INTIMA-ADVENTITIA APPOSITION IN END-TO-SIDE ARTERIAL ANASTOMOSIS - ANEXPERIMENTAL-STUDY IN THE PIG

Background. To prevent ischemic complications during coronary bypass g rafting on the beating heart, a nonocclusive distal anastomosis techni que is needed. One recently developed nonocclusive technique requires apposition of the intima of the graft to the adventitia of the recipie nt artery, in contrast to current surgical;practice, which dictates ap position of both intimas. Methods. To compare the sole effect of intim a-adventitia apposition (n = 18) versus traditional intima-intima appo sition (n = 18), we investigated radiolabeled platelet deposition and histomorphologic aspects of vascular wall healing quantitatively in a porcine carotid artery bypass graft model. Both groups were evaluated at 2 hours, 2 days, or 4 weeks. Results. Within the first 2 hours, 3 o f 6 pigs with intima-adventitia apposition exhibited cyclic flow reduc tions as a result of massive mural thrombosis. After intima-adventitia apposition, the number of deposited platelets was significantly highe r compared with intima-intima apposition, 147.1 +/- 73.0 x 10(6) and 4 .6 +/- 1.0 x 10(6) platelets/cm(2) (mean +/- standard error of the mea n), respectively (p = 0.03). At 2 days, the suture line was covered wi th Small mural thrombi, whereas no thrombi were found after intima-int ima apposition. At 4 weeks, intimal hyperplasia at heel and toe was no t significantly different from that with intima-intima apposition. Con clusions. Despite thrombotic phenomena in the early phase, intima-adve ntitia apposition yielded a patent anastomosis with a small intimal hy perplasia response. (C) 1998 by The Society of Thoracic Surgeons.