Myocardial Revascularization of the Canine Circumflex Coronary Artery Using Retrograde Internal Mammary Artery Flow Without Cardiopulmonary Bypass

A new surgical technique using perfusion of the circumflex coronary artery with retrograde blood flow of the internal mammary artery (IMA) is described. This project was undertaken because the IMA is uniquely well supplied with blood: proximally through its attachment to the subclavian artery, along the sternum by the intercostal arteries to the aorta, and distally from the iliac artery by the epigastric and musculophrenic arteries.In this experimental study, the IMA in 16 dogs was ligated and divided at the subclavian artery, then dissected free down along the sternum to obtain sufficient length. The large subclavian end was then anastomosed to the circumflex coronary artery using a metal cannula technique to perfuse the circumflex bed while the anastomosis was being done. In all 16 dogs, the retrograde flow of the IMA was adequate to maintain the circumflex bed. It is postulated that this technique may have some limited use in man.