[Double coronary revascularization using the internal mammary arteries. Mid-term results of 74 cases].

This study reports our experience of 74 multiple coronary artery bypass, using either the two internal mammary arteries (IMA) (43 cases), or the left internal mammary artery (LIMA), alone for sequential bypass (31 cases). Comparison with a series of 200 patients operated upon in a previous period (1981-83), when the LIMA was used alone for single bypass, showed that post-operative mortality, post-operative infarction and mediastinitis were significantly more frequent with double bypass using the two IMA; similarly, the mid-term results seemed to be less satisfactory with the double IMA bypass technique. This difference was due to the fact that using the right and left IMA means longer dissection time, greater problems of haemostasis, stronger surgical trauma and prolonged exposure of the sternum, which is a source of infection. In addition, the right internal mammary artery (RIMA) being further away from the sites of coronary grafting lends itself less readily than the LIMA to this type of bypass, and it is often used for the right and marginal coronary artery which is less suitable for surgery. Using the LIMA alone for sequential bypass does not seem to produce more complications than using that vessel for single bypass. On the basis of the results obtained, we consider that the double IMA bypass should only be used when the internal saphenous vein bypass is contraindicated (past history of stripping, varices, fragile aorta forewarning of difficult grafting).(ABSTRACT TRUNCATED AT 250 WORDS)