Ex vivo magnifying endoscopic observation of bile duct mucosa using narrowband imaging

Detailed endoscopic findings of the bile duct mucosa have not been fully established. This fundamental ex vivo study assesses the relationship between magnified endoscopic findings and pathological findings of the bile duct mucosa.

Forty-one surgically resected common bile duct mucosae were investigated. Each common bile duct was cut open longitudinally for ex vivo endoscopic observation. A magnifying endoscope commonly used for the gastrointestinal tract was used, using both white light imaging and narrowband imaging. After pathological diagnosis, the association between the magnifying endoscopic findings and histopathology was evaluated.

Totally, 39 non-neoplastic mucosae and 13 neoplastic mucosae were evaluated. In 13 non-neoplastic mucosae without inflammation, an oval-shaped depressed area and a fine, regular network of microvessels were observed. These findings were not clearly seen or not seen at all in the non-neoplastic mucosae with inflammation. Although vessels with loop-like structure were observed on all eight papillary tumors of 13 neoplastic mucosae, no characteristic vessels were seen on the other five.

Ishida and colleagues assessed the association between magnifying endoscopic findings and histopathological findings of the bile duct mucosa ex vivo. Oval-shaped, depressed areas and a fine, regular network of microvessels are characteristic features of normal bile duct mucosa, while loop structures may be indicative of a type of tumor vessel.