P134. The impact of wireless capsule endoscopy in suspected Crohn's disease – a longitudinal study
B. Hall, G. Holleran, D. Costigan, O. Thornton, M. Dobson, D. McNamara, Department of Clinical Medicine and Gastroenterology, AMNCH & Trinity College, Dublin, Ireland
A definitive diagnosis of Crohn's disease (CD) can be difficult to make, often resulting in a significant lag between symptom onset and diagnosis, leading to an unnecessary delay in commencement of treatment. Wireless Capsule Endoscopy (WCE) is a relatively new imaging modality which has a significantly enhanced diagnostic yield for CD in comparison studies with other imaging modalities. The ability of WCE to differentiate CD from other causes of small bowel inflammation has been questioned. Longitudinal studies are required to assess the long term impact and significance of WCE findings in suspected CD.
A retrospective review was carried out on WCE procedures performed for suspected CD since 2010. Only patients with at least 6 months documented follow up were included. A chart review was undertaken to assess the impact of WCE findings and to correlate with subsequent clinical diagnosis and outcome. Clinical and biochemical parameters (Harvey–Bradshaw Index and C-reactive protein [CRP]) were also documented when available. All statistics were performed using SPSS 19.
In all 130 patients with a WCE for suspected CD were identified. In 35 (27%) follow up data was not available as they were referred from other institutions. Of the remaining 95 patients, 56 (58%) were female. The mean age was 44 (range 17–69). In total, 72 (76%) WCE's were negative and 23 (24%) positive for CD. The mean follow up was 13 months (range 8–24). Of the 72 negative tests, three patients (4%) were later diagnosed with CD, following histological confirmation one year after WCE. Of the 23 positive WCE investigations, 20 (87%) have a confirmed diagnosis of CD. The negative and positive predictive values are 96% and 87%, respectively. A univariate analysis using Pearson's coefficient showed a strongly positive correlation between results of WCE and subsequent clinical diagnosis (0.828 p < 0.01). Of interest, the HBI and CRP were both poorly correlated with WCE findings and final diagnosis.
Our data suggests that WCE is a reliable tool in effectively out-ruling the diagnosis of CD where baseline investigations have been inconclusive. Furthermore, WCE can successfully “pick-up” CD otherwise missed by conventional investigations. The poor correlation between the HBI and CRP with WCE findings suggests the possibility of a reservoir of small bowel disease not previously recognised and poorly correlated with current established tests.