Abre Venous Stent Trial: 24-Month Update

In an ISET 2022 Late-Breaking Clinical Trial session, Erin Murphy, MD, from Sanger Heart and Vascular, Atrium Health, in Charlotte, North Carolina, presented new data on the Abre venous stent (Medtronic) showing sustained effectiveness and safety out to 24 months.

The Abre venous stent system (Medtronic) is designed for the unique challenges of venous disease. It is a Nitinol self-expanding stent with an open cell design and 3 offset connection points that spiral around the stent to provide stability during deployment, but with good flexibility, said Dr. Murphy.

The device is available in diameters up to 20 millimeters and length up to 150 millimeters, is over-the-wire 9 Fr, 0.035 guidewire compatible. The triaxial shaft design controls friction and stabilizes stent, “and it has a thumbwheel actuated deployment that we're pretty familiar with,” she told attendees.

The Abre IDE study was designed to prospectively test the safety and effectiveness of the device for the treatment of symptomatic iliofemoral venous outflow obstruction. A total of 200 patients (66.5% female) were enrolled into the single-arm study at one of 24 global sites in the US and EU.

Mean age was 51.5 years, mean BMI was 29.5, and 52% of the study cohort had a previous history of venous thromboembolism. The patient sample included “all patient subtypes that develop venous obstruction,” said Dr. Murphy, including those with post-thrombotic syndrome, non-thrombotic iliac vein lesion (NIVL) and acute deep vein thrombosis. In 92% of patients, the left limb was the target limb.

Of note, she said, the sample represented a challenging group of patients, with stents in 88 subjects (44%) extending below the inguinal ligament.

The procedural data showed a mean percent area stenosis of 75%, a percent diameter stenosis of 62.8%, and a mean lesion length of 112.4 mm. Total stented length was 134.3 mm. Dr. Murphy also presented detailed data on the stent lengths used in different patient subtypes (see slide below).

Both of the primary safety and effectiveness endpoints were met, with a rate of major adverse events within 30-days of 2.0%, well below the performance goal of 12.5% (P<0.0001) and a primary patency at 12 months of 88.0%, above the performance goal of 75.0% (P<0.0001).

Dr. Murphy noted that there were a few patients lost to COVID-19, with final data available in only 176 out of 194 patients available for a follow-up visit. “Hopefully, we'll get those people back for year 3 follow-up.”

In a Kaplan Meier- analysis, primary patency at 24 months is 85.7% and freedom from target lesion revascularization (TLR) is 85%, with 90.9% of patients being free from clinically driven TLR.

“Importantly, there have been no stents with fracture, and there were no stents with migration in the trial through 24 months. And probably most importantly, and this is good data that we're getting from pretty much all the trials, is that the quality-of-life via the VEINES-QOL and EQ5D results showed there was significant improvement in quality-of-life at six months, which was pretty well sustained out to 24 months,” reported Dr. Murphy.

“All of these data show that, so far, the Abre stent remains safe and effective for treatment of iliofemoral disease,” Dr. Murphy concluded.