The partial occlusion of the inferior vena cava in the prevention of fatal pulmonary embolism has been used for years in different ways. Over a period of one, and a half year, we put 11 clips of Miles, once for prophylaxis and 10 times after pulmonary embolism. Two patients died during the first 15 postoperative days. Seven patients had a phlebologic control by a Doppler ultrasound, venous plethysmography, isotopic cavography, and grey scale ultrasound. It has been proved that the inferior vena cava was permeable in 6 of the 7 controlled patients. The indications as well as the late results of these operations are discussed.