Detection of Polyps Including Adenomas in the Ascending Colon by Cap-assisted Chromocolonoscopy with Indigo Carmine

chromocolonoscopy using indigo carmine increases the detection of colorectal polyps remains controversial. Additional indigo carmine spraying during cap-assisted colonoscopy is expected to improve the detection rate of colon polyps, especially adenomatous polyps. Therefore, this study aimed to evaluate the usefulness of cap-assisted chromocolonoscopy in the proximal colon for routine colonoscopic examinations. Hood cap-assisted colonoscopic examination was first performed, followed by hood capassisted chromocolonoscopy with 0.2% indigo carmine, from the cecum to the hepatic flexure. The total number and characteristics of polyps were compared before and after spraying indigo carmine. Cap-assisted chromocolonoscopy was performed in 86 consecutive patients. Before indigo carmine spraying, a mean of 0.56 polyps per patient and 0.29 adenomas per patient (52% of the polyps) were found. After spraying of the dye, a mean of 0.62 polyps and 0.22 adenomas (36% of these additional polyps) were found additionally. Most (85%) of these additional polyps found after spraying were small (<0.5 cm). In total, a mean of 1.17 polyps and 0.51 adenomas (44% of total polyps) were found before and after spraying of the dye. In this study, hood cap-assisted chromocolonoscopy using indigo carmine showed a higher detection rate of polyps (especially, small polyps <0.5 cm) and adenomas in the ascending colon than cap-assisted colonoscopy without spraying of the dye. It is unclear whether cap-assisted chromocolonoscopy can increase the detection rate of polyps and adenomas compared with chromocolonoscopy without cap. Detection of Polyps Including Adenomas in the Ascending Colon by Cap-assisted Chromocolonoscopy with Indigo Carmine