NEW YORK (Reuters Health) - More and more doctors are using a new high-tech device to treat chronic wounds such as bed sores and diabetic ulcers, but there is little evidence the device is any better than standard therapies, according to a review of studies on the technique.

In fact, the new method ¿ known as topical negative pressure ¿ may cause harm in some cases, warn the authors of the report. "It would be wrong to sort of suggest its very dangerous, that would be unfair, but on the other hand it certainly isn't risk-free," Dr. Ike Ikeanacho, the editor of Drug and Therapeutics Bulletin, where the review is published, told Reuters Health.

The treatment, also called vacuum-assisted closure or V.A.C. Therapy, involves placing a foam dressing on a wound, which is then attached to a device that exerts suction, drawing out wound fluid. Makers of the V.A.C. Therapy device recommend that it be used continuously for the first 48 hours, and then intermittently thereafter.

The approach may indeed speed healing and help to remove harmful substances such as bacteria from a wound, at least in theory, Ikeanacho and his colleagues say. However, the 11 published clinical trials with the therapy have been small and have had major flaws, such as comparing the new treatment to an old-fashioned and labour-intensive therapy such as wet gauze dressing, they add.