Title: Comparison of Laser Versus Scissor Cutting in Closed Lateral Internal Sphincterotomy for Chronic Anal Fissure With Severe Sphincter Spasm: A Prospective Randomized Study of 50 Patients

Background: Lateral internal sphincterotomy (LIS) is the gold-standard surgical treatment for chronic anal fissure (CAF) refractory to conservative therapy. The 980-nm diode laser has been proposed as a less invasive alternative, but comparative data with the conventional scissor technique are limited. Objective: To compare postoperative outcomes of closed LIS using scissor cutting versus 980-nm diode laser in patients with CAF and severe sphincter spasm. Methods: Fifty patients with CAF >6 weeks, age ≤60, and without hemorrhoids, fistulae, diabetes, hypertension, or heart disease were randomized to scissor LIS (Group S, n=25) or laser LIS (Group L, n=25). The primary outcome was postoperative pain assessed via VAS at 6–72 hours and day 7. Secondary outcomes included complications, wound healing, time to return to work, and continence (Wexner score at 6 months). Results: Group S had significantly lower pain scores at 24–48 hours, fewer immediate complications, and earlier return to work compared with Group L. Wound healing and continence at 6 months were similar between groups. Conclusion: Closed scissor LIS provides superior early postoperative comfort and fewer complications than 980-nm laser LIS, while long-term outcomes remain comparable. Larger multicentric studies are required to validate these findings.