Classification systems of gastritis that are currently utilized internationally are the Updated Sydney System and the International Statistical Classification of Diseases and Related Conditions （ICD-10）. The former system is mostly used for research purposes whereas the latter system is used for health statistics. However, both classification systems are unsatisfactory due to the ambiguous principle of classification. Furthermore, a number of categories are unlisted. To develop an internationally acknowledged etiological classification system for gastritis, which is critical for providing effective management and prevention, a consensus document was published as a result of the Kyoto Global Consensus Conference. This etiology-based classification system, achieved through international consensus, should be considered as a springboard for building a more detailed and organized classification system, as a number of issues still remain. To achieve this goal, further progress in basic gastric biology such as histogenesis, gastric microbiome, and epithelial immune mechanisms linking the pathophysiological basis of gastritis is required.

Background and Aim:Ischemic right-sided colitis is rare in Japan. We describe clinical characteristics and endoscopic findings of our cases of ischemic right-sided colitis.

Methods:In the past 11 years, we experienced seven cases of ischemic right-sided colitis. They consisted of one transient type, five stricture type and one gangrenous type. We retrospectively analyzed their clinical characteristics and imaging findings （mainly endoscopic findings）.

Results:Our cases had mainly vascular factors such as coronary artery disease and chronic kidney failure. Clinical symptoms of our cases were mainly abdominal pain. CT imaging revealed severely thickened wall of the right-side colon. Endoscopic findings of non-gangrenous right-sided colitis were incomplete annular-like ulcer or belt-shaped ulcer. These ulcers were wide and deep on the antimesenteric side, and were narrow and shallow on the mesenteric side.

Conclusions:The clinical characteristics and endoscopic findings of ischemic right-sided colitis were different from those of ischemic colitis. These results suggest that the pathogenesis of ischemic right-sided colitis is different from that of ischemic colitis.

A 59-year-old woman visited our hospital with alternating episodes of bowel movement abnormalities and abdominal pain. The diagnosis of cap polyposis （CP） localized in the transverse colon was established by colonoscopy, histopathological findings and Barium enema examination. Helicobacter pylori（HP） infection was diagnosed by positive results in the rapid urease test during esophagogastroduodenoscopy （EGD） and serum examination of anti-HP IgG antibody. After written informed consent, the patient received H. pylori eradication therapy with 60 mg lansoprazole, 1,500mg amoxicillin, and 400 mg clarithromycin daily for 7 days, but primary eradication therapy was unsuccessful. At that time, the patient developed a new lesion limited to the region where endoscopic mucosal resection （EMR） （and clipping） of a polyp had been performed. The second eradication therapy consisting of 20 mg rabeprazole, 1,500mg amoxicillin, and 500mg metronidazole daily for 7 days was successful. After the second eradication therapy, her symptoms disappeared and the CP resolved. In cases where there is persistent HP infection, a systemic immune abnormality may lead to the pathogenesis of CP, and further mechanical stimulation （stimulation with EMR/clipping） is likely to act as an exacerbating factor. We recommend an HP test in all CP cases. If the test is positive, HP eradication therapy is necessary.

We report two patients with duodenal variceal bleeding. A 57-year-old woman （Case 1） was referred to our hospital by a nearby clinic with the chief complaints of vomiting and black stools. Her medical history was unremarkable. Upper gastrointestinal endoscopy showed F3 venous varices in the descending part of the duodenum；thus, balloon-occluded retrograde transvenous obliteration was performed. A 54-year-old man （Case 2） presented with a history of type C liver cirrhosis, esophageal varices, and hepatocellular carcinoma. He visited our hospital with the chief complaints of black stools and hematemesis. Upper gastrointestinal endoscopy showed F3 venous varices with projectile bleeding in the horizontal part of the duodenum. A mixture of Histoacryl and lipiodol was injected to achieve hemostasis. Both patients did not show rebleeding.

A 49-year-old man who underwent esophagogastroduodenoscopy （EGD） owing to positive fecal occult blood test results, had a 0-Ⅰs＋Ⅱc-like lesion of 15 mm in diameter in the duodenum. During the preoperative EGD, the lesion was found to be elastic and soft on palpation with a forceps and was visualized as an abnormal area with various echo levels including anechoic areas in the 2nd to 3rd layers on endoscopic ultrasonography （EUS）. The surface pattern was clearly visible on NBI magnification endoscopy. We first considered that the lesion was a duodenal cancer with massive submucosal invasion based on its macroscopic shape. However, findings of the preoperative EGD suggested that the lesion could be mucosal cancer or an adenoma. Therefore, we performed endoscopic mucosal resection （EMR） to determine malignancy and invasion depth of the tumor. Histology showed a high-grade adenoma with Brunner’s gland hyperplasia. The macroscopic shape of 0-Ⅰs＋Ⅱc was due to inverted growth and cystic expansion of the tumor glands. The findings of this case suggest that minimally invasive treatment should be pursued using every endoscopic modality in the case of a duodenal lesion that is suspected of being a submucosal cancer.

A 57-year-old man presented to our hospital with a chief complaint of diarrhea. Colonoscopic examination revealed a submucosal tumor of 3 cm in diameter appearing as a nodular elevation on the posterior wall of the lower part of the rectum （Rb）. Endoscopic ultrasonography （EUS） demonstrated a lesion composed of multiple cysts located in the submucosa. A biopsy and EUS-guided fine needle aspiration （FNA） failed to yield findings allowing a definitive diagnosis to be made. In order to establish a diagnosis and devise the optimal treatment, the lesion was transanally resected and examined histopathologically. This confirmed the diagnosis of colitis cystica profunda （CCP）. This disease is also subclassified as a gross morphologic type of rectal mucosal prolapse syndrome, but the frequency of CCP is rare. We herein discuss the clinical features of this uncommon disease with a review of the relevant literature.

This report describes a 65-year-old woman who underwent insertion of a self-expandable metallic stent （SEMS） for malignant biliary obstruction caused by gallbladder cancer. The cancer had metastasized to the cervical column, and was invading the liver and duodenum. The patient was admitted to our hospital because of nausea and vomiting. Detailed examination showed gallbladder cancer causing duodenal obstruction and perforation of the first part of the duodenum. We attempted to perform endoscopic placement of a duodenal SEMS, but the guidewire migrated into the fistula and could not pass through the stricture. Thus, we used a balloon catheter with a side hole, which is generally used for endoscopic removal of biliary stones. The balloon catheter with the side hole was inserted into the fistula, and the balloon was dilated to occlude the fistula. The guidewire was pushed through the side hole against the dilated balloon to change its direction. This action allowed us to finally pass the guidewire through the stricture. The endoscopic placement of the duodenal SEMS was successful and it enabled the patient to begin oral intake on the day following the procedure. This finding shows that a balloon catheter with a side hole can be effective for insertion of a duodenal SEMS past a stricture in a patient with malignant gastric outlet obstruction with duodenum perforation.

We report a rare case of a bile duct stone whose formation was induced by a fish bone that had migrated into the bile duct after pancreatoduodenectomy. A 71-year-old man was admitted to our hospital because of high fever and elevated liver function test. Abdominal computed tomography （CT） detected a foreign body and a stone in a bile duct, and also showed severe cholangitis. The foreign body was suspected of being a fish bone due to its linear appearance and CT density. Single balloon enteroscopy was performed to remove the foreign body and stone from the bile duct. The pathological diagnosis of the foreign body was that it was a bone. Based on the results of pathological diagnosis and the lifestyle habit of the patient, we considered that it was a fish bone. In conclusion, a bile duct stone whose formation was induced by a fish bone after pancreatoduodenectomy is rare, and we need to be aware of such possibility.

The number of cases of esophageal adenocarcinoma now exceeds those of squamous cell carcinoma in Western countries, and the annual number of cases of Barrett’s esophagus leading to esophageal cancer has increased more than 6 times over the past 25 years. We are also concerned with the increased incidence of Barrett’s adenocarcinoma in Japan. We believe that careful examination of the esophago-gastric junction is very important and necessary for accurate diagnosis of palisade vessels, upper end of the gastric folds, and consecutive columnar epithelium. Superficial cancer of short segment Barrett’s esophagus was often present in the direction of the anterior-right wall. It is primarily important not to miss redness or a rough surface on conventional white light endoscopy for detecting superficial Barrettʼs adenocarcinoma. White-light imaging, magnifying endoscopy with image-enhanced endoscopy （IEE）, endoscopic ultrasonography, and X-ray are useful for diagnosing the invasion depth. Flat 0−Ⅱb and 0−Ⅱa　lesions, 0-Ⅰlesions with a narrow base, and 0−Ⅱc lesions with a slight depression indicate mucosal cancer. IEE with magnifying endoscopy using acetic acid is useful for diagnosing the lateral extent of the lesions. Diagnosis of the invasion depth of superficial Barrett’s esophageal cancer is important for determination of the therapeutic strategy. Attention should be paid to the indications for endoscopic treatment of T1a-DMM and SM tumors.

Duodenal varices, one of the ectopic varices excluding esophagogastric varices, is a relatively rare disease, and if there is bleeding from the varices, it could be fatal. There is still no one established treatment for duodenal varices. Treatments include endoscopic treatment by endoscopic injection sclerotherapy （EIS） and embolization therapy with interventional radiology （IVR）. Prior to treatment, it is important to evaluate the hemodynamics using three-dimensional computed tomography （3D-CT）. For treatment of duodenal varices rupture, EIS by using cyanoacrylate drug seems to be effective. When carrying out EIS, the procedure is stabilized by placing the patient in the prone position. If varices remain after hemostatic treatment, additional treatment with EIS or IVR should be administered.

Background and Aim：Endoscopic submucosal dissection （ESD） becomes more difficult with an increased risk of complications if patient sedation is insufficient. We assessed the safety and effectiveness of propofol-based monitored anesthesia care （MAC） without intubation during ESD for early esophageal cancer （EEC） or early gastric cancer （EGC） in the endoscopy room.

Methods：We investigated 1013 consecutive patients with 1126 lesions who underwent ESD for EGC/EEC with either MAC or regular sedation by endoscopists （control group） between July 2010 and March 2013. Patient characteristics, endoscopic findings, technical results, body movement, oxygen saturation （SpO₂）, and drug dosages were then examined.

Results：MAC was carried out in 137 EGC （16％） and 82 EEC patients （57％）, whereas regular sedation was used in 731 EGC （84％） and 63 EEC patients （43％）. MAC was conducted in 21％ of all ESD procedures. In the MAC and control groups, body movement requiring a third person for control occurred in 30 （22％） and 533 （72％） cases during gastric ESD （P＜0.0001） and 36 （44％） and 53 （84％） cases during esophageal ESD （P＜0.0001）, respectively. The median minimum SpO₂ was significantly lower in the MAC group than in the control group during both gastric and esophageal ESD （96％ vs. 98％, P＜0.0001； 96％ vs. 98％, P＜0.0004, respectively）. MAC did not cause any adverse effects requiring prolongation of hospitalization.

Conclusions：Propofol-based MAC without intubation provided a safer treatment environment by significantly reduced body movement and was very effective for difficult cases requiring longer procedure times or more powerful sedation.