Incidence and risk factors for incisional surgical site infection in patients with Crohn's disease undergoing bowel resection

Background: Patients with Crohn's disease (CD) are often reported to be at a high risk for incisional surgical site infection (SSI). The aim of this study was to identify the risk factors associated with post-operative incisional SSI in CD patients after bowel resection.

Method: CD patients undergoing bowel resection between 2007 and 2015 were enrolled. Demographic and clinical features related to post-operative incisional SSI were analysed using both univariate and multivariate logistical analyses.

Results: Of all eligible patients (n = 159), 123 (77.4%) were male, with a mean age at surgery of 33.4 ± 11.8 years. A total of 35 (22.0%) CD patients developed post-operative incisional SSI. Post-operative incisional SSI was more likely to happen in patients who had penetrating type of disease (P = 0.018), underwent bowel resection for the indication of chronic fistula (P = 0.005) and had an intra-operative finding of fistula (P = 0.001). A greater proportion of patients with post-operative incisional SSI were found to have anemia (P = 0.019) but elevated levels of white blood cells (P = 0.027), neutrophils (P = 0.006) as well as an elevated percentage of neutrophils (P = 0.005). Multivariate logistic regression analysis showed that anemia (odds ratio [OR]: 3.31, 95% confidence interval [CI]: 1.05-10.46, P = 0.041), an elevated percentage of neutrophils (OR: 2.85, 95% CI: 1.23-6.59, P = 0.014) and an intra-operative finding of fistula (OR: 3.76, 95% CI: 1.53-9.21, P = 0.004) were significantly associated with the risk for post-operative incisional SSI.

Conclusions: Anemia, elevated percentage of neutrophils and intra-operative finding of fistula are predictors for the development of post-operative incisional SSI in CD patients undergoing bowel resection. Favorable pre-operative nutrition status and low inflammatory status may lessen the incidence of post-operative incisional SSI.