Anorectal dysfunction following low anterior resection for rectal carcinoma: a comparison between handsewn and stapled anastomosis

Abstract

Sphincter-saving resection for rectal carcinoma is frequently accompanied by anorectal dysfunction (increased stool frequency and varying degrees of faecal incontinence). Although numerous reports regarding this dysfunction have been published, the exact mechanism is still controversial. The purpose of the present study was to compare the functional results of low anterior resection (LAR) for rectal carcinoma following handsewn and stapled anastomosis. The patients with rectal carcinoma were divided into two groups: LAR with handsewn anastomosis (HS) (n = 15), and LAR with stapled EEA (U.S. Surgical Corporation) anastomosis (EEA) (n = 16; four with 28 mm stapler, 12 with 31 mm stapler). Sixteen patients with carcinoma of sigmoid colon who received high anterior resection (HAR) were taken as the control group. Anorectal functional study was performed preoperatively and post-operatively at 1 week and another after 6 months, whereas routine clinical assessment was carried out preoperatively and 6 months post-operatively. The post-operative maximal resting pressure was significantly reduced in both HS and EEA groups, while a tendency to recovery was observed in the HS and 28 mm stapler group 6 months later. A significant decrease in rectal capacity was noted in the EEA group. The return of rectoanal inhibitory reflex was observed in 67% of the HS group and 37.5% of the EEA group. Although clinically increased stool frequency was experienced in both HS and EEA groups, continence was significantly worse in the EEA group. LAR for rectal carcinoma results in impaired anorectal function, which might present clinically with increased stool frequency and minor faecal soiling. The former may be due partially to reduced neorectal capacity, while the latter may be due to internal anal sphincter dysfunction, possibly because of damage to innervation.