Purpose: The VIVO Clinical Study (NCT01970007) assessed the safety and effectiveness of the Zilver Vena Venous Stent in the treatment of symptomatic iliofemoral venous outflow obstruction. The aim of this update is to report on 2-year outcomes.
Materials and Methods: Between December 2013 and October 2016, 243 patients (70% female; mean age: 53 ± 15 years) with symptomatic obstruction (i.e., CEAP clinical classification of ≥3 or VCSS pain score ≥2) of one iliofemoral venous segment were enrolled. Data included baseline patient characteristics, primary and secondary endpoints (30-day freedom from major adverse events, 12-month primary quantitative patency, change in VCSS from baseline to 1 month and 12 months), as well as patency, reintervention, clinical outcomes (measured by VCSS, VDS, CEAP “C”, and CIVIQ), and stent integrity through 2 years.
Results: The majority of patients had current or past deep vein thrombosis (67.5%) prior to stent placement. Mean study lesion length was 98.6±69.8 mm, with 23.3% characterized as total occlusions. Stents extended below the inguinal ligament in 32.5% of patients. Primary safety (30-day freedom from MAE rate was 96.7%; p<0.0001) and effectiveness (12-month primary quantitative patency rate was 89.9% by venography; p<0.0001) endpoints were met. Likewise, the mean change in VCSS from baseline was significant at 1 month (mean change: -3.0; p<0.0001) and was sustained through 12 months (mean change: -4.2). Results observed at 1 year were maintained. Specifically, 2-year outcomes included high rates of patency by ultrasound (90.3%±2.2%), freedom from clinically-driven reinterventions (93.2%±1.8%), and freedom from reinterventions (83.4%±2.5%). Clinical improvement, as measured by VCSS, VDS, CEAP “C”, and CIVIQ, was sustained through 2 years. Finally, stent integrity was demonstrated by no core laboratory reported stent fractures through 2 years.
Conclusion: The 2-year results of the VIVO Clinical Study support the continued safety and effectiveness of the Zilver Vena Venous Stent.