The results of a two-year study support the continued safety and effectiveness of the Zilver Vena Venous Stent (Cook Medical) in treating symptomatic iliofemoral venous outflow obstruction, according to findings presented at the 2021 meeting of the Society of Interventional Radiology (SIR; 20–26 March, online).
The stent met primary safety and effectiveness endpoints at one month, and continued to do so through one- and two-year intervals during the VIVO Clinical Study.
In addition, the Zilver Vena Venous Stent demonstrated high rates of patency by ultrasound, freedom from clinically-driven reinterventions and freedom from reinterventions more generally throughout—all of which were clinical outcomes being assessed in the study.
According to Lawrence “Rusty” Hofmann, professor of interventional radiology at Stanford Medicine (Stanford, USA) and the study’s presenting author, the stent’s integrity was also indicated by the fact there were no core laboratory reports of stent fractures across the two-year study period.
“There has been concern over the years at some centres about stenting below the inguinal ligament,” he said. “In this study, more than 20% of stents extended into this region, and there were not any stent fractures.”
The VIVO Clinical Study took place between December 2013 and October 2016, and enrolled 243 patients (70% female; mean age: 53±15 years) with symptomatic obstruction of one iliofemoral venous segment.
Data assessed during the study included baseline patient characteristics, primary and secondary endpoints—such as 30-day freedom from major adverse events, 12-month primary quantitative patency, and changes in venous clinical severity score (VCSS) from baseline to one month and 12 months—as well as patency, reintervention, clinical outcomes and stent integrity through two years.
The Zilver Vena Venous Stent met primary endpoints for both safety and effectiveness, with a 96.7% rate of 30-day freedom from major adverse events and an 89.9% rate of 12-month primary quantitative patency.
In addition, Hofmann said the mean change (-3.0; p<0.0001) in VCSS from baseline was “significant” at one month and was sustained through 12 months (-4.2), and maintained at two years. Specifically, two-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%).
“This landmark study moves the ball forward in the treatment of deep venous disease,” Hofmann concluded.