Immediate postoperative recovery of regional wall motion after unilateral and bilateral internal mammary artery revascularization.

Abstract

Within the last few years the importance of the internal mammary artery (IMA) for coronary revascularization has increased rapidly. Although there is no doubt about the superior long-term patency of this artery in comparison to saphenous vein grafts, the discussion about early postoperative results is controversial. The aim of the present study was to assess segmental wall motion after unilateral and bilateral IMA revascularization. Thirty-three patients who underwent elective myocardial revascularization were examined. In addition to vein grafts, bilateral IMA grafts were used in 8 patients and unilateral ones in 25 patients. Myocardial segmental wall motion was assessed by transesophageal echocardiography perioperatively. Myocardial protection was achieved by standard cold blood cardioplegia. Global left ventricular function remained unchanged postoperatively (4 h) in both groups (unilateral IMA: 52.8% +/- 7.1% vs 49.8% +/- 11.1%; bilateral IMA; 47.7% +/- 8.7% vs 48.7% +/- 7.7%, ns). Anterior wall motion (left IMA grafts to left anterior descending artery (LAD) was decreased early postoperatively (30 min) in both groups (unilateral IMA: 50.9% +/- 15.3% vs 37.8% +/- 14.5%; bilateral IMA: 47.3% +/- 20.1% vs 30.4% +/- 8.5%, P < 0.05). Posterior wall motion was decreased in the bilateral IMA group (right IMA to right coronary artery (RCA), 47.8% +/- 7.2% vs 28.0% +/- 8.9%, P < 0.05) and remained unchanged in the unilateral IMA patients (vein grafts to RCA, 39.5% +/- 9.9% vs 41.4% +/- 17.5%, ns). Internal mammary artery revascularization may result in deterioration of segmental myocardial function in the early (< 4 h) postoperative period. Bilateral IMA grafts should therefore be used with caution in patients with impaired ventricular function.