A Comparison of Conventional Endoscopy and the Flexible Spectral-Image Color Enhancement System for the Detection of Colorectal Polyps

Abstract

Purpose: Chromocolonoscopy using indigo carmine dye is a reliable method for detecting colorectal polyps. However, dye spray is essential for this method and consequently a longer procedure time is required. The flexible spectral-image color enhancement (FICE) system enhances the contrast of the mucosal surface without the use of dyes, thus allowing the detection of colorectal polyps. Methods: Between September 2007 and October 2008 in one institution, 27 patients who underwent their first surveillance colonoscopy after a bowel resection for rectal or left-sided colon cancers were entered into the study. Prior to colonoscopy, 27 cases were divided into 2 groups; Group A: The cecum to the splenic flexure was observed using conventional endoscopy. After reaching the splenic flexure, the FICE system was used and then returned to the cecum. A second observation from the cecum to the splenic flexure was made using the FICE system. Between the splenic flexure and the anus, the first and second observations were made in the same order. Group B: Observation by conventional and FICE endoscopy were made in reverse order. All examinations were performed using high-resolution colonoscopes (EC-590ZW) with the FICE system to detect colorectal polyps. During the second observation, lesions were resected using standard endoscopic techniques. The number of the lesions detected was set as the endpoint. The paired student t test was applied to compare the number of the lesions detected in each stage. Results: Twenty-seven patients comprising 16 patients in Group A and 11 patients in Group B were studied. In Group A, total 58 lesions (mean size 3.7 mm; proximal colon 40, distal colon 14, rectum 4) were detected and the histology showed adenomas in 51, inflammatory polyps in 3, hyperplastic polyps in 2 and mucosal tags in 2. The mean number of polyps detected by FICE endoscopy was significantly higher than that using conventional endoscopy (3.56 ± 1.04 vs. 2.38 ± 0.71, p=0.0081). Also, the mean number of adenomas demonstrated a significant difference between FICE and conventional endoscopy (3.13 ± 0.91 vs. 2.06 ± 0.59, p=0.0079). In Group B, there was no significant difference in the mean number of polyps and adenomas comparing FICE and conventional endoscopy. Conclusion: FICE endoscopy detected a greater number of colorectal polyps compared with conventional endoscopy. Furthermore, this method may be efficient at detecting neoplastic polyps. The FICE system may be applicable for routine colonoscopy.