Isolated gastrocnemius and soleal vein thrombosis: should these patients receive therapeutic anticoagulation?

OBJECTIVE: To determine the incidence of isolated gastrocnemius and soleal vein thrombosis (IGSVT) and the effect of anticoagulation on venous thromboembolism (VTE) events in patients with IGSVT.

SUMMARY BACKGROUND DATA: Although IGSVT is diagnosed with increasing frequency, the clinical significance and optimal management remains unknown.

METHODS: Vascular laboratory studies from April 2002 to April 2007 were retrospectively reviewed to identify patients with IGSVT. Medical records were reviewed for demographic data, risk factors, treatment modalities, and VTE events. Univariate and multivariate analysis were performed.

RESULTS: Of 38,426 lower extremity venous duplex studies, 406 patients with IGSVT were included in this study. Mean follow-up was 7.5 +/- 11 months. The overall incidence of VTE among the entire cohort was 18.7%, which included 3.9% pulmonary embolism and 16.3% deep venous thrombosis, with 1.5% of patients having both pulmonary embolism and deep venous thrombosis. However, the incidence of VTE was 30% (36/119) and 27% (13/48) in patients who received no or prophylactic anticoagulation, respectively, but only 12% in patients treated with therapeutic anticoagulation (23/188; P = 0.0003). Multivariate analysis identified lack of therapeutic anticoagulation (P = 0.017) and history of VTE (P = 0.011) as independent predictors of subsequent VTE development. The rate of IGSVT resolution during follow up was 61.2% with therapeutic anticoagulation, but only 40.0% and 41.0% with prophylactic or no anticoagulation, respectively (P = 0.003).

CONCLUSIONS: IGSVT is associated with a clinically significant rate of VTE which is dramatically reduced with therapeutic anticoagulation. These data warrant further investigation, taking into account the risks and benefits of anticoagulation.