Antiplatelet Therapy is Associated with Stent Patency After Iliocaval Venous Stenting

Purpose: To examine the effectiveness of antithrombotic medications to prevent venous stent malfunction for iliocaval occlusive disease. Materials and Methods: A retrospective analysis was performed on 62 patients who underwent technically successful endovascular iliocaval stent placement between May 2008 and April 2017. Clinical records were reviewed for demographic information, procedure details, post-stenting antithrombotic prophylaxis and stent patency on follow-up. Stent malfunction was defined as > 50% stenosis or occlusion at follow-up. Risk factors for stent malfunction were assessed with univariable and multiple Cox proportional hazard models. Results: The median follow-up period was 11.6 months (range 0.1–76.4). Overall primary and secondary cumulative patency rates at 12 months were 70.0% and 92.4%, respectively. After stent placement, 97% of patients received anticoagulation with warfarin, enoxaparin or a factor Xa inhibitor. In addition, 61% received antiplatelet prophylaxis with aspirin, clopidogrel or a combination. In multiple Cox regression analysis, post-stenting antiplatelet use remained significantly associated with primary stent patency (HR = 0.28, P = 0.022). Conclusion: After iliocaval venous stenting, stent patency was best predicted by concomitant antiplatelet and anticoagulation therapy rather than anticoagulation alone. This novel finding warrants further research underlying mechanisms leading to venous stent thrombosis, and has implications for optimal medical management after venous stenting.