More Filters, More Problems in Distal Deep Vein Thromboses

Abstract

To determine the necessity, efficacy, and complication rates of inferior vena cava (IVC) filters for distal deep vein thrombosis (DVT). Vascular laboratory studies of patients who received an IVC filter for isolated, distal DVTs (anterior and posterior tibialis, peroneal, soleal, and gastrocnemius arteries) from April 2002 to January 2014 were retrospectively analyzed. A contemporary cohort of patients with isolated, distal DVTs without filters were used as controls. Of 647 patients who had an isolated distal DVT, 285 (44%) underwent an IVC filter insertion, while 362 (64%) underwent conservative treatment (surveillance and/or anticoagulation). Univariate and multivariate analyses were performed on abstracted data, which included demographics, risk factors, treatment modalities, thromboembolic events, and postoperative complications (ie, filter tilting >15 degrees, perforation >3 mm, fracture, migration). The incidence of pulmonary embolism was 2.5% in the IVC filter group and 3.3% in the control group (P = .27). The most common causes of contraindication to anticoagulation were bleeding (35%) or recent surgery (27%). Overall number of postoperative complications in the IVC filter group was 31 (10.8%). However, the IVC filter group was older (mean age, 65 vs 61 years; P = .004), more likely to have a history of thromboembolic events (56% vs 16%; P < .0001), and malignancy (49% vs 28%; P < .0001). Complication and thromboembolic rates did not differ for muscular (soleal, gastrocmenius) vs tibial DVTs (anterior, posterior, peroneal arteries). Of the conservative group, 179 (49%) patients were therapeutically anticoagulated with low complication rates of bleeding (<3%), and 107 (60%) of those patients had resolution of DVTs at subsequent surveillance study. Distal DVTs are associated with risk of thromboembolic events, which is reduced with therapeutic anticoagulation. When anticoagulation is contraindicated, IVC filters should be inserted with caution because of postoperative complications and relatively low risk of pulmonary embolism. Continued surveillance of distal DVTs should be considered when anticoagulation is not feasible.