LARS is Associated with Lower Anastomoses, but not with the Transanal Approach in Patients Undergoing Rectal Cancer Resection

BACKGROUND: Low anterior resection syndrome (LARS) is a defecation disorder that frequently occurs after a low anterior resection (LAR) with a total mesorectal excision (TME). The transanal (ta) TME for low rectal pathologies could potentially overcome some of the difficulties encountered with the abdominal approach in a narrow pelvis. However, the impact of the transanal approach on functional outcomes remains unknown. Here, we investigated the effect of the taTME approach on functional outcomes by comparing LARS scores between the LAR and taTME approaches in patients with colorectal cancer. METHODS: We conducted a retrospective cohort study including 80 patients (n = 40 LAR-TME, n = 40 taTME) with rectal adenocarcinoma. We reviewed medical charts to obtain LARS scores 6 months after the rectal resection or a reversal of the protective ileostomy. RESULTS: At the 6-month follow-up, 80% of patients exhibited LARS symptoms (44% minor LARS and 36% major LARS). LARS scores were not significantly associated with the T-stage, N-stage, or neo-adjuvant radiotherapy. The mean distance of the anastomosis from the anal verge was 4.0 ± 2.0 cm. The taTME group had significantly lower anastomoses compared with the LAR-TME group (median 4.0 cm [IQR1.8] vs. median 5.0 cm [IQR 2.0], p < 0.001). Univariable analysis revealed significantly higher LARS scores in the taTME group compared with the LAR-TME group (median LARS scores: 29 vs. 25, p = 0.040). However, multivariable regression analysis, adjusting for neo-adjuvant treatment, anastomosis distance from the anal verge, anastomotic leak rate, and body mass index, revealed no significant effect of taTME on the LARS score (adjusted regression coefficient: − 2.147, 95%CI: − 2.130 to 6.169, p = 0.359). We also found a significant correlation between LARS scores and the distance of the anastomosis from the anal verge (regression coefficient: − 1.145, 95%CI: − 2.149 to − 1.141, p = 0.026). CONCLUSION: Fifty percentage of patients in this cohort exhibited some LARS symptoms after a mid- or low-rectal cancer resection. As previously described, LARS scores were negatively correlated with the distance of the anastomosis from the anal verge. TaTME was after adjustment for the height of the anastomosis not associated with higher LARS at 6 months when compared with LAR-TME.