[The risk of lung emolism in isolated thrombosis of the V. saphena magna].

Within 1 1/2 years we have seen 4 pulmonary emboli, one of which was fatal. The origin was an isolated thrombophlebitis of the great saphenous vein. An autopsy, with dissection of the veins of the legs and of the pelvis, and phlebographies where there is any doubt of deep venous thrombosis, allow us to speak of isolated thrombosis of the great saphenous vein. The clinical level is always lower than the real level and the thrombus can grow through the saphenofemoral junction. The conservative treatment (anticoagulation and mobilisation) do not prevent a cranial ascension of the thrombus nor a pulmonary embolism. So, when the thrombosis is higher than the knee, we do a crossectomy of the great saphenous vein. We did this operation 8 times without complications.