Tailored lateral internal sphincterotomy: a retrospective analysis on functional and recurrence outcomes in a highly selected cohort

Background Lateral internal sphincterotomy (LIS) is the gold standard treatment for chronic anal fissure (CAF), but concerns regarding postoperative fecal incontinence limit its acceptance. Tailored LIS, restricted to the fissure apex, has been proposed to preserve continence while maintaining efficacy. This study aimed to evaluate functional outcomes and recurrence rates after tailored LIS in a highly selected cohort. Methods A retrospective single-center study was conducted including patients with idiopathic CAF and increased anal sphincter tone undergoing tailored LIS between January 2019 and December 2024 after failure of conservative therapy. Patients with preoperative continence impairment or additional confounding factors were excluded. Continence was assessed pre- and postoperatively using the Vaizey score. Postoperative continence disorder was defined as Vaizey ≥ 1. Recurrence was defined as fissure persistence or relapse requiring re-intervention. Results Sixty-two patients completed at least 1-year follow-up (median 3 years). All had a preoperative Vaizey score of 0. Clinical success was achieved in 60 patients (96.8%; 95% CI 88.8–99.6%), while recurrence occurred in 2 patients (3.2%; 95% CI 0.4–11.2%). Nine patients (14.5%; 95% CI 6.9–25.8%) developed some degree of continence alteration within the first postoperative year. No cases of solid stool incontinence were observed (0%; 95% CI 0–5.8%). Gas incontinence occurred in 14.5% (95% CI 6.9–25.8%) and liquid stool incontinence in 4.8% (95% CI 1.0–13.5%). Mild continence alteration (Vaizey 1–4) was observed in 9.7% (95% CI 3.6–19.9%) and moderate incontinence (Vaizey 5–9) in 4.8% (95% CI 1.0–13.5%). Conclusions In appropriately selected patients, tailored LIS achieves high healing rates with a low incidence of clinically relevant continence impairment at mid-term follow-up. Limiting sphincter division to the fissure apex appears to balance efficacy and continence preservation.