ANGIOGENESIS AFTER TRANSPLANTATION OF A FREE SKELETAL-MUSCLE FLAP ON THE DOG MYOCARDIUM

For the study of the process of neovascularization the effects of the transplantation of a free skeletal muscle flap on the heart of the dog were studied. For this purpose, in 14 mongrel dogs a myocardial infarction of the anterior wall of the heart was produced by the selective injection of microspheres into the left anterior descending artery. In 12 of those, on the area of infarction 4 weeks later a free pectoralis muscle flap was transplanted with its pars anterior in contact with the myocardium (group A). The arterial anastomosis was achieved with the internal mammary artery, the venous flow directed into the right atrium. In 2 other dogs (group B) the pectoralis flap was transplanted with irt pars anterior on a healthy myocardium. In 2 further dogs (group C) the pectoralis flap was transplanted on a infarcted myocardium with its pars posterior, i.e. the muscle fascia interponed. 16 weeks later a micro-corrosion-cast-preparation and histological examinations showed in group A and B a prominent capillary network penetrating from the muscle into the myocardium, whereas in group C the muscle fascia inhibited this process. Thus, for the process of neovascularization the <<bloody>> contact between a skeletal muscle graft and the myocardium is necessary. Results are discussed with regard to possible factors inducing neo-angiogenesis.