[Morphological assessment of autovenous conduits in the composition of perivascular adipose tissue]

Myocardial revascularization is most often performed using the internal thoracic artery. However, its uniqueness as a transplant is limited by length and the necessity to use several conduits, which in turn does not decrease the requirements to use the great saphenous vein for surgical treatment of ischemic heart disease. Competence of autovenous conduits is lower as compared to that of the internal thoracic artery. One of the causes of decreased competence of venous shunts may be thrombotic occlusion associated with peculiarities of procurement of and damage to the vein. We performed a morphological study of autovenous conduits in 60 patients subjected to isolated coronary artery bypass grafting. Depending on the autovenous conduit harvesting technique, the patients were divided into 2 groups. In Group One patients (n=30), the great saphenous vein was harvested using the classical method described by Favaloro. In Group Two patients (n=30), the great saphenous vein was procured in the composition of perivascular adipose tissue without hydraulic dilatation. To assess morphological changes occurring while exposing the autovein, we examined 30 specimens containing fragments of the autovein of patients of the first group and 30 specimens containing fragments of the autovein of patients of the second group. The obtained specimens were analyzed using the light microscope Carl Zeiss & MT at 20× and 100× magnification. Photography was performed using the light microscope Axioscop 40 and camera Pixera Pro 150ES (Germany). We assessed endothelial damage to the autovein, as well as preservation of the vasa vasorum. It was determined that procurement of the great saphenous vein in the composition of the perivascular adipose tissue was accompanied by an increased number of the vasa vasorum, thus decreasing severity of endothelial damage, with the use of systemic pressure for dilatation of the vein making it possible to preserve thickness of the intimal and adventitial layers.