[Reappearance of collateral vessels in patients with chronic total coronary occlusion]

The reappearance of collateral vessels in patients with subtotal coronary artery occlusion or chronic total coronary artery occlusion was investigated. In all patients, the target vessels revealed restenosis after initial percutaneous transluminal coronary angioplasty (PTCA), so a 2nd PTCA was performed for the same lesions. Each collateral vessel was evaluated before, during, and after PTCA by contralateral contrast injection during balloon inflation. Grading of collateral filling was as follows: 0 = none, 1 = filling of side branches only, 2 = partial filling of the epicardial segment, 3 = complete filling of the epicardial segment. Before the 1st PTCA, group A (n = 11) had subtotal occlusions (75-95%) at the target vessels, and group B (n = 8) had chronic total occlusions. Collateral vessels reappeared in all patients (100%) in group A, with good images. Reappearance of collateral vessels was good in 6 patients (75%) and poor in 2 (25%) in group B. Both the latter patients suffered from acute myocardial infarction. These results suggest that reappearance of collateral vessels may be relatively poor in chronic total occlusion patients, who may suffer from acute myocardial infarction due to acute coronary occlusion.