The role of mechanical bowel preparation and oral antibiotics for left-sided laparoscopic and open elective restorative colorectal surgery with and without faecal diversion

BackgroundThere is significant variation in the use of mechanical bowel preparation and oral antibiotics prior to left-sided elective colorectal surgery. There has been no consensus internationally.MethodsThis was a retrospective analysis of the 2015 American College of Surgeons National Surgical Quality Improvement Program database. Patients were divided into four groups: those who had mechanical bowel preparation with oral antibiotics, mechanical bowel preparation alone, oral antibiotics alone and no preparation. The main outcome measures included overall, superficial, deep and organ/space surgical site infections. Secondary outcomes included anastomotic leak, ileus and rate of Clostridium difficile.ResultsA total of 5729 patients were included for analysis. The overall surgical site infection rate (any superficial, deep or organ/space infection) was significantly lower in the mechanical bowel preparation and oral antibiotics approach when compared to no preparation (OR=0.46, 95% CI 0.36-0.59, P<0.0001). On multivariable logistic regression analysis, mechanical bowel preparation with oral antibiotics maintained a lower risk of overall surgical site infections. MBP and OAB also had a protective effect on anastomotic leak in both the laparoscopic and open cohorts (laparoscopic multivariable adjusted OR = 0.42 (0.19-0.94), P = 0.035; open multivariable adjusted OR = 0.3 (0.12-0.77), P = 0.012). Mechanical bowel preparation alone and oral antibiotics alone was not associated with a significant decrease in surgical site infections. There was no increase in C. difficile occurrences with the use of oral antibiotics.ConclusionMechanical bowel preparation with oral antibiotics significantly minimised surgical site infections and anastomotic leak following both laparoscopic and open left-sided restorative colorectal surgery. Mechanical bowel preparation alone did not reduce surgical site infections. There was a trend to reduction in surgical site infections with oral antibiotics alone.