eP220 - Postoperative Bowel Dysfunction in Patients with Rectal Cancer – Does a Minimally Invasive Surgical Approach Improve Outcomes?

Purpose/Background: Several tumor- and treatment-level factors have been associated with the development of Low Anterior Resection Syndrome (LARS) following surgery for rectal cancer, with the majority being non-modifiable. Surgical approach has been proposed as a potentially modifiable risk factor for LARS, given the improved pelvic visualization and potential for nerve preservation with minimally invasive surgery (MIS). The purpose of this study was to evaluate the association of MIS approaches for rectal cancer with long-term postoperative bowel dysfunction.Methods/Interventions: This was an Institutional Review Board-approved observational cohort study including patients with rectal or rectosigmoid cancer who underwent surgical resection between 2007 and 2017 at a single tertiary-care institution. Patients were surveyed in 2019-2020 using the LARS score and only those who responded and who were stoma-free were included for analysis. Patient demographics, disease characteristics, and treatment details were retrospectively collected from the electronic medical record. MIS was defined as the use of laparoscopy or robotic surgery for the pelvic dissection; laparoscopic-assisted cases whereby the mesorectal excision was performed through a lower midline laparotomy were considered open surgery. The primary outcome was major LARS, defined as a LARS score of >/= 30. Multivariable logistic regression was used to evaluate the association of MIS approaches for rectal cancer with major LARS, adjusting for known confounders. A subgroup analysis was performed including patients with mid and low ( < 10cm from anal verge) rectal cancers only.Results/Outcomes: Among 749 potentially eligible patients, 514 (68.6%) responded to the survey and were included for analysis. The median age at surgery was 57.0 (50.0-65.0) years and the majority of patients were male sex (58.6%). In total, 195 (37.9%) patients underwent an MIS approach – 117 (60.0%) laparoscopic and 78 (40.0%) robotic. Over one-third (38.3%) of all patients underwent a total mesorectal excision (TME) with low colorectal or coloanal anastomosis, 50.2% had a diverting loop ileostomy, and 35.0% received radiation therapy (Figure 1). At a median follow-up of 6.1 (3.7-9.6) years from surgery, 222 patients (43.2%) had major LARS when surveyed (MIS: 41.0% vs. open: 44.5%, p=0.44). On multivariable logistic regression, surgical approach had no association with major LARS (MIS, aOR: 1.22, 0.80-1.86). Older age (aOR: 1.03, 1.01-1.04), female sex (aOR: 1.75, 1.16-2.67), TME (aOR: 1.74, 1.01-2.99), diverting ileostomy (aOR: 2.75, 1.50-5.04) and radiation therapy (aOR: 2.63, 1.60-4.33) were all associated with major LARS. On subgroup analysis of patients with mid and low rectal cancers (n=183), there remained no association between surgical approach and major LARS (p=0.07).Conclusion/

Discussion: MIS approaches were not associated with decreased major LARS following surgery for rectal cancer. Future studies should evaluate the impact of MIS approaches on other functional outcomes (genitourinary, sexual), where the loss of rectal reservoir and exposure to pelvic radiation may be less preeminent factors.Baseline characteristics