Anatomicosurgical segmentectomy of the left ventricle for systematized partial resection of the heart: an experimental study

Abstract

A surgical experimental investigation is being carried out in an attempt to provide a viable alternative to the current approaches to cardiac resection of the left ventricular myocardium in cases of cardiomyopathies with dilated ventricle. The experiments are based upon the presence of anatomicosurgical segments in the dog's heart similar to those existing in the atria and ventricles of humans. So far three mongrel dogs (weight 15 kg) were submitted to cardiac catheterism to evaluate the anatomy of the coronary arteries and their branches, the function and cavity of the left ventricle (LV). A lateral thoracotomy on the left side was performed to expose the heart. Cardiopulmonary bypass (CPB) of each animal was established through the right atrium and the femoral artery (4 mg/kg Heparin, at 32°C, intermittent aorta cross-clamping). The left marginal artery and veins were ligated, causing an area of acute myocardial infarction, showing well-defined sharp limits. Such an area was then resected and the left ventricle was reconstructed. The animals were weaned from CPB, one dog having remained in a stable condition during a 7-day period of observation. The second was sacrificed after 4-day period of observation and the third dog died four hours after CPB owing to an excessive reduction of the LV chamber related to an anatomical variation. Pre and post operation transthoracic echocardiograms were obtained after undergoing cardiac catheterism. The echocardiogram revealed discrete mitral insufficiency, reduction of the diameter of the left ventricle with approximation of the papillary muscles, a dysfunction and an impressive reduction of the cavity of the left ventricle. Peri-sutural areas of infarction were not observed. The orientation given by the anatomicosurgical segmentation of the coronary circulation is an important alternative to the present surgical treatment of cardiomyopathies with dilated ventricle.<br>Uma investigação experimental cirúrgica está sendo realizada, numa tentativa de fornecer uma alternativa viável às atuais abordagens para ressecção cardíaca do ventrículo esquerdo em casos de cardiomiopatias com dilatação ventricular. Os experimentos são baseados na presença de segmentos anatomocirúrgicos em corações de cães, similares aos existentes nos átrios e ventrículos humanos. Três cães (peso 15kg) foram submetidos a cateterismo cardíaco, para avaliar a anatomia das artérias coronárias e de seus ramos, a função e cavidade do ventrículo esquerdo (VE). Toracotomia lateral esquerda foi realizada para expôr o coração. Circulação extracorpórea (CEC) de cada animal foi estabelecida através do átrio direito e da artéria femoral (4 mg/kg Heparina, 32°C, clampeamento intermitente da aorta). Artéria e veias marginais esquerdas foram ligadas, causando uma área de infarto agudo do miocárdio, exibindo limites de corte bem definidos. Desta forma, uma área foi ressecada e o ventrículo esquerdo foi reconstruído. Os animais foram desconectados da CEC. Um cão permaneceu em condição estável durante um período de 7 dias de...

Ciências veterinárias: Pensamento científico e ético 2

“…Didio and Rodrigues (1983) recommended anatomic-surgical segments, according to the distribution of the main branches, presenting three segments of the right portion of the heart, namely: cone, right marginal and posterior interventricular; and four segments of the left portion: anterior, lateral, left marginal and posterior ventricular interventricular. This cardiac segmentation is crucial to delimit the resection area of the left ventricles in partial ventriculectomy surgeries aiming at the treatment of dilated cardiomyopathy, where the connection of the marginal branch and its satellite veins would cause an area of ischemia, indicating the resection site (DIDIO et al, 1998).…”