Randomized trial assessing anal sphincter injuries after stapled haemorrhoidectomy

Background: Conventional stapled haemorrhoidectomy involves the use of a large circular anal dilator (DL technique), which may cause anal sphincter injuries. This study compared whether the procedure can be effectively performed without this dilator (ND technique), with better sphincter preservation. Methods: Fifty-eight patients vith symptomatic prolapsed irreducible haemorrhoids were randomized to DL (n=29) and ND (n=29) groups. Preoperative continence scoring, anorectal manometry and endoanal ultrasonography were performed. These were repeated at up to 14 weeks after operation, with additional pain scores, analgesic requirements and quality of life assessments. Results: DL haemorrhoidectomy took significantly longer to perform (P=0.02). However, there were fewer residual skin tags (P=0.044) and less perianal pruritis (P=0.007) at 2 weeks, although such symptoms subsided to an equivalent level in both groups afterwards. Internal anal sphincter fragmentation persisting to at least 14 weeks was found in four patients after DL, but not after ND haemorrhoidectomy (P=0.038). However, these were asymptomatic and no differences were found in continence scores and anal pressures. The pain scores, satisfaction scores, quality of life assessments and time off work were similar. Conclusion: The large circular anal dilator used for stapled haemorrhoidectomy increased the risk of anal sphincter injuries, which may become problematic with ageing.