COMPARISON OF PARTIAL INTERNAL SPHINCTEROTOMY (PIS) AND LATERAL INTERNAL SPHINCTEROTOMY (LIS) IN THE TREATMENT OF FISSURE IN ANO: A CRITICAL REVIEW

Anal fissures, which are small tears in the mucosal lining of the anus, can cause significant pain and discomfort. Partial Internal Sphincterotomy (PIS) and Lateral Internal Sphincterotomy (LIS) are two surgical interventions commonly employed to manage chronic anal fissures, aiming to reduce sphincter hypertonia and promote healing. This review article provides a comprehensive comparison of PIS and LIS in terms of efficacy, safety, and patient outcomes. PIS involves a limited incision of the internal anal sphincter, preserving more sphincter muscle and potentially reducing the risk of postoperative complications such incontinence. LIS, on the other hand, entails a more extensive lateral incision, which has been traditionally favored due to its high success rates in achieving fissure healing and pain relief. In evaluating the efficacy of both procedures, this review synthesizes data from multiple studies and clinical trials. LIS consistently demonstrates higher rates of fissure resolution, with healing rates often exceeding 90%. However, PIS shows comparable healing outcomes in many cases, particularly in patients with less severe fissures. The time to symptom resolution is generally shorter with LIS, but PIS presents a lower risk profile concerning postoperative fecal incontinence. The safety profile of both procedures is critically analyzed. LIS is associated with a higher incidence of temporary and, less commonly, permanent fecal incontinence, a significant concern for patient quality of life. PIS, while reducing this risk, may sometimes result in incomplete fissure healing or recurrence, necessitating further intervention. Patient satisfaction and quality of life metrics reveal that while LIS offers quicker symptom relief, the long-term satisfaction with PIS is comparable, given its conservative nature and lower complication rates. The choice between PIS and LIS should be tailored to individual patient needs, considering factors such as fissure severity, patient comorbidities, and risk tolerance for postoperative complications. In conclusion, both PIS and LIS are effective surgical options for treating chronic anal fissures. Further comparative studies are needed to refine surgical guidelines and optimize patient outcomes in the management of fissure in ano.