CORONARY-ARTERY BYPASS-GRAFTING WITHOUT CARDIOPULMONARY BYPASS AND WITHOUT INTERRUPTION OF NATIVE CORONARY FLOW USING A NOVEL ANASTOMOSIS SITE RESTRAINING DEVICE (OCTOPUS)

Objective. This study assessed the feasibility of coronary artery bypa ss grafting on the beating heart without interruption of native corona ry blood flow using a novel anastomosis site restraining device. Backg round. Recently, an end-to-side bypass technique was described that do es not require interruption of flow in the recipient artery. Methods. By means of a suction device (''Octopus''), in 31 pigs the epicardium was grasped and immobilized through an arm contraption fixed to the op erating table. In the first 15 consecutive pigs (study I), the two-dim ensional motion of an epicardial beacon was monitored. In 16 subsequen t pigs (study II), an internal mammary artery was grafted under the mi croscope in two steps to a proximal coronary artery segment, without c ardiopulmonary bypass. First, the internal mammary artery was sutured end-to-side to the outside of the coronary artery. Secondly, an orific e was punched in the partitioning coronary wall by an excimer laser ca theter introduced through a temporary side-branch of the internal mamm ary artery. Results. Study II: During 43 suction periods in four anast omosis areas, immobilization,was achieved for 15 to 169 min (>30 h in total) in 13 open- and 9 closed-chest procedures without hemodynamic d eterioration, The area circumscribed by the edges of the beacon trajec tory (area in which the anastomosis is to be tracked) was reduced from 73.0 +/- 43.0 mm(2) (mean +/- SD) to 1.3 +/- 0.5 mm(2) (p < 0.001) in the open-chest and to 0.2 +/- 0.2 mm(2) in the closed-chest procedure . At 6 weeks, no myocardial or coronary suction lesions were found. St udy II: Nonocclusive anastomosis surgery required 25 +/- 3 min. No lea kage, serious arrhythmias, graft closure or hemodynamic deterioration occurred during the procedure or for 2 h after ligating the coronary a rtery proximally. At 6 weeks, all seven grafts were patent. Conclusion s. Coronary bypass on the beating heart without interruption of corona ry how is feasible. In both open- and in closed-chest procedures, the ''Octopus'' reduced anastomosis site motion to about 1 x 1 mm without adverse consequences.