical treatment of acute type a dissection: is rupture a risk factor?. Ann Thorac Surg;73:1843-1848. 2002. Word

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Ehrlich. Results of Immediate Surgical Treatment of All Acute Type A Dissections. Circulation.;102:III-248. 2000. Word PDF (volver)One hundred twenty-four consecutive patients with acute type A aortic dissection between 1984 and 1998 were reviewed. All underwent operation with resection of the intimal tear and open distal anastomosis: 107 patients had surgery within 24 hours and 17 patients had surgery within 72 hours of symptom onset. Median age was 62 years (23 to 89); 89 were men. Forty-three patients had ascending aortic replacement only, 72 had hemiarch repair, in 2 the entire arch was replaced, and in 7 replacement included the proximal descending aorta. The aortic valve was replaced in 54 patients, resuspended in 52, and untouched in 18. Hospital mortality rate was 15.3% (19 of 124): of these, 3 patients died during surgery, 4 had fatal rupture of the distal aorta before discharge, and 2 died of malperfusion-related complications. Multivariate analysis revealed age >60, hemodynamic compromise, and absence of hypertension as preoperative indicators of hospital death (P<0.05); the presence of new neurological symptoms was a significant preoperative risk factor in univariate analysis. Ominous intraoperative factors included contained hematoma and a comparatively low esophageal temperature but not cerebral ischemic time (mean 32 minutes). The site of the intimal tear did not influence outcome, but mortality rate was higher with more extensive resection: 43% with resection including the descending aorta died versus 14% with only ascending aorta or hemiarch replacement. Overall 5- and 10-year survival was 71% and 54%, respectively; among discharged patients (median follow-up 41 months) survival was 84% and 64% versus expected US survival of 92% and 79%. Conclusions—Immediate surgical treatment of all acute type A dissections with resection of the intimal tear and use of hypothermic circulatory arrest for distal anastomosis results in acceptable early mortality rates and excellent long-term survival.

Ehrlich. Impact of retrograde cerebral perfusion on aortic arch aneurysm repair. J Thorac Cardiovasc Surg;118:1026-1032. 1999. Word PDF (volver)Fifty-five patients had profound hypothermic circulatory arrest alone, and 54 patients had supplemental cerebral protection with retrograde cerebral perfusion. Mean age was 61 ± 13 years and 58 ± 14 years, respectively (mean ± standard deviation). Twenty-two preoperative and intraoperative characteristics, including age, sex, acuity, presence of aortic dissection, and aneurysm rupture, were similar in the 2 groups (P > .05). Results: Mean circulatory arrest times (in minutes) were 30 ± 19 in the group without retrograde cerebral perfusion and 33 ± 19 in the group with retrograde cerebral perfusion, respectively. Analysis revealed that patients operated on with the use of retrograde cerebral perfusion had significantly lower hospital mortality (15% vs 31%; P = .04) and in-hospital permanent neurologic complications (9% vs 27%;P = .01

Erbel. Diagnosis and management of aortic dissection: Task Force on Aortic Dissection, European Society of Cardiology. Eur Heart Journal;22:1642-1681. 2001. PDF (volver)

Erbel. GENERAL CARDIOLOGY: Diseases of the thoracic aorta. Heart;86:227-234. 2001. Word PDF

Esmailian. Retrograde Cerebral Perfusion as an Adjunct to Prolonged Hypothermic Circulatory Arrest. Chest.;116:887-891. 1999. Word PDF (volver)RCP is a reliable and technically appealing tool that does the following: (1) it improves DHCA safety and is applicable in a variety of clinical settings with relative ease; (2) it potentially provides oxygen and nutritional support to the brain during DHCA; (3) it helps remove air and other debris from the cerebral vessels; and (4) it is useful in dealing with congenital heart disease and tumor extension into the IVC.

Evangelista. Acute Intramural Hematoma of the Aorta: A Mystery in Evolution. Circulation;111:1063-1070. 2005. Word PDFWe studied 1010 patients with acute aortic syndromes who were enrolled in the International Registry of Aortic Dissection (IRAD) to delineate the prevalence, presentation, management, and outcomes of acute IMH by comparing these patients with those with classic aortic dissection (AD). Fifty-eight (5.7%) patients had IMH, and this cohort tended to be older (68.7 versus 61.7 years; P<0.001) and more likely to have distal aortic involvement (60.3% versus 35.3%; P<0.001) compared with 952 patients with AD. Patients with IMH described more severe initial pain than did those with AD but were less likely to have ischemic leg pain, pulse deficits, or aortic valve insufficiency; moreover, they required a longer time to diagnosis and more diagnostic tests. Overall mortality of IMH was similar to that of classic AD (20.7% versus 23.9%; P=0.57), as was mortality in patients with IMH of the descending aorta (8.3% versus 13.1%; P=0.60) and the ascending aorta (39.1% versus 29.9%; P=0.34) compared with AD. IMH limited to the aortic arch was seen in 7 patients, with no deaths, despite medical therapy in only 6 of the 7

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individuals. Among the 51 patients whose initial diagnostic study showed IMH only, 8 (16%) progressed to AD on a serial imaging study.Conclusions--The IRAD data demonstrate a 5.7% prevalence of IMH in patients with acute aortic syndromes. Like classic AD, IMH is a highly lethal condition when it involves the ascending aorta and surgical therapy should be considered, but this condition is less critical when limited to the arch or descending aorta. Fully 16% of patients have evidence of evolution to dissection on serial imaging.

Fann, Surgical Management of Aortic Dissection During a 30-Year Period. Circulation.;92:113-121. 1995. Word (volver)Between 1963 and 1992, 360 patients (256 men and 104 women; mean±1 SD age, 57±14 years) underwent surgery for aortic dissection: 174 patients had an acute type A (AcA), 46 an acute type B (AcB), 106 a chronic type A (ChA), and 34 a chronic type B (ChB) aortic dissection. The overall operative mortality rate was 24±8% (26±3% for AcA, 39±8% for AcB, 17±4% for ChA, and 15±6% for ChB, [±70% confidence limit]). The operative mortality rates for patients with acute aortic dissection (AcA or AcB) were assessed for five time "windows": 1963 to 1972 (42±8%), 1973 to 1977 (37±8%), 1978 to 1982 (15±6%), 1983 to 1987 (27±6%), and 1988 to 1992 (26±6%). Logistic regression analysis suggested that the low operative mortality rate during the 1978-to-1982 interval occurred by chance. Multivariate analysis showed earlier operative year, hypertension, cardiac tamponade, renal dysfunction, and older age were independent determinants of operative death. Actuarial survival rates (including early deaths) after 5, 10, and 15 years for AcA patients were 55%, 37%, and 24%; for AcB, 48%, 29%, and 11%; for ChA, 65%, 45%, and 27%; and for ChB, 59%, 45%, and 27%. Multivariate analysis revealed that older age and previous operation were significant predictors for late death. Freedom from reoperation for all patients was 84%, 67%, and 57% at 5, 10, and 15 years, respectively. Conclusions Although the operative mortality rate decreased over time for patients with aortic dissection, the risk for those with acute aortic dissection during the last 10 years (1983 to 1992) is probably more realistic than that observed in the preceding 5-year interval (1978 to 1982). The operative mortality rates for patients with chronic aortic dissection have remained relatively static. Earlier diagnosis of acute aortic dissection before development of cardiac tamponade and renal impairment is critical to improve the operative salvage rate

Fleck. A double patch sandwich technique for surgical repair of acute aortic dissection type A. Ann. Thorac. Surg.;76:499-502. 2003. Word (volver)

Fleck. The incidence of transient neurologic dysfunction after ascending aortic replacement with circulatory arrest. Ann Thorac Surg;76:1198-1202. 2003. Word (volver)Between January 1997 and January 2003, 160 consecutive patients (130 type A dissections [81%] and 30 elective atherosclerotic aneurysms [19%]) had surgical repair with DHCA for a thoracic aortic aneurysm limited to the ascending aorta. From those, 40 patients (25%) underwent DHCA alone, whereas in 13 patients (8%) antegrade cerebral perfusion and in 103 patients (64%) retrograde cerebral perfusion was used for further brain protection. RESULTS: The overall incidence of TND was 18% (28 of 160) with a significant association between duration of circulatory arrest and the incidence of TND (13.8% in DHCA < 30 minutes versus 37.9% in DHCA > 40 minutes; p < 0.05). Furthermore the severity of TND was directly associated with the duration of circulatory arrest and age. In contrast, however, the use of retrograde cerebral perfusion had no influence on the incidence of TND, (p < 0.05). Intensive care unit stay as well as hospital stay were prolonged in the patients with TND (intensive care unit 14.3 ± 14.2 days versus 10.8 ± 13.7 days, p < 0.05; hospital stay 15.6 ± 10.1 days versus 11.4 ± 7.9 days, p < 0.05). CONCLUSIONS: Duration of DHCA, regardless of whether retrograde cerebral perfusion was used, was the most important predictor of the incidence of transient neurologic dysfunction in patients who had replacement of the ascending thoracic aorta.

Fusco. Femoral Cannulation is Safe for Type A Dissection Repair. Ann Thorac Surg;78:1285-1289. 2004. Word (volver)

Ganzel. Neurophysiological monitoring to assure delivery of retrograde cerebral perfusion. J Thorac Cardiovasc Surg;113:748-57. 1997. Word (volver)Thirty patients underwent complex aortic procedures necessitating circulatory arrest, 22 with retrograde cerebral perfusion. The mean retrograde perfusion pressure of 40 mm Hg (30 to 49 mm Hg, 95% confidence interval) and flow rate of 1.2 L/min (0.9 to 1.6 L/min) necessary to achieve documented retrograde cerebral perfusion was much higher than previously recommended. During both retrograde

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cerebral perfusion and rewarming, cerebral oximetric monitoring guided adjustments in perfusion parameters to limit the rate of desaturation to 0.4% per minute (0.3% to 0.6%). With retrograde cerebral perfusion there was a rapid (1) recovery of electroencephalographic activity during rewarming (21 minutes [range 16 to 26 minutes]) and (2) return of consciousness after the operation (81% [58% to 95%, 95% confidence interval] awake by 12 hours). There was no transcranial Doppler evidence of cerebral edema with retrograde cerebral perfusion. Two neurologic complications occurred in the 22 patients managed with retrograde cerebral perfusion and one in the eight patients managed with arrest only. Conclusions: Multimodality neurologic monitoring assured optimal brain cooling and bihemispheric delivery of retrograde cerebral perfusion. Necessary retrograde pressure and flow were often higher than values previously reported. Avoidance of profound cerebral venous oxygen desaturation during retrograde cerebral perfusion and rewarming was associated with rapid recovery of neurologic function.

Genoni. Predictors of complications in acute type B aortic dissection. Eur J Cardiot Surg;22:59-63. 2002. Word (volver)Rupture, shock and malperfusion are significant predictors of poor survival in patients with acute type B aortic dissection..

Gowda. Endovascular Stent Grafting of Descending Thoracic Aortic Aneurysms. Chest.;124:714-719. 2003. Word PDF (volver)The placement of endoluminal stent-grafts to exclude the rupture sites of descending thoracic aortic aneurysms is a technically feasible and relatively safe procedure. It may improve the short-term outcomes of patients with dissecting thoracic aneurysms with or without rupture or dissection. Extended follow-up is necessary to determine the long-term outcome. At the present time, it seems to be an acceptable option in high-risk elderly patients and in patients for whom no other feasible therapy exists.

Grabenwoger. Secondary surgical interventions after endovascular stent-grafting of the thoracic aorta. Eur J Cardiothorac Surg;26:608-613. 2004. Word (volver)The objective of the study was to evaluate mid-term durability and need for reinterventions after endovascular stent-grafting (ESG) in descending aortic aneurysms and dissections. Patients and Methods: Between November 1996 and February 2003 a total of 80 patients underwent ESG for the following indications: atherosclerotic aneurysms (50/80; 63%), type B dissections (20/80; 25%), penetrating ulcers (6/80; 8%), traumatic aneurysms (4/80; 5%). Two types of commercially available ESG (Talent, Medtronic, Santa Rosa, CA and Excluder, WL GORE, Flagstaff, AZ) were inserted via the femoral artery in 53 patients, via the iliac artery in 21 patients and via the abdominal aorta in 6 patients. Results: In-hospital mortality was 3.8% (n=3). Type I endoleak formation requiring endovascular reintervention was observed in 3.8% (n=3). Surgical reintervention became necessary in 4 patients (4/80; 5%). One patient experienced a retrograde type A dissection, detected in the 3 month control after ESG of an acute type B dissection, consecutively undergoing frozen elephant trunc repair. Three patients with late type I endoleak formation (mean interval: 62 months) after ESG (two atherosclerotic aneurysms, one penetrating ulcer) underwent open thoraco-abdominal repair in deep hypothermia or left heart bypass technique. All patients had an uneventful postoperative course. Conclusions: Occurrence of late endoleak formation requiring surgical reintervention after ESG is acceptably low.

Graeter. Valve-preserving operation in acute aortic dissection type A. Ann Thorac Surg;70:1460-1465. 2000. Word (volver)From October 1995 to December 1999, 52 patients (35 men, 17 women) underwent repair of AADA. Patient ages ranged from 30 to 83 years. Composite replacement was chosen for degenerated aortic valves or prior valve replacement (group A; n = 8). With normal root diameter, supracommissural replacement of the ascending aorta was performed (group B; n = 22). For preexisting root dilatation the aortic root was either remodeled (root diameter 30 to 50 mm, group C; n = 17) or the valve reimplanted within a vascular graft (root diameter more than 50 mm, group D; n = 5). Results. All patients underwent either proximal (n = 46) or total (n = 6) arch replacement under circulatory arrest. Eight patients (15.4%) died (group A: n = 3; group B: n = 3; group C: n = 2). Freedom from aortic regurgitation of grade 2 or more at 2 years was 100% in groups A and D, 90.9% in group C, and 75% following supracommissural replacement. At 2 years freedom from proximal reoperation was 100% in groups A, C, and D and 84.5% in group B. Conclusions. In AADA valve-preserving root replacement leads to improved stability of aortic valve function without an increased operative risk. Midterm results are promising and may show further superiority over supracommissural aortic replacement in the future.

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Hagan, The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA 283,897-903. (2000). Word PDF (volver)Participants A total of 464 patients (mean age, 63 years; 65.3% male), 62.3% of whom had type A dissection. Main Outcome Measures Presenting history, physical findings, management, and mortality, as assessed by history and physician review of hospital records. Results While sudden onset of severe sharp pain was the single most common presenting complaint, the clinical presentation was diverse. Classic physical findings such as aortic regurgitation and pulse deficit were noted in only 31.6% and 15.1% of patients, respectively, and initial chest radiograph and electrocardiogram were frequently not helpful (no abnormalities were noted in 12.4% and 31.3% of patients, respectively). Computed tomography was the initial imaging modality used in 61.1%. Overall in-hospital mortality was 27.4%. Mortality of patients with type A dissection managed surgically was 26%; among those not receiving surgery (typically because of advanced age and comorbidity), mortality was 58%. Mortality of patients with type B dissection treated medically was 10.7%. Surgery was performed in 20% of patients with type B dissection; mortality in this group was 31.4%. Conclusions Acute aortic dissection presents with a wide range of manifestations, and classic findings are often absent. A high clinical index of suspicion is necessary. Despite recent advances, in-hospital mortality rates remain high.

Hagl. Hypothermic circulatory arrest with and without cold selective cerebral perfusion: impact on neurological recovery and tissue metabolism in an acute porcine model Eur J Cardiothorac Surg;26:73-80. 2004. Word PDF

Hagl. Mount Sinai. Neurologic outcome after ascending aorta-aortic arch operations: effect of brain protection technique in high-risk patients J Thorac Cardiovasc Surg;121:1107-1121. 2001. Word PDF (volver)Methods: All 717 patients who survived ascending aorta–aortic arch operations through a median sternotomy since 1986 were examined for factors influencing stroke. Temporary neurologic dysfunction was assessed in all patients who survived the operation without stroke since 1993. Multivariate analyses were carried out to determine independent risk factors for neurologic injury.Results: Independent risk factors for stroke were as follows: age greater than 60 years (P < .001; odds ratio, 4.5); emergency operation (P = .02; odds ratio, 2.2); new preoperative neurologic symptoms (P = .05; odds ratio, 2.9); presence of clot or atheroma (P < .001; odds ratio, 4.4); mitral valve replacement or other concomitant procedures (P = .055; odds ratio, = 3.7); and total cerebral protection time, defined as the sum of hypothermic circulatory arrest and any retrograde or antegrade cerebral perfusion (P = .001; odds ratio, 1.02/min). In 453 patients surviving operations without stroke after 1993, independent risk factors for temporary neurologic dysfunction included age (P < .001; odds ratio, 1.06/y), dissection (P = .001; odds ratio, 2.2), need for coronary artery bypass grafting (P = .006; odds ratio, 2.1) or other procedures (P = .023; odds ratio, 3.4), and total cerebral protection time (P < .001; odds ratio, 1.02/min). When all patients with total cerebral protection times between 40 and 80 minutes were examined, the method of cerebral protection did not influence the occurrence of stroke, but antegrade cerebral perfusion resulted in a significant reduction in incidence on temporary neurologic dysfunction (P = .05; odds ratio, 0.3). Conclusions: The occurrence of stroke is principally determined by patient- and disease-related factors, but use of antegrade cerebral perfusion can significantly reduce the occurrence of temporary neurologic dysfunction.

Hanafusa. Total arch replacement with elephant trunk procedure for retrograde dissection. Ann Thorac Surg;74:S1836-S1839. 2002. Word PDF (volver)From January 1995 to December 2001, 12 (8.6%) consecutive patients aged 40 to 71 years underwent total arch replacement with an elephant trunk procedure through a median sternotomy for retrograde dissection of the ascending aorta (acute: 10, chronic: 2) among 139 patients with type A dissection. The intimal tear was located in the descending aorta in all patients. Dissection extended proximally to the aortic root in 7 patients and to the ascending aorta in 5, and extended distally to the abdominal aorta in 4 and to the common iliac artery in 8. Hospital mortality occurred in 1 patient (8%) owing to multiple organ failure after malperfusion of the renal arteries. Postoperatively the false lumen in the descending aorta was closed in all patients who survived but the false lumen in the abdominal aorta was patent in 9. The thoracic and abdominal aorta had slight dilatation in 2 patients.

Harringer. Ascending Aortic Replacement With Aortic Valve Reimplantation. Circulation.;100:II-24. 1999. Word (volver)

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From July 1993 to November 1998, a replacement of the ascending aorta with a repair of the aortic valve was performed in 75 patients (53 men and 22 women aged 50±19 years). Twenty-one patients (28%) had Marfan syndrome, and 11 patients (15%) had an aortic dissection, type Stanford A (6 acute, 5 chronic). In 17 patients (23%), concomitant replacement of the aortic arch was necessary. Clinical and echocardiographic follow-up was performed in 6- to 12-month intervals for a cumulative study period of 137 patient-years. No operative deaths occurred. Two patients (3%) died 5 and 20 months postoperatively. Three patients (4%) with progressive aortic insufficiency required aortic valve replacement after 9, 11, and 14 months. The repairs have now remained stable for 65 months (mean, 22±20 months). Other valve-related complications did not occur. Conclusions—Our results demonstrate that this type of aortic valve repair achieves excellent results in selected patients.

Hayashi. Penetrating Atherosclerotic Ulcer of the Aorta: Imaging Features and Disease Concept. Radiographics.;20:995-1005. 2000. Word PDF (volver)

Herold. Endoluminal stent graft repair for acute and chronic type B aortic dissection and atherosclerotic aneurysm of the thoracic aorta: an interdisciplinary task. Eur J Cardiothorac Surg;22:891-897. 2002. Word (volver)Between August 1999 and August 2001, endovascular stent graft repair was performed in 34 patients (27 male, seven female) with a mean age of 68.6±7 years (range 58–84). Indication for treatment was an acute Type B aortic dissection in six patients (18%), a symptomatic chronic Type B dissection in 12 patients (35%), a true aneurysm of the descending aorta in seven patients (21%) and an atherosclerotic contained rupture of the descending aorta in nine (26%) patients. Out of six acute type B dissections three patients (8.8%) and one patient (2.9%) out of the chronic dissection group were in severe haemorrhagic shock, ventilated and required high-dose adrenergic support. The others (30 patients, 88.3%) remained symptomatic despite maximum medical treatment. In a special case a combined surgical and endoluminal stent graft repair was performed. Individually manufactured Talent, Medtronic AVE (33), and Gore (1) stents were used. Follow-up examination was performed 1 week after implantation and repeated every 3 months (mean follow-up 8 months, range 1–24). Results: In all patients the aneurysm or the entry of the dissection could be excluded. The observed hospital mortality was 2.9% (one patient). No perivascular leakage, no stent dislocation, no neurological deficit or perfusion impairment was observed. All patients except four were extubated immediately after the procedure and discharged from hospital on postoperative day 2–3. The late procedure-related mortality was 5.8% (two patients) resulting in an overall mortality of 8.8% (three patients). Conclusion: Stent graft repair is a safe and feasible treatment option for selected patients, especially in emergency situations, if the aortic lesions can be clearly identified and localized. The use of biplane X-ray control combined with simultaneous intravascular and transoesophageal ultrasound imaging in an interdisciplinary approach enables a more precise targeting of the stent landing zone, resulting in low morbidity and mortality rates

Higami. Retrograde cerebral perfusion versus selective cerebral perfusion as evaluated by cerebral oxygen saturation during aortic arch reconstruction Ann Thorac Surg;67:1091-1096. 1999. Word PDF

Hirotani. Results of a total aortic arch replacement for an acute aortic arch dissection. J Thorac Cardiovasc Surg;120:686-691. 2000. Word (volver)During the past 4 years, 27 consecutive patients who had an aortic arch dissection underwent a total aortic arch replacement. Twenty-five patients underwent an emergency operation. In 5 patients the intimal tear was located in the aortic arch, but in the rest of the patients, it was located in the ascending aorta or the proximal descending aorta. To obliterate any false channels, gelatin-resorcin-formol glue was used.Results: The hospital mortality was 11%, and no cerebral complications were observed. Postoperative aortography and computed tomography showed no evidence of any persisting false channels in 15 patients (65%). During the follow-up period (ranging from 5 months to 4 years), two patients underwent a reoperation because of the recurrence of a dissection at the sinus of Valsalva. All patients, except for one who died after a reoperation, are still alive and free from any serious events at this writing.

Hsu. Outcome of Medical and Surgical Treatment in Patients With Acute Type B Aortic Dissection. Ann. Thorac. Surg.;79:790-794. 2005. Word (volver)In the last 8 years, 107 patients were admitted for acute type B aortic dissection. We medically treated patients at the time of onset with antihypertensives. Surgery was considered if there is intractable pain, uncontrolled hypertension, severe aortic branch malperfusion, or aneurysm expansion. RESULTS: Twenty-nine patients had pleural effusion (27%), 9 patients had leg ischemia (8%), 5 patients had impending rupture, and 2 patients had aneurysm enlargement exceeding 60 mm on repeated imaging

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studies. A total of 16 patients (15%) underwent surgical intervention: 8 extra-anatomical bypass for leg ischemia, 1 in situ infrarenal aortoiliac bypass for distal aortic obstruction, and 7 thoracic aortic graft replacement. Of the 8 patients with extra-anatomic bypass, 3 patients died: 2 patients died of catastrophic aortic rupture 2 and 9 days after bypass, and 1 patient died of dissection progression to type A lesion 9 days after bypass. There was no in-hospital death in 92 medically treated patients. Follow-up was 92% complete. The mean follow-up duration was 36.1 months (range, 2 to 96 months). The 6-month, 1-year, and 5-year survival rates of all patients were 96.2 ± 1.9%, 95.2% ± 2.1%, and 95.2% ± 2.1%. CONCLUSIONS: Medical treatment of acute type B aortic dissection produced good outcomes. Central aortic procedures such as aortic fenestration and endovascular stenting should be the preferred methods to treat patients with acute type B aortic dissection and leg ischemia because there was high risk of central aortic complications after extra-anatomic bypass.

IRAD-manuscripts. 2000. Word

Kaji. Long-Term Prognosis of Patients With Type B Aortic Intramural Hematoma. Circulation.;108:II-307. 2003. PDF

Kaji. Prognosis of Retrograde Dissection From the Descending to the Ascending Aorta. Circulation.;108:II-300. 2003. Word PDF (volver)Study population consisted of 109 patients with acute type A AD. There were 27 patients (25%) with retrograde AD and 82 patients (75%) with intimal tear in the ascending aorta (antegrade AD). In antegrade AD patients, 60 patients underwent surgery and 22 patients were treated medically. In retrograde AD patients, 14 patients showed localized crescentic high attenuation area along the ascending aortic wall without enhancement in computed tomography. Transesophageal echocardiography revealed complete thrombosis of false lumen (FL) in the ascending aorta (retrograde thrombosed). The remaining 13 patients showed incomplete or no thrombosis (retrograde nonthrombosed). All retrograde nonthrombosed AD patients underwent surgery except for 1 patient with stroke, whereas all retrograde thrombosed AD patients were treated medically. In-hospital mortality rate of retrograde AD patients was significantly lower than that of antegrade AD patients (15% versus 38%, P=0.027). The survival rates in retrograde AD patients were all 85% at 1, 2, and 5 years, which were significantly higher than those of antegrade AD patients (63%, 62%, and 57%, respectively)(P=0.009). Conclusions— Patients with type A retrograde AD have better medium-term prognosis than patients with antegrade AD. Retrograde AD patients with thrombosed FL in the ascending aorta could be treated medically with timed surgical repair.

Kallenbach. Evolving Strategies for Treatment of Acute Aortic Dissection Type A. Circulation;110:II-243-II-249. 2004. Word PDF (volver) Between October 1990 and October 2003, we operated on 295 patients (pts) for AADA. Follow-up was complete for 257 pts (87%). Supracommissural replacement (SCR) of the ascending aorta was applied to 145 pts, 64 pts received a composite replacement (comp), and 48 pts were treated with the aorta valve-sparing (AVS) reimplantation technique. Pts in SCR were older compared with AVS and comp (P=0.002), gender (overall 65% male, P=0.143) and presence of Marfan syndrome (overall 5%, P=0.109) were comparable. Cannulation of the aorta was performed more often in AVS (58%) than in comp (19%) or SCR (22%; P<0.001). Mean operation time, extracorporeal circulation time, and aortic cross-clamp time differ significantly between groups (P<0.001, respectively). Stay in the intensive care unit (P=0.12) and time of hospitalization (P=0.32) were comparable. Overall perioperative mortality was 24% and did not show significant differences between groups (AVS 10.4% versus comp 28% versus SCR 26%; P=0.053). Incidence of neurological complications was similar between groups (P=0.95). Mean time of follow-up was shorter for AVS (19±20 months) compared with comp (48±48 months) and SCR (46±45 months). Survival at 5 years was comparable with 89% for AVS, 85% for comp, and 80% for SCR (P=0.61). Two patients from AVS (4.1%) required reoperation for failure of the reconstructed valve. Pts in comp required less aortic reoperations than pts in SCR (comp 6.3% versus SCR 22%; P=0.005).Conclusions—: In acute aortic dissection type A, the reimplantation technique leads to results comparable to established techniques.

Katz. Distribution of cerebral flow using retrograde versus antegrade cerebral perfusion Ann Thorac Surg;67(4):1065-1069. 1999. Word PDF

Kato. The results of total arch graft implantation with open stent-graft placement for type A aortic dissection. J Thorac Cardiovasc Surg;124:531-540. 2002. Word

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From October 1994 through October 1999, 19 patients with type A aortic dissection (13 acute and 6 chronic dissections) underwent total arch graft implantation with open-style stent-graft placement. After achievement of general anesthesia and hypothermic extracorporeal circulation, we replaced the dissected ascending aorta and neck vessels with a 4-branched graft and repaired the descending aorta with a stent graft to close the entry site completely and to obtain better peripheral perfusion. We then examined the acute-phase and chronic-phase results and the outcomes of the false lumen and dissected aorta. Results: There were 1 (5.3%) hospital death and 2 late deaths. The survivals at 1 and 3 years were 89.5% and 82.6%, respectively. The following complications occurred in the perioperative period: 1 stroke, 2 cases of temporary paraparesis, 2 cases of temporary hemodialysis, and 3 cases of mediastinitis. No pulmonary complications were observed.

Kazui. Role of biologic glue repair of proximal aortic dissection in the development of early and midterm redissection of the aortic root. Ann Thorac Surg;72:509-514. 2001 Word PDF (volver)From January 1983 to September 2000, 130 patients had emergency operation for acute type A aortic dissection. Of them, 57 patients underwent root reconstruction using biologic glues and 4 patients (7.0%) developed redissection of the aortic root associated with moderate to severe aortic regurgitation 5 to 27 months after the initial operation. In all patients, the proximal false lumen was obliterated with infusion of gelatin-resorcinol-formaldehyde (GRF) glue or BioGlue and the aorta was reinforced with Teflon felt strip or Surgicel placed on its outside wall. Conclusions. The use of biologic glues for reapproximating the layers of the dissected aortic root is associated with a certain amount of risk of aortic wall necrosis. Therefore, care should be taken to ensure proper use of these glues. Full root replacement could be a preferable technique for treating redissection of the aortic root.

Kazui. Extended total arch replacement for acute type a aortic dissection: experience with seventy patients. J Thorac Cardiovasc Surg. Mar;119(3):558-65. 2000. Word PDFBetween December 1988 and August 1998, 70 patients underwent emergency graft replacement of both the ascending aorta and the total aortic arch for acute type A aortic dissection. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and open distal anastomosis. Concomitant procedures included aortic valve resuspension in 18 patients, composite graft replacement in 10 patients, and coronary artery bypass grafting in 5 patients. Results: The early mortality rate was 16% (11 of 70 patients). Multivariable analysis showed that renal-mesenteric ischemia and coronary artery bypass grafting were independent determinants for early death. Survival rates at 3 and 5 years postoperatively, including the early deaths, were 75% ± 5% and 73% ± 6%, respectively. Multivariable analysis showed that renal-mesenteric ischemia and en bloc repair were independent determinants for late death. Freedom from reoperation was 91% ± 4% and 77% ± 8% at 3 and 5 years, respectively. Multivariable analysis showed that anastomotic leakage was the only significant determinant for late reoperation.

Kazui. Extended aortic replacement for acute type a dissection with the tear in the descending aorta. J Thorac Cardiovasc Surg;112:973-978. 1996. Word (volver)

Kirsch. Risk factor analysis for proximal and distal reoperations after surgery for acute type A aortic dissection. J Thorac Cardiovasc Surg;123:318-325. 2002. WordBetween 1980 and 2000, a total of 160 consecutive patients (mean age 57.5 ± 13.3 years, 126 men) underwent surgery for acute type A aortic dissection. Proximal repair was performed by means of ascending aorta replacement with valve resuspension in 130 cases (81.3%), composite graft replacement in 19 cases (11.9%), separate aortic valve and ascending aorta replacement in 7 cases (4.4%), and aortic repair in 1 case (0.6%). Distal repair required arch replacement in 23 cases. Follow-up time averaged 4.51 ± 5.6 years per patient. Results: Survival estimates after initial operation were 66.1% ± 3.8%, 57.7% ± 4.2%, 52.2% ± 4.6%, and 42.5% ± 5.8% at 1, 5, 10, and 15 years, respectively. Thirty patients required 37 reoperations at a mean interval of 5.7 ± 4.5 years after the initial operation. Freedoms from reoperation were 96.9% ± 1.8%, 74.7% ± 5.3%, 60.8% ± 6.8%, and 39.3% ± 9.1% at 1, 5, 10, and 15 years, respectively. Reoperations included procedures on the proximal aorta (aortic root or valve) in 21 cases and on the distal aorta or its side branches in 19 cases

von Kodolitsch. Intramural Hematoma of the Aorta. Predictors of Progression to Dissection and Rupture. Circulation.;107:1158. 2003. Word PDF (volver)A multicenter study was conducted comprising 66 patients with IMH and hospital admission 48 hours after onset of initial symptoms. Among these, progression to aortic dissection or rupture occurred in 30

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(45%) and death occurred in 13 (20%) patients within 30 days. Late progression was noted in 14 (21%) and death in 11 (17%) patients, yielding a 1-, 2-, and 5-year survival of 76%, 73%, and 43%, respectively. In a set of 9 variables, multivariate analysis identified IMH location in the ascending aorta (type A; P=0.02) and moderately ectatic aortic diameters (49±13 mm with progression versus 57±16 mm without progression; P=0.03) as independent predictors of early progression. In type A IMH, early mortality was 8% with swift surgery versus 55% without surgery (P=0.004). The risk of late progression of IMH was independently associated with age at index diagnosis (P=0.01) and absence of ß-blocker therapy during follow-up (P=0.03). Kaplan-Meier analysis confirmed improved 1-year survival of IMH with ß-blocker therapy (95% versus 67% without ß-blockers; P=0.004). Conclusions— Regardless of aortic diameter, IMH of the ascending aorta (type A) is at high risk for early progression, and, thus, undelayed surgical repair should be performed. Moreover, oral ß-blocker therapy may improve long-term prognosis of IMH independent of anatomical location.

Küçüker. Arch repair with unilateral antegrade cerebral perfusion. Eur J Cardiothorac Surg;27:638-643. 2005. Word (volver)Between January 1996 and March 2004, 181 patients underwent aortic arch repair via the right upper brachial artery with the use of low-flow (8–10ml/kg per min) antegrade selective cerebral perfusion under moderate hypothermia (26°C). Mean patient age was 58±12 years. Presenting pathologies were Stanford type A aortic dissection in 112, aneurysm of ascending and arch of aorta in 67, and isolated arch aneurysm in two patients. Ascending and/or partial arch replacement was performed in 90 patients and ascending and total arch replacement in 91 patients (including 27 with elephant trunk). In a subset of patients, renal and hepatic effects of ischemic insult were assessed. Free hemoglobin and lactate dehydrogenase levels were measured pre and postoperatively to identify hemolytic effects of brachial artery cannulation. Results: Mean antegrade cerebral perfusion time was 36±27min. Three patients with acute proximal dissection died due to cerebral complications. One patient had transient right hemiparesis. Total major neurological event rate was 2.2%. Brachial artery was able to carry full cardiopulmonary bypass flow with mild hemolysis. Renal and hepatic tests showed no deleterious effects of limited ischemia at moderate hypothermia. Conclusions: Arch repair with antegrade cerebral perfusion through right brachial artery has excellent neurological results, provides technical simplicity and optimal repair without time restraints, does not necessitate deep hypothermia and requires shorter CPB and operation times.

Kunzelman. Aortic root and valve relationships: Impact on surgical repair. J Thorac Cardiovasc Surg;107:162-170. 1994. Word

Lai. Stanford. Does Profound Hypothermic Circulatory Arrest Improve Survival in Patients With Acute Type A Aortic Dissection?. Circulation;106:I-218-I-228. 2002. Word PDF (volver)Methods Records of 307 patients with acute type A aortic dissection from 1967 to 1999 were retrospectively reviewed. The influence of repair using PHCA (n=121) versus without PHCA (n=186) on death and freedom from distal aortic reoperation was analyzed using multivariable Cox regression models. Propensity score analysis identified a subset of 152 comparable patients in 3 quintiles (QIII–V) in which the effects of PHCA (n=113) versus no PHCA (n=39) were further compared. Results For all patients, 30-day, 1-year, and 5-year survival estimates were 81±2%, 74±3%, and 63±3% (±1 SE). Survival rates and actual freedom from distal aortic reoperation was not significantly different between treatment methods in the entire patient cohort nor in the matched patients in quintiles III–V. Treatment method was not associated with differences in early major complications, late survival, or distal aortic reoperation rates in the entire patient sample or in quintiles III–V. Conclusions Aortic repair with or without circulatory arrest was associated with comparable early complications, survival, and distal aortic reoperation rates in patients with acute type A aortic dissection. Despite the lack of concrete evidence favoring the use of PHCA, it does no harm, and most of our group uses PHCA regularly because of its practical technical advantages and theoretical potential merit.

Lansman. Mount Sinai.Acute type B aortic dissection: surgical therapy . Ann Thorac Surg;74:S1833-S1835. 2002. Word PDF (volver)Surgery for acute type B aortic dissection is associated with significant mortality. We report the results for 34 consecutive patients who underwent urgent surgery because they met criteria for operation during the acute phase (< 14 days) of acute type B dissection. METHODS: The average patient age was 64 (32 to 88) years. Indications for surgery were persistent pain (12), threatened exsanguination (18), malperfusion (renal [3], limb [3]), rapid aortic enlargement (4), and uncontrolled hypertension (1). The mean interval from onset of pain to operation was 7 (1 to 14) days.

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Resection included the proximal descending aorta in 32, the distal aortic arch in 10, extension to the diaphragm in 10, and involved a thoracoabdominal procedure in 3. Surgical techniques included hypothermic circulatory arrest (16 [47%]), distal bypass, monitoring of somatosensory-evoked potentials, sequential intercostal sacrifice (average, 5.6 pairs), cerebrospinal fluid drainage, and steroid administration. RESULTS: There was no hospital mortality. Important complications occurred in 16 patients (47%): 10 respiratory requiring tracheostomy, six infectious, four dialysis, two myocardial infarctions, and two neurologic (one transient stroke, one paraplegia). Mean intensive care unit and hospital stays were 10 (3 to 32) and 35 (7 to 107) days. Survival at 5 and 10 years was 80% and 57%, respectively (mean follow-up, 5.8 years). CONCLUSIONS: Patients meeting criteria for urgent surgery have a low perioperative risk for mortality and paraplegia, and are relatively free from long-term aorta-related complications. These findings warrant consideration of earlier surgery for appropriate patients with acute type B aortic dissection.

LePage. Aortic Dissection.CT Features that Distinguish True Lumen from False Lumen. AJR; 177:207-211. 2001. Word PDF (volver)

Leurs. Endovascular treatment of thoracic aortic diseases: combined experience from the EUROSTAR and United Kingdom Thoracic Endograft registries. Vasc Surg. Oct;40(4):670-9; discussion 679-80. 2004. Word PDF (volver)Four hundred forty-three patients underwent endovascular repair of thoracic aortic disease between September 1997 and August 2003 (EUROSTAR, 340 patients; UK, 103 patients). Patients represented 4 major disease groups: degenerative aneurysm (n = 249), aortic dissection (n = 131), false anastomotic aneurysm (n = 13), and traumatic aortic injury (n = 50). RESULTS: Mean age in the entire study group was 63 years. Fifty-two percent of patients were deemed at high risk for open surgery because of major comorbidity. Sixty percent of patients underwent an elective procedure, and 35% required emergency treatment. Conventional indications for treatment of aortic dissection, including aortic expansion, continuous pain, rupture, or symptoms of branch occlusion constituted the basis for endograft placement in 57% of patients, whereas in 43% of patients aortic dissections were asymptomatic. Primary technical success was obtained in 87% of patients with degenerative aneurysm and in 89% with aortic dissection. Paraplegia was a postoperative complication in 4.0% of patients with degenerative aneurysm and 0.8% of patients with aortic dissection (not significant). Thirty-day mortality in the entire study group was 9.3%, with mortality rates after elective procedures of 5.3% for degenerative aneurysms and 6.5% for aortic dissection. Mortality for degenerative aneurysm after emergency repair was higher (28%; P <.0001) then after elective procedures. For aortic dissection the emergency repair rate was 12% (not significant compared with elective repair of aortic dissection, and P = .025 compared with emergency repair of degenerative aneurysm). One-year follow-up was complete in 195 patients. The outcome at 1 year was more favorable for aortic dissection than for degenerative aneurysm with regard to aortic expansion (0% vs 15%; P = .001) and late survival (90% vs 80%; P = .048). In the groups with false anastomotic aneurysm and traumatic aortic injury, 30-day mortality rates were 8% and 6%, respectively. CONCLUSION: This multicenter experience demonstrates acceptable rates for operative mortality and paraplegia after endovascular repair of thoracic aortic disease. Outcome after 30 days and 1 year was more favorable for aortic dissection than for degenerative aneurysm. However, the durability of this technique is currently unknown, and continued use of registries should provide data from long-term follow-up.

Leyh. High Failure Rate After Valve-sparing Aortic Root Replacement Using the "Remodeling Technique" in Acute Type A Aortic Dissection. Circulation.;106:I-229. 2002. Word PDF (volver)From August 1995 to November 2000, 30 patients with acute type A dissection received valve-sparing aortic root replacement. Two different techniques were performed: the "remodeling" technique, first described by Yacoub in 1983 (8 patients) and the "reimplantation" technique, initially described by David and Feindel, in 1992 (22 patients). Endpoints of the study were early and late mortality, as well as aortic valve-related complications and reoperations. Results The mean follow-up time was 22.6±15.4 months. The overall 30 day mortality was 17% (5/29) and the late mortality 4% (1/24). During the observation period, 4 patients had to be reoperated (n=3) for acute aortic valve regurgitation after aortic root remodeling and for acute aortic valve endocarditis (n=1) after aortic root reimplantation. In the 3 patients with acute aortic valve regurgitation, symptoms occurred 44, 24, and 17 months after the initial operation in these patients. Intraoperatively prolapsing aortic leaflets because of commissural detachment was found in all 3 cases. In all other patients the latest echocardiographic follow-up examination revealed freedom from aortic regugitation higher than grade 1.

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Conclusions The high failure rate of aortic root remodeling inpatients with acute type A aortic dissection is discouraging. Whether this technique should be applied in acute type A aortic dissection is questionable. In contrast, aortic root reimplantation lead to favorable midterm outcome

Long. Preoperative shock determines outcome for acute type A aortic dissection. Ann. Thorac. Surg.;75:520-524. 2003. Word (volver)Average age was 59 ± 2 years. Comorbidities included hypertension (66%), coronary artery disease (17%), and Marfan’s syndrome (11%). At presentation, 23% were in shock, 17% had neurologic dysfunction, and 36% had coronary ischemia. The aortic valve was preserved in 55. Distal aortic anastomosis was performed under aortic cross-clamp ("closed") in 32 and "open" under circulatory arrest in 38 patients. Operative mortality was 18.6% (13 of 70 patients). Patients in shock had an operative mortality of 50% compared with stable patients of 9% (p = 0.0002). Mortality was similar regardless of technique. Univariate analysis revealed preoperative shock (p = 0.0002), tamponade (p = 0.003), and neurologic deficit (p = 0.02) to be associated with mortality. Multivariate analysis revealed hemodynamic stability (odds ratio = 0.10, p = 0.04) and outside transfer (odds ratio = 0.12, p = 0.03) to be negative predictors of mortality. Of 57 survivors, follow-up was 93% complete for an average of 46 ± 6 months. The overall late reoperation rate was 24.6% (14 of 57 patients) at 50.3 ± 12.3 months. Twelve patients (21%) underwent future aortic aneurysmal repair. No difference in reoperation rate was seen comparing "closed" (26%) with "open" (18%; p = 0.46). Of 42 preserved native valves, only 3 (7.1%) needed future valve replacement. CONCLUSIONS: In our experience, operative mortality was determined by preoperative hemodynamic instability. Technique did not impact survival or late reoperation. Early diagnosis and repair is critical to improving survival

Marin. Endovascular stent graft repair of abdominal and thoracic aortic aneurysms: a ten-year experience with 817 patients. Ann Surg. Oct;238(4):586-93; discussion 593-5. 2003. Word PDF (volver)Over a 10-year period, 817 patients were treated with ESGs for AAA (723) or TAA (94). Patients received 1 of 12 different stent graft devices. Technical and clinical success of ESGs was reviewed, and the incidence of procedure-related complications was analyzed.Results: The mean age was 74.3 years (range, 25–95 years); 678 patients (83%) were men; 86% had 2 or more comorbid medical illnesses, 67% of which included coronary artery disease. Technical success, on an intent-to-treat basis was achieved in 93.8% of patients. Primary clinical success, which included freedom from aneurysm-related death, type I or III endoleak, graft infection or thrombosis, rupture, or conversion to open repair was 65 ± 6% at 8 years. Of great importance, freedom from aneurysm rupture after ESG insertion was 98 ± 1% at 9 years. There was a 2.3% incidence of perioperative mortality. One hundred seventy five patients died of causes not related to their aneurysm during a mean follow-up of 15.4 months. Conclusions: Stent graft therapy for aortic aneurysms is a valuable alternative to open aortic repair, especially in older sicker patients with large aneurysms. Continued device improvements coupled with an enhanced understanding of the important role of aortic pathology in determining therapeutic success will eventually permit ESGs to be a more durable treatment of aortic aneurysms.

Martín. Tratamiento percutáneo de las afecciones de la aorta torácica. Una labor multidisciplinaria. Rev Esp cardiol. Enero Volumen 58 - Número 01 p. 27 - 33 . 2005. Figura stent. Word (volver)

Matalanis. A retrospective comparative study of deep hypothermic circulatory arrest, retrograde, and antegrade cerebral perfusion in aortic arch surgery J Thorac Cardiovasc Surg;9(3):174-179. 2003.

Mehta. Acute type B aortic dissection in elderly patients: clinical features, outcomes, and simple risk stratification rule. Ann. Thorac. Surg.;77:1622-1628. 2004. Word (volver)

Mehta. Chronobiological Patterns of Acute Aortic Dissection. Circulation;106:1110-1115. 2002. PDF

Mehta, Acute type A aortic dissection in the elderly: clinical characteristics, management, and outcomes in the current era, J Am Coll Cardiol. 40 (2002), pp. 685–692. (volver)

Mehta. Predicting Death in Patients With Acute Type A Aortic Dissection. Circulation.;105:200. 2002. Word

Mészáros. Epidemiology and Clinicopathology of Aortic Dissection. Chest.;117:1271-1278. 2000. Word (volver)

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A population-based longitudinal study over 27 years on a study population of 106,500, including 66 hospitalized and 18 nonhospitalized consecutively observed patients. Results: Altogether, 86 cases of aortic dissection were found in 84 patients, corresponding to a 2.9/100,000/yr incidence. Sixty-six of the 84 patients (79%) were admitted to the hospital, and 18 patients (21%) died before admission. Their ages ranged from 36 to 97 years, with a mean of 65.7 years. The male/female ratio was 1.55 to 1. A total of 22.7% of the hospitalized patients died within the first 6 h, 33.3% within 12 h, 50% within 24 h, and 68.2% within the first 2 days after admission. Six patients were operated on, with a perioperative mortality of two of six patients and a 5-year survival of two of six patients. All patients who were not operated on died. Pain was the most frequent initial symptom. Every patient had some kind of cardiovascular and respiratory sign. Neurologic symptoms occurred in 28 of 66 patients (42%). Five patients presented with clinical pictures of acute abdomen and two with acute renal failure. Trunk arteries were affected in 33 of the 80 autopsied cases (41%), and rupture of aorta was seen in 69 cases (86%). In five cases, spontaneous healing of dissection was also found. The ratio of proximal/distal dissections was 5.1 to 1. All 18 prehospital cases were acute. Fifty-nine cases (89.4%) were acute at admission, and 7 cases (10.6%) were chronic dissections. Hypertension and advanced age were the major predisposing factors.

Mitsumasa. Optimal treatment of type B acute aortic dissection: long-term medical follow-up results. Ann Thorac Surg;75:1781-1784. 2003. Word PDF (volver)In the last 8 years, 79 patients were admitted to our hospital with type B acute aortic dissection. We medically treated patients at the time of onset, regardless of the aortic diameter and blood patency status in the false lumen. If the maximum diameter of dissected aorta exceeded 60 mm in any stage, early or elective surgery was performed. The mean follow-up duration was 41.2 months. We evaluated operation free rate and actuarial survival rate. RESULTS: Thirteen patients underwent early or elective operations of the descending aorta. At the time of onset, the maximum aortic diameter of these patients was significantly larger than that of medically managed patients (55.8 ± 4.4 mm vs 44.6 ± 8.2 mm; p = 0.0004). Two patients underwent emergency axillo-femoral bypass for leg ischemia. Of the other 64 patients, who were medically managed, 2 patients had type A dissection develop during follow-up, 3 died during the initial hospital stay (1 from rupture, 1 from bronchial asthma, and 1 from gut ischemia), and 1 died of pneumonia 6 months after onset. Operation free rate was 98.6% at 1 month, 90.0% at 1 year, 78.7% at 3 years, and 69.5% at 8 years. Actuarial survival rate of medically managed patients was 98.4% at 1 month and 93.5% at 8 years. CONCLUSIONS: Medical treatment of type B acute aortic dissection produced good results. Surgical intervention for type B dissection should be done when the maximum aortic diameter exceeds 60 mm

Moffatt. Endovascular Stent Management of Thoracic Aneurysms and Dissections. Card Surg Adult; Cap 49. 2:1191-1204. 2003. Word Moon. Influence of retrograde cerebral perfusion during aortic arch procedures Ann Thorac Surg;74(2):426-431. 2002. Word PDF

Moon. Washington University. St Luis.Does the extent of proximal or distal resection influence outcome for type A dissections? . Ann Thorac Surg;71:1244-1249. 2001. WordFrom 1984 to 1999, 119 patients underwent repair of an acute type A dissection. Distal resection was to the ascending aorta in 78 (66%) and hemiarch in 41 (34%) patients. Proximally, the aortic valve was preserved in 69 (58%) patients, 40 (34%) underwent composite valve grafting, and 10 (8%) underwent separate graft and valve replacement. Results. Operative mortality was higher for separate graft and valve (50% ± 16%) than for valve preservation (16% ± 5%) or composite grafts (20% ± 7%) (p < 0.05). Hemiarch replacement did not increase operative risk compared to distal reconstruction to the ascending aorta (17% ± 6% versus 22% ± 5%, p > 0.71). Conclusions. An aggressive surgical approach, including a full root or hemiarch replacement, is not associated with increased operative risk and should be considered when type A dissections extensively involve the valve, sinuses, or arch.

Moore. Choice of computed tomography, transesophageal echocardiography, magnetic resonance imaging, and aortography in acute aortic dissection: International Registry of Acute Aortic Dissection (IRAD). Am J Card; 89;N10 • May 15, 2002. Word PDF (volver)

Neri. Cerebral autoregulation after hypothermic circulatory arrest in operations on the aortic arch Ann Thorac Surg;77:72-80. 2004. PDF

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Neri, Axillary artery cannulation in type a aortic dissection operations. J Thorac Cardiovasc Surg;118:324-329. 1999. Word PDF 22 of 152 operations (14.4%) for acute type A aortic dissection were performed with the use of the axillary artery for the arterial inflow. Axillary artery cannulation was undertaken in the presence of femoral arteries bilaterally compromised by dissection in 12 patients (54.5%), abdominal aorta and peripheral aneurysm in 5 patients (22.7%), severe atherosclerosis of both femoral arteries in 3 patients (13.6%), and aortoiliac occlusive disease in 2 patients (9.1%). In all patients, distal anastomosis was performed with an open technique after deep hypothermic circulatory arrest. Retrograde cerebral perfusion was used in 9 patients (40.9%). Results: Axillary artery cannulation was successful in all patients. The left axillary artery was cannulated in 20 patients (90.9%), and the right axillary artery was cannulated in 2 patients (9.1%). Axillary artery cannulation followed an attempt of femoral artery cannulation in 15 patients (68.2%). All patients survived the operation, and no patient had a cerebrovascular accident. No axillary artery thrombosis, no brachial plexus injury, and no intraoperative malperfusion were recorded in this series. Two patients (9.1%) died in the hospital of complications not related to axillary artery cannulation. Conclusions: In patients with type A aortic dissection in whom femoral arteries are acutely or chronically diseased, axillary artery cannulation represents a safe and effective means of providing arterial inflow during cardiopulmonary bypass.

Niederhäuser. Conservative treatment of the aortic root in acute type a dissection. Eur J Cardiothorac Surg;15:557-563. 1999. Word In acute type A dissection long-term results of conservative aortic root surgery were compared with the outcome of primary valve and/or root replacement. Methods: Between 1985 and 1995, 199 patients (mean age 59 years, 154 men) were operated on. The aortic root was involved in the dissection process and valve incompetence of varying degree was present without exception. Replacement of a proximal aortic segment was standard procedure in all patients. The aortic valve was preserved in 126 patients: commissural suture resuspension (12 patients), root reconstruction with GRF-glue (gelatine-resorcin-formaldehyde/glutaraldehyde-glue) (114 patients). Valve replacement was performed in 73 patients (50 composite grafts, 23 valve prostheses with separate supracoronary grafts). Preoperative risk factors (valve replacement vs. preservation): coronary artery disease (11 vs. 8%, NS), tamponade (18 vs. 17%, NS), unstable hemodynamics (22 vs. 15%, NS), renal failure (4 vs. 6%, NS), neurologic disorder (19 vs. 32%, NS). Results: The overall early mortality was 23.6% (47/199 patients) and increased after commissural suture resuspension compared with GRF-glue reconstruction (P=NS).

Nienaber. To stent or not to stent aortic dissection: good news for a chosen few, but who? . European Heart Journal. Vol. 26 No. 5 Pp. 431-432. (March 2005). Word PDF (volver)

Nienaber. Gender-Related Differences in Acute Aortic Dissection. Circulation;109:3014-3021. 2004. Word (volver)Of the patients enrolled in IRAD (32.1%) with AAD, 346 were women. Although less frequently affected by AAD (32.1% of AAD), women were significantly older and had more often presented later than men (P=0.008); symptoms of coma/altered mental status were more common, whereas pulse deficit was less common. In-hospital complications of hypotension and tamponade occurred with greater frequency in women, resulting in higher in-hospital mortality compared with men. After adjustment for age and hypertension, women with aortic dissection die more frequently than men (OR, 1.4, P=0.04), predominantly in the 66- to 75-year age group. Moreover, surgical outcome was worse in women than men (P=0.013); type A dissection in women was associated with a higher surgical mortality of 32% versus 22% in men despite similar delay, surgical technique, and hemodynamics.

Nienaber.Intramural Hematoma in Acute Aortic Syndrome.Circulation.106:284 2002. Word PDF (volver)

Nienaber, Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement. N Engl J Med 340,1539-1545. (1999).

Noiseux. Aortic cannulation for type A dissection: guidance by transesophageal echocardiography. Interactive Cardiovascular and Thoracic Surgery 2:178-180(2003) Word PDF (volver)Ascending aorta remains the preferred site of arterial cannulation for cardiopulmonary bypass but this approach may be risky in the presence of aortic aneurysm, aortic dissection or severe arteriosclerosis.

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Femoral artery cannulation with retrograde flow is the usual alternative under these circumstances. However, aorto-iliac aneurysm, occlusive disease, or distal extension of the aortic dissection may preclude the use of femoral arterial cannulation [1,2]. Alternative cannulation sites include the axillary or innominate arteries and the apex of the left ventricle [1–5]. This report describes an innovative technique for cannulation during repair of acute type A aortic dissection, which permits direct aortic arch cannulation and antegrade flow. Transesophageal echocardiography (TEE) is used to identify the true lumen of the distal arch and to guide arterial cannulation.

O'Gara. Case 12-2004 - A 38-Year-Old Woman with Acute Onset of Pain in the Chest. N Engl J Med;350:1666-1674. 2004. Word PDF

Okita. Prospective comparative study of brain protection in total aortic arch replacement: deep hypothermic circulatory arrest with retrograde cerebral perfusion or selective antegrade cerebral perfusion Ann Thorac Surg;72(1):72-79. 2001. Word PDF (volver)60 consecutive patients who underwent total arch replacement through a midsternotomy were alternately allocated to one of two methods of brain protection: deep hypothermic circulatory arrest with retrograde cerebral perfusion (RCP: 30 patients) or with selective antegrade cerebral perfusion (SCP: 30 patients). Hospital mortality occurred in 2 patients in the RCP group (6.6%) and 2 in the SCP group (6.6%). New strokes occurred in 1 (3.3%) of the RCP group and in 2 (6.6%) of the SCP group (p = 0.6). The incidence of transient brain dysfunction was significantly higher in the RCP group than in the SCP group (10, 33.3% vs 4, 13.3%, p = 0.05. Conclusions. Both methods of brain protection for patients undergoing total arch replacement resulted in acceptable levels of mortality and morbidity. However, the prevalence of transient brain dysfunction was significantly higher in patients with the RCP.

Passage. BioGlue surgical adhesive—an appraisal of its indications in cardiac surgery. Ann Thorac Surg;74:432-437. 2002. PDF

Perez. D-Dimers in the Emergency Department Evaluation of Aortic Dissection. Acad Emerg Med;11:397-400. 2004. Word (volver)

Prifti. Early and long-term outcome in patients undergoing aortic root replacement with composite graft according to the Bentall's technique. Eur J Cardiothorac Surg;21:15-21. 2002. Word (volver)

Raanani. 'BioGlue' for the repair of aortic insufficiency in acute aortic dissection. J Heart Valve Dis. Sep;13(5):734-7. 2004. Word (volver)

Rokkas. Single-stage extensive replacement of the thoracic aorta: the arch-first technique. J Thorac Cardiovasc Surg;117:99-105. 1999. Word PDF Roseborough. Jhons Hopkins. Twenty-year experience with acute distal thoracic aortic dissections. J Vasc Surg. Aug;40(2):235-46. 2004. Word (volver)There were 119 patients who fit the criteria of ADDA. Medical management was performed in 92 patients, with an overall mortality in this group of 13% (12/92 patients). Major morbidity occurred in 34 of the 83 surviving patients managed nonoperatively. Percutaneous interventions consisting of aortic fenestration and branch vessel stenting in 5 patients had a mortality rate of 40% and was only effective in the treatment of isolated renal artery malperfusion. Twenty-two patients underwent aortic surgery for complications or risk of impending rupture. Postoperative mortality was 18% (4/22 patients). Significant risk factors for death were rupture, acute renal failure, mesenteric ischemia, and age >70. No patient who had surgical fenestration required reoperation on the tailored segment.

Safi. Houston. Staged Repair of Extensive Aortic Aneurysms: Long-term Experience With the Elephant Trunk Technique. Annn Surg 240(4), pp 677-685. October 2004. Word PDF (volver)Between January 1991 and March 1995, 161 patients were operated on for aneurysms of the ascending aorta and transverse arch. Thirty-three of the patients (20%) had an aneurysm of the ascending aorta only and 128 (80%) had aneurysms of both the ascending aorta and the transverse arch. All the patients underwent cardiopulmonary bypass, profound hypothermia, and circulatory arrest, and 120 (74%) also underwent retrograde cerebral perfusion. Median pump time was 143 minutes (range, 21 to 461 minutes). Median circulatory arrest time was 42 minutes (range, 8 to 111 minutes), and median myocardial ischemic time was 71 minutes (range, 14 to 306 minutes).

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Results. The overall 30-day mortality rate was 6% (9 patients) and the incidence of stroke was 4% (7 patients). The use of retrograde cerebral perfusion demonstrated a protective effect against stroke (3 of 120 patients, or 3%) compared with no retrograde cerebral perfusion (4 of 41 patients, or 9%; odds ratio, 0.24; confidence interval, 0.06 to 0.99; p < 0.049). This was most significant in patients more than 70 years of age; none of the 36 elderly patients who received retrograde cerebral perfusion had a stroke, compared with 3 of the 13 (23%) who did not (p < 0.003). Only pump time was associated with an increased risk of stroke (odds ratio, 1.01; 95% confidence interval, 1.00 to 1.02; p < 0.005). Pump time also was associated with increased mortality (odds ratio, 1.01; 95% confidence interval, 1.00 to 1.02; p < 0.008). Conclusion. Retrograde cerebral perfusion decreased the incidence of stroke in patients undergoing repair of aneurysms of the ascending aorta and transverse arch.

Safi, Houston. Staged Repair of Extensive Aortic Aneurysms. Morbidity and Mortality in the Elephant Trunk Technique. Circulation.;104:2938. 2001. Word PDFBetween February 1991 and May 2000, we performed a total of 1146 aortic aneurysm operations. Of these, 182 (15.9%) operations were first- or second-stage elephant trunk procedures, performed in a total of 117 patients. Stage 1 was completed in all 117 patients. Stage 2 was completed in 65 (55.6%) of 117 patients. Thirty-day mortality rate for the first stage was 5.1% (6 of 117). Mortality rate during the interval between operations was 3.6% (4 of 111), of which 75% (3of 4) were the result of aneurysm rupture. Thirty-day mortality rate for the second stage was 6.2% (4 of 65). A total of 43 patients did not return for second-stage repair. Among these patients, within an average period of 3.4 years (range, 1.5 months to 4.9 years), 13 of 43 (30.2%) died, 4 of 13 (30.8%) as the result of rupture. Two of 117 (1.7%) first-stage patients had postoperative stroke. No spinal cord dysfunction occurred in second-stage patients. Conclusions— Extensive aortic aneurysms can be repaired with acceptable morbidity and mortality rates through the use of the elephant trunk technique. Death was most commonly the result of rupture, both in interval patients awaiting scheduled second-stage repair and in patients who did not return. After the first stage, prompt treatment of the remaining segment is crucial to the success of staged repair.

Safi. Impact of Retrograde Cerebral Perfusion on Ascending Aortic and Arch Aneurysm Repair. Ann Thorac Surg;63:1601-1607. 1997. Word (volver)

Sakurada. Comparative experimental study of cerebral protection during aortic arch reconstruction Ann Thorac Surg;61(5):1348-1354. 1996. Word

Schachner. Technical problems and complications of axillary artery cannulation. Eur J Cardiothorac Surg;27:634-637. 2005. Word (volver)Sixty-five patients underwent cannulation of the axillary artery. The indication for operation was acute aortic dissection type A in 57%, chronic aortic dissection in 8%, aortic aneurysm in 18%, pseudoaneurysm in 3%, and others in 14%. Results: Technical problems and complications occurred in 14%, and in 11% the perfusion had to be switched to either femoral (n=5) or aortic cannulation (n=2). Arterial damage or dissection of the axillary artery or the aorta occurred in 0% of the sidegraft technique, whereas they were found in 9% with direct cannulation (P=n.s.). Cannulation problems or insufficient CPB flow due to a narrow vessel occurred in 0% of the sidegraft technique, whereas they were found in 4% with direct cannulation (P=n.s.). Malperfusion in aortic dissections occurred in 20% of the sidegraft technique, whereas they were found in 0% with direct cannulation (P=0.016). No postoperative complications related to axillary cannulation which were evaluated by clinical examination, such as brachial plexus injury, axillary artery thrombosis or local wound infection were observed. Conclusions: Although axillary artery cannulation is an attractive alternative to femoral cannulation there needs to be an alertness for technical problems Schäfers. Valve-preserving replacement of the ascending aorta: remodeling versus reimplantation. J Thorac Cardiovasc Surg;116:990-996. 1998. WordOf 107 patients undergoing operation for proximal aortic disease between October 1995 and November 1997, 40 patients had morphologically intact aortic valve leaflets in conjunction with dilatation of the aortic root. Of these, 15 patients underwent an operation as a surgical emergency for acute aortic dissection type A. In 29 instances, root remodeling in conjunction with ascending aortic replacement was performed; 11 patients underwent radical replacement of the proximal aorta with reimplantation of the aortic valve. Partial or total arch replacement was performed additionally in 27 of these patients. Other concomitant procedures were coronary artery bypass grafts (n = 11) and mitral reconstruction (n = 1).

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Results: Two patients died after repair of acute aortic dissection, for a total operative mortality rate of 5%. No patient died after elective surgery. Aortic valve function could be effectively restored with both techniques Scheinert. Endoluminal stent–graft placement for acute rupture of the descending thoracic aorta. European Heart Journal. Vol. 25 No. 8; 694-700 (April 2004). Word PDFA total of 31 consecutive patients underwent interventional treatment for perforating lesions of the descending aorta. In 21 cases (group A), the aortic perforation was due to rupture of a descending thoracic aneurysm or dissection, whereas 10 patients (group B) were treated for traumatic transection of the descending aorta. A total of 42 endoprostheses were implanted. The implantation procedure was successful in all cases without peri-interventional complications. In one case, implantation of a second endoprosthesis became necessary due to type I endoleak. Overall, the 30-day mortality was 9.7%. As all three deaths occurred in group A, the mortality rate in this group was 14.3% versus 0% in group B. Similarly, postinterventional complications were more prevalent, with 28.6% in group A (renal failure ; stroke ) versus 10.0% in group B (renal failure ). No paraplegia and no further deaths or ruptures occurred during follow-up (mean 17 months).

Sebastià. Aortic Dissection: Diagnosis and Follow-up with Helical CT. Radiographics.;19:45-60. Vall D’Hebron. Muchas Figuras. 1999. Word PDF

Settepani. Aortic valve-sparing operations in patients… Interactive Cardiovascular and Thoracic Surgery. Feb 2005. PDF

Shakibaie. Indications for operative management of abdominal aortic aneurysms. ANZ J S: 74(6); 470–476 June 2004. Word PDF. (volver)

Simon. Aortic Valve Resuspension in Ascending Aortic Aneurysm Repair With Aortic Insufficiency. Ann Thorac Surg;60:176-180. 1995. Word (volver)In selected patients undergoing ascending aortic aneurysm repair who have normal aortic leaflets but secondary aortic regurgitation, the native valve can be spared through this novel operation. The aortic annulus size is reduced significantly, thereby effectively eliminating hemodynamically significant aortic regurgitation. The intermediate-term results are promising, but the long-term durability of this type of repair needs to be determined.

Sinatra. Emergency operation for acute type A aortic dissection: neurologic complications and early mortality. Ann Thorac Surg;71(1):33-38. 2001. Word PDF (volver)85 pacientes. All patients underwent surgical procedures under deep hypothermic circulatory arrest. Antegrade or retrograde cerebral perfusion was used in 23 patients (27.1%) and 18 patients (21.2%), respectively. Forty-three patients underwent arch/hemiarch replacement and the ascending aorta was replaced in 42 patients. Overall mortality rate was 25.9% (22 of 85 patients). Multiple logistic regression analysis showed that lack of cerebral perfusion (p = 0.021) and postoperative renal failure (p = 0.006) were the best predictors for hospital death. Twenty-one patients (24.7%) experienced neurologic accidents. The risk factor for postoperative neurologic complication was lack of cerebral perfusion (p = 0.013). Hospital mortality was 13% (3 of 23 patients) and 16.7% (3 of 18 patients) in the antegrade and retrograde cerebral perfusion groups (p > 0.05) and neurologic deficit was 13% (3 of 23 patients) and 11.1% (2 of 18 patients), respectively (p > 0.05). Conclusions. Hospital mortality and neurologic complications in patients undergoing emergent operation for acute type A aortic dissection were reduced when cerebral perfusion was used with deep hypothermic circulatory arrest.

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Song. Outcomes of medically treated patients with aortic intramural hematoma. American Journal of Medicine. Volume 113 • Number 3 • August 15, 2002. Word (volver)A total of 124 patients with acute aortic intramural hematoma (41 in the proximal aorta and 83 in the distal aorta) was enrolled from five institutions in South Korea. Patients received medical treatment without surgery. A follow-up imaging study was performed in 105 patients. Pericardial (59% [n = 24] vs. 11% [n = 9], P <0.004) and pleural effusions (63% [n = 26] vs. 45% [n = 37], P = 0.05) were more common in patients with the proximal type than in those with the distal type. In-hospital mortality was somewhat higher with proximal hematomas (7% [n = 3 deaths] vs. 1% [n = 1 death], P = 0.11). A follow-up imaging study in 36 patients with proximal hematomas confirmed resorption of the hematoma in 24 patients (67%) and development of aortic dissection in 9 (25%). Resorption was confirmed in 54 (78%) of the 69 patients with distal hematomas who underwent follow-up imaging; localized aortic dissection developed in 11 (16%) of these patients. The 3-year survival rate was 78% in the proximal type and 87% in the distal type (P = 0.10). Conclusion: Patients with aortic intramural hematoma had a high rate of resorption with medical treatment regardless of the affected site. Further investigation is necessary to determine the optimal treatment strategy and timing of surgical intervention, especially for patients with proximal hematomas.

Spielvogel. Aortic arch replacement using a trifurcated graft and selective cerebral antegrade perfusion. Ann Thorac Surg;74:S1810-S1814 . 2002. Word (volver) 22 pacientes.

Stanger. Late dissection of the ascending aorta after previous cardiac surgery: risk, presentation and outcome. Eur J Cardiothorac Surg;21:453-458. 2002. Word (volver)Dissection of the ascending aorta occurred in 83 patients, of whom 11 (13.2%, six acute and five chronic) had undergone previous cardiac surgery (four aortic valve replacements (AVR), two double valve replacements (DVR), two AVR+coronary artery bypass grafts (CABG), three CABGs). Conclusions: Type-A aortic dissection can follow cardiac operations at any time with no typical interval or associated histology and with high overall hospital mortality. Male patients with arterial hypertension are at increased risk.

Stecker. Deep hypothermic circulatory arrest: I. Effects of cooling on electroencephalogram and evoked potentials. Ann Thorac Surg;71:14-21. 2001. Word PDF (volver)

Strauch. Axillary artery cannulation: routine use in ascending aorta and aortic arch replacement. Ann Thorac Surg;78:103-108. 2004.. Word (volver)109 pac. The mean nasopharyngeal temperature when periodic complexes appeared in the electroencephalogram after cooling was 29.6°C ± 3°C, electroencephalogram burst-suppression appeared at 24.4°C ± 4°C, and electrocerebral silence appeared at 17.8°C ± 4°C. The N20-P22 complex of the somatosensory evoked response disappeared at 21.4°C ± 4°C, and the somatosensory evoked response N13 wave disappeared at 17.3°C ± 4°C. The temperatures of these various events were not significantly affected by any patient-specific or surgical variables, although the time to cool to electrocerebral silence was prolonged by high hemoglobin concentrations, low arterial partial pressure of carbon dioxide, and by slow cooling rates. Only 60% of patients demonstrated electrocerebral silence by either a nasopharyngeal temperature of 18°C or a cooling time of 30 minutes. Suzuki. Clinical Profiles and Outcomes of Acute Type B Aortic Dissection in the Current Era: Lessons From the International Registry of Aortic Dissection (IRAD). Circulation;108:II-312-317. 2003. Word PDFFactors associated with increased in-hospital mortality on univariate analysis were hypotension/shock, widened mediastinum, periaortic hematoma, excessively dilated aorta (6 cm), in-hospital complications of coma/altered consciousness, mesenteric/limb ischemia, acute renal failure, and surgical management (all P<0.05). A risk prediction model with control for age and gender showed hypotension/shock (odds ratio [OR] 23.8, P<0.0001), absence of chest/back pain on presentation (OR 3.5, P=0.01), and branch vessel involvement (OR 2.9, P=0.02), collectively named ‘the deadly triad’ to be independent predictors of in-hospital death.

Suzuki, Diagnostic implications of elevated levels of smooth-muscle myosin heavy-chain protein in acute aortic dissection: the smooth muscle myosin heavy chain study. Ann Intern Med 133,537-541. 2000. Word PDFPatients with acute aortic dissection who presented within 3 hours after onset had elevated levels of circulating smooth-muscle myosin heavy-chain protein. In these patients, the assay had a sensitivity of

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90.9%, a specificity of 98% compared with healthy volunteers, and a specificity of 83% compared with patients who had acute myocardial infarction; the clinical decision limit was 2.5 µg/L. All patients with proximal lesions had elevated levels of smooth-muscle myosin heavy-chain protein, and only patients with distal lesions had decreased levels (<2.5 µg/L).

Svensson. Intimal tear without haematoma. Circulation;99:1331-1336. 1999. Word (volver)

Tanoue. Comparative study of retrograde and selective cerebral perfusion with transcranial Doppler. Ann Thorac Surg;67(3):672-675. 1999. Word PDF (volver)Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion.The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.

Therasse. Stent-Graft Placement for the Treatment of Thoracic Aortic Diseases. RadioGraphics;25:157-173. 2005. Word (volver)Stent-graft placement is now an alternative to surgery for the treatment of descending thoracic aortic aneurysms, ulcers, and fistulas and is sometimes indicated in cases of mycotic aneurysm, posttraumatic aortic rupture, or thoracic descending aortic dissection. Pretreatment imaging is crucial for evaluating patient eligibility, selecting the appropriate stent-graft, and planning the intervention. Stent-graft treatment of long atherosclerotic aneurysms, lesions close to aortic branch vessels, and aortic dissections is subject to technical pitfalls, and adverse events such as endoleaks, stent migration or misplacement, aortic perforation, and vascular trauma will require specific interventions, although they occur in only a minority of patients. Thoracic stent-graft placement in good surgical candidates remains controversial because long-term results are unknown. However, short-term morbidity and mortality rates from endovascular treatment compare favorably with those from surgery, and stent-graft placement is proving to be a safe, minimally invasive, and effective treatment for thoracic aortic diseases and is already the best option in many affected patients who are poor surgical candidates.

Thoongsuwan. Chest CT Scanning for Clinical Suspected Thoracic Aortic Dissection: Beware the Alternate Diagnosis. Emergency Radiology 9: 257-261. (2002). PDF (volver)We performed a retrospective medical records review of 86 men and 44 women (ages ranging between 23 and 106 years) with clinically suspected aortic dissection, for CT scan findings and final clinical diagnoses. We found aortic dissection in 32 patients (24.6%), 22 of which were Stanford classification type A and 10 Stanford type B. In 70 patients (53.9%), chest pain could not be explained by the CT scan findings. However, in 28 patients (21.5%), CT scanning did reveal an alternate diagnosis that, along with the clinical impression, probably explained the patients' presenting symptoms, including: hiatal hernia (7), pneumonia (5), intrathoracic mass (4), pericardial ef-fusion/hemopericardium (3), esophageal mass/rupture (2), aortic aneurysm without dissection (2), pulmonary embolism (2), pleural effusion (1), aortic rupture (1), and pancreatitis (1). In cases where there is clinical suspicion of aortic dissection, CT scan findings of an alternate diagnosis for the presenting symptoms are only slightly less common than the finding of aortic dissection itself. Although the spectrum of findings will vary depending upon your patient population, beware the alternate diagnosis.

Trimarchi. Contemporary results of surgery in acute type A aortic dissection: The International Registry of Acute Aortic Dissection experience. J Thorac Cardiovasc Surg;129:112-122. 2005. Word PDF (volver) (volver 2º). A comprehensive analysis was completed of 290 clinical variables and their relationship to surgical outcomes in 526 of 1032 patients enrolled in the International Registry of Acute Aortic Dissection from 1996 through 2001. Extracted cases, categorized according to risk profile, were defined as unstable (group I) in the presence of cardiac tamponade; shock; congestive heart failure; cerebrovascular accident; stroke; coma; myocardial ischemia, infarction, or both; electrocardiograms with new Q waves or ST elevation; acute renal failure; or mesenteric ischemia-infarction at the time of the operation. Outside of an unstable condition, patients were categorized as stable (group II). Results: The overall in-hospital mortality was 25.1%. Mortality in group I was 31.4% compared with 16.7% in group II (P < .001). Independent preoperative predictors of operative mortality were history of aortic valve replacement (odds ratio = 3.12), migrating chest pain (odds ratio = 2.77), hypotension as sign

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of acute type A aortic dissection (odds ratio = 1.95), shock or tamponade (odds ratio = 2.69), preoperative cardiac tamponade (odds ratio = 2.22), and preoperative limb ischemia (odds ratio = 2.10).

Umaña. Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? . J Thorac Cardiovasc Surg;124:896-910. 2002. Word (volver)Objective: The optimal treatment of patients with acute type B dissections continues to be debated. Methods: A 36-year clinical experience of medical and surgical treatments in 189 patients was retrospectively analyzed. Results: Shock (hazard ratio 14.5, 95% confidence interval 4.7-44.5, P < .001) and visceral ischemia (hazard ratio 10.9, 95% confidence interval 3.9-30.3, P < .001) largely predominated as determinants of death, along with 6 other risk factors (arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease), which roughly doubled the hazard of death. Female sex was a significant but weaker predictor of death. Renal dysfunction, year of presentation, age, and mode of therapy (medical vs surgical) had no important bearing on overall survival. The actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. Conclusions: The prognosis for patients with acute type B aortic dissection is bleak and determined primarily by dissection-related and patient-specific risk factors, which do not appear to be readily modifiable.

Veeragandham. Experience with antegrade bihemispheric cerebral perfusion in aortic arch operations . Ann Thorac Surg;66:493-499. 1998. Word PDF (volver)There was no in-hospital or 30-day mortality. The blood product requirements were significantly less with moderate hypothermia. One patient suffered cerebrovascular accident (5%). None of the 7 patients with cerebral perfusion times of 60 to 120 minutes had any neurologic deficits. These results are superior to those reported for hypothermic circulatory arrest with or without retrograde cerebral perfusion. Conclusions. Antegrade bihemispheric cerebral perfusion is an optimal adjunct for cerebral protection during aortic arch operations.

Vilacosta. Síndrome aórtico agudo. Rev Esp Cardiol; 56: 29 – 39. 2003. Word PDF

Vogt. MR angiography of the chest. Radiologic Clinics of North America. Volume 41: 1 • January 2003. Word (volver)

Weber. D-dimer in Acute Aortic Dissection. Volume 123 • Number 5 • May 2003. Word PDF PDF-2 (volver)The result of the d-dimer test was positive (ie, > 0.5 μg/mL) in all patients (sensitivity of the test, 100%) with a mean value of 9.4 μg/mL and a range of 0.63 to 54.7 μg/mL. The degree of the elevation was correlated to the delay from the onset of symptoms to laboratory testing (mean, 12.6 h; range, 1 to 120 h) and showed a trend to the extent of the dissection, but not to the outcome (14 patients could be discharged; 10 patients died).Conclusions:Based on our observation, we suggest that testing for d-dimer should be part of the initial assessment of patients with chest pain, especially if aortic dissection is suspected. A negative test result makes the presence of the disease unlikely.

Westaby. Editorial comment.Eur J Cardiothorac Surg;27:632-633. 2005.

Westaby. Aortic Valve Conservation in Acute Type A Dissection . Ann Thorac Surg;64:1108-1112. 1997. WordWe retrospectively studied 64 patients with an acute type A dissection, an ascending aortic tear, and aortic regurgitation operated on by the same surgeon between 1988 and 1996. Three had Marfan's syndrome and 2 had a bicuspid valve. The valves in all patients without Marfan's syndrome were repaired with gelatin-resorcinol-formol glue. The valve and root were reinvestigated by echocardiography. Some patients underwent nuclear magnetic resonance imaging. Results. There were four hospital (6%) and three late deaths. Aortic root reoperation was required in 2 of the 60 survivors (3.3%) and operation on the distal aorta in 2. Root reoperations were required within 3 years. The remaining proximal repairs remained stable. Conclusions. The native aortic valve can be conserved in most patients, and glue repair is durable

Wiesenfarth. E-medicine Disección aórtica. 2004. Word

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Willens. Transesophageal Echocardiography in the Diagnosis of Diseases of the Thoracic Aorta. Part 1. Aortic Dissection, Aortic Intramural Hematoma, and Penetrating Atherosclerotic Ulcer of the Aorta. Chest.;116:1772-1779. 1999. Word PDF (volver)

Winsor. Inadequate hemodynamic management in patients undergoing interfacility transfer for suspected aortic dissection . American Journal of Emergency Medicine. Volume 23 • Number 1 • January 2005. Word PDF

Yamada. Central cannulation for type A acute aortic dissection . Interactive Cardiovascular and Thoracic Surgery 2:175-177(2003). Word PDF (volver)

Yoshida. Thoracic Involvement of Type A Aortic Dissection and Intramural Hematoma: Diagnostic Accuracy—Comparison of Emergency Helical CT and Surgical Findings. Radiology 228:430-435. 2003. WordCONCLUSION: Emergency helical CT of the thorax depicts findings that are highly accurate in the evaluation of acute type A AD and IMH

Yu. Late outcome of patients with aortic dissection: study of a national database. Eur J Cardiothorac Surg;25:683-690. 2004. WordA total of 5654 cases of aortic dissection (3871 males) were collected from the National Health Insurance Databases from 1996 to 2001. Age, gender, Marfan syndrome, and initial treatment modality were the main factors to be investigated. Corrective group was defined by surgical operation with cardiopulmonary bypass and palliative group for the remaining. Late aortic events were defined by late aneurysmal evolution of diseased aorta needing surgical intervention or death of aortic causes from 6 months to 6 years. Results: The incidence of aortic dissection was 43 per 1 000 000 population in our country. Corrective group accounted for 19.3% of them and palliative group for 80.7%. Marfan syndrome accounted for 1.5% of all cases (4.3% of corrective surgery group). The rate of freedom from mortality at 1, 6 months, and 6 years was 80.4±1.3, 69.0±1.5, and 56.5±2.9% for corrective group and 89.5±0.5, 78.4±0.6, and 46.1±1.35% for palliative group. Nearly half of the late mortalities were attributed to atherosclerosis-related conditions (cardiac, stroke, or aortic causes). The incidence of late aortic events was 2.48% per year on an average, comparable between corrective and palliative groups. This incidence increased since the fourth year after their initial episode. For corrective group, young age was a risk factor of late aortic events (relative risk of 0.60–0.82 per decade, P=0.037). For palliative group, Marfan syndrome and male gender were risk factors of late aortic events (relative risk of 4.08–10.7, P<0.001 in the former; relative risk of 1.46–2.1, P=0.002 in the latter).

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