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

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.

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.

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.

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.