Effects of rectal mobilization and lateral ligaments division on colonic and anorectal function

PURPOSE: Colonic and anorectal function are altered after posterior rectopexy. The aim of this randomized, prospective study was to evaluate the effects of rectal mobilization and division of the lateral ligaments on colonic and anorectal function. METHODS: Posterior rectopexy was performed in 18 patients with complete rectal prolapse. Anal manometry and measurement of rectal compliance, total and segmental colonic transit time, constipation score, and defecation frequency were performed preoperatively and three months postoperatively. Ligaments were divided in ten patients. RESULTS: Mean preoperative total transit time was similar between the two patient groups and doubled postoperatively (P=0.03). Mean postoperative segmental transit time increased by a factor of 1.7 in segments I (ascending colon) and II (descending colon) and by a factor of 2.3 in segment III (rectosigmoid). The same pattern was found in both groups. Mean resting pressure decreased after division of the lateral ligaments and increased after preservation. Mean rectal compliance decreased after division of the ligaments and increased when they were preserved. Mean postoperative constipation score differed little from the preoperative score. Mean defecation frequency was decreased in the group with the ligaments preserved and increased in the group with the ligaments divided. None of the effects of rectal mobilization or division of the lateral ligaments on anorectal function reached statistical significance. CONCLUSION: Rectal mobilization had a statistically significant effect on colonic function. Total and segmental colonic transit times doubled. The effects on anorectal function were not significant. Division of the lateral ligaments did not significantly influence postoperative functional outcome.