Sedation plays an integral role in various clinical settings, including screening endoscopy and advanced gastrointestinal endoscopic procedures. However, sedative agents that have long been used in Japan are not approved for insurance coverage. Current Japanese guidelines for sedation in gastrointestinal endoscopy are largely based on evidence derived from studies conducted in other countries. In Japan, sedation is commonly administered by endoscopists rather than anesthesiologists during routine clinical practice. Ideal sedation regimens offer rapid induction and recovery while ensuring high levels of safety and satisfaction for patients and physicians. Because deeply sedating agents may adversely affect cardiopulmonary function, minimizing drug dosage through combination therapy with analgesics or adjunctive agents is preferable. Future trends in sedation are expected to shift toward ultra-short-acting medications with reduced cardiopulmonary suppression, while also considering health care economics.

In ulcerative colitis (UC), mucosal healing (MH) is a central therapeutic target strongly associated with favorable long-term outcomes. Endoscopy remains the most direct and reliable method for evaluating MH, and endoscopic activity indices have progressed from early systems, including the Baron index and Matts grading system, to more standardized tools such as the Mayo endoscopic subscore (MES) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Although MES is widely adopted because of its simplicity, the clinical distinction between MES 0 and 1 remains controversial. UCEIS was developed to enable more precise evaluation of inflammatory severity; however, its routine use in clinical practice remains limited. More recently, the concept of deep remission, defined as the combination of endoscopic MH and histological remission, has gained increasing attention. Accumulating evidence suggests that sustained endoscopic and histological remission over time, rather than a single cross-sectional evaluation, is critical for predicting disease relapse. Accordingly, treatment response in UC should be assessed longitudinally as a “line,” rather than as a single “point.” Advances in next-generation endoscopic technologies, including high-definition and image-enhanced endoscopy, endocytoscopy, and confocal laser endomicroscopy, as well as the development of artificial intelligence (AI)-based automated scoring systems, have improved diagnostic precision. These innovations reduce interobserver variability and enhance differentiation between MES 0 and 1 in routine clinical settings. Furthermore, integrated monitoring strategies that combine AI-assisted endoscopic assessment with noninvasive biomarkers, such as fecal calprotectin and serum leucine-rich α2-glycoprotein, are expected to play an increasingly important role. This review summarizes the evolution of endoscopic activity assessment in UC, the definition and clinical significance of mucosal healing, its association with histological remission, and the emerging role of AI and next-generation technologies in disease monitoring. It also discusses the future role of endoscopy in personalized UC management.

An 83-year-old man was admitted to our hospital with a hemorrhagic duodenal ulcer. Following successful endoscopic hemostasis, a choledochoduodenal fistula was identified. To mitigate the risk of cholangitis and facilitate ulcer healing, a fully covered self-expanding metal stent was deployed into the common bile duct, thereby isolating the duodenal lumen from the biliary system. No significant complications were observed. This report presents a rare case of choledochoduodenal fistula successfully managed with endoscopic intervention.

A 75-year-old woman who had been diagnosed with liver cirrhosis was admitted to our hospital for the treatment of choledocholithiasis. ERCP was performed, and an intradiverticular papilla was identified at the inferior duodenal angle. We attempted the two-devices-in-one-channel method and used traction clips, but cannulation was unsuccessful due to the long distance to the duodenal papilla. Therefore, we performed ERCP using a forward-viewing endoscope, which allowed for successful guidewire placement in the pancreatic duct. A side-viewing endoscope was then reintroduced over the pancreatic guidewire, enabling subsequent bile duct cannulation, endoscopic sphincterotomy, and stent placement. Such scope exchange method under pancreatic duct guidewire placement may be an effective technique for managing difficult-to-approach intradiverticular papilla.

A 56-year-old man was found to have a tumor in the pancreatic tail following an episode of acute pancreatitis. MRI revealed a 20-mm cystic lesion communicating with the main pancreatic duct, with a solid component inside. Contrast-enhanced CT and contrast-enhanced endoscopic ultrasonography (EUS) demonstrated that the solid component had an enhancement similar to that of the surrounding pancreatic parenchyma. Endoscopic retrograde cholangiopancreatography (ERCP) revealed a cystic lesion continuous with the main pancreatic duct, without evidence of mucus production. Brush cytology of the main duct near the cyst revealed Class Ⅳ atypia. Based on the preoperative diagnosis of intraductal tubulopapillary neoplasm (ITPN), the patient underwent surgical resection. However, the final pathological diagnosis was an intraductal oncocytic papillary neoplasm (IOPN). IOPN is often asymptomatic, and cases associated with acute pancreatitis are extremely rare. Mucin-poor intraductal neoplasms of the pancreas include IOPN, ITPN, and the pancreatobiliary type of intraductal papillary mucinous neoplasm (IPMN), all of which are often difficult to distinguish preoperatively. A comprehensive understanding of the clinicopathological characteristics of these tumors is essential for their accurate diagnosis and management.

EIS for esophageal varices has been widely performed in Japan due to its therapeutic efficacy. However, owing to its technical complexity and the risk of complications such as bleeding, the simpler approach of endoscopic variceal ligation (EVL) alone has become more prevalent. Endoscopic injection sclerotherapy with ligation (EISL), which combines EIS with EVL, is an effective treatment modality that enhances the therapeutic efficacy of EIS while reducing the procedural burden on the endoscopist. In this article, we provide a detailed description of EISL, including evaluation methods using EUS before and after EIS, to facilitate its practical implementation.

ESD of colorectal tumors has been established as a minimally invasive technique that can reliably achieve en bloc resection. However, colorectal ESD has several unique technical difficulties. Endoscopists have attempted to overcome these difficulties in colorectal ESD. The pocket-creation method (PCM) is one such procedure and has four advantages: 1) prevention of leakage of locally injected solution, 2) both strong traction and countertraction by the tip of the hood, 3) easy tangential approach to the submucosal layer by enabling optimal angle adjustment even when the muscle layer is oriented vertically, and 4) stabilization of the tip of the endoscope. The first report stated that PCM enabled ESD in cases of giant subpedunculated colorectal tumors with severe fibrosis. Recently, PCM has been shown to have advantages not only for colorectal tumors, but also for gastric and duodenal tumors. A technical review by the European Society for Gastrointestinal Endoscopy (ESGE) reported that the advantages of PCM are easier to understand when it is recognized as a type of traction method. Meanwhile, the underwater technique, in which the lumen is filled with saline, is useful for treating gastrointestinal neoplasms. Underwater endoscopic mucosal resection without injection has already been established as a standard treatment for duodenal and colorectal tumors. The advantages of underwater treatment include mucosal contraction, natural traction owing to buoyancy, and improved visibility. PCM and underwater treatment appear to be complementary in maintaining visibility in a narrow space. In general, traction gradually disappears during pocket opening; however, natural traction, such as buoyancy, can be maintained continuously underwater, leading to a synergistic effect. This article outlines the background and actual techniques of PCM and discusses their integration with those of the underwater technique, as well as the application of new equipment with reference to the latest information.

Objectives: A pancreatic cyst >5mm in diameter that communicates with the dilated main pancreatic duct (MPD) ≥5mm on imaging is defined as mixed type intraductal papillary mucinous neoplasm (MX-IPMN). However, the frequency of tumor involvement of the MPD in MX-IPMN remains unknown. This study investigated how often MX-IPMNs involve the MPD and whether MPD involvement can be diagnosed by peroral pancreatoscopy (POPS).

Methods: This retrospective cohort study included patients who underwent POPS for MX-IPMN followed by surgical resection between July 2018 and December 2021. The pathological features of MX-IPMN, including tumor extension to the MPD, were analyzed. Additionally, the diagnostic performance of various imaging modalities in detecting tumor extension to the MPD was evaluated.

Results: Among a total of 15 patients, 10 (67%) had pathologically confirmed tumor extension to the MPD. In most cases with pathologically confirmed MPD involvement, the main tumor was diagnosed as high-grade dysplasia (60%) or invasive carcinoma (10%). Conversely, low-grade dysplasia was the main lesion in most cases without MPD involvement (low-grade dysplasia 80%; high-grade dysplasia 20%, invasive carcinoma 0%). The diagnostic accuracy, sensitivity, and specificity of POPS with or without biopsy was 93.3%, 90.0%, and 100%, respectively. POPS demonstrated higher accuracy and sensitivity than computed tomography, magnetic resonance cholangiopancreatography, and endoscopic ultrasonography (accuracy: 93.3%, 40%, 60%, and 80%; sensitivity: 93.3%, 10%, 40%, and 70%, respectively).

Conclusions: Overall, 67% of MX-IPMNs had pathologically proven MPD involvement. Tumor extension to the MPD is highly suspicious of malignancy, and POPS may be useful for evaluating MPD involvement.

Trial registration: The study was registered in the University Hospital Medical Information Network clinical trials registry (UMIN000051649).