Trial reveals leg ulcer treatment dilemma
Posted on 20 March 2009
Academics in the University's Department of Health Sciences co-ordinated a three-year trial comparing different therapies for treating leg ulcers. The condition affects one per cent of the population and treatment is estimated to cost the NHS £600 million a year.
The trial run in partnership with health trusts across the North, the Midlands and Northern Ireland is the largest clinical study into larval therapy ever mounted.
Although larval therapy is more effective in cleaning wounds than hydrogel, there is no evidence to recommend it for routine use to speed healing
Professor Nicky Cullum
The results published in BMJ Online today revealed that larval (maggot) therapy has similar health benefits and costs compared with a standard treatment for leg ulcers.
Leg ulcers are chronic wounds most commonly caused by diseased veins in the legs. The removal of dead tissue from the ulcer surface is a common part of ulcer management and is widely viewed as having a role in promoting wound healing.
The medical value of maggots for cleaning wounds of dead tissue has been well known to physicians for centuries. They were still used by doctors in the 1920s and 1930s only to be discarded when the development of antibiotics gathered pace.
The randomised trial involved a total of 267 leg ulcer sufferers. During the wound cleaning phase, a third of patients were treated with loose sterile maggots, a third with sterile maggots in a bag while the remainder were treated with hydrogel.
The trial called VenUS II compared the clinical and cost-effectiveness of the two types of larval therapy with the more conventional treatment, as well as the effect on patients' quality of life over 12 months.
Larval therapy significantly reduced wound cleaning time compared with hydrogel, but there was no evidence of a difference in time to ulcer healing (half of patients allocated to the larvae group were healed by 236 days compared with 245 days for the hydrogel group). There was no difference between larvae and hydrogel groups in health-related quality of life or in bacterial load (including MRSA). Larval therapy was associated with twice as much pain in the 24 hours prior to removal of the first application compared with hydrogel.
Professor Nicky Cullum, who headed the trial, said: . "Although larval therapy is more effective in cleaning wounds than hydrogel, there is no evidence to recommend it for routine use to speed healing or reduce bacterial load in leg ulcers. We believe further research is required to explore the relationship between wound cleansing, healing and microbiology, and to better understand the value of a clean wound to patients."
In a separate analysis, the researchers calculate that larval therapy is likely to have similar cost-effectiveness to hydrogel.
The three-year trial being run in partnership with a number of health trusts across the North, the Midlands and Northern Ireland is the largest clinical study into larval therapy ever mounted.
The trial was funded by the UK National Institute for Health Research Health Technology Assessment Programme.
ENDS
Notes to editors:
- More information on the Department of Health Sciences at the University of York is available at http://www.york.ac.uk/healthsciences/