Evaluating the Role of Mechanical Bowel Preparation in Anterior Resection Through a Prospective Randomized Single-Blinded Trial.

Introduction Mechanical bowel preparation (MBP) before colorectal surgery is a common practice to reduce bacterial levels and infection. However, recent studies and data analyses have shown that this practice may increase the incidence of postoperative septic complications. Limited information is available regarding MBP for rectal surgeries. Our study aimed to examine the impact of MBP on postoperative outcomes in patients undergoing anterior resection with primary anastomosis for rectal cancer in a single-blinded, single-center, prospective, randomized trial. Materials and methods Data were collected between September 2013 and December 2015 at the Amrita Institute of Medical Sciences, Kochi, India. All patients scheduled for elective anterior resection with primary anastomosis for cancer between 5 cm and 15 cm were included in the study. All patients were randomized into the MBP and non-MBP groups after obtaining consent using a computer-based randomizer. The MBP group underwent bowel preparation with polyethylene glycol 24 hours before the operation and received sodium phosphate rectal enemas the night before the procedure. In the non-MBP group, only dietary restriction with a low-residue diet for 48 hours was recommended. Laparoscopic and open surgeries were performed. A contrast enema with barium was performed on all patients on postoperative days 6-8 to detect an anastomotic leak. Our primary endpoint was to assess the rate of anastomotic leakage between the two groups. The secondary endpoints were surgical site infection and postoperative morbidity. Results A total of 78 patients were recruited in the trial, and 18 were excluded because the surgery was the Hartmann procedure or abdominal perineal resection. The remaining 60 patients were divided equally into the MBP and non-MBP groups. No clinically significant disparities were evident between the groups concerning the preoperative prognosticators of anastomotic leak. Among the cohort, anastomotic leakage occurred in eight patients, representing a 13.3% incidence. Remarkably, within this subset, seven patients (23.3%) were attributed to the non-MBP cohort, whereas only one patient (3.3%) belonged to the MBP group. These findings demonstrated a statistically noteworthy discrepancy. The two groups had no statistically significant difference in surgical site infection and postoperative morbidity. Conclusion Our study suggests the benefit of preoperative MBP in sphincter-preserving rectal surgery to reduce the anastomotic leak rate. Additionally, incorporating large-scale studies and meta-analyses could enhance the robustness of our conclusions.