Angiographic Changes in Internal Mammary Artery and Saphenous Vein Grafts, Two Weeks, One Year and Five Years after Coronary Bypass Surgery

Abstract

Coronary angiography was performed two weeks after coronary bypass surgery on 112/121 consecutive operative survivors (93%), on 97/119 one-year survivors (82%) and on 79/108 five-year survivors (73%). Occlusions of the grafts were uncommon after the first year. The cumulative five-year patency, calculated with the actuarial method, was 89% for internal mammary artery (IMA) grafts and 77% for aortocoronary saphenous vein (SV) grafts. Almost 70% of the SV grafts exhibited a 15-50% reduced diameter after one year and 10% showed progressive narrowing at five years. Diffuse luminal narrowing did not predict graft failure. The incidence of localized narrowings present at two weeks after surgery was, however, significantly higher among SV grafts, which occluded within one year, than among those patent after five years. In 5% of the IMA grafts the diameter was reduced 15-80% after five years. This was related either to obstruction at the anastomotic site or to low-grade proximal coronary stenosis. No less than 12% of the IMA grafts increased 20-50% in diameter as an adaptation to good distal runoff.

Angiotensin II and IGF-1 Regulate Connexin43 Expression Via ERK and p38 Signaling Pathways in Vascular Smooth Muscle Cells of Coronary Artery Bypass Conduits

“…In most cases, CABG is performed with autologous saphenous vein (SV) or internal mammary artery (IMA) [2]. Unfortunately, vein grafts have a greater incidence of restenosis than their arterial counterparts due to intimal hyperplasia that results in failure rates of 20% and 50% at 5 y and 10 y, respectively [3,4]. Vascular smooth muscle cell (VSMC) proliferation and migration play an important role in intimal thickening in atherosclerosis and restenosis and influence the long-term patency of venous grafts [5].…”

Atresia of internal thoracic artery grafts following placement to noncritically obstructed vessels

“…Atresia of ITA grafts (the so-called ''string sign'') has been previously described [1][2][3]. Bjork et al [1] performed follow-up angiography 2 wk, 1 yr, and 5 yr following bypass surgery in 99 patients who had received an ITA graft.…”

“…Bjork et al [1] performed follow-up angiography 2 wk, 1 yr, and 5 yr following bypass surgery in 99 patients who had received an ITA graft. They observed that grafting noncritically obstructed vessels, postoperative ''regression,'' and technical factors involving the coronary anastomosis were the major factors in reduction of ITA graft diameters.…”

Disturbed Endothelial Function of the Internal Thoracic Artery in Patients with Coronary Artery Disease

“…The low incidence of atherosclerosis and the deccelerated development of stenoses are major reasons for the superiority of ITA grafts [3][4][5]. Furthermore, ITA grafts resemble ''live conduits'' with maintained ability of autoregulation in contrast to venous autografts [6][7][8][9][10][11][12].…”