Evaluation of Closed Cardiopulmonary Bypass Circuit for Aortic Valve Replacement

Since 2005, we have used a novel technique based on the closed cardiopulmonary bypass system without cardiotomy suction (minimal cardiopulmonary bypass mini-CPB) for aortic valve replacement (AVR). In this study, we investigated the clinical advantages of this approach. We prospectively studied 32 patients who underwent isolated AVR using the mini-CPB (group M, n 13) or conventional CPB (group C, n 19). We compared the hemodilution ratio, serum interleukin (IL)-6 and IL-8 levels, and blood transfusion volume between the two groups. The characteristics, duration of CPB, and aortic cross-clamping time did not differ between the two groups. The hemodilution ratio was significantly lower in group M just after starting CPB (M vs.C: 14% ± 2% vs.25% ± 3%, p0.0009). IL-6 levels increased significantly after surgery in both groups, but the postoperative levels were significantly lower in group M at 6 (84.9 ± 24.9 pg/ml vs.152 ± 78 pg/ml, p0.042) and 12 (72.7 ± 36.1 pg/ml vs.123 ± 49.6 pg/ml, p0.029) hours after CPB. There were no differences in IL-8 or blood transfusion volume after CPB. Mini-CPB offers an alternative to conventional CPB for AVR and has some advantages regarding hemodilution and serum IL-6 levels. However, it is unlikely to become the standard approach for AVR because there are no marked clinical advantages of mini-CPB.