Surgical wounds close more frequently and faster, infections are rarer than with standard care. However, 23% of the data from completed studies are still not available.
The German Institute for Quality and Efficiency in Health Care (German acronym: IQWiG) has published its second evaluation on the benefit assessment of vacuum wound therapy. This technique is known as VAC (Vacuum-Assisted Closure of a Wound) or NPWT (Negative-pressure wound therapy). The institute certifies that the VAC method has a higher benefit for wound healing when compared to conventional wound care.
In both evaluations, the institute downgraded the results because study data are missing and the reliability of the results is therefore reduced. This is because the missing data could make the benefit or damage appear greater or smaller.
For the final report on primary wound healing, the institute had available data from a total of 45 randomized controlled trials. Wounds from surgery were examined primarily in obstetrics, abdominal, vascular and cardiac surgery, and in endoprosthetics (such as in joint replacement).
A total of 6,981 patients participated in these studies. Most of them were expected to have difficulty in wound healing because they had at least one risk factor, such as obesity or diabetes mellitus.
VAC is superior to standard care in terms of infections. With such a method, these were less common in the wounds. However, information from the studies suggests that this difference between treatment groups is mainly due to mild infections rather than severe infections. It should also be noted that the higher infection rate in the comparison group is not reflected in a longer stay in hospital.
With regards to wound closure, there are advantages in favor of VAC: more wounds heal and the process is faster. However, the reliability of the studies in this respect is even lower than that of the infections.
With regard to the other endpoints (including mortality, pain, quality of life), the studies show no relevant differences in the benefit or harm of VAC. Overall, IQWiG found a higher benefit from the VAC method over standard wound care.
"For more than 20 years, VAC has been used in clinics; more than 100 studies have been completed. Nevertheless, some statements on benefits and harms are uncertain because those responsible for the study keep the results under wraps. Some studies were completed more than 10 years ago," commented IQWiG Head of Department Stefan Sauerland. The institute therefore still considers the transparency rules for clinical trials with medical devices to be inadequate and demands that the same requirements be met as for drugs.
Original publication (in German):