Real-life chromoendoscopy for dysplasia surveillance in ulcerative colitis

AIM To evaluate the use of chromoendoscopy for surveillance of ulcerative colitis in a real-life community hospital setting.METHODS Patients with extensive ulcerative colitis, having disease duration of more than 8 years and who presented between the years of 1999 to 2013, were offered enrolment in this single cohort prospective study. All participants underwent standard bowel preparation with sodium phosphate and chromoendoscopy. Two expert endoscopists, novice to chromoendoscopy, evaluated each segment of the colon with standarddefinition colonoscopes after spray application of 0.4% indigo carmine. All observed lesions were recorded and evaluated before being removed and/or biopsied. In addition, nontargeted biopsies were taken from each segment of the colon. The dysplasia detection rate and dysplasia detection yield were ascertained. RESULTS A total of 21 neoplastic lesions(2 carcinomas, 4 of high-grade dysplasia and 15 of low-grade dysplasia) and 27 nondysplastic lesions were detected in 16 of the total 67 patients(70% male; median disease duration: 17 years; median age at diagnosis: 25 years; 92% aminosalicylate-treated). The dysplasia detection rate was 10.5%(7/67 patients). The dysplasia detection yield was 20.8%(10/48) for targeted biopsies and 3.5%(11/318) for nontargeted biopsies. The sensitivity and specificity for the macroscopic evaluation of neoplasia using chromoendoscopy were 48% [95% confidence interval(CI): 26%-70%] and 96%(95%CI: 93%-98%), respectively. The positive predictive and negative predictive values were 42%(95%CI: 27%-59%) and 97%(95%CI: 95%-98%), respectively. A total of 19/21 dysplastic lesions were detected in mucosa with histologic inflammation.CONCLUSION Chromoendoscopy seems to be of value for dysplasia surveillance of ulcerative colitis in a community hospital setting. The yield of non-targeted biopsies is negligible.