Wool-derived keratin dressings versus usual care dressings for treatment of slow healing venous leg ulceration: a randomised controlled trial (Keratin4VLU)

Abstract

Objective: To determine the effect of a keratin dressing for treating slow-to-heal venous leg ulcers (VLU) on VLU healing.

Design: Pragmatic parallel group randomised controlled trial.

Setting: Community-dwelling participants.

Participants: People aged 18 or more years with VLU (either present for more than 26 weeks or ulcer area larger than 5 cm² or both).

Intervention: Wool-derived keratin dressing or usual care formulary of non-medicated dressings, on a background treatment with compression.

Primary and secondary outcome measures: Healing at 24 weeks based on blinded assessment of ulcer photographs. Other outcomes included time to complete healing, change in ulcer area to 24 weeks, change in health-related quality of life and incidence of adverse events.

Results: We screened 1068 patients with VLU and randomised 143 participants (51.1% of target recruitment), 71 to the keratin dressing group and 72 to the usual care group.The mean age was 66.1 years (SD 15.9) and 53 participants (37.1%) were women. There were no significant differences between the groups on the primary outcome (risk difference -6.4%, 95% CI -22.5% to 9.7%), change in ulcer area (-1.9 cm², 95% CI -16.5 to 12.8 cm²), time to complete healing (HR 0.80, 95% CI 0.52 to 1.23) or the incidence of adverse events (incidence rate ratio 1.19, 95% CI 0.89 to 1.59) in the intention-to-treat analyses. However, the direction of effect on the primary outcome was reversed in a per protocol analysis specified a priori (risk difference 6.2%, 95% CI -12.4% to 24.9%).

Conclusion: The effect of adding a keratin dressing to the treatment regimen for prognostically slow-to-heal VLU remains unclear.

Trial registration number: NCT02896725.

Keywords: clinical trials; dermatology; geriatric medicine; vascular medicine; wound management.