Cavopulmonary anastomosis improves left ventricular assist device support in acute biventricular failure.

OBJECTIVE: Right ventricular failure during left ventricular assist device (LVAD) support can result in severe hemodynamic compromise with high mortality. This study investigated the acute effects of cavopulmonary anastomosis on right ventricular loading and LVAD performance in a model of severe biventricular failure. METHODS: LVAD support was performed by means of centrifugal pump implantation in 14 anesthetized dogs (20-30 kg) with severe biventricular failure obtained by ventricular fibrillation induction. Animals were randomized to be submitted to classical cavopulmonary anastomosis (Glenn shunt) or to control group and were maintained under LVAD support for 2h. Left and right atrial, right ventricular and systemic pressures were monitored, while total pulmonary flow was simultaneously recorded by transonic flowmeters located on the superior vena cava and pulmonary trunk. Blood gas and venous lactate determinations were also obtained. RESULTS: Ventricular fibrillation maintenance resulted in acute LVAD performance impairment after 90 min in the control group, while animals with Glenn circuit maintained normal LVAD pump flow (55+/-13 ml kg(-1)min(-1) vs 21+/-4 ml kg(-1)min(-1), p<0.001) and better peripheral perfusion (blood lactate of 29+/-10 pg/ml vs 46+/-9 pg/ml, p<0.001). Left and right atrial pressures did not change significantly, while right ventricular pressure was lower in animals with Glenn circuit (13+/-3 mm Hg vs 22+/-8 mm Hg, p=0.005). Right ventricular unloading with Glenn shunt also resulted in superior total pulmonary flow (59+/-13 ml kg(-1)min(-1) vs 17+/-3 ml kg(-1)min(-1), p<0.001). CONCLUSION: The concomitant use of cavopulmonary anastomosis during LVAD support in a model of severe biventricular failure limited right ventricular overloading and resulted in better hemodynamic performance.

Limited Left Thoracotomy for Reoperative Coronary Artery Bypass Grafting without Cardiopulmonary Bypass for Circumflex Grafting in Patients with Patent Internal Thoracic Artery Graft.

Abstract Background: We describe our experience with the limited left thoracotomy strategy for reoperative coronary artery bypass graft (CABG)to the circumflex coronary artery system, emphasizing the indications, our particular operative technique, and early clinical follow-up. Methods: From January 2001 to January 2002, 8 consecutive patients underwent redo revascularization via limited left thoracotomy and without cardiopulmonary bypass. This operation was indicated for patients with recurrent myocardial ischemia confined to the lateral wall of the left ventricle, especially if a patent left internal thoracic artery (LITA)-to-left anterior descending coronary artery (LAD)graft was present. Results: All 8 patients underwent successful redo revascularization via limited left thoracotomy. Eight patients received 14 saphenous vein grafts (mean 1.7 grafts/patient). No instances of postoperative myocardial infarction or death occurred. During a follow-up period ranging from 1 to 12 months (mean, 5. 2 months), all patients were asymptomatic and without evidence of ischemia or infarction. Conclusions: For select patients who have patent LITA grafted into the LAD and who need redo CABG to the coronary artery circumflex system, the limited left thoracotomy approach without cardiopulmonary bypass is a safe operation and a less invasive alternative to repeat sternotomy and conventional CABG.

Substituição da valva mitral nas cardiomiopatias dilatadas com insuficiência mitral secundária / Replacement of the mitral valve in dilated cardiomyopathy with secondary mitral regurgitation

A insuficiência mitral funcional nas cardiomiopatias dilatadas ocorre em razão das alterações da geometria do ventrículo esquerdo e dos aparelhos valvar e subvalvar. A sobrecarga de volume decorrente da insuficiência mitral resulta no aumento progressivo da cavidade ventricular e do anel mitral, agravando a disfunção ventricular. O objetivo deste trabalho é estudar o resultado da substituição valvar mitral associado ao remodelamento ventricular nesse grupo de pacientes. No período de julho de 2000 a fevereiro de 2003, 20 pacientes consecutivos portadores de insuficiência mitral funcional (classe funcional III e IV) e cardiomiopatia dilatada idiopática foram submetidos a troca da valva mitral associada ao remodelamento ventricular esquerdo. Foram avaliados segundo as alterações hemodinâmicas e ecocardiográficas e quanto à evolução clínica. A análise estatística foi obtida por meio do teste t de Student e a análise de sobrevida, pelo método de Kaplan-Meyer. A mortalidade hospitalar foi de 10 por cento e a curva atuarial demonstrou sobrevida de 74 por cento + 14,8 por cento aos 30 meses de seguimento; após seguimento médio de 11,2 meses, 82 por cento dos pacientes encontram-se em classe funcional I e II. A avaliação hemodinâmica apresentou melhora do débito e do índice cardíacos (p < 0,00001 para ambos). A avaliação ecocardiográfica demonstrou melhora da fração de ejeção (p = 0,01), redução dos diâmetros sistólico e diastólico final esquerdo (p = 0,0007 e p = 0,03) e redução do volume sistólico final esquerdo (p = 0,03). A troca valvar mitral associada ao remodelamento ventricular foi capaz de reduzir os sintomas, melhorar a qualidade de vida e prolongar a sobrevida desses pacientes.