Long term functional outcomes after transabdominal versus transanal total mesorectal excision: a matched comparative study

Background Transanal total mesorectal excision (TaTME) offers advantages for resection of low rectal tumours in patients with challenging access to the pelvis, but the functional outcomes relative to the conventional transabdominal approach are poorly understood. Methods Patients undergoing TaTME for cancer between 2009–2018 at 9 sites across Australia and New Zealand were eligible. Patients with a stoma or recurrent disease were excluded. Outcomes were compared to a matched cohort of patients who underwent transabdominal (laparoscopic or open) total mesorectal excision as part of the ALaCaRT trial. Patients were surveyed regarding bowel, urinary and overall function using the Low Anterior Resection Syndrome (LARS), International Prostate Symptom Score (IPSS) and the European Organization for Research and Treatment of Cancer (EORTC) CR29 validated scoring tools. Results In the TaTME group, 200 eligible patients were invited to participate, with 100 patients enrolled (survey response rate 50%). Major LARS was reported in 69.3% of patients. Mahalanobis distance matching was used to compare functional outcomes in interventional and control groups (83 patients in each group), showing poorer outcomes in the TaTME group regarding faecal incontinence (median EORTC CR29 score 28.5 vs 18.8, p  = 0.005), blood and mucus in stool (8.03 vs 4.02, p  = 0.04) and flatulence (42.6 vs 32.5, p  = 0.01). There were no significant differences in other domains. No difference was observed in urinary function (median IPSS score 6.38 vs 6.22, p  = 0.87) Conclusions While it affords advantages when pelvic access is challenging, TaTME may compromise functional outcomes relative to the transabdominal approach, particular regarding faecal incontinence.