The Efficacy of Chemical Bowel Preparation Against Incisional Surgical Site Infection in Colorectal Cancer Surgery: A Propensity Score Matching Study

Abstract

Background/Aim: In colorectal cancer surgery, the risk of surgical site infection (SSI) is relatively high. The development of SSI is related to longer and costlier hospitalization and reduced quality of life; therefore, perioperative prevention of SSI is important. Chemical bowel preparation (CBP) combined with mechanical bowel preparation (MBP) may be more effective in preventing surgical site infection (SSI) compared to MBP alone. Since May 2021, we have been administering oral kanamycin and metronidazole as CBP, in addition to MBP, as a preoperative treatment for colorectal cancer surgery on the day before surgery. In this study, we investigated the clinical value of CBP in addition to MBP in colorectal cancer surgery using propensity score matching (PSM). Patients and Methods: From January 2017 to December 2021, 136 consecutive patients underwent radical surgery for sigmoid colon and rectal cancer at the Osaka Metropolitan University Hospital. Patients were divided into two groups: CBP and N-CBP. In the N-CBP group, we performed only preoperative MBP, whereas in the CBP group, we performed preoperative CBP in addition to MBP. We retrospectively analyzed this relationship with PSM. Results: Overall, 46 patients underwent preoperative CBP and MBP, 90 patients underwent preoperative MBP only. PSM was performed between the CBP and N-CBP groups based on the following ten factors: age, sex, diabetes mellitus, preoperative therapy, Glasgow Prognostic Score (GPS), operative time, blood loss, stoma, and pathological stage. After PSM, univariate and multivariate analyses of the relationship between SSI and clinicopathological factors were performed. Univariate analysis showed that age and CBP were correlated with the rate of SSI (p=0.039 and p=0.017, respectively), whereas sex was relatively correlated with the rate of SSI (p=0.066). The multivariate analysis of significant factors identified age of 75 or more and non-CBP as an independent risk factor for incisional SSI (HR=9.5; p=0.049 and HR=5.4×e⁻⁸; p=0.020). Conclusion: Preoperative CBP in addition to MBP was effective in preventing incisional SSI during colorectal cancer surgery.