P-LUM-17: Comparison of two-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 nature of fistula is vital for surgery. Endoanal ultrasonography (EAUS) plays a major role in fistula assessment. EAUS can be performed using two-dimensional (2D) and three-dimensional views. The study objectives were to compare 2D EAUS with surgical findings and to determine the role of 2D 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. A total of 101 were analyzed. The association was determined using Cohen’s Kappa test. RESULTS: Male/female ratio was 92:9. Mean age was 39.56 years. On 2D EAUS, primary tract was transsphincteric and intersphincteric in 74 (73.3%) and 16 (15.8%), respectively. Abscesses were detected in 22 (21.8%). At surgery, transsphincteric and intersphincteric tracts were found in 69 (68.3%) and 21 (20.8%), respectively. Abscesses were detected in 18 (17.8%). 2D views showed fair association (κ= 0.298) with surgical findings. Moderate association (κ= 0.440) exists between abscess detection by 2D EAUS and surgery. CONCLUSION: 2D EAUS has fair association with surgical findings in preoperative fistula assessment and moderate association in abscess detection.