Diagnostic value of trans-recto-perineal ultrasound in perianal fistula—preoperative versus intraoperative findings: A comparative cross-section study

Abstract

Abstract Background Perianal fistula is a common and annoying anal problem. It needs only surgery. Magnetic resonance imaging is the best preoperative diagnostic tool, but it is demanding as it is expensive, time-consuming, and requires an experienced radiologist. Therefore, we endeavored to identify an alternative diagnostic tool that offers cost-effectiveness, efficiency, and accuracy. Subsequently, we conducted a comparative analysis between its preoperative outcomes and intraoperative observations. Materials and Methods This is a single-center comparative cross-section study held in the surgery department from September 2023 to March 2024. It included 93 patients with perianal fistulas who were diagnosed clinically and radiologically by trans-recto-perineal ultrasound and comparing preoperative ultrasound findings with intraoperative surgical findings. Results Trans-recto-perineal ultrasound demonstrated favorable sensitivity and specificity in diagnosing perianal fistulas. It exhibited accuracy in identifying external and internal openings, their locations, fistula branches, fistula types, and their relationship to anal sphincters, as well as the presence of abscess or fibrosis, with a significant statistical association ( p value <0.001). Conclusions Trans-recto-perineal ultrasound is an accurate, fast, and cheap diagnostic tool for perianal fistula; however, it can be used as an alternative to perianal magnetic resonance imaging.