Abstract
An one piece diaphragm type transapical assist pump was developed. The pump consists of an inflow Dacron graft, inflow polyvinylchloride (PVC) tube, inflow bovine pericardial xenograft, pump body, outflow bovine pericardial xenograft, outflow PVC tube and Dacron graft. The pump body is lined with polyurethane. The design provides a seamless blood chamber, free of the seam at the junction of the pump housing and the diaphragm, a known location of thrombus formation. One piece fabrication is achieved by dipping the diaphragm mold in polyurethane, placing the epoxy housing on the diaphragm mold, then dipping the pump housing diaphragm mold assembly. This process coats both surfaces and forms an air dried film completely lining the blood chamber. Maximum stroke volume of the pump is around 40ml. The pump was paracorporeally implanted in seven sheep. Sheep survived up to 14 days. Causes of termination were infection, pump rupture, bleeding and lung edema. Examination of the pump revealed tiny spotted thrombus in one pump and ringlike thrombus at the junction of the PVC tube and the pump body in two pumps. It can be concluded that one piece fabrication is effective for prevention of thrombus generation in the pump.
