%0 Journal Article
%T A Systematic Review of the Utility of Residual Vein Obstruction Studies in Primary and Secondary Venous Thrombosis
%A Murali Janakiram
%A Matthew Sullivan
%A Marina Shcherba
%A Shuang Guo
%A Henny H. Billett
%J Thrombosis
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/247913
%X Background. Residual vein obstruction (RVO), the persistence of venous thrombosis with time and often after anticoagulation, may indicate a systemic prothrombotic condition. Prior studies have shown varying efficacy in using RVO as a risk factor for future venous thromboembolic (VTE) recurrence. Methods. To assess whether positive RVO imaging predicts recurrent VTE events, we performed a meta-analysis on studies in which patients with documented VTEs, anticoagulated for a minimum of 4 weeks, had repeat sonography to assess RVO and were subsequently followed for recurrent events. Results. Thirteen studies met inclusion criteria: 3531 patient VTE events with 3474 evaluable results were analyzed. The presence of RVO was associated with recurrence in all VTE (OR 1.93; 95% CI: 1.29, 2.89) and secondary VTE (OR 2.78; 95% CI: 1.41, 5.5) but not for primary VTE (OR 1.35; 95% CI: 0.87, 2.08). When cancer patients were eliminated from the secondary VTE group, there was no longer a significant association of RVO with VTE recurrence (OR 1.73; 95% CI: 0.81, 3.67) while in the subset of cancer patients, presence of RVO was associated with an increase in VTE recurrence risk (OR 5.14; 95% CI: 1.59, 16.65, ). Conclusions. We conclude that the presence of RVO is associated with recurrence in secondary VTE but not in primary VTE and that association may be driven by the subset with cancer. 1. Background Venous thromboembolism (VTE) is a common disease and long-term anticoagulation is effective in the prevention of recurrent deep venous thrombosis (DVT) and pulmonary embolism (PE). But anticoagulation is associated with bleeding complications necessitating a continuous assessment of bleeding risk versus recurrent thrombosis risk. Recent guidelines suggest that primary (unprovoked) VTE should be anticoagulated for 3 months and be evaluated for lifelong anticoagulation, whereas only 3-month anticoagulation is recommended for secondary (provoked) VTE [1¨C5]. In order to predict who will recur at the end of 3 months after a period of anticoagulation, clinical decision rules and laboratory surrogate markers have been developed. Current markers, however, are poor in predicting individual recurrence risk and better surrogate tests are needed [6¨C10]. One such test is using the presence of residual vein obstruction (RVO), after completing the period of anticoagulation, as demonstrating increased recurrence risk. However, various investigators have used different definitions for RVO [11, 12] and different studies assessing the predictability of RVO have yielded different results.
%U http://www.hindawi.com/journals/thrombosis/2013/247913/