Preoperative mechanical bowel preparation using conventional versus hyperosmolar polyethylene glycol-electrolyte lavage solution before laparoscopic resection for colorectal cancer (TLUMP test): a phase III, multicenter randomized controlled non-inferiority trial.

Background: A hyperosmolar ascorbic acid-enriched polyethylene glycol-electrolyte (ASC-PEG) lavage solution ensures excellent bowel preparation before colonoscopy; however, no study has demonstrated the efficacy of this lavage solution before surgery. This study aimed to establish the non-inferiority of ASC-PEG to the standard polyethylene glycol-electrolyte solution (PEG-ELS) in patients undergoing laparoscopic resection for colorectal cancer.

Methods: This was a prospective, single-blind, multicenter, randomized, controlled, non-inferiority clinical trial. Overall, 188 patients scheduled for laparoscopic colorectal resection for single colorectal adenocarcinomas were randomly assigned to undergo preparation with different PEG solutions between August 2017 and April 2020 at four hospitals in Japan. Participants received ASC-PEG (Group A) or PEG-ELS (Group B) preoperatively. The primary endpoint was the ratio of successful bowel preparations using the modified Aronchick scale, defined as "excellent" or "good."

Results: After exclusion, 86 and 87 patients in Groups A and B, respectively, completed the study, and their data were analyzed. ASC-PEG was not inferior to PEG-ELS in terms of effective bowel preparation prior to laparoscopic colorectal resection (0.93 vs. 0.92; 95% confidence interval, - 0.078 to 0.099, p = 0.007). The total volume of cleansing solution intake was lower in Group A than in Group B (1757.0 vs. 1970.1 mL). Two and three severe postoperative adverse events occurred in Groups A and B, respectively. Patient tolerance of the two solutions was almost equal.

Conclusions: ASC-PEG is effective for preoperative bowel preparation in patients undergoing laparoscopic resection for colorectal cancer and is non-inferior to PEG-ELS.