POSTOPERATIVE SYMPTOMATIC INTERNAL THORACIC ARTERY-STENOSIS AND SUCCESSFUL TREATMENT WITH PTCA

From 1988 to 1992, 4,182 coronary bypass grafting procedures were perf ormed at the University of Ottawa Heart Institute. The left internal t horacic artery (ITA) was used in 2,913 patients, the right ITA in 79, and bilateral ITAs in 61 for a total of 3,053 patients with ITAs. This study assessed patients requiring angioplasty for symptomatic ITA ste nosis after operation. A total of 29 patients (0.95%) with a mean age of 55.3 +/- 1.9 years underwent angioplasty for ITA stenosis from 4 da ys to 34 months after operation (mean, 6.5 +/- 1.6 months). Internal t horacic artery stenosis was identified in 18 patients (62.1%) within 3 months after operation. Angina was present in 26 patients (89.7%), a positive stress test in 8 (27.6%), and myocardial infarction in 1 (3.4 %). At angiography, a total of 34 stenotic sites were identified in IT A grafts. Angioplasty was successful (<50% residual stenosis) in 31 si tes (91.2%). Follow-up was available for 28 of 29 patients (96.6%) at 24.6 +/- 2.3 months. Four patients (14.3%) returned with restenosis wi thin 3 months, 2 of whom had successful repeat angioplasty, and 1 requ ired reoperation. Canadian Cardiovascular Society anginal class after angioplasty was less than class II in 84.6% of patients. In conclusion , symptomatic postoperative ITA stenosis is uncommon, occurs most freq uently at the site of distal anastomosis, and generally presents withi n 3 months of operation. It may be safely and effectively treated with angioplasty with a low recurrence rate.