1.Image-Enhanced Endoscopy and Its Corresponding Histopathology in the Stomach
Hisashi DOYAMA ; Hiroyoshi NAKANISHI ; Kenshi YAO
Gut and Liver 2021;15(3):329-337
In recent years, the technological innovation and progress of endoscopic equipment have been remarkable, and various endoscopic observation techniques have been developed. Among them, representative techniques are magnified observation and narrow-band imaging. Magnifying endoscopy with narrow-band imaging (M-NBI) can visualize superficial microanatomies in the stomach. The normal morphology of the microanatomy visualized using M-NBI differs according to the part of the stomach. The vessel plus surface (VS) classification system has been developed as a diagnostic criterion for early gastric cancer using M-NBI, and its usefulness has been proven. Based on the VS classification system, a magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G), a simplified algorithm used for early gastric cancer diagnosis, was created. We aimed to describe the anatomic structure of the stomach that can be viewed using M-NBI and outline the principles and clinical application of the VS classification system and MESDA-G.
2.Image-Enhanced Endoscopy and Its Corresponding Histopathology in the Stomach
Hisashi DOYAMA ; Hiroyoshi NAKANISHI ; Kenshi YAO
Gut and Liver 2021;15(3):329-337
In recent years, the technological innovation and progress of endoscopic equipment have been remarkable, and various endoscopic observation techniques have been developed. Among them, representative techniques are magnified observation and narrow-band imaging. Magnifying endoscopy with narrow-band imaging (M-NBI) can visualize superficial microanatomies in the stomach. The normal morphology of the microanatomy visualized using M-NBI differs according to the part of the stomach. The vessel plus surface (VS) classification system has been developed as a diagnostic criterion for early gastric cancer using M-NBI, and its usefulness has been proven. Based on the VS classification system, a magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G), a simplified algorithm used for early gastric cancer diagnosis, was created. We aimed to describe the anatomic structure of the stomach that can be viewed using M-NBI and outline the principles and clinical application of the VS classification system and MESDA-G.
3.E-learning system to improve the endoscopic diagnosis of early gastric cancer
Kenshi YAO ; Takashi YAO ; Noriya UEDO ; Hisashi DOYAMA ; Hideki ISHIKAWA ; Satoshi NIMURA ; Yuichi TAKAHASHI
Clinical Endoscopy 2024;57(3):283-292
We developed three e-learning systems for endoscopists to acquire the necessary skills to improve the diagnosis of early gastric cancer (EGC) and demonstrated their usefulness using randomized controlled trials. The subjects of the three e-learning systems were “detection”, “characterization”, and “preoperative assessment”. The contents of each e-learning system included “technique”, “knowledge”, and “obtaining experience”. All e-learning systems proved useful for endoscopists to learn how to diagnose EGC. Lecture videos describing “the technique” and “the knowledge” can be beneficial. In addition, repeating 100 self-study cases allows learners to gain “experience” and improve their diagnostic skills further. Web-based e-learning systems have more advantages than other teaching methods because the number of participants is unlimited. Histopathological diagnosis is the gold standard for the diagnosis of gastric cancer. Therefore, we developed a comprehensive diagnostic algorithm to standardize the histopathological diagnosis of gastric cancer. Once we have successfully shown that this algorithm is helpful for the accurate histopathological diagnosis of cancer, we will complete a series of e-learning systems designed to assess EGC accurately.
4.Non-atrophic gastric mucosa is an independently associated factor for superficial non-ampullary duodenal epithelial tumors: a multicenter, matched, case-control study
Azusa KAWASAKI ; Kunihiro TSUJI ; Noriya UEDO ; Takashi KANESAKA ; Hideaki MIYAMOTO ; Ryosuke GUSHIMA ; Yosuke MINODA ; Eikichi IHARA ; Ryosuke AMANO ; Kenshi YAO ; Yoshihide NAITO ; Hiroyuki AOYAGI ; Takehiro IWASAKI ; Kunihisa UCHITA ; Hisatomi ARIMA ; Hisashi DOYAMA
Clinical Endoscopy 2023;56(1):75-82
Background/Aims:
The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy.
Methods:
This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions.
Results:
For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44–8.40; p<0.001).
Conclusions
Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.