PRAGUE – Maggot debridement of wounds proved significantly faster, less painful, and less labor intensive than surgical debridement and conventional dressings in a randomized, multicenter clinical trial.
"There was quite an amazing debridement after 7 days of maggot therapy," Dr. Kristina Opletalova said of the phase III study findings presented at the annual congress of the European Academy of Dermatology and Venereology.
Courtesy National Institutes of Health
The investigator said that maggot therapy is likely to be particularly useful in patients with wounds that need rapid debridement, such as those with diabetes, or to prepare a wound for skin grafting or when there is an increased risk for infection.
She reported on 119 patients hospitalized for 2 weeks for treatment of nonhealing sloughy wounds, most of which were venous ulcers on the lower limbs. Participants were randomized to maggot therapy or to thrice-weekly surgical debridement with topical anesthesia and conventional dressings.
The maggot therapy was administered via a novel delivery system: 80 maggots of Lucilia sericata were bagged in a special two-layer dressing, known as a Vitapad (BioMonde Laboratories), which allowed the critters to move and feed on the wound surface and kept them from escaping. The dressing was changed twice weekly.
Patients were blindfolded for all dressing changes so they didn’t know which study arm they were in. Wound sloughing was analyzed using computerized planimetry software, and other end points were assessed by an investigator blinded to treatment arm.
After 7 days of therapy, the wound status was significantly better in the maggot debridement group. The mean percentage of slough in wounds was 54.5%, compared with 66.5% in controls, but the significantly faster debridement didn’t boost the final healing rate. The day 15 percentage of slough in the wounds didn’t differ significantly between the two groups: 55.4% with maggot therapy and 53.8% in controls.
"So we think maggot debridement therapy should be stopped after 1 week and other types of dressings should then be used," said Dr. Opletalova, a dermatologist at the University of Caen (France).
Kristina Opletalova
Pain scores, which were assessed on a weekly basis, were similarly low in the two groups, but it must be noted that the control group received topical anesthetic and the maggot therapy group did not. Nursing time was four-fold greater in the control group. The study didn’t include a formal cost analysis, but the markedly reduced nursing time in the maggot therapy group is likely to spell cost savings, she said.
Maggot therapy was well tolerated. Patients expressed no reticence about it. A similar number of patients in both study arms reported a crawling sensation on their wounds.
Dr. Opletalova said that maggot therapy is likely to be particularly useful in patients with wounds that need rapid debridement, such as those with diabetes, or to prepare a wound for skin grafting or when there is an increased risk for infection.
Further details of the recently published randomized trial can be found in the Archives of Dermatology (2012;148:432-8).
The study was supported by university hospital research funding and by a grant from the French Society of Dermatology. Dr. Opletalova reported having no financial conflicts.