First Patient Enrolled in DEEPER CHALLENGE Trial of Reflow Spur in Select CLTI Cohort

July 2, 2026—Reflow Medical, Inc. announced the enrollment of the first patient in the DEEPER CHALLENGE clinical trial, which is investigating early vessel recoil after below-the-knee treatment using the company’s Spur peripheral retrievable scaffold system in combination with a commercially available drug-coated balloon. The investigator-initiated, single-center, single-arm, prospective study is being conducted at Medical University of Graz in Graz, Austria.

According to the company, the study plans to enroll up to 40 patients with chronic limb-threatening ischemia (CLTI) across two distinct cohorts: patients with diabetes and patients with end-stage renal disease receiving hemodialysis for at least 6 months, with women comprising no less than 50% of each cohort.

The study aims for a better understanding of the mechanical response of vessels immediately after treatment in patient populations that often experience complex lesion morphology and higher rates of restenosis.

The primary endpoint is early vessel recoil, assessed by angiography within 15 minutes after treatment. Secondary endpoints include major adverse limb events, mortality, and reintervention outcomes through 12 months, as well as hemodynamic outcomes through 30 days.

“This study is an important step in understanding early vessel recoil in challenging below-the-knee interventions,” commented Katharina Kurzmann-Gütl, MD, Principal Investigator of DEEPER CHALLENGE, in the Reflow Medical’s press release.

Dr. Kurzmann-Gütl continued, “By focusing on selective patient cohorts and ensuring balanced female representation, this research aims to generate data that more accurately reflect the clinical realities of treating complex peripheral artery disease.”

Professor Marianne Brodmann, MD, Head of the Division of Angiology at the Medical University of Graz, is coinvestigator of the trial.

Prof. Brodmann stated, “Patients with end-stage kidney disease or diabetes are often underrepresented in CLTI studies, despite facing higher risks of restenosis and limb-threatening ischemia, while females are underrepresented in most medical studies. This study’s specific inclusion criteria and focus on early vessel recoil will provide insights into the vessel’s immediate mechanical response after endovascular therapy.”