P485 Do intestinal ultrasound scores have a role in the diagnosis of post-operative recurrence?

Abstract

Abstract Background Ileocolonoscopy and Rutgeerts endoscopic score remains the gold standard to evaluate post-operative recurrence (POR) in Crohn's disease (CD) patients. Intestinal ultrasound (IUS) is proposed as a non-invasive alternative to ileocolonoscopy for the diagnosis of POR, with a sensitivity of 94% and specificity of 84%. There are several IUS scores that evaluate CD disease activity such as SUS-CD (validated), IBUS-SAS and Simple US Score, which have not yet been studied in the diagnosis of POR. The aim of this study is to assess whether IUS parameters and ultrasound scores correlate with endoscopy in the diagnosis of POR. Methods A unicentric retrospective study was performed. There were included patients with CD with both an ileocolonoscopy and intestinal ultrasound performed for the detection of POR, the time between tests was less than 6 months and there was no therapeutic change between tests. Endoscopic POR was evaluated with Rutgeers score (RS), considering POR RS ≥i2b. In IUS, were used: Simple US Score, SUS-CD and IBUS-SAS. Results 103 patients were included, baseline characteristics are in Table 1. 30 patients (29.1%) had no endoscopic POR, 22 (21.4%) had RS i2a, 12 (11.6%) RS i2b and 39 (37.9%) had severe POR (RS i3-i4). The mean wall thickness measured by IUS in patients without endoscopic POR was 2.7 mm (SD +/- 1.3) versus 5.0 (SD +/- 1.7) in patients with RS ≥i2b (p 0.001). Hyperemia (Limberg >1) was present in 60 patients (82.2%) with RS ≥i2a vs in 4 patients (13.3%) without endoscopic POR (p 0.001). Both hyperemia and wall thickness had a sensitivity of 89.0% and specificity of 76.7% in the diagnosis of POR. The mean values for IUS scores were: Simple US Score 5.5 (SD +/- 3.1), SUS-CD 2.1 (SD +/- 1.8) and IBUS-SAS 32.9 (SD +/- 26.3). There were positive correlation for IUS scores (Simple US Score r 0.68, SUS-CD r 0.68 and IBUS-SAS r 0.67) with RS (p <0.0001). For the Simple US Score an area under the ROC curve (AUC) of 84.13% (95% CI 76.81 – 91.45) was obtained, with a score ≥3, the sensitivity (S) was 82.19% and specificity (E) 80.0%. IBUS-SAS presented an AUC of 84.93% (95% CI 77.98 - 91.87), a result ≥15 granted a S 82.19% and E 80.0%. The SUS-CD index had an AUC of 83.38% (95% CI 75.55 - 91.20), a result ≥1 presented S 82.19% and E 80.0%. Conclusion In our experience, IUS scores (IBUS-SAS, SUS-CD and Simple US Score) show a high sensitivity and specificity in the diagnosis of POR. The three scores had AUC greater than 80%, IBUS-SAS showed slightly higher AUC results.