P-LUM-03: Comparison of three-dimensional endoanal ultrasonography and findings at surgery in fistula-in-ano

BACKGROUND AND OBJECTIVES: Fistula-in-ano remains a diagnostic and treatment challenge. Accurate preoperative assessment of the nature of fistula is vital for surgery. Endoanal ultrasonography (EAUS) plays a major role in fistula assessment. EAUS can be performed using two-dimensional and three-dimensional (3D) views. The study objectives were to compare 3D EAUS with surgical findings and to determine the role of 3D view in fistula assessment. METHODS: A retrospective analysis was performed using a database maintained prospectively by a tertiary care unit in Sri Lanka since 2007. Twenty-eight were analyzed. The association was determined using Cohen’s Kappa test. RESULTS: Male/female ratio was 25:3. Mean age was 36.75 years. On 3D EAUS, primary tract was transphincteric and intersphincteric in 17 (60.7%) and 1 (3.6%), respectively. Abscesses were detected in 11 (39.3%). At surgery, transphincteric and interspincteric tracts were found in 22 (78.6%) and 5 (17.9%), respectively. Abscesses were detected in 6 (21.4%). 3D views showed poor association (κ = 0.164) with surgical findings. Poor association (κ = 0.105) exists between abscess detection by 3D EAUS and surgery. CONCLUSION: 3D EAUS has poor association with surgical findings in preoperative fistula assessment and abscess detection.