Vacuum assisted closure therapy for wound care
Ontario Ministry of Health and Long-Term Care
Record ID 32005000112
This study aims to provide a health technology and policy appraisal of vacuum assisted closure (V.A.C.) therapy (trademarked by KCI, Inc.) for acute and chronic wounds. This technology, a form of negative topical pressure therapy, is said to promote the healing of chronic wounds for patients when conventional, first-line treatments have failed. V.A.C. therapy also is used to heal acute, non-healing, or dehisced (i.e., ruptured or split-open) wounds postoperatively.
Authors' results and conclusions:
The authors of 4 international health technology assessments concluded that although there were small, published RCTs supporting the use of V.A.C. therapy to treat wounds, its effectiveness could not be established because of poor study designs and analyses; small sample sizes; and patient populations, comparators and outcome measures that could not be compared.
In addition to the international health technology assessments, this review found 11 studies: 1 small RCT (N = 54), 6 single-site case series, and 4 retrospective chart reviews.
In the RCT, hospitalized patients who were waiting for surgery for their severe wounds were randomized to receive either V.A.C. therapy (n = 29) or conventional wet-moist gauze therapy (CMG; n=25). The aim was to determine if the higher rate of healing for V.A.C. therapy compared with CMG was due to changes in bacterial count.
A Kaplan-Meier survival analysis found no statistically significant difference in the time to ready for surgery (defined as a clean, red, granulating wound bed) for wounds treated with V.A.C. therapy and those treated conventionally with moist gauze (6 days [SD, 52]for V.A.C. therapy and 7 days [SD, 81]for CMG). In a subset of patients (15/29 in the V.AC. therapy group, and 13/25 in the CMG group) V.A.C. therapy resulted in a significant reduction of wound surface area per day from baseline (3.8% [SD, 0.5]; P = .0001). The size of wounds treated with CMG also shrank from their baseline size (1.7 % [SD, 0.6]; P = .05). There was a statistically significant difference in the reduction of wound surface area in wounds treated with V.A.C. therapy compared with those treated with CMG (P < .05); however, the methods used to calculate this result are unclear.
Neither the reason for the use of the patient subset for this analytic component nor the characteristics of the patients in these subgroups compared to those of the initially randomized patients is clear. There was a significant change in the bacterial count in wounds treated with V.A.C. therapy over time (P < .05).
Despite the authors' conclusion that V.A.C. therapy is beneficial, the Medical Advisory Secretariat concluded that its effectiveness could not be established, owing to the limitations of the studys methods.
The other studies retrieved during the systematic review also had weak methods. The 6 case series and the 4 retrospective studies had small sample sizes, and focused on varying patient populations, conditions, and wound types. Furthermore, their authors sometimes came to conclusions not supported by the results.
Based on the evidence to date, the clinical effectiveness of V.A.C. therapy to heal chronic wounds is unclear. Authors of some level 2 studies have concluded that V.A.C. therapy may be at least as effective as saline dressings, but the quality of these studies is poor. Furthermore, saline dressings are not the standard of practice in Ontario, thereby rendering the literature base irrelevant in an Ontario context. Nonetheless, despite the lack of methodologically sound studies, V.A.C. therapy has diffused across Ontario.
Discussions with Ontario clinical experts have highlighted some deficiencies in the current approach to chronic wound management, especially in the community. Because V.A.C. therapy is readily available, easy to administer, and may save costs, compared with multiple daily conventional dressing changes, it may be used inappropriately. The discussion group highlighted the need to put in place a coordinated, multidisciplinary strategy for wound care in Ontario to ensure the best, continuous care of patients.
English language abstract:
An English language summary is available
- Wound Healing
- Wounds and Injuries
Medical Advisory Secretariat
Medical Advisory Secretariat, 20 Dundas Street West, 10th Floor, Toronto, ON M5G 2N6 CANADA. Tel: 416-314-1092l; Fax: 416-325-2364;
Medical Advisory Secretariat, Ontario Ministry of Health and Long-Term Care