P175 Clinical outcome of ulcerative colitis with mucosal healing demonstrated by white light endoscopy but with subtle abnormalities detected by high definition iSCAN endoscopy
M. Fort Gasia*1, R. Panaccione1, G. Kaplan1, S. Ghosh1, X. Gui2, M. Iacucci1
1University of Calgary, Department of Gastroenterology, Inflammatory Bowel Disease Clinic, Alberta, Canada, 2University of Calgary, Department of Pathology, Calgary, Canada
Current practice is to assess mucosal inflammation in patients with ulcerative colitis (UC) with white light endoscopy (WLE). However, novel endoscopic techniques such as high definition (HD) iSCAN endoscopy can demonstrate inflammation by showing changes in mucosal and vascular pattern in the apparently healed mucosa on WLE. However, the clinical significance of these subtle abnormalities is still unknown. We aimed to monitor the clinical outcome of patients with Mayo subscore of 0 and to determine if abnormalities detected on HD iSCAN endoscopy is associated with a worse prognosis of the disease
41 patients (16 female, median age 49) with quiescent UC Mayo subscore of 0 were followed during a median period of 20.3 months. All patients were previously endoscopically assessed by WLE and HD iSCAN (Pentax EPKi processor (EC-3490Fi; Pentax Tokyo) and Mayo endoscopic subscore was assigned to patients according to WLE findings. Mucosal pattern on iSCAN was graded as 1=normal, 2=mosaic pattern, 3=tubular-gyrus, 4=nodular rosette. The vascular pattern was graded as 1= normal, 2=spiral isolated vessels, 3=crowded tortuous vessels, 4=Irregular vessels. The validated New York Mount Sinai score was used to assess the grading of inflammation on histology. The clinical outcome was assessed by monitoring CRP levels, Mayo clinical score, further endoscopic evaluation, changes in treatment, use of steroids, introduction of new medication, admission to hospital and colectomy rate. Statistical analysis was performed with Chi Square test and compared the endoscopic findings between patients that flared and patients that remained stable.
Six patients (14.6%) out of 41 developed a relapse of UC during follow up. The initial endoscopic assessment of these six patients showed an abnormal mucosal pattern in 2 patients (33.3%) and an abnormal vascular pattern in 4 patients (66.6%). Among 35 patients that remained stable, 27 (77.1%) presented an abnormal vascular pattern and 5 (14.3%) had an abnormal mucosal pattern on HD iSCAN colonoscopy. Histologic assessment showed quiescent colitis in all patients. There was no statistical significance between patients that relapsed and those that did not relapse when comparing the distribution of normal and abnormal iSCAN scoring.
A high proportion of patients with mucosal healing on WLE have residual changes detected by HD iSCAN endoscopy. However, we could not demonstrate that this is associated with increased frequency of relapse or worse outcome of the disease. In addition, 14.6% of patients with Mayo endoscopic subscore of 0 relapsed during the follow up period. A more precise endoscopic score is needed to better describe the endoscopic features of mucosal healing in patients with UC.