How effective and useful VAC Therapy, or Topical Negative Pressure is in the treatment of long-term wounds is questioned in an article in this month’s Drug and Therapeutics Bulletin (DTB). This treatment has become progressively more popular.
Topical Negative Pressure involves placing a foam dressing, cut to shape, into the wound. A tube is attached to the foam with a suction device, at the other end the tube is attached to a canister. The whole area is then sealed with a sticky film.
This therapy is said to accelerate healing by increasing oxygen flow to the wound, cleansing the area of harmful bacteria and other substances that may slow wound healing down, and raise the production of chemicals that encourage tissue growth. This treatment is used for pressure ulcers (bed sores), diabetic foot ulcers, skin grafts and venous ulcers.
However, the authors of this report have concluded that “the clinical effectiveness of this therapy is unclear,” after reviewing the available evidence. They comment that several studies done on the use of this technique were flawed in such a way as to “cast doubt on the validity and reliability of the results.”
None of the evidence is compelling enough to show that this technique helps bed sores or uncomplicated diabetic foot ulcers heal more quickly, or that it aids skin grafts to ‘take’, say the researchers.
Where faster healing may take place the circumstances and setting are uncommon. For example, the patients with venous ulcers who receive this treatment and get plenty of bed rest in hospital may benefit. However, the authors say such patients are hardly ever treated in this way as it is very expensive.
The article adds that the evidence that this technique is good value for money is also lacking. The rental of a suction unit in the UK costs about £39 ($78) a day. The dressing has to be changed every 48 hours at £50 ($100) a go.
Topical negative pressure for chronic wounds?
Drug Ther Bull 2007; 45: August 2007
http://dtb.bmj.com/dtb/do/home
Written by: Christian Nordqvist