Long-term results of the Ross operation in rheumatic valve disease.

AIMS: The aim of this study was to evaluate the impact of rheumatic heart disease (RHD) on the long-term outcomes of the Ross operation when compared to patients with bicuspid aortic valves (BAV). METHODS AND RESULTS: We analysed patients with rheumatic disease and BAV who underwent a Ross operation between 1995 and 2020. The primary outcomes were late survival and reoperations on the pulmonary autograft and the right ventricular allograft. We also performed a propensity score analysis to adjust for differences in baseline characteristics. The cumulative incidence of the events in the matched cohorts was compared using the Fine-Gray model. There were 147 patients with rheumatic disease and 314 with bicuspid valves. In the unmatched population, patients with rheumatic disease were younger, more symptomatic, had worse left ventricular function and were more likely to present a preoperative diagnosis of aortic insufficiency. Propensity matching resulted in 86 pairs with similar baseline characteristics. Compared with those with bicuspid valves, rheumatic patients had similar 20-year survival both in the unmatched (RHD = 67.8% vs BAV = 79.7%, P = 0.27] and matched cohorts (RHD = 72.5% vs BAV = 82.9%, P = 0.46). Cumulative incidence of reoperations on the pulmonary autograft after 20 years was also comparable between them in the unmatched (RHD 13.4% vs BAV 14.4%, P = 0.67) and matched patients (RHD 11.6% vs BAV 21.1%, P = 0.47). Pulmonary autograft dysfunction due to rheumatic involvement was detected in only three occasions. Cumulative incidence of reoperations on the right-sided allograft was higher in the unmatched cohort (RHD = 5.5% vs BAV = 16.7%, P = 0.035) but became nonsignificant after propensity score matching (RHD = 9.9% vs BAV = 32.3%, P = 0.051). The cumulative incidence of all Ross-related reoperations was similar in both groups. CONCLUSIONS: Among patients undergoing Ross operation, patients with RHD had similar long-term survival and rates of reoperations, when compared to patients with BAV.

Eficacia y seguridad de la prótesis valvular pulmonar percutánea para el tratamiento de pacientes pediátricos con antecedente de malformación congénita e historia de cirugía reconstructiva del tracto de salida del ventrículo derecho que presentan regurgitación valvular pulmonar / Efficacy and safety of percutaneous pulmonary valve prosthesis for the treatment of pediatric patients with a history of congenital malformation and history of reconstructive surgery of the right ventricular outflow tract who present pulmonary valve regurgitation

ANTECEDENTES: En el marco de la metodología ad hoc para evaluar solicitudes de tecnologías sanitarias, aprobada mediante Resolución de Instituto de Evaluación de Tecnologías en Salud e Investigación N° 111-IETSI-ESSALUD-2021, se ha elaborado el presente dictamen, el cual expone la evaluación de la eficacia y seguridad de la prótesis valvular pulmonar percutánea (PVPP) para el tratamiento pacientes pediátricos con antecedente de malformación congénita e historia de cirugía reconstructiva del tracto de salida del ventrículo derecho (TSVD) que presentan regurgitación valvular pulmonar. De este modo, el Dr. Miguel Arboleda Torres, siguiendo la Directiva N° 001-IETSI-ESSALUD-2018, envió al Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI) la solicitud de aprobación del dispositivo médico PVPP. ASPECTOS GENERALES: Aproximadamente un 10 % de pacientes con malformaciones cardiacas congénitas poseen alteraciones anatómicas que obstruyen el tracto de salida del ventrículo derecho (TSVD), el cual conecta el ventrículo derecho del corazón y la arteria pulmonar. La malformación congénita más común que afecta al TSVD es la tetralogía de Fallot y se estima que el 90 % de los pacientes con esta patología son sometidos a una cirugía a corazón abierto durante la infancia temprana para reconstruir el TSVD (que se encuentra obstruido o estrecho [estenótice. Por lo general, la reconstrucción se realiza mediante la colocación de un parche, una prótesis o un conducto entre el ventrículo derecho y la arteria pulmonar. No obstante, con el transcurrir de los años, estos pacientes desarrollan anormalidades de la válvula pulmonar, lo que requiere que se sometan a nuevas intervenciones quirúrgicas para reemplazarla por una prótesis valvular (Alkashkari et al., 2018; Gutiérrez-Larraya et al., 2021, p.). METODOLOGÍA: Se llevó a cabo una búsqueda bibliográfica exhaustiva con el objetivo de identificar la mejor evidencia sobre la eficacia y seguridad del reemplazo valvular pulmonar percutáneo empleando el dispositivo PVPP. La búsqueda bibliográfica se realizó en las bases de datos PubMed, The Cochrane Library y LILACS. Asimismo, se realizó una búsqueda manual dentro de las páginas web pertenecientes a grupos que realizan evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC) incluyendo el National Institute for Health and Care Excellence (NICE), Canadian Agency for Drugs and Technologies in Health (CADTH), Scottish Medicines Consortium (SMC), Scottish Intercollegiate Guidelines Network (SIGN), Institute for Clinical and Economic Review (ICER), El Instituto de Calidad y Eficiencia en la Atención de la Salud (IQWiG, por sus siglas en alemán), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA), la OMS, el Ministerio de Salud del Perú (MINSA) y el Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI). Además, se realizó una búsqueda de GPC de las principales sociedades o instituciones especializadas en cardiología y cirugía torácica, tales como: American Heart Association (AHA), American College of Cardiology (ACC), European Society of Cardiology (ESC), European Association for Cardio-Thoracic Surgery (EACTS), y la Sociedad Española de Cardiología. Finalmente, se realizó una búsqueda en ClinicalTrials.govpara identificar ensayos clínicos aleatorizados (ECA) en curso o que no hayan sido publicados aún. RESULTADOS: Luego de la búsqueda bibliográfica hasta noviembre del 2021, no se identificaron ECA que compararan las tecnologías de interés. Además, tampoco se encontraron guías de práctica clínica (GPC), evaluaciones de tecnología sanitaria (ETS), revisiones sistemáticas (RS), ni estudios realizados en población pediátrica exclusivamente. En consecuencia, se consideró la inclusión de evidencia científica con una población mixta (adultos y niños) que respondiera a la pregunta PICO. Así, se incluyeron dos GPC (Baumgartner et al., 2021; National Institute for Health and Care Excellence, 2013), dos revisiones sistemáticas (Ribeiro et al., 2020; Zhou et al., 2019), y dos estudios observacionales comparativos que no se encontraban incluidos en ninguna de las dos RS previas (Hribernik et al., 2021; OuYang et al., 2020). CONCLUSIÓN: Por lo expuesto, el IETSI aprueba el uso de prótesis de válvula pulmonar de inserción percutánea en pacientes pediátricos con antecedente de malformación cardiaca congénita e historia de cirugía reconstructiva del tracto de salida del ventrículo derecho que presenten una regurgitación valvular pulmonar moderada a severa, según lo establecido en el Anexo N° 1. La vigencia del presente dictamen preliminar es de un año a partir de la fecha de publicación y la continuación de dicha aprobación estará sujeta a la evaluación de los resultados obtenidos y de mayor evidencia que pueda surgir en el tiempo.

Decellularized Versus Standard Pulmonary Allografts in the Ross Procedure: Propensity-Matched Analysis.

BACKGROUND: It is hypothesized that decellularization of allografts used for right ventricular outflow tract reconstruction may result in decreased valve deterioration. This study compared the durability of fresh decellularized pulmonary allografts with standard cryopreserved pulmonary allografts in patients undergoing the Ross procedure. METHODS: The Ross procedure was performed in 144 patients with decellularized allografts (DA) from 2005 to 2014 and in 619 with standard cryopreserved allografts (SCA) from 1990 to 2014. Propensity score matching was used to compare early and midterm clinical outcome and echocardiographic allograft function over time between the two groups. RESULTS: We matched 94 DA patients (79.3% male; median age, 34.0 years; mean follow-up, 2.4 ± 1.9 years) to 94 SCA patients (78.3% male; median age, 35.0 years; mean follow-up, 9.4 ± 4.2 years). There were no significant differences in baseline characteristics after matching. The matched DA vs SCA groups, respectively, were comparable in actuarial 5-year freedom from allograft dysfunction (85.6% [95% confidence interval {CI}, 53.9% to 96.2%] vs 93.3% [95% CI, 85.7% to 96.9%], p = 0.892), freedom from allograft reintervention (98.8% [95% CI, 91.7% to 99.8%] vs 95.5% [95% CI, 88.5% to 98.3%], p = 0.383), survival (95.3% [95% CI, 87.8% to 98.2%] vs 97.7% [95% CI, 91.3% to 99.4%], p = 0.323), and event-free survival (83.5% [95% CI, 70.6% to 91.1%] vs 84.5% [95% CI, 75.2% to 90.5%], p = 0.515). Longitudinal echocardiographic analyses showed a similarly modest increase in allograft gradient and regurgitation grades over time in both groups, although direct statistical comparison was not possible. CONCLUSIONS: Up to 5 years of follow-up, DA and SCA used for right ventricular outflow tract reconstruction in the Ross procedure are associated with comparably excellent clinical and hemodynamic outcome. Longer follow-up and dedicated echocardiographic studies will shed light on the long-term performance of DAs.

Decellularized Allografts for Right Ventricular Outflow Tract Reconstruction in Children.

OBJECTIVE: Determine the midterm outcomes of decellularized allografts for right ventricular outflow tract (RVOT) reconstruction in children less than 12 years of age. METHODS: The study included all consecutive patients submitted to RVOT reconstruction with decellularized allografts between June 2006 and June 2016. Besides clinical and echocardiographic control, 20 patients with more than five years of follow-up were evaluated with computed tomography (CT) scans to determine allograft diameters and calcium scores. Structural valve deterioration was defined as any peak gradient above 40 mm Hg and/or insufficiency of moderate or severe degree. Conduit failure was defined as the need for allograft reintervention. RESULTS: There were 59 patients with a median age of six years (range = 0.01-12 years). The most common operation was the Ross procedure (34%). Mean clinical follow-up was 5.4 (2.8) years and was 94% complete. At eight years, only two patients needed a reintervention, with a 90.9% freedom from this event. Structural valve deterioration occurred in 13 patients, 5 due to stenosis and 8 due to insufficiency, with a freedom from structural valve deterioration due to any cause of 64.9% at eight years. Late CT scans demonstrated the absence or minimal calcification of the conduits. CONCLUSIONS: Decellularized allografts for RVOT reconstruction in children were associated with a low incidence of structural valve deterioration and conduit failure. Although these results still need to be confirmed in larger series and with longer follow-up, our data suggest favorable outcomes, at least in the first decade after the operation.

20 years experience with the Ross operation in middle-aged patients: the autologous principle is still alive.

Objectives: Review our long-term results with the Ross operation in middle-aged patients. Methods: Between 1995 and 2016, 129 consecutive patients (106 males); mean age (47.2 ± 5.2 years) underwent a Ross operation. Right ventricular outflow tract (RVOT) reconstruction was performed with cryopreserved (n = 45) or decellularized allografts (n = 84). Mean follow-up was 8.4 ± 5.3 years (0.1 20.5 years). We analyzed early and late mortality, as well as valve related events and the need for reoperations. Results: Early mortality was 1.6% and late survival was 87.6% at 16 years. There were 4 reoperations on the pulmonary autograft (96% freedom at 16 years) and 2 on the pulmonary allografts (99% freedom at 16 years). The 16-year freedom from more than mild aortic insufficiency (AI) and a late root diameter >45 mm was 64% and 71%, respectively. Patients with the preoperative diagnosis of AI are at greater risk for these complications. Among the allografts, decellularized allografts showed superior freedom from structural valve dysfunction. Conclusions: The Ross operation in this cohort was associated with long-term survival similar to the general population and low incidence of reoperations. Patients with the preoperative diagnosis of AI are at increased risk for late autograft insufficiency and root dilatation. Decellularized allografts presented the best results for reconstruction of the RVOT. These results support the conclusion that the Ross operation has an important role in the treatment of middle-aged patients with aortic valve disease, especially those with pure aortic stenosis.

Long-term results of the Ross operation: an 18-year single institutional experience.

OBJECTIVES: The purpose of the study was to assess the 18-year outcome of the Ross operation (RO), with emphasis on survival, reoperations, and late function of the pulmonary autografts (PAs) and the right-sided pulmonary allografts. METHODS: Between May 1995 to July 2013, 414 patients with a mean age (mean ± standard deviation) of 30.8 ± 13.1 years were submitted to an RO with the root replacement (n = 356) or the inclusion (n = 58) technique. The most prevalent aetiology was bicuspid valve (n = 206, 49.8%). Patients were divided in four groups depending on the type of allograft used on the right side. The mean follow-up was 8.2 ± 5.2 years and was 97.7% complete. In addition to longitudinal outcomes determined by means of the Kaplan-Meier analysis, log-rank test and Cox regression analysis were used to identify predictors of valve failure. RESULTS: The early mortality rate was 2.7% and the late survival rate was 89.3% at 15 years, similar to an age- and sex-matched population. There were 22 reoperations on the PA (90.7% freedom at 15 years) and 15 on the pulmonary allografts (92.5% freedom at 15 years). The freedom rate from more than mild aortic insufficiency (AI) was 73.1% at 15 years. Thirty-three patients presented with a late root diameter >45 mm, corresponding to a freedom rate of 72.4% at 15 years. Patients with AI and a dilated annulus, especially males, are at greater risk for these complications. Among the right-sided allografts, fresh decellularized allografts showed significantly superior freedom from structural valve dysfunction. CONCLUSIONS: The RO was associated with excellent long-term survival and low incidence of reoperations up to 15 years. Male patients with AI and dilated annulus are at increased risk for late insufficiency and root dilatation. Fresh decellularized allografts presented the best results for reconstruction of the right ventricular outflow tract.

Evaluation of humoral immune response to donor HLA after implantation of cellularized versus decellularized human heart valve allografts.

We have evaluated the development of antibodies in response to donor allograft valve implant in patients who received cellularized and decellularized allografts and determined possible immunogenic epitopes considered responsible for antibodies reactivity. Serum samples from all recipients who received cellularized allografts or decellularized allografts were collected before valve replacement and at 5, 10, 30 and 90 days post-operatively and frozen until required. Tests were performed using the Luminex-based single human leukocyte antigen (HLA)-A, -B, -C and HLA-DR, -DQ antigen microsphere assay. To determine possible immunogenic epitopes, we used the HLAMatchmaker (HLAMM) software if applicable. Decellularized grafts elicited lower levels of anti-HLA class I and II antibody formation after implantation than cellularized allografts. All patients from cellularized group presented donor-specific antibodies class I and II within 3 months of observation period. In HLAMM analysis, the cellularized group had significantly higher numbers of immunogenic epitopes than decellularized group for both class I and II (p: 0.002 - cl I / p: 0.009 - cl II / p: 0.004 - cl I and II). Our findings demonstrate that the anti-HLA antibodies detected in the cellularized group were against donor HLA possible immunogenic epitopes and that in the decellularized group the anti-HLA antibodies were not against donor HLA possible immunogenic epitopes. These findings lead us to suggest that choosing sodium dodecyl sulfate decellularization process is the best alternative to decrease the immunogenicity of allograft valve transplant.

Comparative experimental study between L-Hydro treated pulmonary homograft and fresh pulmonary homograft.

OBJECTIVE: In an effort to make available homografts preserved in a simpler and less costly way, we evaluated the polyethyleneglycol, L-Hydro (LH) method, that consists in the controlled extraction of antigenic substances and the incorporation of anti-inflammatory and anti-thrombotic agent. METHODS: We substituted the pulmonary trunk in ten ovines, seven received LH treated pulmonary homografts and three, fresh pulmonary homografts, orthotopically implanted and followed-up for 320 days. Ovines where evaluated by means of laboratory tests, echocardiographic exams. At the 320 days, were euthanized, hemodynamic, radiology, macroscopic, optic/electronic microscopic, scanning/transmission evaluations were performed. Results were analyzed by Student t test of independent samples for continuous data, by variance analysis of repeated measures, and by Fisher exact test for categorical data. RESULTS: We couldn't establish relevant differences in clinical evolution and laboratory tests between groups. Echocardiogram revealed difference in pulmonary medium gradient, which was significant 10 months follow-up, higher in the control group. Radiologic and macroscopic evaluations didn't established differences. In the optic/electronic microscopic evaluation, liner and interstitial cells were equally found in both groups. The cell liner percent calculated in both groups was similar. Cellularity nodules were observed only infresh homograft group. CONCLUSIONS: These data indicate that both groups presented similar clinical/hemodynamic performances. The LH group's echocardiogram presented a better performance. It also presented histological evidences of interstitial and endothelial cell repopulation. In the macro/optic and electronic microscopic analysis, group L-H presented macroscopy/histological structure and ultra-structural similar to the fresh group, with the exception of nodules with higher interstitial cellularity, present only in the fresh homograft group.

O ecocardiograma transesofágico na cirurgia de Ross / Transesophageal echocardiography in Ross procedure / El ecocardiograma transesofágico en la cirugía de Ross

JUSTIFICATIVA E OBJETIVOS: Uma das cirurgias corretivas para a insuficiência aórtica congênita grave é a cirurgia de Ross. O ecocardiograma transesofágico intraoperatório é indispensável para uma boa avaliação cirúrgica. Além disso, é capaz de avaliar o perfil volêmico e a necessidade de se administrar drogas vasoativas ao longo da cirurgia. RELATO DO CASO: Adolescente de 15 anos apresentava insuficiência aórtica grave de origem congênita, programando-se correção cirúrgica pela técnica de Ross. No centro cirúrgico, o paciente foi monitorado com eletrocardiograma e oxímetro de pulso, recebendo pré-medicação com midazolam. Após a pré-medicação, puncionaram-se a artéria radial esquerda e a veia subclávia direita. A indução anestésica foi feita com etomidato, cisatracúrio e fentanil, e a manutenção anestésica com sevoflurano. A sonda do aparelho do ecocardiograma transesofágico foi introduzida imediatamente após a intubação traqueal e mostrava aumento do ventrículo esquerdo; insuficiência aórtica grave por falha de coaptação dos três folhetos; válvula pulmonar competente sem alterações anatômicas e fisiológicas. A cirurgia transcorreu sem intercorrências, com 120 minutos de circulação extracorpórea (CEC) e 8 horas de cirurgia. Imediatamente após a saída de CEC, o ecocardiograma transesofágico mostrava bom funcionamento tanto do auto como do homoenxerto, porém o ventrículo direito encontrava-se hipocontrátil, o que foi corrigido com bolus de milrinona, seguido de infusão contínua. O paciente foi encaminhado ao pós-operatório intubado, estável hemodinamicamente, com infusão de milrinona e nitroprussiato de sódio. CONCLUSÕES: Uma das técnicas de correção da insuficiência aórtica congênita é a cirurgia de Ross, em que o ecocardiograma transesofágico intraoperatório orienta o cirurgião de maneira precisa sobre o status fisiológico e anatômico dos enxertos vasculares.

BACKGROUND AND OBJECTIVES: Ross procedure is one of the surgical procedures for correction of severe congenital aortic insufficiency. Intraoperative transesophageal echocardiography is essential for optimal surgical evaluation. Furthermore, it is able to assess the blood volume profile and the need for administration of vasoactive drugs during surgery. CASE REPORT: This is a 15-year old teenager with severe congenital aortic insufficiency scheduled for corrective surgery with the Ross procedure. In the operating room, the patient was monitored with electrocardiography and pulse oximeter, and he was premedicated with midazolam. After the administration of premedication, the left radial artery and right subclavian vein were punctured. Anesthetic induction was accomplished with etomidate, cisatracurium, and fentanyl while maintenance was achieved with sevoflurane. The probe of the transesophageal echocardiography equipment was introduced immediately after tracheal intubation, showing increased left ventricle; severe aortic insufficiency due to coaptation failure of the three leaflets; and competent pulmonary valve without anatomical and physiological changes. Intercurrences were not observed during surgery, with 120 minutes of extracorporeal circulation (ECC) and 8 hours of surgery. Immediately after removal from ECC the transesophageal echocardiography showed good function of both the auto- and homograft; however, the right ventricle presented hypocontractility, which was corrected with a bolus of milrinone followed by continuous infusion. The patient was transferred to the postanesthetic recovery unit intubated and hemodynamically stable with infusion of milrinone and sodium nitroprusside. CONCLUSIONS: Ross procedure is one of the techniques for correction of congenital aortic insufficiency in which transesophageal echocardiography guides the surgeon precisely on the physiological and anatomical status of vascular grafts.

JUSTIFICATIVA Y OBJETIVOS: Una de las cirugías correctivas para la insuficiencia aórtica congénita grave es la cirugía de Ross. El ecocardiograma transesofágico intraoperatorio es indispensable para una buena evaluación quirúrgica. Además, es capaz de evaluar el perfil volémico y la necesidad de administrar fármacos vasoactivos durante la operación. RELATO DEL CASO: Adolescente de 15 años, que presentaba insuficiencia aórtica grave de origen congénito, citado para la corrección quirúrgica por la técnica de Ross. En quirófano, el paciente fue monitorizado con electrocardiograma y oxímetro de pulso, recibiendo premedicación con midazolan. Después de la premedicación, se puncionaron la arteria radial izquierda y la vena subclavia derecha. La inducción anestésica se hizo con etomidato, cisatracurio y fentanil, y el mantenimiento anestésico con sevoflurano. La sonda del aparato del ecocardiograma transesofágico fue introducida inmediatamente después de la intubación traqueal e indicaba aumento del ventrículo izquierdo; insuficiencia aórtica grave por falla de coaptación de las tres capas; válvula pulmonar competente sin alteraciones anatómicas y fisiológicas. La cirugía trascurrió sin intercurrencias, con 120 minutos de circulación extracorpórea (CEC), y 8 horas de cirugía. Inmediatamente después de la salida de CEC, el ecocardiograma transesofágico mostraba un buen funcionamiento tanto del auto como del homoinjerto, sin embargo, el ventrículo derecho estaba hipocontráctil, lo que fue corregido con un bolo de milrinona, seguido de infusión continua. El paciente fue derivado al postoperatorio intubado, estable hemodinámicamente, y con infusión de milrinona y nitroprusiato de sodio. CONCLUSIONES: Una de las técnicas de corrección de la insuficiencia aórtica congénita es la cirugía de Ross, en que el ecocardiograma transesofágico intraoperatorio orienta al cirujano de manera precisa sobre el status fisiológico y anatómico de los injertos vasculares.

Estudo experimental comparativo do enxerto homólogo pulmonar tratado pelo processo L-Hydro com o homoenxerto pulmonar a fresco / Comparative experimental study between L-Hydro treated pulmonary homograft and fresh pulmonary homograft

OBJETIVO: Buscando novas formas de preservação de tecidos utilizamos o polietileno-glicol, método L-Hydro (LH), que consiste na extração controlada de substâncias antigênicas e incorporação de agente antinflamatório e antitrombótico. MÉTODOS: Em dez carneiros jovens, substituímos o tronco pulmonar, em sete, por homoenxertos pulmonares (HP) tratados pelo processo L-H e, em três, por HP a fresco, implantados ortotopicamente, seguidos por 320 dias. Os carneiros foram avaliados por exames laboratoriais e ecocardiográficos. Ao cabo dos 320 dias foram sacrificados, procedendo-se à avaliação hemodinâmica, radiológica, macro/microscópica, óptica e eletrônica, varredura e transmissão. Resultados foram analisados pelo teste t de Student de amostras independentes para dados contínuos, análise de variância para medidas repetidas, pelo teste exato de Fisher para dados categóricos. RESULTADOS: Evolução clínica e exames laboratoriais não conseguiram estabelecer diferenças significativas entre os grupos. Ecocardiograma revelou diferença quanto ao gradiente médio pulmonar, significativa aos 10 meses, maior no grupo controle. Avaliação radiológica e macroscópica não estabeleceu diferenças. Na avaliação microscópica, óptica/eletrônica, células de revestimento e intersticiais foram encontradas nos dois grupos igualmente. O porcentual de revestimento celular calculado nos dois grupos foi semelhante. Nódulos de celularidade foram observados somente no grupo de homoenxertos a fresco. CONCLUSÕES: Estes dados indicam que os dois grupos apresentaram desempenho clínico e hemodinâmico semelhante. Ao ecocardiograma o grupo LH apresentou melhor desempenho, e evidências histológicas de repopulação celular intersticial e endotelial. Na análise macro/microscópica, óptica/eletrônica, o grupo L-Hydro apresentou macroscopia, estrutura histológica e ultraestrutural semelhante ao homoenxerto fresco, à exceção de nódulos de maior celularidade intersticial, presentes apenas no homoenxerto a fresco.

OBJECTIVE: In an effort to make available homografts preserved in a simpler and less costly way, we evaluated the polyethyleneglycol, L-Hydro (LH) method, that consists in the controlled extraction of antigenic substances and the incorporation of anti-inflammatory and anti-thrombotic agent. METHODS: We substituted the pulmonary trunk in ten ovines, seven received LH treated pulmonary homografts and three, fresh pulmonary homografts, orthotopically implanted and followed-up for 320 days. Ovines where evaluated by means of laboratory tests, echocardiographic exams. At the 320 days, were euthanized, hemodynamic, radiology, macroscopic, optic/electronic microscopic, scanning/transmission evaluations were performed. Results were analyzed by Student t test of independent samples for continuous data, by variance analysis of repeated measures, and by Fisher exact test for categorical data. RESULTS: We couldn't establish relevant differences in clinical evolution and laboratory tests between groups. Echocardiogram revealed difference in pulmonary medium gradient, which was significant 10 months follow-up, higher in the control group. Radiologic and macroscopic evaluations didn't established differences. In the optic/electronic microscopic evaluation, liner and interstitial cells were equally found in both groups. The cell liner percent calculated in both groups was similar. Cellularity nodules were observed only infresh homograft group. CONCLUSIONS: These data indicate that both groups presented similar clinical/hemodynamic performances. The LH group's echocardiogram presented a better performance. It also presented histological evidences of interstitial and endothelial cell repopulation. In the macro/optic and electronic microscopic analysis, group L-H presented macroscopy/histological structure and ultra-structural similar to the fresh group, with the exception of nodules with higher interstitial cellularity, present only in the fresh homograft group.

[Transesophageal echocardiography in Ross procedure]. / El ecocardiograma transesofágico en la cirugía de ross.

BACKGROUND AND OBJECTIVES: Ross procedure is one of the surgical procedures for correction of severe congenital aortic insufficiency. Intraoperative transesophageal echocardiography is essential for optimal surgical evaluation. Furthermore, it is able to assess the blood volume profile and the need for administration of vasoactive drugs during surgery. CASE REPORT: This is a 15-year old teenager with severe congenital aortic insufficiency scheduled for corrective surgery with the Ross procedure. In the operating room, the patient was monitored with electrocardiography and pulse oximeter, and he was premedicated with midazolam. After the administration of premedication, the left radial artery and right subclavian vein were punctured. Anesthetic induction was accomplished with etomidate, cisatracurium, and fentanyl while maintenance was achieved with sevoflurane. The probe of the transesophageal echocardiography equipment was introduced immediately after tracheal intubation, showing increased left ventricle; severe aortic insufficiency due to coaptation failure of the three leaflets; and competent pulmonary valve without anatomical and physiological changes. Intercurrences were not observed during surgery, with 120 minutes of extracorporeal circulation (ECC) and 8 hours of surgery. Immediately after removal from ECC the transesophageal echocardiography showed good function of both the auto- and homograft; however, the right ventricle presented hypocontractility, which was corrected with a bolus of milrinone followed by continuous infusion. The patient was transferred to the postanesthetic recovery unit intubated and hemodynamically stable with infusion of milrinone and sodium nitroprusside. CONCLUSIONS: Ross procedure is one of the techniques for correction of congenital aortic insufficiency in which transesophageal echocardiography guides the surgeon precisely on the physiological and anatomical status of vascular grafts.

Evaluation of the biological behavior of decellularized pulmonary homografts: an experimental sheep model.

INTRODUCTION: The cryopreserved homograft is a good valve substitute due attributes like excellent hemodynamics, low incidence of thromboembolic events, infection resistance and good mid-term durability. However, progressive homograft degeneration and fibrocalcification may occur, particularly in the childhood and young adults. Their antigenicity triggers an immunological reaction that plays an important role in their degeneration and failure. The decellularization process was proposed to decrease this antigenicity. By the action of detergents and enzymes, this process removes all cellular components from the homograft matrix, diminishing immunogenicity and probably delaying its degeneration. OBJECTIVE: The objective of this experimental and descriptive study is to evaluate the biological and functional behavior of decellularized pulmonary homografts (Decell-H), treated by a sodium dodecil sulfate solution (0.1%), developed in our University (Pontifícia Universidade Católica do Paraná). For the characterization of Decell-H performance, parameters like recellularization, calcification, and echocardiographic data will be analyzed. METHODS: Eight juvenile sheep were submitted to the implantation of the Decell-H sutured into orthotopic position, through a left thoracotomy and with cardiopulmonary bypass support. They were followed-up clinically and by periodical echocardiograms until the explantation, which were performed in different time for every two sheep: seven, 30, 90 and 180 postoperative days. For histological analysis we used Hematoxilin-eosin, Movat and Alizarin-Red staining. RESULTS: The sheep reached their follow-up period in a good clinical state. There was no valve regurgitation or stenonis by the echocardiogram. The animals submitted to the explantation in 90 and 180 days had a significant somatic growth and these Decell-H(s) had a diameter increase, without central valve insufficiency. Histologically, all homografts preserved their extra-cellular matrix organization and were progressively recellularized, without calcification. CONCLUSION: In this experimental model, the Decell-H behaved as an excellent valve substitute.

Avaliação do comportamento biológico de homoenxertos valvares pulmonares descelularizados: estudo experimental em ovinos / Evaluation of the biological behavior of decellularized pulmonary homografts: an experimental sheep model

INTRODUÇÃO: Não havendo um substituto valvar ideal, os homoenxertos criopreservados são considerados uma boa opção, pelo excelente perfil hemodinâmico, baixa incidência de tromboembolismo, resistência a infecções e durabilidade a médio prazo. Porém, estão sujeitos à progressiva degeneração, especialmente em crianças e adultos jovens. Sua antigenicidade desencadeia uma resposta imunológica que contribui para sua degeneração, calcificação e falência. Para diminuir esta antigenicidade, desenvolveu-se o processo de descelularização. Pela ação de detergentes e enzimas, este processo remove os componentes celulares do homoenxerto, diminuindo sua imunogenicidade e, provavelmente, retardando sua degeneração. OBJETIVO: O objetivo deste estudo, experimental e descritivo, é analisar o comportamento histológico e funcional de homoenxertos pulmonares ovinos descelularizados (H-descel) por uma nova solução, composta principalmente de dodecil sulfato de sódio a 0,1 por cento e desenvolvida na PUCPR. Para caracterizar este comportamento, serão avaliados o repovoamento celular, a ocorrência de calcificação e a função valvar ao ecocardiograma. MÉTODOS: A amostra foi constituída de oito ovinos, submetidos ao implante de H-descel em posição ortotópica, através de uma toracotomia esquerda, com auxílio de circulação extracorpórea. Os animais foram acompanhados clinicamente e por ecocardiogramas periódicos até o explante, realizados em prazos predefinidos para cada dois animais: sete, 30, 90 e 180 dias. A análise histológica foi realizada por colorações Hematoxilina-eosina, Pentacrômio de Movat e Alizarina Red. RESULTADOS: Todos os animais sobreviveram ao procedimento e atingiram seus períodos de seguimento. Não houve insuficiência ou estenose destes enxertos ao ecocardiograma. Os animais submetidos aos explantes em 90 e 180 dias tiveram significativos ganhos ponderais e estes H-descel aumentaram de diâmetro, sem desenvolver insuficiência. À histologia, todos mantiveram a organização de sua matriz extracelular, foram progressivamente repovoados e não apresentaram calcificação. CONCLUSÃO: Neste modelo experimental, os H-descel mostraram-se excelentes substitutos valvares a médio prazo.

INTRODUCTION: The cryopreserved homograft is a good valve substitute due attributes like excellent hemodynamics, low incidence of thromboembolic events, infection resistance and good mid-term durability. However, progressive homograft degeneration and fibrocalcification may occur, particularly in the childhood and young adults. Their antigenicity triggers an immunological reaction that plays an important role in their degeneration and failure. The decellularization process was proposed to decrease this antigenicity. By the action of detergents and enzymes, this process removes all cellular components from the homograft matrix, diminishing immunogenicity and probably delaying its degeneration. OBJECTIVE: The objective of this experimental and descriptive study is to evaluate the biological and functional behavior of decellularized pulmonary homografts (Decell-H), treated by a sodium dodecil sulfate solution (0.1 percent), developed in our University (Pontifícia Universidade Católica do Paraná). For the characterization of Decell-H performance, parameters like recellularization, calcification, and echocardiographic data will be analyzed. METHODS: Eight juvenile sheep were submitted to the implantation of the Decell-H sutured into orthotopic position, through a left thoracotomy and with cardiopulmonary bypass support. They were followed-up clinically and by periodical echocardiograms until the explantation, which were performed in different time for every two sheep: seven, 30, 90 and 180 postoperative days. For histological analysis we used Hematoxilin-eosin, Movat and Alizarin-Red staining. RESULTS: The sheep reached their follow-up period in a good clinical state. There was no valve regurgitation or stenonis by the echocardiogram. The animals submitted to the explantation in 90 and 180 days had a significant somatic growth and these Decell-H(s) had a diameter increase, without central valve insufficiency. Histologically, all homografts preserved their extra-cellular matrix organization and were progressively recellularized, without calcification. CONCLUSION: In this experimental model, the Decell-H behaved as an excellent valve substitute.

[Ross operation in Chile]. / Operación de Ross en Chile.

BACKGROUND: Donald Ross introduced the pulmonary autograft for aortic valve replacement with reconstruction of the right ventricular outflow tract with a homograft. Despite its advantages over conventional valve prostheses, the Ross Operation is performed in a minority of patients who need an aortic valve replacement throughout the world. AIM: To report the operative and long term results of a series of patients subjected to Ross operation in Chile. PATIENTS AND METHODS: Between 1996 and 2006, 131 patients aged 35+/-11 years (62% males) were subjected to an aortic root replacement with a pulmonary autograft and reconstruction of the right ventricular outflow tract with a pulmonary homograft. Seventy percent had congenital valve disease. Associated procedures were done in 39%. Patients were followed for a mean of 56+/-30 months. RESULTS: Operative mortality was 2.3%. Two patients had the autografts replaced intraoperatively because of tears in the proximal suture line and one within a month of the operation after suffering autograft endocarditis. At last follow up all patients are in functional class 1 or 2. Autograft reoperations were done in two patients who developed dilation with valve regurgitation (both had aortic regurgitation as primary indication for aortic valve replacement). Three patients required reoperation for pulmonary homograft dysfunction. Another three patients had uneventful pregnancies with normal newborns. Actuarial freedom from any reoperation at 10 years is 93%. CONCLUSIONS: The Ross Operation has low operative morbidity and mortality with excellent long term results. Reoperations have been rare within 10 years of follow up both for the autograft or the homograft.

Hospital mortality in surgery for reconstruction outflow right ventricle with pulmonary homograft.

BACKGROUND: Hospital mortality for surgical reconstruction of the outflow of the right ventricle with pulmonary homograft is variable. OBJECTIVES: To identify risk factors associated with hospital mortality and clinical profile of patients. METHODS: Children underwent reconstruction of the outflow tract of right ventricle with pulmonary homograft. Analyzed as risk factors for the clinical, surgical and morphological aspects of the prosthesis. RESULTS: Ninety-two patients operated on between 1998 and 2005 presented mainly pulmonary atresia with ventricular septal defect and tetralogy of Fallot. Forty patients were treated in the first month of life. He needed 38 surgeries to Blalock Taussig due to clinical severity. The median age at surgery for total correction was 22 months, ranging from 1 to 157 months. Size pulmonary homograft ranging from 12 to 26 mm and length of bypass was 132 +/- 37 minutes. After surgery there were seventeen deaths (18% cases) on average 10.5 +/- 7.5 days. The predominant cause was multiple organ failure. In the univariate analysis between the types of heart disease, they found in favor of age at surgery, size of homograft, pulmonary valve Z value, CPB time, maintaining the integrity of the homograft and pulmonary tree change. There was no statistical difference in hospital mortality between the variables and the type of heart disease. CONCLUSION: The congenital obstructive right requires surgical care in the first days of life. The total correction surgery has a risk rate of 18% but there was no association with any variable studied.

Operación de Ross en Chile / Ross operation in Chile

Background: Donald Ross introduced the pulmonary autografit for aortic valve replacement with reconstruction of the right ventricular outfow tract with a homografit. Despite its advantages over conventional valve prostheses, the Ross Operation is performed in a minority of patients who need an aortic valve replacement throughout the world. Aim: To report the operative and long term results of a series of patients subjected to Ross operation in Chile. Patients and Methods: Between 1996 and 2006, 131 patients aged 35 ± 11 years (62 percent males) were subjected to an aortic root replacement with a pulmonary autografit and reconstruction of the right ventricular outfow tract with a pulmonary homografit. Seventy percent had congenital valve disease. Associated procedures were done in 39 percent. Patients were followed for a mean of 56 ± 30 months. Results: Operative mortality was 2.3 percent. Two patients had the autografits replaced intraoperatively because of tears in the proximal suture line and one within a month of the operation after suffering autografit endocarditis. At last follow up all patients are in functional class 1 or 2. Autografit reoperations were done in two patients who developed dilation with valve regurgitation (both had aortic regurgitation as primary indication for aortic valve replacement). Three patients required reoperation for pulmonary homografit dysfunction. Another three patients had uneventful pregnancies with normal newborns. Actuarial freedom from any reoperation at 10 years is 93 percent. Conclusions: The Ross Operation has low operative morbidity and mortality with excellent long term results. Reoperations have been rare within 10 years of follow up both for the autografit or the homografit.

Mortalidade hospitalar na cirurgia de reconstrução da via de saída do ventrículo direito com homeonxerto pulmonar / Hospital mortality in surgery for reconstruction outflow right ventricle with pulmonary homograft

FUNDAMENTO: Mortalidade hospitalar na cirurgia de reconstrução da via de saída do ventrículo direito com homoenxerto pulmonar é variável. OBJETIVOS: Identificar os fatores de risco associados à mortalidade hospitalar e ao perfil clínico dos pacientes. MÉTODOS: Estudo de crianças submetidas à reconstrução da via de saída do ventrículo direito com homoenxerto pulmonar. Analisados como fatores de risco as variáveis clínicas, cirúrgicas e de aspectos morfológicos da prótese. RESULTADOS: Noventa e dois pacientes foram operados entre 1998 e 2005, apresentando principalmente atresia pulmonar com comunicação interventricular e a tetralogia de Fallot. Quarenta pacientes foram atendidos no primeiro mês de vida. Necessitaram de 38 cirurgias de Blalock Taussig devido à gravidade clínica. A idade mediana na cirurgia de correção total foi de 22 meses, variando de 1 mês a 157 meses. O tamanho homoenxerto pulmonar variou de 12 a 26 mm e o tempo de extracorpórea foi 132 ± 37 minutos. Após a cirurgia houve 17 óbitos (18 por cento casos), em média 10,5 ± 7,5 dias após. A causa predominante foi falência de múltiplos órgãos. Na análise univariada entre os tipos de cardiopatia, estas deferiram na idade, momento da cirurgia, tamanho do homoenxerto, valor Z da valva pulmonar, tempo de circulação extracorpórea, manutenção da integridade do homoenxerto e alteração da árvore pulmonar. Não houve diferença estatística com relação à mortalidade hospitalar entre as variáveis e o tipo de cardiopatia. CONCLUSÃO: As cardiopatias obstrutivas do lado direito necessitam de atendimento cirúrgico nos primeiros dias de vida. A cirurgia de correção total apresenta risco de mortalidade de 18 por cento, mas não houve associação com nenhuma variável estudada.

BACKGROUND: Hospital mortality for surgical reconstruction of the outflow of the right ventricle with pulmonary homograft is variable. OBJECTIVES: To identify risk factors associated with hospital mortality and clinical profile of patients. METHODS: Children underwent reconstruction of the outflow tract of right ventricle with pulmonary homograft. Analyzed as risk factors for the clinical, surgical and morphological aspects of the prosthesis. RESULTS: Ninety-two patients operated on between 1998 and 2005 presented mainly pulmonary atresia with ventricular septal defect and tetralogy of Fallot. Forty patients were treated in the first month of life. He needed 38 surgeries to Blalock Taussig due to clinical severity. The median age at surgery for total correction was 22 months, ranging from 1 to 157 months. Size pulmonary homograft ranging from 12 to 26 mm and length of bypass was 132 ± 37 minutes. After surgery there were seventeen deaths (18 percent cases) on average 10.5 ± 7.5 days. The predominant cause was multiple organ failure. In the univariate analysis between the types of heart disease, they found in favor of age at surgery, size of homograft, pulmonary valve Z value, CPB time, maintaining the integrity of the homograft and pulmonary tree change. There was no statistical differencein hospital mortality between the variables and the type of heart disease. CONCLUSION: The congenital obstructive right requires surgical care in the first days of life. The total correction surgery has a risk rate of 18 percent but there was no association with any variable studied.

Biointegration and growth of porcine valved pulmonary conduits in a sheep model.

As there is currently no suitable valved pulmonary conduit for small children, porcine conduits treated by the L-Hydro process were implanted into 9 newborn lambs to investigate growth potential. Of the 8 survivors, 7 were kept alive for 12 months after implantation. The diameter of the conduit and gradient across the valve were evaluated at surgery and at 3 and 9 months postoperatively using bidirectional echocardiographic and angiographic methods. After sacrifice, histological and radiological analyses were performed. The mean weight of the animals was 4.2 +/- 1.1 kg at implantation and 43.1 +/- 6.2 kg at sacrifice. There was a significant increase in mean valve area from 139.9 +/- 18.0 mm2 at implantation to 443.5 +/- 89.2 mm2 at 12 months. Pre-sacrifice angiography showed no transvalvular gradient, and radiographic analysis did not reveal significant conduit wall or leaflet calcification in any of the animals. Histological examination of the grafts demonstrated total integration, with native-like intact valve leaflets. Thus functional evaluation, echocardiography, and histology demonstrated growth of the grafts with completely endothelialized and apparently normal pulmonary valve leaflets without calcification.