LimFlow Deep Vein Arterialization System to Treat CLTI Evaluated in 2-Year PROMISE I Data

October 6, 2021—Daniel Clair, MD, presented 2-year results from the PROMISE I trial, which is evaluating the LimFlow system (LimFlow SA) for creating deep vein arterialization in the treatment of patients with severe, unreconstructable chronic limb-threatening ischemia (CLTI).

The study's primary endpoints include a composite endpoint of amputation-free survival, overall survival, and freedom from amputation.

Dr. Clair presented the findings during a late-breaking clinical trials session at the VIVA 2021, the annual Vascular InterVentional Advances meeting held October 4-7 in Las Vegas, Nevada.

The PROMISE I investigators enrolled 32 patients at seven United States sites from 2017 to 2019, representing the initial experience with this technique in the country. There was a very high incidence of diabetes (69%) and hypertension (88%) in the group overall, and approximately one-third of patients had renal insufficiency. An independent review board consisting of vascular specialists confirmed enrollees had no option for revascularization.

Dr. Clair reported a technical success rate of 97%, with just one technical failure related to inability to gain distal venous access. The amputation-free survival rates were 74%, 70%, and 59% at 6, 12, and 24 months, respectively.

Of note, there were no amputations in any patient after day 75, and there were no limb-related mortality events. Freedom from amputation in this very high-risk patient group was 77% out to 2 years, at which point 85% of wounds were completely healed, and 92% of patients were either healed or healing.

Dr. Clair noted that significant lessons have been learned in this initial experience, including the benefit of gaining initial venous access in the foot, maintaining current arterial inflow in the foot until the deep vein arterialization matures, and the critical management of these foot wounds.

The study further highlighted improvements in arteriovenous crossing and stent graft deployment ease and precision with technology improvements in the system. All of these enhancements will be included in the PROMISE II trial. PROMISE II is a global, multicenter registry to assess the outcome of deep vein arterialization in the “no-option” CLTI patient population, advised Dr. Clair in the VIVA announcement.

Details of the PROMISE II pivotal trial plan were announced in September 2019.