Clinical Outcomes of an Individualized Surgical Approach to Fistula-in-Ano: A Prospective Observational Study

Background: Fistula-in-ano is a common anorectal condition with significant morbidity.Optimal surgical management requires balancing fistula eradication with preservation of continence, particularly in complex cases.This study aims to evaluate outcomes of a tailored surgical approach using different modalities based on fistula complexity and sphincter involvement.Methods: This prospective comparative study includes 55 patients with fistula-in-ano, treated at a tertiary care center in India between August 2023 and July 2024.We evaluated patients clinically and with imaging (fistulogram/MRI) as needed.We then classified fistulas using Parks' and St. James University Hospital classifications.We selected surgical procedures (fistulotomy, fistulectomy, cutting seton, or fistulectomy with primary sphincter reconstruction) based on intraoperative findings of tract complexity and external anal sphincter involvement.Primary outcomes were healing time, time to return to work, recurrence, and fecal incontinence (assessed by Wexner score).Statistical analysis used Fisher's exact test.Results: We observed the highest incidence of fistula-in-ano in the 30-45-year age group (19, 34.5%).There were 43 males (78.2%) and 12 females (21.8%).Simple fistula was present in 43 patients (78.2%), while 12 (21.8%)had complex fistula.Multiple external openings were seen in 12 patients (21.8%), most commonly in suprasphincteric fistulas.The external opening was anterior to the transverse anal line in 40 patients (72.7%) and posterior in 15 (27.3%).We then performed MR fistulography in 12 patients (21.8%) with complex fistulas.Intersphincteric fistula was the most common type (41, 74.5%), followed by trans sphincteric (nine,16.4%)and suprasphincteric (five, 9.1%).Fistulectomy was the most common procedure (31, 56.4%), followed by fistulotomy (17, 30.9%), seton (five, 9.1%), and fistulectomy with primary sphincter reconstruction (two, 3.6%).Postoperative flatus incontinence occurred in three patients (5.4%), and we found recurrence in one patient (3.2%).Histopathology shows nonspecific inflammation in 55 patients (100%), with no granulomatous or malignant pathology.Conclusion: A tailored surgical strategy for fistula-in-ano, guided by precise classification and intraoperative assessment, achieves excellent healing with low recurrence (1.8%) and minimal impact on continence (5.4% minor incontinence).Fistulotomy is ideal for simple fistulas; seton or sphincter-preserving reconstruction for complex/high fistulas optimizes outcomes.