Fewer than 10 days of low-molecular-weight heparin (LMWH) after stenting for extensive iliofemoral venous occlusion prior to transition to oral anticoagulation reduces early thrombosis, according to a multicenter study.
Thrombosis following iliofemoral venous stenting is frustrating to both the patient and clinician and is an understudied phenomenon, according to a study in the November issue of the Journal of Vascular Surgery: Venous and Lymphatic Disorders.
“Most reported data describing stent occlusion after venous intervention have included patients across the full spectrum of venous disease. Including patients with non-thrombotic disease and limited anatomic involvement as well as patients with more extensive disease has prevented the identification of specific variables relating to the outcomes for either group of patients separately,” said principal investigator William Marston, MD, chief in the division of vascular surgery the University of North Carolina in Chapel Hill, North Carolina.
“In this study, we investigated a patient cohort with venous outflow occlusion requiring recanalization before stenting to determine the outcomes after intervention. We focused on the variables associated with early stent thrombosis in this high-risk segment of patients presenting with iliocaval outflow obstruction,” he continued.
Marston’s team retrospectively studied patients undergoing iliofemoral venous stenting at their institution (11 practitioners, two hospitals) from 2010 to 2020. Some 106 patients with type III (single segment) and type IV (multiple segment) iliofemoral venous occlusions were included.
Three months following the procedure, occlusion of the stented region occurred in 26%. The observed three-year patency rates were primary, 59%, and secondary, 76%. Risk factors for early (within three months) stent thrombosis were type IV disease (odds ratio 4.6) and hypercoaguable state (odds ratio 3.8). Treatment with LMWH for >10 days was associated with lower odds (0.01) of early thrombosis.
“Patients with more extensive disease (type IV) experienced a greater incidence of thrombosis,” said Marston. “Therefore, studies that group non-thrombotic with post-thrombotic patients who have undergone stenting will be less able to identify the best treatment protocols. No consensus has been reached regarding the optimal postoperative anticoagulation therapy for these patients. Our study suggests that extended use of LMWH reduces early thrombosis.”