Vacuum assisted cardiopulmonary bypass in minimally invasive cardiac surgery: Its feasibility and effects on hemolysis

The present study describes a cardiopulmonary bypass (CPB) technique that i ncorporates vacuum assisted venous drainage and arterial return using a cen trifugal pump in minimally invasive cardiac surgery (MICS). The technique w as performed on 40 patients scheduled to undergo MICS. The proposed CPB tec hnique enables a good operative field to be obtained even through a limited incision through the use of peripheral cannulation using small cannulae. V acuum pressure was applied to the venous reservoir (-43 +/- 14 mm Hg) to ma intain adequate CPB flow (> 2.4 L x min(-1) x M-2). The effects of CPB on h emolysis were subsequently compared between patients who underwent the prop osed procedure (MICS group; n = 6) and a control group who underwent corona ry arterial bypass grafting (CABG group; n = 6) with conventional CPB. Plas ma free hemoglobin (FHb) increased and plasma haptoglobin (Hp) decreased du ring CPB in both groups, with no significant difference between the groups. By the next day, FHb had returned to pre-CPB levels whereas Hp remained lo wer in both groups. Again, these values did not differ significantly betwee n groups. Thus, we conclude that the proposed CPB technique is useful in MI CS with acceptable effects on hemolysis.