Vacuum Assisted Wound Closure Therapy May Be Pointless

Negative-pressure wound therapy (NPWT) probably does not promote wound healing after all, according to a new meta-analysis.

Researchers at the Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen (IQWiG; Cologne, Germany) conducted a systematic search of the PubMed and the Cochrane Library databases for randomized, controlled trials (RCTs) of NPWT for the treatment of acute or chronic wounds. The primary outcome was complete wound closure; secondary endpoints included adverse events such as death, secondary amputations, fistula formation, wound infection, time to complete wound closure, and reduction in wound size. In all, 21 reports met selection criteria.

Of these studies, 9 RCTs were new, in addition to 12 studies already covered by earlier IQWiG reviews; 5 of the 9 new trials involved NPWT systems that are not on the market. The researchers found that the frequency of complete wound closure was stated in only five of the nine new reports, and a statistically significant effect in favor of NPWT was found in only two trials. The results of eight of the nine new trials were hard to interpret, both because of apparent bias and because diverse types of wounds were treated. The researchers concluded that although there may be a positive effect of NPWT, there was no clear evidence that wounds heal any better or worse with NPWT than with conventional treatment. The study was published in the June 3, 2011, edition of Deutsches Ärzteblatt International.

"The available pool of only 21 RCTs remains too small to provide a clear answer to the question of whether or not NPWT is superior to conventional wound treatment," said lead author Frank Peinemann, MD, MSc. "The difficulty of interpreting the RCTs is caused essentially by the heterogeneity of the various indications for NPWT on the one hand, and the considerable qualitative and quantitative shortcomings of the trials on the other."

NPWT is a therapeutic technique used to promote healing in acute or chronic wounds and enhance healing of first- and second-degree burns, by controlled application of subatmospheric pressure to the local wound environment using a sealed wound dressing connected to a vacuum pump. The use of this technique in wound management increased dramatically over the 1990s and 2000s. Research on the effectiveness of NPWT is generally flawed and methodologically poor quality, but does support the use of the technique for diabetic ulcers.

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