Prophylaxis of Pulmonary Embolism

MASSIVE pulmonary embolism continues to be a frequent cause of death in the postoperative patient as well as in the patient hospitalized for nonsurgical illness. One author has estimated in a recent publication1that 47,000 patients die each year in the United States of pulmonary embolism. Vena cava ligation or one of its modifications, such as plication or compartmentation, have evolved as the most successful procedures in prevention of fatal emboli. However, such procedures require a major operation on a patient under general anesthesia who is often seriously or desperately ill from his underlying disease process. Such caval operations carry a mortality as high as 20% to 50% in several reported series,2and significant lower extremity edema in the survivors. This study was designed to test the hypothesis that an intracaval device capable of preventing passive pulmonary embolism might be constructed, which could be introduced into the inferior