12-Month VIVO Clinical Study Cohort Analysis of Patients with Stent Extension Below the Inguinal Ligament

Purpose: The VIVO Clinical Study (NCT01970007) supported the safety and effectiveness of the Zilver Vena Venous Stent (Cook Medical) in the treatment of patients with symptomatic iliofemoral venous outflow obstruction. The purpose of this cohort analysis was to assess patients with stent extension below the inguinal ligament, specifically baseline characteristics and 12-month outcomes.

Materials and Methods: Eligible patients were those with symptomatic venous obstruction (assessed by a CEAP “C” classification of ≥3 or a VCSS pain score ≥2) of one iliofemoral venous segment. The primary safety and effectiveness endpoints included the 30-day freedom from major adverse events (MAEs) and the 12-month rate of primary quantitative patency (a treated venous segment that retained uninterrupted [intervention-free] an MLD >50% of the immediate postprocedure stent MLD by core laboratory venography), respectively. The secondary endpoint was the change in VCSS from baseline to 1 month and 12 months.

Results: The cohort group included 79 patients (79 of 243; 32.5%) with stent extension below the inguinal ligament. Baseline characteristics were similar among the cohort group and overall study population (73.4% female; mean age, 51.4 ± 16.6 years vs 70.0% female; mean age, 53.0 ± 15.3 years). However, the cohort group was more likely to have current or past deep vein thrombus (DVT) (89.9% vs 67.5%) and longer mean lesion lengths (155.9 ± 73.7 mm vs 98.6 ± 69.8 mm). The 30-day freedom from MAE rate and the change in VCSS from baseline to 12 months for the cohort group was similar to the overall study population (96.2% vs 96.7% and -4.6; range, -5.5 to -3.7 vs -4.2; range, -4.7 to -3.7, respectively). The 12-month primary quantitative patency rate was lower for the cohort group (83.3% vs 89.9%) compared with the overall study population. No stent fractures, as assessed by the core laboratory, were demonstrated.

Conclusions: This cohort analysis demonstrated that VIVO Clinical Study patients with stent extension below the inguinal ligament were more likely to have DVT, longer lesions, and a decreased quantitative patency rate; these findings are consistent with prior results from patients with more challenging, extensive venous disease. However, these attributes did not impact the primary safety analysis, clinical measures, or stent durability outcomes.