Literature review of the role of lateral internal sphincterotomy (LIS) when combined with excisional hemorrhoidectomy

Pain following hemorrhoidectomy is a distressing sequel to the procedure. Various methods have been used to alleviate post-hemorrhoidectomy pain; among these methods is the lateral internal sphincterotomy (LIS). This review aimed to analyze all studies that evaluated the impact of LIS on the outcome of excisional hemorrhoidectomy. Seventeen studies were included after organized search of the literature using electronic databases including PubMed/Medline and EMBASE. The studies included comprised 2180 patients with median age of 44 years. Variables selected for the review comprised patients' characteristics, postoperative pain assessment, analgesic consumption, and complications as fecal incontinence (FI), urinary retention, and anal stenosis. Overall, 933 (42.7 %) patients underwent LIS. Almost all studies assessing postoperative pain reported lower pain scores and less need for postoperative analgesia among patients who underwent LIS in comparison with patients who did not have LIS. Eleven of 13 studies that assessed continence state postoperatively reported higher rates of FI among patients who had LIS with a median rate of 7.7 % versus 1.25 % for patients who did not have LIS. Incidence of urinary retention after LIS ranged from 0 to 60 %. Anal stenosis occurred in 0-14.5 % of patients who had LIS versus 0-36.4 % in patients without LIS. LIS effectively reduced postoperative pain and need for analgesics following excisional hemorrhoidectomy. LIS also managed to decrease incidence of postoperative urinary retention and anal stenosis significantly. The negative aspect of adding LIS to excisional hemorrhoidectomy was developing minor FI after surgery which was temporary in duration.