The importance of reforming university and medical educations in Japan has been attracting attention. Looking at the details of higher education reforms in other countries, such as the U.S. and the U.K., we can see the philosophy of developing good doctors and good researchers. This philosophy has promoted research in education and created new terms and concepts. In Japan, third-party evaluations of the quality of education at each university are underway, and it would be a shame if some of these universities were to change the terminology and concepts only formally to superficially get through these evaluations; this is not conducive to true growth. Therefore, the purpose of this paper was to summarize the background of some important terms related to education that have been developed in Europe and the United States as a result of such reforms, and to introduce their importance to doctors who will design the gastrointestinal endoscopy education curriculum in the future.

Endoscopic full-thickness resection (EFTR) is categorized as exposed and non-exposed EFTR. In exposed EFTR, a full circumferential incision is made in the area surrounding the lesion to perform full-thickness resection first, with subsequent full-thickness closure of the defect. There are several options for defect closure, including the PolyLoop-and-clips method and endoscopic suturing. In non-exposed EFTR, the lesion base is closed using a dedicated full-thickness closure device, followed by full-thickness removal of the lesion. Exposed EFTR allows tumor resection regardless of tumor size, and it may result in higher R0 resection rate compared to non-exposed EFTR. However, a secure closure is essential to avoid peritoneal contamination and tumor dissemination after exposed EFTR. Although non-exposed EFTR can minimize these risks, the maximum size of the lesion that can be resected is limited by the size of the dedicated closure device, resulting in a substantial number of incomplete resections.

Many companies aiming at developing robotic surgical platforms have been emerging in the United States. Currently, several robotic surgical platforms for both laparoscopic and flexible endoscopic surgery are commercially available. In our prospective randomized study, robotic-assisted endoscopic submucosal dissection (ESD) resulted in significantly shorter procedure time, higher en-bloc resection rate, and lower perforation rate than conventional ESD. Newly developed flexible robotic surgical platforms are equipped with the latest robotic technology for the dedicated flexible endoscope and articulating surgical devices, which allows bimanual control of the surgical tools and potentially improves the precision and safety of flexible endoscopic surgery.

Aim: This study aimed to investigate the difference between white globe appearance (WGA) in patients with gastric cancer and non-cancerous gastric mucosa.

Methods: In this study, we retrospectively analyzed the clinical and pathological features of 41 patients with WGA in the stomach.

Results: WGA was found in patients with gastric cancer (n = 18) and those without gastric cancer (n = 23). Seven patients with gastric cancer (38.9%) and 17 patients without gastric cancer (73.9%) had been taking proton pump inhibitors (PPIs). Histologically, in the gastric cancer group, cystic dilatation of the gland was observed in 12/18 patients (66.7%), intraglandular necrotic debris (IND) in 12/18 patients (66.7%), and parietal cell protrusion (PCP) in 1/18 patients (5.6%). On the other hand, in patients without gastric cancer, cystic dilatation of the gland was observed in 8/14 patients (57.1%) and PCP in 7/14 patients (50.0%). IND was not found in patients without gastric cancer. In patients with autoimmune gastritis (n = 2), cystic dilatation of the gland duct was observed in both cases, but neither PCP nor IND was found. Some of the patients without gastric cancer had concomitant pathological features, including autoimmune gastritis (n = 2), scarring after endoscopic submucosal dissection (n = 2), adenoma (n = 1), lanthanum deposition (n = 1), and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in the stomach (n = 1).

Conclusions: These results suggest that the pathogenesis of WGA in patients with gastric cancer may be different from that of non-cancerous gastric mucosa. Using PPIs may contribute to the development of WGA in patients without gastric cancer.

A 70-year-old man with laryngeal and lung cancers presented for endoscopy. Esophagogastroduodenoscopy (EGD) revealed a 20-mm Type 0-Ⅱa＋Ⅱc gastric cancer located in the lesser curvature of the upper stomach. Since the gastric cancer was early-stage and asymptomatic, we proceeded with surgical treatment for the laryngeal and lung cancers because they had good prognosis. Histopathological examination revealed primary laryngeal cancer with lung metastasis. Three months later, he was diagnosed with anemia, and EGD showed that the gastric cancer had progressed from a 20-mm Type 0-Ⅱa＋Ⅱc tumor to a 50-mm Type 1 tumor. There was no progression of the laryngeal cancer. He required intermittent blood transfusions; subsequently, surgery was performed for the gastric cancer. Histopathological examination confirmed it as Type 1 gastric cancer (tub1 > tub2）, pT1b2, pN0, Stage IA. No relapse of the laryngeal or gastric cancer was detected for 13 months. We report this case because it exemplifies the rare progression of a gastric cancer.

A 70-year-old woman was referred to our department for further examination of a slightly elevated lesion (10 mm in size, with a depression at the top) located at the greater curvature of the antrum; the lesion was detected during a screening esophagogastroduodenoscopy. She had no history of Helicobacter pylori (H. pylori) eradication therapy, and the H. pylori IgG antibody titer was < 3 U/mL. The gastric mucosa showed no atrophy. Biopsy revealed tubular adenoma; however, magnifying endoscopy could not rule out the possibility of gastric cancer. Endoscopic submucosal dissection was performed with the patientʼs informed consent. Well-differentiated tubular adenocarcinoma was identified on histopathologic examination. Immunohistochemical staining was positive for CD10 and CDX2 and partially positive for MUC2, MUC5AC, and MUC6. This was a rare case of well-differentiated tubular adenocarcinoma with a predominantly intestinal phenotype pattern in the absence of H. pylori infection that developed in a mucosa without atrophy and intestinal metaplasia.

This case involved a 66-year-old male patient. He had left hemiplegia due to stroke and cervical injury and was experiencing repeated episodes of aspiration pneumonia. He could not take nutrients orally and was admitted to our hospital for gastrostomy placement. Chest radiography and abdominal computed tomography revealed complete visceral inversion. Percutaneous endoscopic gastrostomy was performed to prevent aspiration pneumonia. The gastrostomy was successfully used without any complications, and the patient was transferred to another hospital on the 27th postoperative day.

Patients with complete visceral inversion are relatively rarely encountered in clinical practice, and percutaneous endoscopic gastrostomy in these patients has not been previously reported because the techniques for positioning and intragastric manipulation have not been established.

An 81-year-old woman with hematochezia was referred to our hospital. Although iron-deficiency anemia was observed, we did not detect any bleeding source on contrast computed tomography, esophagogastroduodenoscopy, and colonoscopy. Capsule endoscopy revealed active bleeding at the ileum. Double-balloon endoscopy revealed an 8-mm torose lesion on the ileum. Clinical follow-up was done without resection of the polyp as the patient was taking two antiplatelet agents at the time of diagnosis. Since hematochezia and anemia had not improved at the follow-up visit, we decided to resect the polyp by cold snare polypectomy as the procedure is associated with less post-procedural bleeding when combined with local saline injection. Microscopic findings of the resected specimen confirmed the presence of an inflammatory polyp. Eighteen months after the polypectomy, there was no recurrence of anemia or rebleeding. These observations suggest that cold snare polypectomy combined with local saline injection may be useful in the management of small benign intestinal polyps.

Second-generation colon capsule endoscopy (CCE-2), PillCam^TM COLON 2, is useful not only for detecting colorectal polyps but also for evaluating vascular lesions and inflammatory lesions, such as ulcers and erosions. CCE-2 enables observation of the entire gastrointestinal tract using an adaptive frame rate (AFR) throughout the examination. Manual setting up of an AFR at the start of the examination allows the observation of small intestinal lesions and colonic lesions with sufficient bowel preparation. Further, it is possible to measure the gastric, small intestinal, and colonic transit times. The manual setup method is also effective for avoiding problems associated with the delay in automatic startup of the AFR. Pan-enteric visualization is useful for evaluating many diseases, such as inflammatory bowel diseases other than Crohnʼs disease, gastrointestinal polyposis, intestinal infections, vasculitis, graft-versus-host disease (GVHD) and nonsteroidal anti-inflammatory drug (NSAID)-induced mucosal injury. For patients with Crohnʼs disease, it is hoped that the pan-enteric PillCam^TM Crohnʼs system will be approved in Japan in the future, as in the Western countries. Herein, we describe our clinical experience with a method to visualize both the small intestine and colon using an AFR.

The pancreatic guidewire (PGW) method is widely used in clinical practice as an option for cases where biliary cannulation is difficult. Placing a guide wire in the pancreatic duct is expected to lead to the fixation of the papilla and straightening of the bile duct in the papilla. However, although the placement of the guidewire in the pancreatic duct makes it possible to suppress the mobility of the papilla itself, it is not possible to completely straighten the flexed intrapapillary bile duct. The endoscopists should always keep this fact in mind.

The PGW method is only one of several options, and successful biliary cannulation cannot be achieved without constructing an intubation strategy based on the morphology of the facing papilla, the shape of the oral protrusion, and the scope position after the placement of the pancreatic duct guidewire.

While the risk of post-operative pancreatitis should always be assumed, it is necessary to logically and protectively manipulate the safety and reliability of the placement of pancreatic duct guidewires and the proper use of various cannulation methods, depending on the case.

In December 1972, the same year that Japan and China normalized diplomatic relations, the first endoscopic examination in China was conducted at Peking Union Medical College with the Japanese doctorsʼ support. Since then, Japan and Chinaʼs gastrointestinal endoscopy societies have continued their friendship, and this history of exchange is now 50 years long. In 1999, the first China-Japan Workshop on Digestive Endoscopy and Gastroenterology was held at Shenyang for the purpose of improving endoscopic quality in China. At that time, Prof. Hirofumi Niwa, then president of the Japan Gastroenterological Endoscopy Society (JGES), Prof. William Chao of Hong Kong, and Prof. Yu Zhonglin of China organized the meeting. Since then, 11 workshops were held until 2018. The workshop scheduled in April 2020 to be held in Hangzhou was postponed due to the coronavirus disease pandemic, and a web-based exchange meeting was held instead in November 2020. JGES has long been in close contact with many Chinese endoscopists through the China-Japan Workshop on Digestive Endoscopy and Gastroenterology. Owing to a long history of exchange between China and Japan, such as these workshops, there is a strong relationship with trust that has been built-up by the senior doctors. I hope that the young doctors who will lead the next generation will continue to deepen their exchanges with Chinese endoscopists and contribute to the development of endoscopic medicine worldwide.

Objectives: We aimed to develop an artificial intelligence (AI) system for the real-time diagnosis of pharyngeal cancers.

Methods: Endoscopic video images and still images of pharyngeal cancer treated in our facility were collected. A total of 4559 images of pathologically proven pharyngeal cancer (1243 using white light imaging and 3316 using narrow-band imaging/blue laser imaging) from 276 patients were used as a training dataset. The AI system used a convolutional neural network (CNN) model typical of the type used to analyze visual imagery. Supervised learning was used to train the CNN. The AI system was evaluated using an independent validation dataset of 25 video images of pharyngeal cancer and 36 video images of normal pharynx taken at our hospital.

Results: The AI system diagnosed 23/25 (92%) pharyngeal cancers as cancers and 17/36 (47%) non-cancers as non-cancers. The transaction speed of the AI system was 0.03 s per image, which meets the required speed for real-time diagnosis. The sensitivity, specificity, and accuracy for the detection of cancer were 92%, 47%, and 66% respectively.

Conclusions: Our single-institution study showed that our AI system for diagnosing cancers of the pharyngeal region had promising performance with high sensitivity and acceptable specificity. Further training and improvement of the system are required with a larger dataset including multiple centers.