title: A systematic review of the utility of residual vein obstruction studies in primary and secondary venous thrombosis.
abstract: 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, P < 0.006). 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.
authors.affiliation: Division of Hematology, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA ; Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA.
authors.forename: Murali
authors.initials: M
authors.lastname: Janakiram
authors.affiliation: Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Sullivan
authors.affiliation: Division of Hematology, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA ; Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA.
authors.forename: Marina
authors.initials: M
authors.lastname: Shcherba
authors.affiliation: Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA.
authors.forename: Shuang
authors.initials: S
authors.lastname: Guo
authors.affiliation: Division of Hematology, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA ; Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, 3411 Wayne Avenue, Ground Floor, Bronx, NY 10467, USA.
authors.forename: Henny H
authors.initials: HH
authors.lastname: Billett