PHOENIX – Applying continuous negative pressure to the incisional wound sharply reduces the incidence of surgical site infection after open colorectal surgery, according to results from a retrospective study.
A team led by Dr. Allison M. Bonds, a general surgery resident at the University of Texas Southwestern Medical Center at Dallas, studied 254 patients who underwent open colorectal surgery, whether planned or converted from a laparoscopic procedure.
In 13% of the patients, surgeons used incisional negative-pressure wound therapy, which entails standard wound closure followed by placement of a wound vacuum device over the completed stapled skin closure.
Study results, reported at the annual meeting of the American Society of Colon and Rectal Surgeons, showed that relative to the group receiving usual wound care, patients receiving incisional negative-pressure wound therapy were two-thirds less likely to develop a surgical site infection.
"Our study, although a retrospective chart review, does seem to show that the use of incisional negative-pressure wound therapy is associated with a decreased risk of surgical site infection," Dr. Bonds asserted. "This finding is significant enough that we feel it further needs a randomized controlled trial to see if there is actually a significant effect in the colorectal population."
Several attendees wondered about the cost of the negative-pressure wound therapy and how that was covered in the study population.
"We didn’t do an official cost analysis," Dr. Bonds replied. "Normally, the device that we used is associated with about $200 extra initially and then ... another $500 a day to use. So it is a fairly expensive addition to the care of the patients." She said she did not have data on how this cost was covered.
Dr. Jason Hall of the Lahey Clinic in Burlington, Mass., asked, "What was the indication to use the vac in those 32 patients?" and further wondered whether the patients receiving this therapy differed in ways that may have confounded the results.
"Placement of the vacuum wound device was left to the discretion of the surgeons," Dr. Bonds replied. "It’s hard to know exactly which patients would have been chosen for the study. There is some chance that the surgeons would have chosen the patients that they didn’t think would have a high rate of infection risk. But from our talking with the surgeons who use this, we believe that most of the vacuum devices were placed on patients who they had a high suspicion were going to get surgical site infections."
She agreed that there might have been selection bias at play, despite the study’s use of multivariate analysis. "That’s exactly why we believe that a randomized controlled trial is really the only way to show whether this is going to be a good technique to use or not," she said.
Cost of the therapy and its coverage will be major issues going forward, according to session comoderator Dr. Mark Welton of Stanford (Calif.) University. "Any time you are talking about downstream benefit to the insurer, they really need to see robust data before they are going to start to pay for that. So, especially in today’s health care environment, it’s going to come back to the patient paying for it. If you could talk about driving the cost associated with the wound infection down significantly, then the insurance companies would pay for it."
"Interestingly, there are companies coming out producing less expensive and less cumbersome devices. So I think it’s actually a very exciting idea, it’s intriguing. But we have a long way to go, and we do get to this cost-benefit question, and who’s going to pay for it," he said in an interview.
Dr. Kim Rhoads, the other session comoderator, also of Stanford University, said that "it’s an interesting concept," but she would like to see a standardized protocol detailing, for example, whether the vacuum and dressing are changed at some point and how long it has to be used for benefit; additionally, the indication for use should be worked out.
Also, "what we didn’t hear is how much fluid actually comes out ... because if nothing is coming out, you have to ask, what’s happening here and would that patient not have otherwise been wound infection free," she said. "We don’t know."
Incisional negative-pressure wound therapy has been used in orthopedic surgery for several years, according to Dr. Bonds. "At UT Southwestern, we began using this in 2010 [in colorectal surgery], and anecdotally saw that it seemed to be decreasing the rate of infections in our patients, so we thought that this warranted further study," she explained.