A multicenter clinical trial evaluating the durability of diabetic foot ulcer healing in ulcers treated with topical oxygen and standard of care versus standard of care alone 1 year post healing.

Multiple clinical trials and real-world studies have demonstrated accelerated healing in diabetic foot ulcers (DFU) treated with advanced modalities, such as topical oxygen therapy (TOT). In addition to healing, the durability of wound closure is a crucial long-term endpoint for DFU clinical trials: an advanced treatment that does not confer a reasonable ulcer-free period will have limited clinical benefit and modest economic value. Preclinical studies suggest that DFUs receiving topical oxygen therapy will experience improved quality of healing: increased collagen deposition and angiogenesis. It is postulated that these changes will translate into a more long-lasting closure for ulcers treated with TOT and SOC compared to ulcers treated with SOC alone. At the conclusion of a recently completed randomised controlled DFU clinical trial evaluating the efficacy of TOT and SOC compared to SOC alone, patients with healed ulcers were asked to enrol in a long-term follow-up study. Healed patients completed four questionnaires through text messages or phone calls within 1-year post completion of the trial. Twenty-nine patients consented to participate in the long-term follow-up trial (17 TOT/SOC and 12 SOC). Only seven subjects were lost to follow up (5 TOT and 2 SOC). This is a surprisingly low number when factoring in the disruption caused by the COVID-19 pandemic that continued throughout the entire follow-up period. In the remaining patients, 85% of the TOT patients and 60% of the SOC remained healed at 1 year. There was one major amputation, which occurred in an SOC-treated patient. The numbers in the long-term follow-up were too small to reach statistical significance; however, there is a strong trend toward more durable closure in ulcers treated with TOT.