Encuesta multinacional y transversal sobre las controversias del reemplazo de la raíz aórtica con conservación valvular / Multinational and Cross-Sectional Survey on Valve-Sparing Aortic Replacement Controversies

RESUMEN Introducción : El reemplazo de la raíz aórtica con conservación valvular (valve-sparing aortic root replacement, VSAR) se ha consolidado como un procedimiento eficaz para el tratamiento del aneurisma de la raíz aórtica, el síndrome de Marfan, la válvula bicúspide y la disección aórtica. Sin embargo, es necesario llegar a una opinión unánime sobre los aspectos clave del VSAR. Material y métodos : Se realizó una revisión bibliográfica de los debates y controversias más frecuentes del VSAR. A partir de esta información se elaboró una encuesta en línea que se envió a cirujanos con experiencia comprobada en VSAR para conocer su opinión sobre los factores relacionados con los pacientes, los aspectos técnicos, la ecocardiografía, la investigación, la formación y el futuro del VSAR. Resultados : Veinte cirujanos completaron la encuesta. Según 14 de cada 20 encuestados, la fracción de eyección grave se consideró una contraindicación para el llevar a cabo este procedimiento. El límite del diámetro del anillo aórtico para la remodelación fue heterogéneo entre los participantes. Todos ellos consideraron que el VSAR es un procedimiento seguro para los pacientes con síndrome de Marfan y válvula bicúspide. En el caso de disección de tipo A, 11 de cada 20 prefirieron este procedimiento solo para los pacientes jóvenes. En lo que respecta al tamaño del injerto, la altura del triángulo intervalvar (8/20) y el diámetro sinotubular (7/20) fueron los más frecuentes. Los cirujanos informaron una tasa de fracaso del 7% en la conversión al procedimiento de Bentall, y un cambio de estrategia intraoperatoria del 26%. No se consideró que un abordaje mínimamente invasivo mejorara los resultados. La mayoría de los cirujanos coincidieron en que el VSAR lo deben realizar cirujanos con mucha experiencia. Conclusiones : El VSAR ha sido aceptado como una opción terapéutica para el aneurisma de la raíz aórtica, y, aunque todavía no es posible llegar a un consenso definitivo, se presenta la valiosa experiencia de los cirujanos más destacados en este campo.

ABSTRACT Background : The valve-sparing aortic root replacement (VSAR) has been established as a successful procedure for aortic root aneurysms, Marfan's syndrome, bicuspid valves, and aortic dissections. However, there is a need for a consensus opinion regarding key aspects of VSAR. Methods : A literature review was performed regarding the most frequent debates and controversies in VSAR. An online survey was developed based on this information, and sent to surgeons with known expertise in VSAR regarding their opinion on patient-related factors, technical aspects, echocardiography, research, training, and the future of VSAR. Results : Twenty surgeons completed the survey. The reduction of left ventricular ejection fraction was considered a contra indication to VSAR when severe by 14/20 surveyed. The aortic annulus diameter cutoff point for the remodeling was heterogenous among participants. All of them felt that VSAR is safe for the Marfan´s syndrome population and bicuspid valves. For type A dissections, 11/20 preferred this procedure only in young patients. Regarding to graft sizing, the height of the interleaflet triangle (8/20) and the sino-tubular diameter (7/20) were the more frequent considered parameters. Surgeons reported a 7% of failure rate, leading to conversion to Bentall surgery, and a 26% change of strategy intraoperatively. A minimally invasive approach was not considered to improve results. Most of the surgeons agreed that VSAR should be performed by high-experienced surgeons. Conclusions : The VSAR has been accepted as a treatment option for the aortic root´s aneurysms, and even though there is still not possible to reach a final consensus, a valuable experience from the most relevant surgeons in the field is presented.

In vivo functional assessment of a novel degradable metal and elastomeric scaffold-based tissue engineered heart valve.

OBJECTIVE: Ideal heart valve solutions aim to provide thrombosis-free durability. A scaffold-based polycarbonate urethane urea tissue-engineered heart valve designed to mimic native valve microstructure and function was used. This study examined the acute in vivo function of a stented tissue-engineered heart valve in a porcine model. METHODS: Trileaflet valves were fabricated by electrospinning polycarbonate urethane urea using double component fiber deposition. The tissue-engineered heart valve was mounted on an AZ31 magnesium alloy biodegradable stent frame. Five 80-kg Yorkshire pigs underwent open tissue-engineered heart valve implantation on cardiopulmonary bypass in the pulmonary position. Tissue-engineered heart valve function was echocardiographically evaluated immediately postimplant and at planned study end points at 1, 4, 8, and 12 hours. Explanted valves underwent biaxial mechanical testing and scanning electron microscopy for ultrastructural analysis and thrombosis detection. RESULTS: All 5 animals underwent successful valve implantation. All were weaned from cardiopulmonary bypass, closed, and recovered until harvest study end point except 1 animal that was found to have congenital tricuspid valve dysplasia and that was euthanized postimplant. All 5 cases revealed postcardiopulmonary bypass normal leaflet function, no regurgitation, and an average peak velocity of 2 m/s, unchanged at end point. All tissue-engineered heart valve leaflets retained microstructural architecture with no platelet activation or thrombosis by scanning electron microscopy. There was microscopic evidence of fibrin deposition on 2 of 5 stent frames, not on the tissue-engineered heart valve. Biaxial stress examination revealed retained postimplant mechanics of tissue-engineered heart valve fibers without functional or ultrastructural degradation. CONCLUSIONS: A biodegradable elastomeric heart valve scaffold for in situ tissue-engineered leaflet replacement is acutely functional and devoid of leaflet microthrombosis.

Molecular evaluation of the great vessels of patients with bicuspid aortic valve disease

OBJETIVO: A valva aórtica bicúspide (VAB) está associada a maior prevalência de ectasia anulo-aórtica, aneurisma e dissecçäo da aorta ascendente. Este estudo investigou a quantidade de fibrilina-1 e elastina nos grandes vasos de portadores de VAB. MÉTODO:Amostras de tecidos foram colhidas da aorta ascendente e tronco da artéria pulmonar de 22 portadores de VAB e 16 portadores de valva aórtica tricúspide (VAT) submetidos a cirurgia cardíaca, incluindo seis portadores de valva aórtica normal, provenientes do programa de transplante. Imunofluorescência indireta e análise computadorizada de imagens foram utilizadas para quantificaçäo das proteínas na camada média dos vasos, expressas como densidade óptica integrada média (DOI). RESULTADOS: Na aorta, a DOI específica para fibrilina-1 foi 15 ± 8 no grupo bicúspide e 24 ± 7 no grupo tricúspide (p=0,001). Na artéria pulmonar, a DOI específica para fibrilina-1 foi 18 ± 10 no grupo bicúspide e 25 ± 9 no grupo tricúspide (p=0,07). A DOI específica para elastina na aorta foi 34 ± 13 no grupo bicúspide e 36 ± 19 no grupo tricúspide (p=0,31). Na artéria pulmonar, a DOI para elastina foi 30 ± 12 no grupo bicúspide e 29 ± 14 no grupo tricúspide (p=0,34). CONCLUSÕES: Os portadores de VAB apresentaram menor quantidade de fibrilina-1, mas näo elastina, na aorta ascendente e artéria pulmonar que os portadores de VAT normal ou doente. Estes achados podem explicar a maior incidência de dilataçäo e dissecçäo da aorta ascendente em portadores desta má-formaçäo da valva aórtica.