Role of Magnetic Resonance Fistulogram in Preoperative Assessment of Anorectal Fistulas: A Prospective Observational Study

BACKGROUND: Anorectal fistulas (AFs) are chronic inflammatory conditions featured by abdominal tracts linking the anal canal to the perineal skin, and precise delineation of such tracts is essential for effective surgical management. Magnetic resonance (MR) fistulogram clearly visualizes fistulous pathways and associated abscesses. However, literature remains limited on its association with intraoperative findings. Thus, the present study explored the role of MR fistulogram in the preoperative assessment of AFs. MATERIALS AND METHODS: This prospective observational study was conducted over 2 years (January 2024-December 2025) in the Department of Radiodiagnosis. The study included 125 adult patients of AF confirmed via clinical examination as well as radiological investigations, and scheduled for surgical intervention. MR fistulogram characteristics were noted, and the findings were confirmed with intraoperative observations. RESULTS: Patients were predominantly female (87.2%), with a mean age of 42.6 ± 13.2 years. Most patients presented within 1-6 months of symptom onset (40.8%), while perianal tenderness and external opening at the left perineum were common clinical findings (each 18.4%). According to the St. James University Hospital classification, Grade 1 (34.4%) and Grade 4 (26.4%) fistulas were most common. In all patients (100%), magnetic resonance imaging findings were confirmed intraoperatively. Fistula grades were significantly associated with male sex (P = 0.020), but not with age groups (P = 0.421) and duration of symptoms (P = 0.767). CONCLUSIONS: MR fistulogram had strong concordance with intraoperative findings, with male sex being significantly associated with fistula grades, thereby highlighting demographic dependency in preoperative AF assessment.