Lateral Internal Anal Sphincterotomy of Chronic Anal Fissure: An Experience of 165 Cases

Background: The anal fissure is frequently seen in surgical practice. It is caused by a longitudinal tear in the anoderm distal to the dentate line. The hallmark feature of the disease is severe pain during defecation. Chronic anal fissure (CAF) causes undue stress that leads to poor quality of life. Different options of treatment, whether medical or surgical, are employed to treat this condition. One of these modalities is lateral internal anal sphincterotomy (LIAS). Objectives: We aimed to assess the safety and efficacy of the LIAS surgical procedure for the treatment of CAF. Materials and methods: This retrospective study was conducted at the Al-Muqdadiya General Hospital, Diala, Iraq, for a period from January 2016 to March 2021. The medical records of the patients with CAF who were subjected to LIAS under local anesthesia were reviewed. Data regarding the age, gender, smoking habit, body mass index (BMI), healing time, complications, and outcome for each participant were recorded. Results: Of 165 participants, there were 91 men. The majority of the cases were ≤ 35 years (78.19%), were non-smokers (80%), and had no history of DM (98.79%). There was complete healing with a resolution of the pain at two months postoperatively in 163 subjects. The most common complication in our study was flatus incontinence (n = 5). All of them were found in the age group > 35 years and women. There were statistically significant differences between the age groups, gender, BMI, and the occurrence of flatus incontinence (P-value = 0.000, 0.012, and 0.009 respectively). However, there was no such association between smoking habit and a history of DM (P-value > 0.05). Conclusion: LIAS is safe and effective in the treatment of CAF, with an excellent outcome in resolving pain and a low complication rate. Age, female gender, and high BMI might affect the occurrence of flatus incontinence.