Hyperbaric Oxygen Therapy in the Treatment of Ischaemic Lower Extremity Ulcers in Patients with Diabetes: Results of the Damocles Multicentre Randomised Clinical Trial

Abstract

Introduction - Conflicting evidence exists on the effects of hyperbaric oxygen therapy (HBOT) in the treatment of chronic ischaemic leg ulcers. The aim of this multicentre trial was to investigate whether HBOT, as an adjunct to revascularisation and standard wound care, can improve wound healing and reduce major amputation rates in patients with diabetes and ischaemic lower extremity ulcers. Methods - The DAMOCLES study was designed as a multicentre, randomised, parallel-group, superiority trial. In total, 120 patients were randomised to standard care without (SC) or with HBOT (SC+HBOT). Eligible diabetic patients had a Wagner grade 2-4 ulcer present for at least 4 weeks and concomitant limb ischaemia with or without revascularisation options. Primary outcomes were limb salvage and complete wound healing after 12 months of follow-up, as well as time to wound healing. Other endpoints were amputation-free survival (AFS) and mortality. Results - Both groups contained 60 patients. Limb salvage was achieved in 47 patients (78%) in the SC group vs. 53 (88%) patients in the SC+HBOT group (risk difference [RD] 0.10, 95% CI -0.04 to 0.23). After 12 months, 28 index wounds were healed in the SC group vs. 30 in the SC+HBOT group (RD 0.03, 95% CI -0.14 to 0.21). AFS was achieved in 41 patients in the SC group and 49 patients in the SC+HBOT group (RD 0.13, 95% CI -0.02 to 0.28). In the SC+HBOT group 21 patients (35%) were unable to complete the HBOT-protocol as initially planned. Those who did had significantly less major amputations and higher AFS (RD 0.26, 95% CI 0.10 to 0.38). Conclusion - Additional HBOT did not significantly improve complete wound healing and limb salvage in patients with diabetes and lower limb ischaemia. However, a trend was seen towards a better amputation-free survival among HBOT-treated patients. The potential efficacy of HBOT may not be realised because a considerable number of patients is unable to complete a full HBOT-regimen.