Chromoendoscopy for Surveillance in Ulcerative Colitis and Crohn's Disease: A Systematic Review of Randomized Trials

BACKGROUND & AIMS: Key international guideline agencies recommend dysplasia surveillance in inflammatory bowel diseases with chromoendoscopy. We performed a systematic review of randomized trials comparing chromoendoscopy vs other endoscopic techniques for dysplasia surveillance in inflammatory bowel diseases. METHODS: We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for relevant studies published through September 2016. We estimated risk ratios (RRs) for dichotomous outcomes (all-cause/colorectal cancer-related mortality, time to interval cancer, patients with dysplasia, total/subtypes of dysplastic lesions, dysplasia detected by targeted biopsies, adverse events), mean differences for continuous outcomes (procedural time, costs, total/targeted biopsies), and their 95% confidence intervals (CIs) using a random-effects model. Subgroup analyses included technique compared with chromoendoscopy, type of disease, and type of dye. We estimated sensitivity and specificity of the techniques with reference to histology. RESULTS: We identified 10 randomized trials (n = 1500 participants). There was a higher likelihood of detecting patients with dysplasia with chromoendoscopy compared with other techniques (RR, 1.37; 95% CI, 1.04-1.79). Subgroup analyses confirmed this effect only if chromoendoscopy was compared with standard-definition white-light endoscopy (RR, 2.12; 95% CI, 1.15-3.91). Chromoendoscopy required a significantly longer procedural time compared with other techniques (mean difference, 8.91 min; 95% CI, 1.37-16.45). There was no difference in the likelihood of detecting dysplastic subtypes and dysplasia by targeted biopsies between groups. Test sensitivity and specificity were similar between groups. CONCLUSIONS: In surveillance of inflammatory bowel diseases, chromoendoscopy identifies more patients with dysplasia only when compared with standard-definition white-light endoscopy. It is associated with longer procedural time with no direct evidence of effect on preventing all-cause/cancer-specific mortality or time to interval cancer.