A prospective follow-up study of acute deep venous thrombosis using colour duplex ultrasound, phlebography and venous occlusion plethysmography

To study the extent of deep venous thrombosis (DVT) and thrombus regression over time and to compare the results obtained with different diagnostic techniques.

A prospective follow-up study with repeated examinations during a 6-month period.

Patients studied at clinical vascular laboratories.

Forty patients hospitalised for acute DVT. Thirty-six of these completed the follow-up period.

The diagnosis of DVT was confirmed with phlebographic and/or ultrasonographic techniques. The patient were then re-examined with colour duplex ultrasound and venous occlusion plethysmography after one week, 3 months and 6 months and with phlebography after 1 week and 6 months. The extent of DVT and number of occluded segments were determined with phlebographic and ultrasonographic techniques. Venous occlusion plethysmography was used to evaluate the functional degree of outflow obstruction.

Colour duplex scanning at 3 months' and 6 months' follow-up showed that 55% and 74% of initially occlusive thrombi, respectively, were recanalized, with thrombus resolution occurring faster and more completely in those initially limited to popliteal and/or calf level. Discrepancies between phlebography and duplex scanning were found in 6% (26/441) of venous segments investigated by both methods, primarily concerning flow in the veins below the knee.

In comparison with phlebography, colour duplex scanning is an accurate method for evaluation and follow-up of patients with DVT. The non-invasive nature of colour duplex scanning makes this method extremely suitable for repeated studies and thus a potentially very valuable tool for both clinical and research studies of circulatory changes involved in acute and chronic DVT.