title: Incisional negative pressure wound therapy decreases the frequency of postoperative perineal surgical site infections: a cohort study.
abstract: BACKGROUND
  Abdominoperineal resection is a procedure associated with high rates of perineal surgical site infections, causing distress to the patient, costs to the hospital system, and delays in further treatment.
  
  
  OBJECTIVE
  The aim of this study was to investigate the role of incisional negative pressure wound therapy in decreasing the rates of perineal surgical site infection.
  
  
  METHODS
  This retrospective cohort study had a historical, consecutively sampled control group.
  
  
  METHODS
  This study was conducted at a single-institution tertiary care academic institution.
  
  
  METHODS
  All patients undergoing an abdominoperineal resection between 2008 and 2012 were assessed.
  
  
  METHODS
  Perineal incisional negative pressure wound therapy was applied to all patients following an abdominoperineal resection between 2010 and 2012 at 125 mmHg continuous suction for 5 days postoperatively.
  
  
  METHODS
  The development of a perineal surgical site infection within the first 30 days postoperatively was the primary outcome measured.
  
  
  RESULTS
  Fifty-nine patients were included: 27 in the incisional negative pressure wound therapy group and 32 in the control group. A statistically lower proportion of perineal surgical site infections were detected in the incisional negative pressure wound therapy group than in the standard dressing group (15% vs 41%; p = 0.02). Both populations were similar in perioperative risk factors, with the exception of increased levels of blood urea nitrogen, a higher proportion of hypertensive patients, and a longer mean operative time in the incisional negative pressure wound therapy group. Additionally, an increased length of stay was observed in the incisional negative pressure wound therapy group (11 vs 8 days; p = 0.03). After adjusting for confounders, including the type of perineal dissection, incisional negative pressure wound therapy was found to be an independent predictor of not developing an surgical site infection (adjusted OR, 0.11; 95% CI, 0.04-0.66; p = 0.01).
  
  
  CONCLUSIONS
  The study's retrospective nature limits the results because of the risk of interpreter bias, although this was addressed in part by reviewing data in duplicate. We controlled for the potential for selection bias with our consecutive sampling model.
  
  
  CONCLUSIONS
  Our study demonstrates a role for incisional negative pressure wound therapy in decreasing rates of perineal surgical site infection following abdominoperineal resection. Prospective randomized trials will be required to further investigate this intervention.
authors.affiliation: 1Division of General Surgery, London Health Sciences Centre, London, Ontario, Canada 2Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
authors.forename: Sami A
authors.initials: SA
authors.lastname: Chadi
authors.forename: Biniam
authors.initials: B
authors.lastname: Kidane
authors.forename: Karen
authors.initials: K
authors.lastname: Britto
authors.forename: Muriel
authors.initials: M
authors.lastname: Brackstone
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ott
mesh_terms: D001005:Anus Neoplasms / Q000473:pathology / Q000601:surgery / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054843:Negative-Pressure Wound Therapy / Q000379:methods*; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D010502:Perineum; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000517:prevention & control*