| Theme |
Re-thinking Chromoendoscopy |
| Title |
Present State and Future Goals for Magnifying Colonoscopy Using Indigocarmine and Crystal Violet Spraying |
| Author |
Kazuhiro Kaneko |
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital |
| Author |
Hiroaki Ikematsu |
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital |
| Author |
Yusuke Yoda |
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital |
| Author |
Tsutomu Saraya |
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital |
| Author |
Chihiro Tsunoda |
Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital |
| [ Summary ] |
Magnifying observation of surface structures using indigocarmine and crystal violet dye is useful in diagnosing colorectal lesions according to pit pattern classification. After conventional observation, dysplastic and non-dysplastic lesions are diagnosed using indigocarmine spraying. In contrast, additional observation with crystal violet spraying is required when deeper lesion infiltration is suspected into the submucosal layer. Lesions without demarcated areas areevaluated as having non-invasive patterns. Those lesions with demarcated areas are evaluated as having invasive patterns, along with irregular, distorted crypts. Lesions displaying non-invasive patterns and invasive patterns are considered to be intramucosal lesions with carcinomas infiltrating deeper into the submucosal layers. The accuracy of histologic diagnosis and findings from magnifying colonoscopic observation is over 95%. In contrast, magnifying observation for Narrow Band Imaging (NBI) colonoscopy is also useful to diagnose colorectal lesions. Accuracy for NBIobservation is the same as that for pit pattern observation. Positive predictive values for NBI observation tend to be low, compared to the evaluations based on pit pattern classification. Thus, the diagnostic values for NBI are inferior to those for pit patterns in cases with carcinomas infiltrating deeper into the submucosal layer. We propose the use of magnifying NBI observation after conventional observation. Additional observation according to pit pattern classification should also be carried out when submucosal carcinomas are suspected. |