RISK AND RESULTS OF BYPASS-GRAFTING USING BILATERAL INTERNAL MAMMARY AND RIGHT GASTROEPIPLOIC ARTERIES

From January 1990 to June 1994, 240 patients (mean age, 60 +/- 10 years) underwent myocardial revascularization with the exclusive use of in situ bilateral internal mammary and right gastroepiploic arteries. Left ventricular function was normal in 34% of patients, moderately impaired in 58.5%, and severely impaired in 7.5%. The mean number of distal anastomoses was 3.5 +/- 0.7 and the rate of complete myocardial revascularization was 80%. Early mortality was 0.4%, and complications occured in 20 patients: myocardial infarction, 1.6%; intraaortic balloon pump, 0.8%; reoperation for bleeding, 0.8%; and mediastinitis, 0.4%. Early (15th postoperative day) angiographic control of grafts was performed in 51 patients; the rate of functional and patent anastomoses was 100% for internal mammary arteries and 96% for gastroepiploic arteries. Early functional results (3 +/- 1 postoperative months) were studied in 141 patients during exercise test with medical treatment: 99% were symptom-free and 14% had ischemic modification of electrocardiograms. A 2-year postoperative functional assessment without medical treatment was performed during exercise test in 66 patients: 98% were symptom-free and 26% had ischemic modification of electrocardiograms; during the same procedure, thallium myocardial scintigraphy was obtained in 50 patients and 18 patients had moderate ischemic defect on exercise, Ischemic modifications of electrocardiograms and defects seen on thallium scintigraphy were correlated significantly with incomplete revascularization (p < 0.05). Ischemic defects seen on thallium scintigraphy demonstrated limited gastroepiploic artery and right internal mammary artery now at the maximum level of exercise in at least 8% and 4% of patients, respectively. The 2-year and 4-year actuarial survival was 96.5% +/- 4.2%; the rate of late cardiac events was 0.6% per patient-year. This technique can be achieved with minimal operative risk and offers good functional results and midterm survival rate.