Ventriculectomia parcial: um novo conceito no tratamento cirúrgico de cardiopatias em fase final Partial ventriculectomy: a new concept for surgical treatment of end stage cardiopathies

Abstract

A melhora clínica da função cardíaca pós aneurismectomia de ventrículo esquerdo e/ou cardiomioplastia com o músculo grande dorsal parece ser, ao menos parcialmente, devida ao remodelamento do ventrículo esquerdo. Através de pesquisa em nosso laboratório experimental com carneiros, demonstramos que o aumento do diâmetro do ventrículo é mais importante que a perda de massa muscular para a deterioração da função ventricular. Sabendo-se que em miocardiopatia dilatada não ocorre aumento de massa muscular, reduzimos o diâmetro do ventrículo para o normal, em uma série consecutiva de pacientes com esta lesão. No período de 1984 a 1995, foram operados com esta nova técnica, denominada, então, "Ventriculectomia Parcial", 103 pacientes portadores de miocardiopatias complexas e insuficiência cardíaca congestiva (NYHA IV). A operação é baseada na lei de Laplace (T=P.11.D) e consistiu na remoção de uma fatia de músculo da parede lateral do ventrículo esquerdo, iniciando-se na ponta deste, estendendo-se entre os músculos papilares e terminando próximo ao anel mitral. A cirurgia é realizada sob circulação extracorpórea normotérmica e não se utiliza cardioplegia. "Todos os pacientes foram avaliados pré-operatoriamente com ecodopplercardiografia e ventriculografia digital, os quais revelaram fração de ejeção The clinical improvement of cardiac function post left ventricular aneurysmectomy and/or cardiomyoplasty with the latissimus dorsi muscle seems to be due to the remodeling of the left ventricle. We did some experiments with sheep in our laboratory and we concluded that the increment of ventricular diameter is more deleterious than loss of muscle mass to the ventricular function. Since there is no increment in muscle mass to the dilated hearts, we reduced their diameter to accomplish a better ventricular function in a series of very sick patients with dilated hearts. From 1984 to 1995, 103 patients with complex cardiac problems and end stage congestive heart failure (NYHA IV) with dilated cardiomyopathy underwent "Partial Ventriculectomy". The operation was based on Laplace's law (T-P.II.D) and consisted of removal of a large wedge of muscle from the lateral wall of the left ventricle beginning at the apex and extending between the papillary muscles, ending proximal to the mitral annulus. The operation was performed under normothermic cardiopulmonary bypass and no cardioplegia was used. Pre-operative left ventriculography and echocardiography showed global hypocontractility of the hearts with ejection fraction lower than 20% in all patients who were considered candidates for cardiac transplantation. Males were predominant (n=73) and the age varied from 19 to 74 years. The pathologies were: viral miocarditis (n=12); post miocardioplasty (n=1); Chagas' disease (n=15); valvular disease (n=38); ischemic disease (n=16); idiopathic (n=21). Hospital mortality (30 days post operative) (n=13): pulmonary embolus (n=4); renal failure (n=5); bleeding (n=4). Late deaths (after 30 days post-operative) (n=10): arhythmia (n=6); "cardiac failure" (n=2); unknown (n=2); 8 patients required reoperation for bleeding. There were no infection and none required IAPB. All patients had nipride and 19 needed inotropics. Post-op ventriculographies and echocardiographies showed improvement of EF (from 100% to 300%). In conclusion, this new technique "Partial Ventriculectomy", with it's purpose of reducing the ventricular diameter, may benefit patients with end stage heart failure. And this new concept may, in our experience, give the patient improvement in his clinical status and increase life span.

Keywords

• Ventriculectomia parcial
• Miocardiopatias
• Miocardiopatias
• Ventriculectomy, partial
• Myocardiopathies
• Myocardiopathies