Larval Therapy as Useful as Standard Care for Leg Ulcers

Debridement of leg ulcers with maggots, also known as larval therapy, is generally comparable in effectiveness and costs to hydrogel dressings, according to the results of two linked studies.

Researchers at the University of York (United Kingdom) participating in the VenUS II study evaluated wound-related outcomes in 267 patients who were randomized to receive loose larvae, bagged larvae, or hydrogel to debride sloughy or necrotic leg ulcers. The larvae were typically left on the ulcer for 3 or 4 days at a time, while the hydrogel dressings were changed at the treating nurse's discretion. The subjects were followed for up to 12 months. The primary outcome was time to healing of the largest eligible ulcer. Secondary outcomes were time to debridement, health related quality of life, bacterial load, presence of methicillin-resistant Staphylococcus aureus (MRSA), adverse events, and ulcer related pain on a visual analogue scale.

The researchers found that the time to healing was not significantly different between the loose or bagged larvae group and the hydrogel group, but larval therapy significantly reduced the time to debridement. The treatments also had comparable effects on quality of life, bacterial load over time, and methicillin-resistant Staphylococcus aureus (MRSA) eradication. Both larval treatments were associated with significantly higher pain scores than hydrogel therapy. The study was published in the march 19, 2009, issued of BMJ.

"One phase of larval therapy used until initial debridement of leg ulcers is likely to produce a similar level of health benefit at a similar cost to hydrogel," said second study lead author Marta Soares, M.Sc., and colleagues of the department of health sciences. "The choice of treatment may then be driven by patients' wishes and experiences of pain with larvae."

In the second study, conducted by the same researchers, a detailed cost-effectiveness analysis of the treatments in the first study was carried out. The researchers found that although larval therapy was more expensive than hydrogel treatment, ulcer healing was faster with the former, and quality of life was improved; however, the authors emphasized, these differences were not statistically significant. 

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