A COMPARISON OF EARLY MORTALITY AND MORBIDITY AFTER SINGLE AND BILATERAL INTERNAL MAMMARY ARTERY GRAFTING WITH THE FREE RIGHT INTERNAL MAMMARY ARTERY

Objective-To compare differences in early mortality and morbidity in p atients receiving a single internal mammary artery graft (SIMA) with t hose receiving bilateral internal mammary artery grafts (BIMA) with a free right internal mammary artery (RIMA). Design-Retrospective analys is of 150 patients undergoing BIMA grafting between 1989-1992 who were carefully matched with 150 patients undergoing SIMA grafting between 1987-1992 for known cardiovascular risk factors, extent of coronary di sease, left ventricular function, and number of coronary grafts. Opera tive variables noted included aortic cross clamp time and bypass time. Postoperative cardiac, respiratory, and wound complications were also noted. Results-Operative mortality was 2% in the SIMA group and 1.3% in the BIMA group (NS). Other than the prevalence of ventricular arrhy thmias (P = 0.025), which were more common in the BIMA group, there we re no significant differences between the two groups in terms of posto perative morbidity. At median (interquartile range) follow up of 27.94 (0.86) and 23.94(0.74) months for the SIMA and BIMA groups respectivel y there were no deaths. 87% of the SIMA group and 91% of the BIMA grou p were free of symptoms at follow up. Conclusions-The earlier fears re garding increased early mortality and morbidity after BIMA surgery wer e not confirmed by this study. All patients receiving both mammary art eries had a free rather than pedicle right internal mammary graft. The early mortality and morbidity reported here compares favourably with previous reports on the use of a pedicle graft.