The impact of the anastomotic configuration on low anterior resection syndrome 3 years after total mesorectal excision for rectal cancer: a national cohort study

Abstract

Aim: After low anterior resection, the bowel can be anastomosed in different ways. It is not clear which configuration is optimal from a functional and complication point of view. The primary aim was to investigate the impact of the anastomotic configuration on bowel function evaluated by the low anterior resection syndrome (LARS) score. Secondarily, the impact on postoperative complications was evaluated. Method: All patients who had undergone low anterior resection from 2015 to 2017 were identified in the Swedish Colorectal Cancer Registry. Three years after surgery, patients were sent an extensive questionnaire and were analysed based on anastomotic configuration (‘J-pouch/side-to-end anastomosis’ or ‘straight anastomosis’). Inverse probability weighting by propensity score was used to adjust for confounding factors. Results: Among 892 patients, 574 (64%) responded, of whom 494 patients were analysed. After weighting, the anastomotic configuration had no significant impact on the LARS score (J-pouch/side-to-end OR 1.05, 95% confidence interval [CI] 0.82–1.34). The J-pouch/side-to-end anastomosis was significantly associated with overall postoperative complications (OR 1.43, 95% CI 1.06–1.95). No significant difference was seen regarding surgical complications (OR 1.14, 95% CI 0.78–1.66). Conclusion: This is the first study investigating the impact of the anastomotic configuration on long-term bowel function, evaluated by the LARS score, in an unselected national cohort. Our results suggested no benefit for J-pouch/side-to-end anastomosis on long-term bowel function and postoperative complication rates. The anastomotic strategy may be based upon the anatomical conditions of the patient and surgical preference.