Porcine mitral stentless valve mid-term clinical results.

OBJECTIVES: Time testing is essential with any valvular procedure, especially when a new concept is introduced such as the mitral stentless valve. Our purpose is to evaluate the results obtained over 4 years with this operation, particularly to attest the impact of preservation of annulo ventricular continuity on the long term results of these patients. METHODS: From March 1992 to August 1996, 120 patients had their mitral valves replaced with a porcine stentless mitral valve. The observation period was 54 months with total patients follow-up of 3424 months with a mean of 28.5 months. The age ranged from 11 to 72 years (mean 35.22 +/- 14.98). There were 73 females (60.8%) and 47 males (39.2%). The predominant etiology was rheumatic heart disease. Associated procedures were performed in 12 patients (10%), and the great majority of the patients were in functional class III and IV (NYHA). RESULTS: Hospital mortality occurred in seven patients (5.83%) non valve related except for one early case of endocarditis. Early reoperation related to technical failure were necessary in 4 patients without mortality. Follow-up was accomplished in 101 patients and ranged from 2 to 54 months. Late reoperations were required in 16 patients (nine due to mitral insufficiency, five because of endocarditis and two for mitral stenosis). Most reoperations were related to technical failure. Among the 82 patients presently in control, 72 showed a competent mitral stentless valve, eight with stable mild mitral regurgitation and in two a decreased mitral orifice. Hemodynamic performance of the valve has been excellent in this group, particularly in patients with left ventricular dysfunction. CONCLUSION: Although technical complexity remains the main cause of reoperations with this valve, experience has shown that it not only provides preservation of the left ventricular function but also promised significant increase of the ejection fraction in patients with poor left ventricular function.

Transversal trans-septal biatrial approach for mitral valve surgery.

A surgical approach to the mitral valve is very important to visualize all valvular and subvalvular structures. We have used a transversal trans-septal biatrial approach in some mitral procedures. From January 1994 to May 1994, 11 patients were operated on using this technique. Patient ages ranged from 28 to 74 years. Five cases (45.5%) were cardiac reoperations and six (54.5%) were first operations. Three case (27.3%) were mitral reconstructions, 3 (27.3%) were mitral replacement due to mechanical mitral valve thrombosis, 1 (9.1%) as a result of bioprosthetic mitral valve degeneration, 4 (36.4%) were mitral valve replacements for calcified mitral valve disease one case (9.1%) was tricuspid valve replacement due to severe tricuspid insufficiency. There were 4 case (36.4%) of tricuspid valvuloplasties besides the mitral procedures. There was no operative mortality, and all patients preserved their preoperative cardiac rhythm. No important bleeding or supra-ventricular arrhythmias were seen in any case. Aortic cross-clamping and extracorporeal circulation times were comparable with the traditional approach through the left atrial alone. So, we think that this is a very easy and useful technique to expose the mitral valve during some procedures above it, overall when the left atrium is small and total visualization of the mitral is not possible with the traditional approach through the left atrial alone.

Válvula mecânica em carbono, de disco basculante, com revestimento de material biológico: princípios e desenvolvimento / Carbon mechanical valve, of pivoting disc covered with biological material: principles and development

Introduçao: após estudo experimental de implante de material biológico e carbono em átrio esquerdo e aorta, foi desenvolvida uma nova prótese, primeira válvula de carbono feita inteiramente no País. A finalidade foi conseguir uma válvula de sistema mecânico durável, de boa aceitaçao orgânica para facilitar a cicatrizaçao a partir do anel e isolar o máximo de material sintético da corrente sangüínea; o objetivo é conseguir menores índices de morbidade e mortalidade, alterando a história natural da prótese mecânica em relaçao a trombose, tromboembolismo, reoperaçoes e menor uso de anticoagulante. Material e Métodos: a válvula é do tipo disco basculante perfurado, fabricada em Carbolite (carbono polimérico endurecido).O anel apresenta haste com pino central para guiar e reter a movimentaçao do disco, batente e dois pinos para limitaçao do grau de abertura. O anel tem perfuraçoes para fixaçao do material biológico (pericárdio e veia). O conjunto é colocado entre dois anéis lisos acoplados revestidos de Poliester com aba de sutura externa. O batente tem aspecto denteado, formando plataformas onde se apóia o disco e entre os dentes existe continuidade do revestimento biológico. A prótese é toda revestida, exceto o pino, o disco, as plataformas do batente e a face interna do orifício menor. A prótese foi testada em duplicador de pulso em teste equivalente a dez anos, sem desgaste aparente com disco de carbono e poliacetal. Cada prótese, antes do implante, é testada individualmente durante cinco dias a 1.000 pulsaçoes por minuto com pressao média de 12 cmHg. Entao, é feita limpeza, esterilizaçao, revestimento de material biológico processado em glicerina, montagem e esterilizaçao final em formol ou gás ETO (conservaçao em glicerina). Existem 7 pacientes mitrais em observaçao com tempo médio de 7,8 meses (mínimo de 4 meses e máximo de 13 meses), sendo mantidos com anticoagulaçao oral. Resultados iniciais: como o número de pacientes é pequeno, destacam-se apenas algumas observaçoes iniciais: ausência de tromboembolismo, ausência de disfunçao mecânica primária, ocorrência de dois acidentes hemorrágicos maiores e um episódio de trombose em paciente com dois meses de evoluçao, por anticoagulaçao inadequada, com reoperaçao e mantendo a mesma prótese com achado de depósito difuso de fibrina e boa evoluçao após dez meses. Conclusoes: os resultados dos testes mecânicos do material e da válvula e os aspectos clínicos iniciais sao favoráveis, devendo-se ampliar a casuística, com proteçao anticoagulante mais efetiva e uniforme nos três primeiros meses. Após três meses, a presença do material biológico e as baixas doses de anticoagulante parecem ser eficientes no controle das complicaçoes pós-operatórias da válvula mecânica, contra a trombose, o tromboembolismo e os acidentes hemorrágicos.

El estudio con ecocardiografía transtorácica y transesofágica del reemplazo valvular aórtico con autoinjerto valvular pulmonar / Transthoracic and transesophageal echocardiographic study in aortic valve replacement with pulmonary valve autograft

Se estudiaron con ecocardiografía, once pacientes sometidos a autotransplante de la válvula pulmonar a posición aórtica, con colocación de prótesis de pericardio bovino en posición valvular pulmonar. En todos se efectuó un ecocardiograma transtorácico previo a la cirugía. Durante el procedimiento quirúrgico se efectuó ecocardiograma transesofágico. Los estudios transtorácicos ayudaron a confirmar la viabilidad de esta cirugía. Los estudios transesofágicos ayudaron en la evaluación postquirúrgica inmediata. La ecocardiografía transtorácica y transesofágica son de utilidad para la evaluación pre, trans y post operatoria de pacientes sometidos a cirugía de Ross

Heterologous mitral valve transplant: the first 50 patients clinical analysis.

From March 1992 to August 1993, 50 patients underwent mitral valve replacement with the new heterologous stentless mitral bioprosthesis in our institution. The development of this heart valve substitute, its technique of implantation and the results observed in the first group of 50 patients have had us to review the initial experience. The surgical protocol included an accurate mitral valve complex analysis, adequate valve size selection, attachment of the papillary muscle to the new chordal origin and approximation of the stentless mitral to the patient's annulus. There was one hospital death (2%), not related to the valve or to the technique and four reoperations: two due to endocarditis, one because of a perivalvular leak and one due to a mismatched stentless valve. The late mortality (4%) was not valve-related. The follow-up has shown excellent valve performance with improved left ventricular function in the great majority of the patients. Based on the current analysis, it can be stated that reproducibility of the surgical technique and the excellence of the clinical follow-up may contribute favorably to a better quality of life and longer valve durability in patients requiring mitral heart valve replacement.

Mitral mechanical valve without long-term anticoagulation. Eight-year follow-up.

In 12 patients with sinus rhythm (including 5 children and 6 young women), mitral valve replacement was performed with a microporous-surfaced valve similar to the Björk-Shiley Monostrut. After the first 3 months, permitting endothelialization of the suture ring to continue over the groove and adjacent metal valve ring, no long-term anticoagulant treatment was given. There was no thromboembolic complication in this group during follow-up for 6-8 years, during which four women gave birth to a total of seven children. In eight other cases, one mitral case with atrial fibrillation, anti-coagulant was not discontinued, and in the remaining aortic cases it was reinstituted. One of them (with atrial fibrillation) had hematuria during inadequate anticoagulant medication, but no thromboembolism. Of five patients with only aortic valve replacement, two had thromboembolic complications, one without residual symptoms and one with slight hand weakness. Another had a transient ischemic attack while on anticoagulant and acetylsalicylic acid was added. Two patients with aortic and mitral valve replacement died, one from heart tamponade and the other from venous thrombosis with pulmonary embolism.

Acceso auricular izquierdo traseptal y superior combinado / Transeptal left auricular access and up combinated

El acceso auricular izquierdo clásico, por detrás y paralelo al surco interauricular, no permite una buena exposición de la válvula mitral cuando la aurícula izquierda es de tamaño normal o sólo ligeramente aumentado. En reoperaciones, este acceso auricular izquierdo requiere de mayor disección del corazón, además, en esta situación, el anillo mitral se fija en una posición de más difícil exposición. Entre diciembre 1991 y octubre 1992, 25 pacientes fueron operados con un nuevo acceso auricular izquierdo transeptal y superior combinado. Se efectuaron 23 procedimientos mitrales (7 reoperaciones), en 8 casos asociados a otros procedimientos quirúrgicos cardiovasculares, una sección de Haz paraespecífico lateral izquierdo y una resección de mixoma auricular izquierdo. La técnica consiste en una amplia auriculotomía derecha, paralela y a 1,5 cm al surco aurículo-ventricular, exponiendo el tabique interauricular totalmente, el que es incidido desde el limbo inferior de la fosa ovalis hasta la incisión auricular derecha previa, extendiendo luego la incisión por el techo de la aurícula izquierda. En todos los casos se obtuvo un excelente acceso a la cavidad auricular izquierda y una muy buena exposición de la válvula mitral. No se produjeron desgarros de la pared auricular izquierda. No hubo hemorragia intraoperatoria por líneas de suturas y ningún paciente fue reexplorado por sangrado postoperatorio. El control ecocardiográfico no demostró comunicación interauricular residual en ningún caso. No hubo trastornos permanentes de la conducción aurículo-ventricular. No se observó una prolongación mayor del tiempo operatorio total, y en reoperaciones se requirió de menor disección del corazón. Este nuevo abordaje auricular izquierdo permite un excelente acceso a la aurícula izquierda, especialmente cuando ésta es de tamaño normal o ligeramente aumentado, y en reoperaciones cardíacas, y por lo tanto una muy buena exposición de la válvula mitral, sin distorsionar ninguna de las estructuras de ésta. La técnica no prolonga el procedimiento operatorio y no tiene morbilidad intrínseca

Cardioplejia retrógrada por canulación transauricular derecha del seno coronario / Retrograde cardioplegia trrough right transatrial cannulation of the coronary sinus

LA infusión de solución cardiopléjica por vía anterógrada tiene una demostrada efectividad protectora del miocardio durante la cirugía cardiaca. Sin embargo, en presencia de enfermedad coronaria grave, reoperaciones e hipertrofia ventricular esta efectividad puede ser limitada. Por otra parte, en cirugía valvular, interfiere con el desarrollo expedito dela operación. En estas circunstancias, la infusión retrógrada de solución cardiopléjica permite una mejor distribución de ésta en el miocardio. En 42 pacientes (32 hombres) operados entre septiembre de 1991 y septiembre de 1992 se utilizó para la protección del miocardio la infusión retrógrada solución cardiopléjica cristaloide, exclusiva o adicionada a la infusión anterógrada, a través de la canulación transauricular derecha del seno coronario, con un catéter especialmente diseñado. Veintidós casos correspondieron a revascularizaciones miocárdicas, y 20, a procedimientos valvulares. Nueve pacientes (21 por ciento ) tenían una disfunción ventricular severa, 8 estaban cursando un infarto miocárdico, y 7 casos fueron reoperaciones. No hubo ningún caso de infarto perioperatorio electrocardiográfico, pero 2 pacientes (4,8 por ciento ) presentaron elevación de CPK-MB significativa para injuria miocárdica. Once pacientes (26 por ciento ) requirieron inótropos en el postoperatorio (dopamina y/o dobutamina en 9 casos). Ninguno requirió balón de contrapulsación. No hubo morbilidad relacionada con la canulación del seno coronario ni con la infusión retrógrada de solución cardiopléjica. No hubo mortalidad hospitalaria. En esta experiencia inicial, la canulación transauricular derecha del seno coronario permite la infusión retrógrada de solución cardiopléjica en forma simple y efectiva, ofreciendo una buena protección miocárdica

Ross operation using a bovine bioprosthetic valve with autologous pericardial conduit in the pulmonary position.

Between 1 February 1992 and 1 March 1993, we performed Ross's aortic replacement in 7 men and 4 women with rheumatic heart disease. The patients' ages ranged from 22 to 60 years (mean, 41 years). All 11 patients had aortic valve disease; 2 also had mitral valve disease. In all patients, the right ventricular outflow tract was reconstructed using an autologous pericardial conduit containing a bovine cardiac valve bioprosthesis manufactured at our institution. The 2 patients who had mitral valve disease underwent a concomitant mitral valvuloplasty. In 1 patient, minimal aortic regurgitation was documented by means of transesophageal echocardiography immediately after the cessation of cardiopulmonary bypass, but no hemodynamic compromise was noted. In another patient, mediastinal exploration was required for bleeding, 3.5 hours postoperatively. The follow-up period ranged from 6 to 16 months (mean, 11.3 months). Results were assessed by means of clinical and transesophageal echocardiographic studies. No infection or technical failure was encountered. No patient died. All patients remain asymptomatic, and follow-up echocardiography has revealed no transaortic or transpulmonary gradient. The Ross operation was chosen for this group of patients because it avoids the use of mechanical valves and subsequent anticoagulant therapy. Most of our patients have a low income and a history of noncompliance with the strict postoperative drug regimen. Although the short-term results have been excellent with the Ross operation and our combination bioprosthesis, long-term evaluation is needed.

Anatomically complete heterograft mitral valve substitute: surgical technique and immediate results.

The use of a totally anatomical mitral valve heterograft as a mitral valve substitute has been proven to be technically feasible. A new stentless mitral porcine heart valve substitute was therefore developed to match the physiology and flow characteristics of the left ventricle and mitral valve complex, and tested in non-survival animal experiments. Having sought the approval of the Hospital Ethics Committee and the consent of each individual patient, this valve was implanted into 18 patients with diseased mitral valves. The duration of the procedure is approximately the same as for standard mitral valve replacement. The sizing of the valve and the anchoring of the sutures to the papillary muscle, although very straightforward, do require adherence to a protocol. The immediate clinical results are encouraging, although the first patient required a reoperation because of a patient/valve mismatch. All patients, including the patient reoperated, are in functional class I after four to 26 weeks of follow up. The patients will be followed by monthly clinical and Doppler echocardiographic examinations, as they have been so far, for the next 12 months, and annually thereafter.

[Long-term follow-up of the Hancock prostheses]. / Evolución a largo plazo de las protesis de Hancock.

Our purpose was to investigate the long term outcome of Hancock bioprostheses at our Hospital. There were 128 bioprostheses, with histopathological study on 17 of them. The 12.8 years follow-up disclosed dysfunction on 48.18% with an annual dysfunction rate of 3.34 +/- 1.3. One half of the patients with prosthetic dysfunction were re-operated. A comparison of our results is made with those of the literature, either with biological or mechanical prostheses.

Válvula de presión variable en el tratamiento de hidrocefalia con ventrículos chicos / Valve of variable pressure in the treatment of hydrocephalus with small ventricles

Se presenta una paciente de 13 años portadora de un síndrome de ventrículos chicos, tratada mediante la instalación de una válvula de presión variable. Partiéndose de una presión de 67 mm de H2O, que va subiendo en forma progresiva hasta 101 mm, observándose una respuesta ventricular, que va aumentando su tamaño en relación directa a la presión valvular. Se estima en definitiva los 84 mm de H2O, la presión más adecuada para tener una buena respuesta clínica con un tamaño ventricular aceptable. No es posible obtener conclusiones, pero se abre una nueva posibilidad terapéutica mediante el uso de las válvulas de presiones variables

Reemplazo de la aorta ascendente y válvula aórtica con reimplante de las arterias coronarias / Replacement of the ascending aorta and aortic valve with reimplantation of the coronary arteries

La reparación paliativa de los aneurismas de la aorta ascendente tiene una recidiva alta por tratarse de una patología degenerativa que compromete la aorta desde el anillo valvular. Actualmente se prefiere el tratamiento definitivo que consiste en el reemplazo de la aorta ascendente junto con la válvula aórtica. Entre marzo de 1978 y octubre de 1983 hemos intervenido 8 pacientes con esta patología. Cinco casos presentaban disección de la aorta de tipo proximal y 2 se operaron en etapa aguda. La indicación operatória fue insuficiencia aórtica grave en 6 pacientes y disección aguda en los 2 restantes. La reparación del aneurisma se realizó con prótesis de dacrón que tiene incorporada una válvula de Bejork-Shiley sobre la cual se reimplantaron los ostia coronarios. El estudio histológico de la aorta demostró necrosis quística de la túnica media en todos los casos. Dos pacientes fallecieron por complicaciones quirúrgicas y los 6 restantes fueron dados de alta bien. El control alejado (x = 21,6 meses) reveló que 5 pacientes están asintomáticos y sin recidiva, 1 falleció a los 15 meses. La técnica de esta grave patología con buenos resultados alejados y sin recidivas

[Implantation of mitral valve prosthesis with continuos suture]. / Colocación de prótesis mitrales con sutura continua.

The results obtained in 20 patients with the use of continue suture technic for prosthetic implantation of the mitral valve were compared to those observed in other 20 patients in which the prothesis were implanted with isolated suture technic. With the first one the aortic clamp time was reduced in average about 50 minutes; the extracorporeal circulation time also diminished in the same proportion. One patient died in each group, meaning a 5% of hospital mortality. The going after time in the first group was 2.5 years and in none was found prosthetic dysfunction or perivalvular lickage. We conclude that prosthetic implantation technic for mitral valve with continue suture, offers the following advantages: a) Important reduction of the transoperative myocardial ischemia. b) Reduction also, of the hole estracorporeal circulation time. c) Minor possibilities of periprosthetic lickage. d) Minor risk of valvular thrombosis in the suture line.