[Systematic research on an etiology in apparently primary deep venous thrombosis. Apropos of 59 cases].

Primary deep vein thrombosis was confirmed by phlebography in 59 cases between Jan. 1981 and Jan. 1984 in the department of Cardiovascular Surgery of the Academic Hospital of the V.U.B. Brussels. Investigations conducted in all patients included blood and urine analyses, chest radiography, electrocardiogram, gynecologic or urologic examinations and abdominal and pelvic ultrasound imaging. Findings demonstrated one or more risk factors in 92% of cases, the principal ones being obesity, a history of thromboemboli and, in women, the use of oral contraceptives. Nine patients had cancer and 4 of these received combined surgery-chemotherapy. All cases of so-called primary deep vein thrombosis should be investigated routinely for risk factors, because of the need and possibilities for treatment in some of them, particularly since procedures are non-invasive, of low cost, and easily performed during initial heparin therapy.