Functional outcome of low rectal resection evaluated by anorectal manometry.

Background: Low anterior resection syndrome (LARS) covers disordered bowel function after rectal resection, leading to deterioration in patients' quality of life. The aim of this study was to evaluate anorectal function after laparoscopic low anterior resection (LAR) by means of standardized instruments.

Methods: This was a prospective clinical cohort study conducted in a single institution to assess functional outcome of patients 1 year after laparoscopic LAR by means of LARS score and high-resolution anorectal manometry.

Results: In total, 65 patients were enrolled in the study. Mean tumour height was 9.4 ± 1.8 cm; total mesorectal excision during laparoscopic LAR with low end-to-end colorectal anastomosis was performed in all patients. One year after the surgery, minor LARS was detected in 33.9% of patients, major LARS in 36.9% of patients. Anorectal manometry revealed decreased resting pressure and normal squeeze pressure of the anal sphincters in the majority of our patients. Rectal compliance and rectal volume tolerability (first sensation, urge to defaecate and discomfort volume) were significantly reduced. The statistical testing of the correlation between LARS and manometry parameters showed that with increasing seriousness of LARS, values of some parameters (resting pressure, first sensation, urge to defaecate, discomfort volume and rectal compliance) were reduced.

Conclusion: This study indicates that the majority of patients after laparoscopic LAR experience symptoms of minor or major LARS. These patients have decreased resting anal sphincter pressures, decreased rectal volume tolerability and decreased rectal compliance.