[Ultrastructural changes in the saphenous vein removed during aorto-coronary bypass].

In order to observe ultrastructural changes of the saphenous vein before implantation during coronary artery by-pass surgery, 58 fragments from a series of 29 consecutive patients, were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Two fragments were taken: the first just before the distal anastomosis; the second just before the last anastomosis on the aorta. The vein graft was kept in a finger solution of 10% nitroglycerin. Forced dilatation was avoided. The EM showed areas of early loss of the endothelial layer, not time-related, deposits of fibrin and blood corpuscular elements with muscular contraction in 75% of the examined grafts. From our experience and according to the literature, loss of the endothelial layer, spasm and early platelet and fibrin aggregation, are constant features of the explanted saphenous vein. In clinical practice, we emphasize, in addition to the "no touch technique", the early use of antiplatelet drugs during coronary artery by-pass coronary surgery.