Outpatient Surveillance Protocol of Isolated Calf Deep-Vein Thrombosis

Abstract

Objectives This study aims to compare the management of isolated soleal, gastrocnemius, peroneal, and posterior tibial vein thrombosis among outpatients with serial duplex ultrasound (DUS) over 30 days, versus anticoagulation. Methods After obtaining IRB approval, a retrospective chart review was conducted from January 2009 to December 2010. A total of 15, 877 lower extremity DUS were performed. Inpatients, trauma patients, and patients with thrombi in or proximal to the popliteal vein were excluded to focus exclusively on an unprovoked outpatient population. Univariate and multivariate analyses were conducted as well as descriptive statistics of the data. Results The cohort consists of one hundred sixty-eight (n = 168) outpatients with isolated calf deep vein thrombosis (ICDVT). Thrombus was most frequently identified in the soleal vein (45%) followed by the peroneal (39%), gastrocnemius (29%), and the posterior tibial vein (23%). Following diagnosis of ICDVT, thirty-eight patients (n = 38) received anticoagulation. The remaining cohort (n = 130) underwent surveillance with serial DUS at 3, 10, and 30 days. Eleven percent (11%) propagated to the popliteal vein or proximally during surveillance, versus 8% following anticoagulation. Among those that propagated proximally, 85% propagated within two weeks of initial diagnosis. Proximal propagation ( p = 0.8328), pulmonary embolism ( p = 0.0537), and development of new thrombus in additional calf veins ( p = 0.1471) did not differ among those treated with anticoagulation or serial DUS. Conclusions Serial DUS without anticoagulation is safe management of ICDVT in unprovoked ambulatory outpatients.