Feasibility of a new hollow fiber silicone membrane oxygenator for long-term ECMO application

Currently in United States, there are no clinically-applicable hollow fiber extracorporeal membrane oxygenation (ECMO) oxygenators available. Therefore, our laboratory is in the process of developing a silicone hollow fiber membrane oxygenator for long-term ECMO usage. This oxygenator incorporates an ultrathin silicone hollow fiber. At this time, a specially-modified blood flow distributor (one chamber distributor) is centered in the module to prevent blood stagnation. An ex vivo long-term durability test for ECMO was performed using a healthy miniature calf for 2 weeks. Venous blood was drained from the left jugular vein of a calf, passed through the oxygenator and infused into the left carotid artery using a Gyro C1E3 centrifugal blood pump. A successful 2-week ex vivo experiment was performed. The O2 and CO2 gas transfer rates were maintained at the same value of 40 m/min at a blood flow rate of 1 L/min flow and V/Q=3 (V=gas flow rate; Q=blood flow rate). The plasma free hemoglobin was maintained around 5 mg/dl. After the experiment, no blood clot formation was observed in the module and no abnormal necropsy findings were found. These data suggest that the performance of this newly-improved oxygenator was stable, reliable, and acceptable for long-term ECMO.