Clinical experience with minimally invasive reoperative coronary bypass surgery.

Abstract

To minimize the risk of standard and reoperative coronary artery bypass, we developed a minimally invasive approach. In this study we have evaluated the effectiveness of this technique. Between April 1994 and September 1995, 12 men and 6 women, aged 55-84 years (mean, 69 years) with chronic stable angina (4) and recent post-myocardial infarction unstable angina (14), with left ventricular ejection fractions ranging 17-60% (mean 37%), underwent reoperative coronary artery bypass grafting using 7-cm mini-left and right anterior thoracotomy and subxiphoid incisions. Coronary artery anastomoses were carried out on beating hearts with local coronary occlusion. Ischemic preconditioning, beta and calcium channel blockers and the maintenance of mean arterial pressure at 75-80 mm Hg, were used as adjuncts for myocardial protection. The internal mammary artery was isolated under direct vision up to the second rib with excision of the fourth costal cartilage. Coronary artery target sites were the left anterior descending in 12, right coronary artery in 4, obtuse marginal in 3, posterior descending in 1 and diagonal branch in 1 patient. Arterial grafts (mammary, right gastroepiploic, radial), either as single or composite grafts, were used liberally. Preoperative risk factors included congestive heart failure (7), chronic renal insufficiency (5), second reoperation (2), third reoperation (1), cerebrovascular disease (5), prior angioplasty (8) and preoperative intra-aortic balloon pumping in two patients. There was no perioperative mortality with minimal morbidity. Twelve patients underwent patency study of the grafts 48-72 h postoperatively. Ten of the twelve grafts were patent; one internal mammary artery graft to the left anterior descending coronary artery (<1.5 mm) early in our series was occluded and one additional left internal mammary graft had a kink several centimeters away from the anastomosis, which was successfully opened by angioplasty. At a mean follow-up interval of 8 months all 16 surviving patients are in functional class I or II and all of them remain free of angina. In selected patients reoperative coronary artery bypass grafting can be performed with this minimally invasive approach with a low perioperative morbidity and mortality rate and satisfactory early graft patency rate with good symptomatic improvement.