[Effects of the site of distal anastomosis on the branch flow of coronary arteries in an A-C bypass grafting].

Hemodynamics of coronary branch with retrograde blood flow of the host artery was examined in seven mongrel dogs, when the distal side of the graft was anastomosed at distal site to branching point in A-C bypass grafting. A Y-shaped tube was interposed to reconstruct coronary blood flow between the right carotid artery and the left anterior descending coronary artery (LAD), its one arm of Y was connected to proximal site of the branching point of the first diagonal artery (proximal anastomosis), and the other arm was connected to distal site of the branching point (distal anastomosis). After the LAD was ligated just distal to the bifurcation from the left main coronary artery, each arm was clamped in turn, and blood flow of the first diagonal branch was evaluated. Heart rate, left ventricular pressure and cardiac output (cardiac function), and blood pressure, flow and resistance of the interposed tube (bypass function) were not changed significantly in each arm clamped. The diagonal branch flow decreased from 11.2 +/- 2.7 ml/min (mean +/- S.D.) in proximal anastomosis to 10.3 +/- 3.1 ml/min in distal anastomosis with significant difference (P less than 0.05). The diagonal branch/bypass graft flow ratio decreased from 0.422 +/- 0.159 in proximal anastomosis to 0.395 +/- 0.160 in distal anastomosis with significant difference (p less than 0.05). The blood flow in systolic phase of the diagonal branch tended to increase in distal anastomosis as compared with proximal anastomosis. However, diastolic flow of the branch significantly decreased from 8.3 +/- 2.1 ml/min in proximal anastomosis to 7.1 +/- 2.2 ml/min in distal anastomosis (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)