For the diagnosis of gastroesophageal reflux disease (GERD), the anti-reflux barrier (ARB) of the stomach and esophagus can be considered extramural or intramural. The extramural ARB includes the diaphragmatic hiatus and the esophageal diaphragmatic ligament. The intramural ARB comprises Phase I on the gastric side (collar sling muscle fibers and clasp muscle fibers), Phase Ⅱ on the esophageal side (LES), and Phase Ⅲ on the esophageal side (upper esophageal sphincter (UES) and peristalsis). This can be inferred by combining endoscopic pressure study integrated system (EPSIS) and high resolution manometry (HRM) to elucidate the pathophysiology of GERD. Regarding GERD, 70% of GERD cases are non-erosive gastroesophageal reflux disease (NERD), and most do not have a hernia. These conditions are good candidates for endoscopic anti-reflux surgery. The treatments range from anti-reflux mucosal resection (ARMS) to anti-reflux mucosal ablation (ARMA), anti-reflux mucoplasty, and anti-reflux mucoplasty with valve formation (ARM-PV). Evidence of the safety and efficacy of ARMS/ARMA has been reported in three systematic reviews. In the future, treatments are expected to develop along two main lines: the ideal pursuit of ARM-PV and the appealing technical simplicity of ARMA.

Gastric adenocarcinoma of the fundic gland type is a gastric epithelial neoplasia newly added to the 15th edition of the Japanese Gastric Cancer Guideline and the 5th edition of the WHO Classification of Tumors. We proposed gastric adenocarcinoma of the fundic gland type as a rare gastric epithelial neoplasia with low-grade atypia in 2010. Gastric epithelial neoplasm of fundic-gland mucosa lineage is considered a Helicobacter pylori-uninfected gastric cancer and can be histopathologically classified as gastric adenocarcinoma of the fundic gland type and gastric adenocarcinoma of the fundic gland mucosa type. Clinicopathological and endoscopic features have also been elucidated. Although there have been several reports on genetic abnormalities, the risk factors and mechanisms of carcinogenesis have not been clarified. In addition, gastric adenocarcinoma of the fundic gland type demonstrates low-grade epithelial neoplasm, and its clinical treatment strategy, including the indication for additional surgery after endoscopic treatment, is controversial. In the future, treatment outcomes and long-term prognostic analysis based on histopathological classification should be performed to establish guidelines for the endoscopic treatment of gastric epithelial neoplasms of fundic-gland mucosa lineage.

Although percutaneous endoscopic gastrostomy (PEG) is safe, hepatic portal venous gas may develop, resulting in death. Among 266 patients who underwent PEG at our hospital, seven developed hepatic portal venous gas. However, all the patients were stable, did not develop gastrointestinal ischemia or peritonitis, and improved with conservative treatment. Fever, nausea, and vomiting are often seen as associated symptoms. Therefore, hepatic portal venous gas should be considered in the differential diagnosis of patients with fever, nausea, or vomiting. Stable patients without gastrointestinal ischemia or peritonitis may improve with conservative treatment.

Reports of duodenal neoplasms have recently increased, possibly because of advances in endoscopic equipment and widespread treatment of Helicobacter pylori eradication. Hida et al. classified gastric-type duodenal neoplasms into “adenomas,”“invasive carcinomas,”and“borderline lesions: neoplasm of uncertain malignant potential (NUMP).” NUMP is a tumor comprising slightly atypical epithelial cells growing in a fused or anastomosing glandular pattern, often with expansive submucosal extension, without severe nuclear atypia or lymphatic or vascular invasion. Here, we report a case of NUMP treated with pancreaticoduodenectomy.

A type 0-I lesion with a submucosal bulge was noted in the duodenal bulb of a 73-year-old man during an upper gastrointestinal endoscopy. A biopsy of the lesion suggested a NUMP. However, because EUS showed submucosal invasion of the duodenum with a concomitant intraductal papillary mucinous tumor of the pancreas, he underwent pancreaticoduodenectomy and was finally diagnosed with NUMP. The treatment of NUMP has not yet been established, and an accumulation of such cases is needed.

A man in his 20s was referred to our hospital with anorectal pain and bloody stools. A colonoscopy revealed a hemorrhagic ulcer in the lower anterior wall of the rectum, lymphofollicular hyperplasia, and longitudinal erosion in the terminal ileum. Biopsy revealed a non-caseating epithelioid cell granuloma, and Crohnʼs disease was suggested as a differential diagnosis. Blood tests were positive for syphilis serodiagnosis, and pathological specimens were positive for antibodies against treponema of syphilis. Stage Ⅱ syphilis was diagnosed based on a history of anal intercourse with a man and skin and pubic findings. The patient was started on AMPC (1,500mg/day), and his skin rash and abdominal symptoms resolved. Three months later, scarring of a rectal ulcer was observed. The incidence of syphilis is increasing in Japan, and the chances of encountering syphilitic enterocolitis are assumed to increase. Therefore, understanding the pathophysiology and endoscopic findings is crucial, and a detailed history-taking and systemic examination should be performed if syphilitic enterocolitis is suspected.

A 77-year-old man undergoing percutaneous endoscopic gastrostomy (PEG) for Parkinsonʼs disease developed an infected hepatic cyst (IHC), and percutaneous drainage was performed repeatedly. In this case, the enlarged and recurrent IHC caused fever and reflux from the PEG owing to compression of the gastric antrum. Because the inside of IHC was suspected to be mucinous, we determined that lumen-apposing metal stent (LAMS), which is a one-step procedure and has a large diameter, is the most suitable stent for the IHC drainage instead of conventional percutaneous drainage.

After LAMS placement using endoscopic ultrasound, purulent contents from the IHC into the stomach were confirmed, symptoms improved, and no adverse events were observed.

With the widespread use of EMR and improvements and refinements to conventional EMR, various modified EMR techniques have been developed to ensure complete resection of lesions with negative margins. Recently, the authors have devised a novel modified EMR using an over-the-scope clip (OTSC) called endoscopic mucosal resection using an OTSC (EMR-O). In EMR-O, an OTSC, a device for gastrointestinal full-thickness suturing, is deployed under the lesion in advance, and the lesion is resected using a snare just above the OTSC. Therefore, EMR-O is considered as a “modified EMR without perforation.” EMR-O is suitable for resecting lesions in thin-walled organs, such as the duodenum and colorectum. Depending on the standard OTSC used, the size of resectable lesions is limited to approximately 10-15 mm. In some cases, full-thickness resection is possible, a feature that is unavailable with conventional modified EMR. EMR-O may be an option for endoscopic treatment of gastrointestinal tumors that are difficult to resect using conventional EMR. This article describes the practices of EMR-Os, procedural tips, and treatment outcomes.

Objectives: This study aimed to elucidate the clinical course and management of adverse events (AEs) after endoscopic resection (ER) for superficial duodenal epithelial tumors (SDETs).

Methods: Consecutive patients who underwent ER of SDETs between January 2008 and July 2018 at 18 Japanese institutions were retrospectively enrolled. The study outcomes included the clinical course, management, and risk of surgical conversion with perioperative AEs after ER for SDETs.

Results: Of the 226 patients with AEs, the surgical conversion rate was 8.0%(18/226), including 3.7% (4/108), 1.0% (1/99), and 50.0% (12/24) of patients with intraoperative perforation, delayed bleeding, or delayed perforation, respectively. In the multivariate logistic analysis, involvement of the major papilla(odds ratio [OR] 12.788; 95% confidence interval [CI] 2.098-77.961, P=0.006) and delayed perforation (OR 37.054; 95% CI 10.219-134.366, P<0.001) were significant risk factors for surgical conversion after AEs. Delayed bleeding occurred from postoperative days 1-14 or more, whereas delayed perforation occurred within 3 days in all cases.

Conclusions: The surgical conversion rate was higher for delayed perforation than those for other AEs after ER of SDETs. Involvement of the major papilla and delayed perforation were significant risk factors for surgical conversion following AEs. In addition, reliable prevention of delayed perforation is required for 3 days after duodenal ER to prevent the need for surgical interventions.