Incidence and Risk Factors for Low Anterior Resection Syndrome following Trans-Anal Total Mesorectal Excision

Background: Trans-anal total mesorectal excision (Ta-TME) is a novel approach for the resection of rectal cancer. Low anterior resection syndrome (LARS) is a frequent functional disorder that might follow restorative proctectomy. Data regarding bowel function after Ta-TME are scarce. The aim of this study was to evaluate the incidence and risk factors for the development of LARS following Ta-TME. Methods: A prospectively maintained database of all patients who underwent Ta-TME for rectal cancer at our institution was reviewed. All patients who were operated on from January 2018 to December 2021 were evaluated. The LARS score questionnaire was used via telephone interviews. Incidence, severity and risk factors for LARS were evaluated. Results: Eighty-five patients underwent Ta-TME for rectal cancer between January 2018 and December 2021. Thirty-five patients were excluded due to ostomy status, death, local disease recurrence, ileal pouch or lack of compliance. Fifty patients were included in the analysis. LARS was diagnosed in 76% of patients. Anastomosis distance from dentate line was identified as a risk factor for LARS via multivariate analysis (p = 0.042). Neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS. Conclusion: LARS is a frequent condition following ta-TME, as it is used for other approaches to low anterior resection. Anastomosis distance from dentate line is an independent risk factor for LARS. In this study neo-adjuvant therapy, hand sewn anastomosis and anastomotic leak did not increase the risk of LARS. Further studies with longer follow-up times are required to better understand the functional outcomes following Ta-TME.