| Abstract: | Todate internal mammary artery (IMA) is routinely used in coronary artery bypass grafting even in elder patients. However in patients with poor left ventricular function use of the IMA is discussed controversely in Germany. Main arguments against IMA are an increased operation time, initially lower blood flow, higher rates of reoperation for bleeding and more perioperative complications. In this study we investigated use of the IMA in patients with poor left ventricular function (LVEF < 40%) compared to exclusively veingraft bypass surgery. 137 patients (105 m/32 f) suffering from coronary artery disease with reduced LVEF (12-40%) were randomized in the study. 67 patients received exclusively vein grafts (group I), 70 patients routinely obtained an IMA graft. Criteria used for evaluation of IMA graft were operation time, postoperative bleeding, need for catecholamines, requirement of intensive care, perioperative myocardial infarction and mortality. The number of distal anastomoses in each group was 3.1 (2-5). The operation time varied in compliance with the number of distal anastomoses, but there were no significant differences between both groups. Postoperative bleeding until the second postoperative day was 905 ml in group II versus 569 ml in group I; the difference was significant (p < 0.05). The need of catecholamines after operation and hemodynamic parameters were comparable in both groups, there were no significant differences. Intensive care was required for a mean of 1.6 days in both groups, postoperative ventilation was 5.8 hours in group I versus 7.9 hours in group II, differences not significant. Ischemia or myocardial infarction could be demonstrated in 2 patients of group I (3%) versus 4 patients of group II (5.7%). The differences between the groups were not significant. Cardiac low output syndromes without sights of myocardial infarction were apparent in 9 patients of group I (13.5%) versus 2 patients of group II (2.9%), this difference being significant (p < 0.05). Mortality after operation in both groups was higher than in patients with normal ventricular function, however the differences between the evaluated groups were not significant (5.9% in group I versus 4.3% in group II). Summarizing the above it can be concluded that patients with poor left ventricular function are at a higher risk when subjected to bypass operation; the use of IMA did not show any disadvantages in comparison to exclusively veingraft surgery, except of a higher perioperative bleeding risk. Due to better long term results IMA should be used routinely also in bypass-patients with poor left ventricular function. |
