Pulmonary embolism is now the commonest single cause of death following major surgical procedures. Bell and associates1 reported 51 deaths in 901 patients who had had operations for cancer of the colon or rectum. Eighteen, or about One-third of these deaths, were attributed to pulmonary embolism. Three of the ten deaths in Hughes'2 series of 227 combined synchronous abdominal-perineal resections of the rectum were due to pulmonary embolism, and other reports confirm the finding that about one-third of the postoperative deaths in major surgery are a direct result of this distressing complication.
We3 believe that venous stasis in the lower extremities is the prime factor in venous thrombosis and subsequent pulmonary embolism. This led us to a study of the pump mechanism, or "peripheral venous heart," in the calf muscles with the hope of finding a means to control venous stasis.
It is still unsettled whether thrombi arise more commonly