Background

Following surgery, incisions are usually closed by fixing the edges together with sutures (stitches), staples, adhesive glue or clips. This process helps the cut edges heal together and is called 'healing by primary intention'. However, not all incised wounds are closed in this way: where there is high risk of infection, or when there has been significant tissue loss, wounds may be left open to heal from the 'bottom up'.

Treating open surgical wounds can be challenging - the wounds can be large, deep, at risk of infection and can produce a lot of liquid (called exudate) which is difficult to manage. Treatment options include wound dressings and the use of negative pressure wound therapy (NPWT), which is becoming a common treatment for a variety of wound types. NPWT involves the application of a wound dressing to the wound, followed by the attachment of a machine that applies a carefully controlled negative pressure (or vacuum) to the dressing. This sucks any wound and tissue fluid away from the treated area into a canister. NPWT may have a more positive effect on wound healing than alternative treatments. We investigated the evidence for the effectiveness of NPWT as a treatment for surgical wounds healing by secondary intention.

What we found

Despite extensive searching for all relevant medical studies that might provide evidence about the effectiveness of NPWT for treating surgical wounds healing by secondary intention, we found only two eligible studies. One study compared NPWT with use of an alginate dressing in surgical wounds healing by secondary intention. The study was small, with only 20 participants, and reported very limited information (data) for wound healing, which was the outcome in which we were most interested. Time to healing was shorter for participants in the NPWT group than participants in the alginate dressing group (median of 57 days to healing for NPWT group compared with 104 days for alginate dressing group). Although some participants in this very small study needed an amputation or died, there was no difference between treatments for the number of amputations or number of deaths. A second study compared NPWT with a silicone dressing in participants who had undergone surgical removal of a pilonidal sinus: median time to healing in the NPWT group was 84 days compared to 93 days in the dressing group.

There is currently a lack of evidence for both the benefits and potential harms of NPWT. More, better quality research is needed to determine the effectiveness of using NPWT on surgical wounds that are healing by secondary intention.

This research was assessed as being up to date in May 2015.