The effectiveness and value of an increasingly popular treatment for long-term wounds are questioned in a recent Drug and Therapeutics Bulletin (DTB)
Topical negative pressure, or VAC therapy as it is sometimes known, involves first placing a foam dressing, cut to shape, into a wound.
A tube attached to a canister at one end and a suction device at the other is then inserted into the foam to remove excess wound fluid, and the area is sealed with a sticky film.
It has been suggested that the procedure might speed healing in various ways, such as by increasing oxygen flow to the wound, removing bacteria and substances that slow healing, and boosting the production of chemicals that promote tissue growth.
VAC therapy has been used for various types of wound, including bed sores (pressure ulcers), diabetic foot ulcers, venous ulcers and skin grafts.
But after reviewing the available evidence the DTB concludes that the “clinical effectiveness of this therapy is unclear”.
Many studies carried out on the use of the technique have been flawed in some way, so as to “cast doubt on the validity and reliability of the results”, it says.
For example, DTB says “there is no compelling evidence” that the therapy helps bed sores or uncomplicated diabetic foot ulcers heal more quickly or that it aids skin grafts to “take”.
The treatment may speed up healing in patients with venous ulcers, given bed rest in hospital, but few such patients are likely to be treated in this way due to cost.
Nor is there sufficient evidence to judge how the technique’s cost-effectiveness compares with that of other available treatments.
A suction unit typically costs some