Surgical considerations in bypassing coronary arteries with 100% proximal occlusion

Abstract

Objective data on the ability of cineangiography to predict the size of reconstituted totally occluded coronary arteries, as well as the clinical outcome of such revascularization, are sparse. Accordingly, we reviewed 200 consecutive cases of coronary revascularization to determine the answers to these questions. Group I patients (n = 57, with 86 totally occluded coronary arteries) had at least one coronary artery with a 100% proximal occlusion that reconstituted distally. Group II patients (n = 143, with 205 subtotally occluded coronary arteries) had 50% to 99% proximal stenosis of at least one coronary artery. Cineangiograms were blindly reviewed to measure the size of the coronary arteries, which were compared with the actual vessel size at operation. In group I, the totally occluded coronary arteries had a cineangiographic size of 1.9 ± 0.7 mm and an actual size of 1.6 ± 0.4 mm ( p = 0.00004). In group II, the subtotally occluded coronary arteries had a cineangiographic size of 1.8 ± 0.4 mm compared with an actual size of 1.8 ± 0.3 mm ( p = not significant). The site of bypass grafting was significantly smaller in group I (1.6 ± 0.4 mm versus 1.8 ± 0.3 mm; p = 0.00008). The two groups were similar with respect to preoperative and intraoperative parameters. Operative mortalities were similar (group I, 1.8%; group II, 3.5%; p = 0.68). Creatine kinase isoenzyme profiles and electrocardiographic changes were similar, except for a significant late rise of creatine kinase-MB in group I (56.1 ± 14.7 versus 30.7 ± 33.7 MIU/mL; p < 0.001). In conclusion, cineangiography significantly overestimates the size of totally occluded coronary arteries. The site of bypass in totally occluded coronary arteries is significantly smaller than in subtotally occluded arteries, and may result in an increased incidence of early graft closure, accounting for the late rise in creatine kinase-MB.