Braided or laser-cut self-expanding nitinol stents for the common femoral vein in patients with post-thrombotic syndrome

Background: Chronic obstruction of the common femoral vein in patients with post-thrombotic syndrome after iliofemoral or iliocaval deep vein thrombosis has remained a challenge for endovascular treatment. The patency rates and clinical outcomes of laser-cut and braided nitinol stents extending to the common femoral vein have not yet been studied. Methods: From the Swiss and Arnsberg Venous Stent Registries, we included 150 patients with post-thrombotic syndrome (mean age, 44 +/- 16 years; 48% women) with laser-cut (n = 101) or braided nitinol (n = 49) stents placed into the common femoral vein across the inguinal ligament. Routine follow-up included duplex ultrasound examinations and assessment of clinical scores. The primary study outcomes were the primary and secondary patency rates at 12 months. Results: Overall, the mean number of implanted stents was 2.6 +/- 1.7. The proximal stent landing zone was the inferior vena cava in 32 patients (21%), the iliac vein in 106 patients (76%), and the common femoral vein in 5 patients (3%). The primary patency rate was 67.3%(95% confidence interval [CI], 58.0%-76.6%) in the laser-cut group and 86.7%(95% CI, 75.3%-98.1%) in the braided stent group (log-rank, P = .016). The corresponding secondary patency rates were 93.9%(95% CI, 89.2%-98.6%) and 100% (log-rank, P = .10). The median improvement in the Villalta score from baseline to the latest follow-up was 4 points (interquartile range, 2-6 points), without significant differences between the two groups. Symptomatic common femoral vein stent fractures were observed in four patients (4%) with laser-cut stents but in no patient with braided stents. Conclusions: The use of braided nitinol stents for common femoral vein obstruction appeared to be associated with favorable primary patency rates at 12 months compared with laser-cut nitinol stents. Further studies are needed to confirm that braided nitinol stents remain patent and might be less prone to fractures in the long term.