Intersphincteric Sublevator Anal Fistula Complicated by Horseshoe Collection: MRI Findings and St James’s Classification

Abstract: Complex anal fistulas represent a diagnostic and therapeutic challenge due to their extension and high recurrence risk. Magnetic resonance imaging (MRI) plays a key role in preoperative assessment, enabling accurate mapping of fistulous tracts and associated collections. We report the case of a 50-year-old patient with an intersphincteric sublevator anal fistula complicated by a horseshoe collection, diagnosed on MRI and classified as grade II according to St James’s classification.