Bacteria in hernia sac: an important risk fact for surgical site infection after incarcerated hernia repair

Although some recent reports have proven that incarcerated and/or strangulated hernia is not contraindication to mesh repair, there is still a common concern owing to increased rate of postoperative surgical site infection (SSI). The aim of this clinical study was to evaluate factors that increase the risk of SSI after incarcerated hernia repair, and to identify the pathogens related to SSI.

A retrospective analysis was performed on data collected prospectively over a 4-year interval from January 2007 to December 2011. A total of 121 patients who underwent emergency surgery for incarcerated hernias were analyzed.

107 hernias were repaired using mesh versus 14 primary suture repairs. SSIs were observed in 9 of the 121 patients. Of 15 preoperative and intraoperative variables studied, duration of symptoms, diabetes mellitus, present of ileus, bowel resection or mesh repair performed, bacteria present in hernia sac and cloudy fluid in hernia sac were found to be significant factors predicting SSI. On multivariate analysis only bowel resection, duration of symptoms and bacteria present in hernia sac were independent variables. The most common pathogen found in hernia sac and cultured from wound drainage or swab was Escherichia coli. The strains of bacteria cultured from wound drainage or swab were same as those cultured from fluid in hernia sac in six of nine patients.

Gut-sourced E. coli is an important common organisms associated with SSI after incarcerated hernia repair. Prosthetic mesh could be used when no bowel resection is performed, duration of symptoms less than 24 h and fluid hernia sac is clear.