Total arterial coronary revascularization-patient selection, stenoses, conduits, targets

Abstract

Graft patency determines prognosis in coronary artery bypass grafting (CABG). Numerous reports over the past 20 years have documented superior patencies and prognosis when multiple arterial grafts are used, yet less than 10% of CABG have multiple arterial grafts. Several conduits have been proposed, with varying degrees of success. Saphenous vein grafts (SVG) begin to fail with intimal hypertrophy and then atheroma after 5 years, with patency rates of 50% to 60% at 10 years, and <30% at 15 years. In contrast, left internal thoracic artery (LITA) patency is >95% at 10 years and >90% at 20 years. The radial artery is extremely versatile and can reach all territories, but is muscular and vulnerable to spasm and competitive flow. Similarly, the right gastroepiploic artery is also muscular, and is best suited to the posterior descending coronary artery, especially in reoperations and is also affected by competitive flow. In addition, bilateral internal thoracic artery grafting (BITA) grafts and total arterial revascularization (TACR) can be performed with identical perioperative mortality (1%) and perioperative morbidity to LITA + SVG. Importantly, survival is superior-85% to 90% at 10 years versus 75% to 80% respectively. BITA/TACR patients also suffer fewer late cardiac events and reoperations, with superior results for older patients, those requiring urgent surgery, diabetics, patients with renal dysfunction and in reoperations. Contraindications to BITA include obesity, insulin dependent diabetics, and severe chronic obstructive airways disease. As such, arterial grafts have better patencies and clinical results. BITA/TACR is often underutilized, but can be achieved in the majority of patients. Opportunities exist to enhance BITA/TACR use in CABG to the potential benefit of our patients.

Keywords: Coronary artery bypass graft; conduits; internal thoracic artery; patient selection.