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

Abstract

BackgroundChronic 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. MethodsFrom 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. ResultsOverall, 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. ConclusionsThe 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.