The method of injecting a clear gel into the lumen, the gel immersion method, was first reported in 2016. The viscosity of the gel prevents it from rapidly mixing with blood, intestinal juice, and food residue. As a result, the space occupied by the gel provides a clear visual field. Viscoclear, the gel dedicated for this method, was launched in October 2020. In addition to endoscopic hemostasis, it has been used in other endoscopic procedures such as ESD, EMR, EUS, reduction of volvulus, and foreign body retrieval. Since the visual field can be secured even while the lumen is collapsed, the redundant scope loop is reduced and maneuverability is improved. A low intraluminal pressure is maintained; this may reduce the patientʼs discomfort and risk of complications.

The incidence of Barrettʼs esophageal adenocarcinoma(BEA) is increasing in Europe and the United States. Recently, BEA has been gradually increasing in Japan. The pathological diagnosis, lesion background(short- or long-segment Barrettʼs esophagus; SSBE or LSBE), associated residual Barrettʼs esophagus(BE), and treatment strategies of these lesions differ between Japan and the West. In Japan, ESD is the mainstay of treatment for BEA, and the majority of cases are SSBE in origin. However, in Europe and the United States, more than half of the patients have LSBE. Furthermore, ablation therapy is recommended for BE itself due to the presence of dysplasia after endoscopic treatment of visible BEA lesions; however, this is not the case in Japan. Herein, we have described the ESD and treatment outcomes based on the changes in the 2022 Esophageal Cancer Treatment Protocol(12th edition) for Barrettʼs esophagus.

A 70-year-old female underwent an esophagogastroduodenoscopy. On white light imaging, a slightly elevated, granular, yellowish-white lesion was observed in the upper esophagus. Using magnifying narrow-band imaging, we observed yellowish-white circular structures arranged in an orderly fashion with dilated but uniformly shaped blood vessels. Histopathological examination revealed hyperkeratosis of the squamous epithelium and aggregation of foamy histiocytes beneath the epithelium, leading to a diagnosis of verruciform xanthoma. Over a three-year follow-up period, there was no change in the lesions. We report a case of esophageal verruciform xanthoma diagnosed using magnifying narrow-band imaging.

In 2016, a 42-year-old man presented to a primary care doctor with epigastric pain that did not improve with proton pump inhibitors. An EGD revealed active ulcers in the antrum of the stomach and duodenal bulb. Despite taking vonoprazan at 20 mg/day, the ulcerative lesions did not improve, and the patient was referred to our department. The initial EGD at our hospital showed no abnormalities in the esophagus but partially scarred multiple ulcers in the antrum and ulcer beds. Biopsy results from a gastric ulcer revealed eosinophil infiltration of ≥100/HPF. Based on these findings, we diagnosed the patient with eosinophilic gastroenteritis and started him on oral steroids. His symptoms improved, and he was subsequently given vonoprazan. His symptoms were stable with vonoprazan at 10 mg/day. However, the improvement of ulcerative lesions in the antrum was poor, and he was started on oral prednisolone (20 mg). One month after oral administration of prednisolone, EGD confirmed a healing tendency of gastric ulcer lesions, and the prednisolone was discontinued. After that, maintenance therapy with vonoprazan at 10 mg/day was continued, and the patientʼs symptoms and endoscopic findings did not show any significant change. However, in 2021, EGD surveillance revealed a coarse mucosal area with a loss of vascular permeability in the lower esophagus, accompanied by circular and longitudinal furrows and white plaque. Biopsy results from the esophageal lesion revealed marked eosinophilic infiltration, and we diagnosed an esophageal lesion of eosinophilic gastroenteritis. Although eosinophilic gastroenteritis can occur throughout the gastrointestinal tract, the asynchronous onset of esophageal lesions is rare in Japan. We report a case of eosinophilic gastritis developing an asynchronous esophageal lesion during surveillance.

A 45-year-old man undergoing hemodialysis was referred for melena. Upper gastrointestinal endoscopy revealed a 20-mm submucosal tumor, likely aberrant pancreas, at the gastric antrum. However, the bleeding point was not detected. Three days later, the patient experienced melena again, and the anemia worsened (hemoglobin, 4.9 g/dL). Another upper gastrointestinal endoscopy was performed, and a clot was found at the opening of the submucosal tumor, leading to suspicion of bleeding from the aberrant pancreas. Despite conservative treatments, the anemia worsened, and blood transfusions were frequently required. EUS revealed a submucosal tumor in the third layer, and ESD was performed for hemostasis. Pathological examination of the resected specimen led to the diagnosis of a hamartomatous inverted polyp, with the bleeding point suspected to have been an ulcer on the inverted mucosa. Hamartomatous inverted polyps are benign tumors that can cause bleeding, and ESD could be an option for hemostasis in certain cases.

A 56-year-old man was diagnosed with prerenal failure secondary to continuous severe diarrhea for one week. He received a large volume of fluid replacement therapy and was fasting for the management of suspected infectious enteritis. However, there was no improvement in both diarrhea and renal function. Stool culture tests showed no pathogenic bacterial growth, and the cause of the diarrhea remained unknown. CS revealed a diminished vascular pattern and crack-like mucosal grooves extending from the sigmoid colon to the rectum. Histopathological examination of random biopsy specimens obtained from different parts of the colon showed intraepithelial lymphocytic infiltration in the surface epithelium, leading to the diagnosis of lymphocytic colitis. Administration of cholestyramine improved diarrhea and renal function. Accurate detection of even minimal endoscopic findings and mucosal biopsy for histopathological evaluation are useful for the diagnosis of microscopic colitis, including lymphocytic colitis, in patients with chronic diarrhea of unknown cause.

Texture and color enhancement imaging (TXI) is a novel image-enhanced endoscopy technology that is available in the EVIS X1 endoscopy system. This imaging technology automatically optimizes the “structure,” “color tone,” and “brightness” of white light images, thereby improving lesion detection and the qualitative and quantitative diagnostic performance of endoscopy. However, there are not enough reports of its efficacy in daily clinical practice, and it is unclear when to use TXI. Based on our experience and previous reports, we aim to explore the efficacy of TXI in esophagogastroduodenoscopy.

Gastrointestinal endoscopy is an essential tool for diagnosing and treating inflammatory bowel disease in children. However, to ensure a safe and effective examination, it is crucial to consider pediatric-specific issues such as the indication for the examination, sedation, and choice of scope for each case. Pediatric gastrointestinal endoscopy involves overcoming several hurdles, including limitations on the scopes used due to the body weight of the child and the need for pediatricians and anesthesiologists to manage sedation and general care alongside the endoscopist. However, overcoming these hurdles and providing endoscopy with minimal pain and anxiety to children with inflammatory bowel disease will pave the way for the future development of inflammatory bowel disease care in Japan.

Objectives: Advances in endoscopic technology, including magnifying and image-enhanced techniques, have been attracting increasing attention for the optical characterization of colorectal lesions. These techniques are being implemented into clinical practice as cost-effective and real-time approaches. Additionally, with the recent progress in endoscopic interventions, endoscopic resection is gaining acceptance as a treatment option in patients with ulcerative colitis (UC). Therefore, accurate preoperative characterization of lesions is now required. However, lesion characterization in patients with UC may be difficult because UC is often affected by inflammation, and it may be characterized by a distinct “bottom-up” growth pattern, and even expert endoscopists have relatively little experience with such cases. In this systematic review, we assessed the current status and limitations of the use of optical characterization of lesions in patients with UC.

Methods: A literature search of online databases (MEDLINE via PubMed and CENTRAL via the Cochrane Library) was performed from 1 January 2000 to 30 November 2021.

Results: The database search initially identified 748 unique articles. Finally, 25 studies were included in the systematic review: 23 focused on differentiation of neoplasia from nonneoplasia, one focused on differentiation of UC-associated neoplasia from sporadic neoplasia, and one focused on differentiation of low-grade dysplasia from high-grade dysplasia and cancer.

Conclusions: Optical characterization of neoplasia in patients with UC, even using advanced endoscopic technology, is still challenging and several issues remain to be addressed. We believe that the information revealed in this review will encourage researchers to commit to the improvement of optical diagnostics for UC-associated lesions.

Currently, only a few drugs are approved for insurance coverage for sedation during endoscopy, and off-label drug use is commonly practiced due to a lack of public knowledge. To evaluate the current status of endoscopic sedation, we conducted a questionnaire-based survey of 270 medical institutions in the Hokuriku area where board-certified fellows of the Japan Gastroenterological Endoscopy Society work. We obtained questionnaire responses from 160 institutions, including 73 hospitals and 87 clinics. Sedation was found to be performed in 38.6% of 307,628 esophagogastroduodenoscopies and 25.4% of 86,034 colonoscopies at all institutions. The median percentage of sedation frequency at each institution was 25.0% (range, 0-98.1%) for esophagogastroduodenoscopies and 2.1% (range, 0-100%) for colonoscopies. Diazepam was the most commonly used sedative at each institution, accounting for 64.1% of esophagogastroduodenoscopies and 52.5% of colonoscopies, followed by midazolam, which accounted for 31.7% of esophagogastroduodenoscopies and 43.6% of colonoscopies. Propofol was used in 16.3% of institutions in one year, with 4,170 patients receiving it overall. Dexmedetomidine hydrochloride was used in 6.9% of institutions in one year, with 393 patients receiving it overall. In the past five years, serious adverse events such as six cases of respiratory arrest and one case of cerebral infarction have been reported. However, no deaths have been reported. Many endoscopists expressed the opinion (in free answers) that insurance coverage for sedation should be provided at the earliest. In conclusion, we assessed and reported the current status of sedation use in endoscopy. Although a few serious adverse events were reported, endoscopy under sedation was generally performed safely at most institutions.