Thrombus formation and microaggregate removal during prolonged extracorporeal circulation using a capillary membrane oxygenator. A scanning electron microscope study.

Despite adequate heparinization, thrombus formation occurs at the blood/foreign material interface. Depending on the part of the device, the material and the blood flow, the amount and the components of thrombi vary greatly. This is not dangerous by itself but clots can be expelled downstream and damage the lungs, brain, kidney and retina. Interposition of a filter may prevent risks of embolization. The present paper reports the scanning electron microscope study carried out on the Awad oxygenator after use during prolonged extracorporeal circulation on 13 dogs. No filter has been inserted in the circuit for the first six experiments. A screen filter (4) or a polyurethane foam filter (3) was employed in the following ones.