Results of coronary bypass surgery of the arteries with extended atherosclerotic abnormalities

Background: In multi-vessel atherosclerotic coronary artery disease, coronary artery bypass grafting remains the method of choice and allows for the best possible revascularization and maximal continuity of the results. Conduit functioning to a large extent depends on the coronary artery (CA) diameter and on the severity of atheromatous involvement and anatomic abnormalities of its walls. However, there is no consensus on what minimal diameter and extent of CA lesions could provide robust long-term results of bypass surgery. Consequently, surgical strategy for bypass grafting in diffuse coronary involvement and small vessel diameters has not been clearly defned.

Aim: To perform a comparative analysis of the bypass grafts functioning depending on CA anatomy and methods of revascularization.

Materials and methods: The study included 98 patients, who, irrespective of their clinical condition, had a control coronary angiography (CAG) with shuntography (SHG) between 6 months to 5 years after they had undergone direct myocardial revascularization by coronary artery bypass grafting. In total, 215 anastomoses were assessed. The bypassed CAs were divided into two groups according to their diameters and into two subgroups depending on the severity of the coronary vasculature involvement. When bypassing an artery with diffuse involvement, angioplastic anastomoses were done in 52.5% of the cases. Long-term graft functioning was assessed by shuntography.

Results: Conduit functioning after bypassing of CA >1.5 mm in diameter and with local CA narrowing did not depend on the graft type and was 95.1% for the internal thoracic artery (ITA) grafts and 90.1% for the great saphenous vein (GSV) grafts. With diffuse lesions, these values decreased to 68.4% for ITA and 69.1% for GSV (р < 0.05). Long-term revascularization results for coronary arteries with a diameter of ≤ 1.5 mm were signifcantly lower for all types of conduits: with local stenosis, 78.6% ITA and 68.4% GSV grafts were patent, whereas in diffuse coronary bed involvement, 50 and 33.3%, respectively (р < 0.05). After placement of an angioplastic anastomosis to the CA with diffuse lesions, 79.3% of the ITA and 69.2% of the GSV grafts were functioning, whereas after the use of the standard technique, such were 55.6 and 40%, respectively (р < 0.05).