Clinical Evaluation of New-generation Oxygenators With Integrated Arterial-line Filters For Cardiopulmonary Bypass

Objectives: New-generation oxygenators with integrated arterial-line filters have been marketed to improve the efficacy of cardiopulmonary bypass (CPB). Differences in designs, materials, coating surfaces, pore size of arterial filter and static prime exist between the oxygenators. Despite abundant preclinical data, literature lacks clinical studies. Methods: From September 2010 to March 2011, 80 consecutive patients undergoing aortic valve replacement were randomized to CPB using Terumo- CapioxFX25 (40 patients, Group-T) or Sorin-Synthesis (40 patients, Group-S) oxygenators. Pressure drop and gas-exchange efficacy were registered during CPB. Fluid balance, ACT, INR, aPTT, fibrinogen, platelets, serum-albumin, total proteins, white blood cells (WBC), high-sensitivity C-reactive protein (hsPCR) were measured after anesthetic induction(T0), at CPB-start(T1), before CPB-discontinuation(T2), at ITU-arrival(T3), 3-hours (T4) and 24-hours (T5) postoperatively. The clinical outcome was recorded. Repeated ANOVA measure and non-parametric statistics assessed between-groups and during time differences. Results: The two groups showed similar baseline and intraoperative variables. No differences were recorded in pressure drop, gas-exchange and acid-balance (p=N.S. for all) during CPB. Despite similar fluid balance (between-groups p=.979), Group-T showed lower serum-albumin (between-groups p=.014), total proteins (between-groups p=.0001), fibrinogen (p≤.004 at T4 and T5), platelets (between-groups p=.021), with higher INR (p≤.005 at T4 and T5), aPTT (between-groups p=.0001), hsPCR (between-groups p=.034), WBC (p=.003 at T5). Group-T also showed higher postoperative bleeding (p=.038) and need for transfusions (p=.0001). However, clinical outcome was comparable (p=N.S. for all clinical end-points). Conclusions: Both oxygenators proved to be effective and resulted incomparable clinical outcome. However, Sorin-Synthesis seems to better preserve coagulative cascade and serum proteins, resulting in lower transfusions and post-CPB inflammatory response.