A novel, minimally invasive procedure is providing a new alternative for patients with chronic limb-threatening ischemia (CLTI), the most severe manifestation of peripheral artery disease. A recent clinical trial demonstrated that the therapy, which bypasses blocked arteries in the leg to restore blood flow to the foot, successfully prevented amputation in the majority of patients who had exhausted all other treatment options and were facing limb loss.
The PROMISE II trial, with results published in the New England Journal of Medicine, evaluated the LimFlow therapy in 105 patients with CLTI. After six months, 76% of participants who underwent the procedure avoided amputation, and a similar percentage saw their chronic wounds completely heal or improve. This successful outcome may lead to the first FDA-approved therapy of its kind, offering a significant advancement in vascular medicine for a condition associated with high rates of amputation and mortality.
A New Approach to Revascularization
The innovative treatment, known as transcatheter arterialization of the deep veins (TADV), addresses a critical challenge in patients with end-stage peripheral artery disease. Many of these individuals, often with long-standing diabetes, have such extensive blockages in the arteries of their lower legs and feet that traditional surgical bypass or angioplasty is not feasible. These patients are often referred to as “no-option” cases, with major amputation being their only remaining recourse.
The LimFlow system creates a bypass not by opening the original blocked arteries, but by diverting blood flow through the venous system. Using a minimally invasive catheter-based approach, the procedure connects an artery in the leg to a vein in the foot. This allows oxygenated blood to reach the foot and facilitate the healing of chronic wounds, often called diabetic ulcers. By restoring perfusion to the affected tissues, the therapy aims to halt tissue death and preserve the limb.
Clinical Trial Demonstrates Efficacy
The PROMISE II multicenter prospective study provided crucial evidence for the therapy’s effectiveness. The trial enrolled 105 patients with CLTI, all of whom had non-healing wounds and were deemed ineligible for other revascularization procedures. The study’s diverse cohort, with 43% of participants identifying as Black, Hispanic, or Latino, reflects the populations disproportionately affected by severe peripheral artery disease.
Key Six-Month Outcomes
The primary results from the trial were highly encouraging. Researchers reported an amputation-free survival rate of 66%, with many patients experiencing significant wound healing. The study found that 76% of patients were able to keep their leg, a significant success given that all were facing imminent amputation before the intervention. Furthermore, 76% of patients had wounds that were either fully healed or in the process of healing six months after the procedure. The rate of freedom from all-cause mortality was 87% at the six-month mark.
Implications for Patient Care
The findings from the PROMISE II trial represent a major step forward for a patient population with a dire prognosis. CLTI is considered a terminal manifestation of systemic atherosclerosis and is linked to a high risk of heart attack, stroke, and death. For those with non-revascularizable disease, amputation rates are high, and mortality rates following amputation are even higher. Some studies have reported five-year mortality rates of up to 85% for elderly patients who undergo major amputations for CLTI.
The TADV procedure offers the potential to not only save a limb but also to preserve a patient’s independence and quality of life. By avoiding amputation, patients can maintain mobility and avoid the significant physical and psychological tolls associated with limb loss. The high rate of wound healing observed in the trial is also critical, as these wounds are a major source of pain, infection, and reduced quality of life.
Broader Context of Limb Salvage
Limb salvage programs are a multidisciplinary effort to prevent amputation in patients with severe peripheral artery disease. These programs utilize a range of techniques to restore blood flow, a process known as revascularization. While the TADV procedure is a new frontier, existing methods have been the cornerstone of treatment for many years.
Established Salvage Techniques
For patients with treatable blockages, several options exist. Angioplasty is a minimally invasive procedure where a small balloon is inserted into a narrowed artery and inflated to open it, often with a mesh tube called a stent placed to keep it open. Atherectomy is another catheter-based technique that uses tiny razors or other tools to scrape plaque from within the artery. For more extensive blockages, a peripheral artery bypass may be performed, where a surgeon uses a vein from another part of the body or a synthetic graft to create a detour around the blocked arterial segment.
The success of the LimFlow therapy in the PROMISE II trial provides a vital new option for patients whose disease is too advanced for these established procedures. As research continues, this innovative approach could become a standard of care, significantly reducing amputation rates for the most vulnerable patients with vascular disease.