December 19, 2011 — Maggot debridement therapy (MDT) appears to be more effective for wound debridement compared with conventional therapy, but only at 1 week; after that time, another type of dressing should be used, new research suggests. Kristina Opletalovà, MD, from the Department of Dermatology, University of Caen, France, and colleagues published online December 19 in the Archives of Dermatology.
Medical maggots were approved by the US Food and Drug Administration as a medical device for wound debridement in 2004. According to the researchers, use of maggots in treating wounds is associated with effective wound debridement, antibacterial effects, and stimulation of wound healing.
However, they point out, "[r]elatively few clinical studies have been conducted and the results are not clear, partly owing to methodologic assessment problems."
In the current prospective, randomized controlled, phase 3 clinical trial, the researchers sought to determine the efficacy of bagged larvae on wound debridement in comparison with conventional treatment.
The primary objective was to compare the mean percentage of slough in wounds treated with MDT with that of conventional treatment at day 15. The study included 119 patients with a nonhealing, sloughy wound that was 40 cm2 or smaller and less than 2 cm deep. Patients also had an ankle brachial index of 0.8 or higher.
Treatment was administered during a 2-week hospital stay. Conventional treatment consisted of surgical debridement 3 times a week with a scalpel, with use of topical anesthesia. The MDT was administered using an enclosed dressing (Vitapad, BioMonde Laboratories) containing 80 sterile maggots. At discharge, a conventional dressing was applied, and patients were followed-up at day 30.
Debridement by MDT was significantly faster than surgical debridement during the first week of treatment, reaching the same level the control group reached at day 15. No benefit for MDT compared with conventional treatment in healing rates was observed. At day 8, 54.5% in the MDT group vs 66.5% in the control group (P = .04) had evidence of slough and wound healing. However, by day 15, the mean percentage of slough was 55.4% in the MDT group and 53.8% in the control group (P = .78).
"Athough MDT shows no significant benefit at day 15 compared with conventional treatment, debridement by MDT is significantly faster and occurs during the first week of treatment," the researchers conclude. "Because there is no benefit in continuing the treatment after 1 week, another type of dressing should be used after 2 or 3 applications of MDT."
Pain scores were similar and mild in both groups, although in contrast to conventional treatment, MDT was performed without topical anesthesia.
According to the researchers, none of the patients were reticent about undergoing MDT. "[A] crawling sensation on the wound was rarely and almost equally noted in both groups, revealing that the sensation was subjective," Dr. Opletalovà and colleagues point out.
Two questions regarding MDT remain unanswered, the authors note. "Can debridement be improved using more maggots per dressing? If so, would these dressings be more painful? Further studies are needed to answer these questions."
The study was supported by grants from the Clinical Research Hospital Program and from the French Society of Dermatology. The authors have disclosed no relevant financial relationships.
Arch Dermatol. Published online December 19, 2011. Full text