Immediate versus early (24-hours) urinary catheter removal after elective minimally invasive colonic resection: study protocol for a randomized, multicenter, non-inferiority trial

Background: Enhanced Recovery After Surgery (ERAS) represents the standard of care in colorectal surgery. Among ERAS items, early removal of urinary catheter (UC) is considered a key issue, though adherence to this specific item still varies among centers. UC placement allows for monitoring of post-operative urinary output but relates to an increased risk of urinary tract infection (UTI), reduced mobility, and patient's discomfort. Several studies investigated the role of early UC removal specifically looking at the rate of acute urinary retention (AUR) but most of them were retrospective, single-center, underpowered, cohort studies. The main purpose of this study is to compare the rate of AUR after immediate (at the end of the surgery) versus early (within 24 h from the completion of surgery) removal of UC in patients undergoing minimally invasive colonic resection (MICR). The secondary outcomes focus on goals that could be positively impacted by the immediate removal of the UC at the end of the surgery. In particular, the rate of UTIs, perception of pain, time-to-return of bowel and physical functions, postoperative complications, and length of hospital stay will be measured.Methods: This is a prospective, randomized, controlled, two-arm, multi-center, study comparing the rate of AUR after immediate versus early removal of UC in patients undergoing MICR. The investigators hypothesize that immediate UC removal is non-inferior to 24-h UC removal in terms of AUR rate. Randomization is at the patient level and participants are randomized 1:1 to remove their UC either immediately or within 24 h from the completion of surgery. Those eligible for inclusion were patients undergoing any MICR with an anastomosis above the peritoneal reflection. Those patients who need to continue urinary output monitoring after the surgery will be excluded. The number of patients calculated to be enrolled in each group is 108 based on an expected AUR rate of 3% for the 24-h UC removal group and considering acceptable an AUR of 9% for the immediate UC removal group.Discussion: The demonstration of a non-inferiority of immediate versus 24-h removal of UC would call into question the usefulness of urinary drainage in the setting of MICR.