Long-term efficacy safety analysis of a woven nitinol venous stent for iliac vein obstruction.

Background: To assess long-term patency rates, clinical outcomes, and device-related adverse events associated with the use of a dedicated woven nitinol venous stent following venoplasty to treat patients with symptomatic iliac and femoral vein obstruction. Material and methods: This single-center, single-arm, observational study consisted of 25 patients with iliofemoral vein obstructions caused by residual thrombosis, non-thrombotic compression, or post-thrombotic stenosis. Lesions were treated with the blueflow Venous Stent, a closed-cell stent made of woven strands of Nitinol wire. Primary outcome measures were primary patency and sustained clinical success at 3 months while secondary clinical measures included the revised Venous Clinical Severity Score (rVCSS), Clinical, Etiological, Anatomical, and Pathophysiological (CEAP) classification, and the number of device-related adverse events through 60 months. Results: Primary patency was 94.7% and sustained clinical success was 76.5% at 3 months. Primary patency was 95.2% and 70% while sustained clinical success was 76.2% and 70% at 12 and 60 months. The mean rVCSS was 7.4 ± 4.0 at baseline, 5.3 ± 1.8 at 3 months, 4.6 ± 1.4 at 12 months, and 2.6 ± 0.9 at 60 months. CEAP classifications at baseline were predominantly C3 (52%) while 36%, 52%, and 40% of scores were C1-C2 at 3, 12, and 60 months. One device-related adverse event (i.e., in-stent restenosis) was reported resulting in reintervention. There were three patient deaths: two from the progression of metastatic cancer and one from a bicycle accident. Conclusions: This exploratory study demonstrated a primary patency rate of 94.7% and a clinical success rate of 76.2% at 3 months. Patency was 70% with a 65% reduction in the mean rVCSS score from baseline at 5 years (-5.2). The blueflow Venous Stent performed adequately with no safety concerns when used for its intended indication.