Chronic wounds, especially those that are hard-to-heal, constitute a serious public-health problem. Although progress has been made in the development of wound dressings for healing, there is little high-quality evidence of their efficacy, with no evidence of superiority in the use of one hydrogel over another. To evaluate the superiority of a hydrogel (EHO-85), containing Olea europaea leaf extract (OELE), over a standard hydrogel (SH), the promotion and/or improvement of healing of difficult-to-heal wounds was compared in a prospective, parallel-group multicenter, randomized, observer-blinded, controlled trial ("MACAON"). Non-hospitalized patients with pressure, venous or diabetic foot-ulcers difficult-to-heal were recruited and treated with standard care, and EHO-85 (n = 35) or VariHesive (n = 34) as SH. Wound-area reduction (WAR; percentage) and healing rate (HR; mm2/day) were measured. EHO-85 showed a statistically significant superior effect over VariHesive. At the end of the follow-up period, the relative WAR decreased by 51.6% vs. 18.9% (p < 0.001), with a HR mean of 10.5 ± 5.7 vs. 1.0 ± 7.5 mm2/day (p = 0.036). EHO-85 superiority is probably based on its optimal ability to balance the ulcer bed, by modulating pH and oxidative stress. That complements the wetting and barrier functions, characteristics of conventional hydrogels. These results support the use of EHO-85 dressing, for treatment of hard-to-heal ulcers. Trial Registration AEMPS:PS/CR623/17/CE.
Keywords: EHO-85; Olea europaea leaf extract; amorphous hydrogel; hard-to-heal wound; randomized active-controlled trial.