Background: Dye-spray chromoendoscopy (DCE) with targeted biopsies is the preferred technique for surveillance of dysplasia in long-standing colonic inflammatory bowel disease (cIBD). The aim of the study was to assess the effectiveness of virtual chromoendoscopy (VCE) with i-Scan and targeted biopsies in dysplasia detection in long-standing cIBD.
Methods: A prospective case-control study of long-standing (>7 years) cIBD patients referred for colorectal cancer (CRC) surveillance colonoscopy was performed from January 2013 to September 2016. Case group: VCE with i-Scan (mode 1 and mode 3 combined); control group: 0.4% indigo carmine DCE. All suspicious areas were biopsied and/or resected. High definition endoscopies and video processors (Pentax, Tokyo, Japan) were used. Exploration time and histologic characteristics were analyzed.
Results: 66 patients were included (33 in each group): 51.5% female; mean (SD) age at inclusion, 48.2 (13.0) yr; and median (IQR) disease duration, 15 (13–21) yr. Ulcerative colitis, 54 (81.8%); pancolitis, 39 (59.1%); smoking history, 52 (78.8%); and high risk of CRC, 59 (89.4%) patients. 44 lesions were detected in 35 patients (Table 1). There were no statistical significance differences in the number of lesions detected (dysplastic or not) between DCE (Figure 1) and VCE (Figure 2) (Fisher exact test). Time to intubation and withdrawal of the endoscope in control group were higher than in case group (mean, 5' vs. 3', p<0.001; and 15' vs. 11', p=0.002, respectively; student's t-test).
Conclusions: VCE with i-Scan present a similar diagnostic performance to conventional 0.4% indigo carmine DCE in the detection of colonic dysplasia in patients with long-standing cIBD. However, VCE with i-Scan appears to be a less time-consuming alternative to DCE.