Prospective study of the duo-hybrid venous stent for treatment of iliac vein obstruction.

Background: This prospective, single center, exploratory study assessed primary patency, clinical performance, and adverse events associated with the DUO-HYBRID Venous Stent used to treat iliac vein obstruction. Materials and methods: Twenty-one patients with symptomatic obstructions were treated with the self-expanding stent designed with varying zones of fatigue and crush resistance to adapt to the challenging iliac vein anatomy. The primary outcome measure was 12-month primary patency, defined as ≤ 50% residual stenosis, the absence of re-thrombosis or reintervention, and the absence of major adverse events from treatment to discharge. Secondary clinical measures included the Villalta score to assess the symptoms of post-thrombotic syndrome (PTS), and the revised Venous Clinical Severity Score (rVCSS) and Clinical, Etiological, Anatomical, and Pathophysiological (CEAP) score, both used to measure the severity of venous disease. Finally, the number of device- or procedure-related adverse events were recorded. Results: Primary patency was 92.9% at 12 months: one patient exhibited restenosis greater than 50% at 12 months. CEAP scores at baseline were predominantly C3 - C5 (78.9%) while at 12 months, 78.6% of scores were C1 - C2 and 14.3% were C0. The mean rVCSS score was 5.5 ± 2.7 at baseline and 1.1 ± 1.0 at 12 months, an 80% reduction in the mean score from baseline. Pre-procedure, 14.3% of patients had a Villalta score of 0-4 while at 12 months, 100% had scores of 0-4 (i.e., no clinically meaningful signs of post-thrombotic syndrome). Two adverse events were reported as possibly related to the device but neither case required revascularization. Conclusions: Observations from this exploratory study demonstrated a primary patency rate of 92.9%, improvements in rVCSS, CEAP, and Villalta scores from baseline, and no cases of target lesion or vessel revascularization at 12 months. The DUO-HYBRID Venous Stent performed appropriately when used for its intended indication.