Massive thrombosis of the superior mesenteric, splenic, and portal veins. Report of a case.

A 19-year-old previously healthy youth developed a deep venous thrombosis and a pulmonary embolism in connection with rupture of a ligament of the left ankle. Two months later, while on effective (thrombotest value 21%) oral anticoagulant therapy, the patient had massive thrombosis of the superior mesenteric splenic and portal veins and died. There was no known predisposition to thrombosis, such as tumour, infection, or trauma. A later examination of a 12-year-old brother revealed decreased fibrinolytic activity in the vessel wall as well as a decreased fibrinolytic response to venous occlusion. Since decreased fibrinolytic activity in the vessel wall is sometimes familial, it seems reasonable to suspect that the same defect might have occurred in the patient with the fatal massive thromboembolic disease.