Free-floating deep venous thrombosis. A retrospective analysis.

Duplex scan to diagnose deep venous thrombosis is an established technique. As experience accumulated, patients with free-floating thrombi were identified. A retrospective review of 65 patients was performed to study these thrombi, to evaluate treatment regimens, and to analyze patient outcome. A 26% incidence of pulmonary embolus occurred. However patients who had bilateral free-floating thrombi had a 42.8% incidence of pulmonary embolus. Receiving a 7-day course of heparin therapy with a partial thromboplastin time (PTT) at 1.5 times control was 53.2% of patients; 55.4% of the patients underwent follow-up examination, and the mean time to clot attachment was 9.2 days. Patients should receive anticoagulation for 10 days or until clot attachment. Patients with persistent, bilateral free-floating thrombi, or propagation of thrombus are candidates for potential caval interruption. Serial scans should be performed to monitor the thrombus for attachment or alteration.