Negative pressure wound therapy for skin grafts and surgical wounds healing by primary intention (Review)

Background: Indications for the use of negative pressure wound therapy (NPWT) are broadening with a range of systems on the market, including those designed for use on clean, closed incisions and skin grafts. Reviews have concluded that the evidence for the effectiveness of NPWT remains uncertain. However, this is a rapidly evolving therapy. Consequently, a systematic review of the evidence for the effects of NPWT on postoperative wounds expected to heal by primary intention is required. Objectives: To assess the effects of NPWT on surgical wounds (primary closure or skin grafting) that are expected to heal by primary intention. Search methods: We searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Group Specialised Register (searched 11 November 2011); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); Database of Abstracts of Reviews of Effects (The Cochrane Library 2011, Issue 4); Ovid MEDLINE (2005 to October Week 4 2011); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 8 November 2011); Ovid EMBASE (2009 to 2011 Week 44); and EBSCO CINAHL (1982 to 04 November 2011). We conducted a separate search to identify economic evaluations. Selection criteria: We included trials if they allocated patients at random and compared NPWT with any other type of wound dressing or compared one type of NPWT with a different type of NPWT. Data collection and analysis: We assessed trials for their appropriateness for inclusion and for their quality. This was done by three review authors working independently, using pre-determined inclusion and quality criteria. Main results: We included five trials with a total of 280 participants. Two trials involved skin grafts, two included orthopaedic patients undergoing arthroplasty and one included general and trauma surgery patients; all had unclear or high risk of bias. Four trials compared NPWT with a standard dressing and one trial compared two NPWT devices. There were no differences in the proportion of wounds completely healed; the incidence of seromas; or failed skin grafts. One trial (87 participants) compared a commercial negative pressure device (VAC® KCI, San Antonio, Texas) with a negative pressure system developed in the hospital (GSUC). The wound complication rate was lower in the GSUC group (VAC® 3/42; GSUC 0/45); the RR was 0.13 (95% CI 0.01 to 2.51). The mean cost to supply equipment for VAC® therapy was USD 96.51/day compared to USD 4.22/day for the GSUC therapy (P = 0.01). Labour costs for dressing changes were similar. Pain intensity score was also reported to be lower in the GSUC group when compared with the VAC® group (p = 0.02). One trial was stopped early because of a high incidence of fracture blisters in the NPWT group (15/24; 62.5%) compared with the standard dressing group (3/36; 8.3%)(RR 7.50; 95%CI 2.43 to 23.14). Authors' conclusions: There is no evidence for the effectiveness of NPWT on complete healing of wounds expected to heal by primary intention. There are clear cost benefits when non-commercial systems are used to create the negative pressure required for wound therapy, with no apparent reduction in clinical outcome. Pain levels are also rated lower when hospital systems are compared with their commercial counterparts. The high incidence of blisters occurring when NPWT is used following orthopaedic surgery suggests that the therapy should be limited until safety in this population is established. Given the cost and widespread use of NPWT, there is an urgent need for suitably powered, high-quality trials to evaluate the effects of the newer NPWT products that are designed for use on clean, closed surgical incisions. Such trials should focus initially on wounds that may be difficult to heal, such as sternal wounds or surgeries for obese patients