Chemical Bowel Preparation Exerts an Independent Preventive Effect Against Surgical Site Infection Following Elective Laparoscopic Colorectal Surgery

Abstract

Background: We investigated the independent clinical value of mechanical bowel preparations (MBP) and chemical bowel preparations (CBP) for preventing surgical site infection (SSI) in patients undergoing elective laparoscopic colorectal surgery. Materials and Methods: This retrospective cohort study included 475 patients who underwent elective laparoscopic colorectal surgery between January 2018 and March 2022. CBP was introduced in January 2021 and included kanamycin (1 g) and metronidazole (1 g) 2 times a day, the day before surgery. In some cases, MBP was omitted in patients who planned to undergo right-sided colectomy, those with tumor obstruction, and those with poor general conditions, depending on the judgment of the physician. The primary endpoint was the overall SSI incidence, while the secondary endpoints were the incidences of incisional SSI and organ-space SSI, culture from the surgical site, and length of postoperative hospital stay. Results: In total, 136 patients underwent CBP. MBP was omitted in 53 patients. Overall, SSI occurred in 80 patients (16.8%), including 61 cases of incisional SSI (12.8%) and 36 cases of organ-space SSI (7.6%). Multivariate logistic regression revealed that CBP exerted an independent preventive effect on overall and incisional SSI, whereas MBP did not. However, CBP was not associated with a decreased risk of overall SSI in patients who had undergone preoperative therapy, those with benign disease, and those with stoma formation in the subgroup analysis. Levels of Bacteroides species at the surgical site were significantly lower in the CBP group than in the non-CBP group. Postoperative hospital stay was significantly longer in the incisional SSI group than in the non-SSI group and was significantly longer in the organ-space SSI group than in the other groups. Conclusions: CBP, but not MBP, exerts an independent preventive effect on SSI, especially incisional SSI, in patients undergoing elective laparoscopic colorectal surgery.