Endoscopic submucosal dissection（ESD）is a curative, minimally invasive treatment for early gastrointestinal cancer. However, preventing post-ESD adverse events, such as delayed bleeding and perforation, remains challenging. With an aging population, more patients are receiving antithrombotic therapy, and the risk of bleeding is clinically significant. Because the incidence and severity of adverse events vary by organ, individualized strategies based on risk stratification that incorporate organ- and patient-related factors are required. Recently, endoscopic defect closure has attracted attention as a preventive strategy with accumulating evidence supporting its efficacy. This review outlines the organ-specific incidence of post-ESD adverse events and summarizes the clinical significance of prophylactic defect closure based on the literature. Closure techniques are categorized as through-the-scope clips, over-the-scope systems, endoscopic suturing, and shielding methods, and their characteristics are briefly described. Further evidence is required to establish optimal strategies that consider organ-specific indications, risk profiles, and technical and economic factors.

Gastric cancer（GC）remains a major global health burden, and early detection and early treatment are essential for improving patient outcomes. Deep-learning artificial intelligence（AI）has accelerated the development of endoscopy-based diagnostic support systems for early GC. This review summarizes the current evidence on AI-assisted diagnosis of early GC, focusing on computer-aided detection, computer-aided diagnosis, invasion-depth prediction, delineation of tumor margins, and diagnosis of precancerous lesions. AI systems are useful for supporting non-expert endoscopists, with some performance comparable to that of experts. For lesion detection, randomized controlled trials have demonstrated reduced miss rates with AI assistance. In Japan, an AI-based upper gastrointestinal lesion detection system received regulatory approval in 2022, an early GC-specific detection AI in 2023, and an invasion-depth prediction AI in 2024. and clinical implementation is now progressing. However, several issues must be addressed before broader social implementation, including insufficient external validation, uncertain cost-effectiveness, reimbursement challenges, and questions regarding explainability and responsibility sharing.

A 67-year-old man underwent annual endoscopic surveillance for a subepithelial lesion in the greater curvature of the lower gastric body. After seven years, endoscopic ultrasound-guided fine-needle aspiration and boring biopsy were performed because of lesion enlargement and a newly observed apical depression; however, a definitive diagnosis could not be established. Local gastric resection confirmed the lesion as an adenocarcinoma. Additional distal gastrectomy was performed. A review of 26 cases of gastric cancer mimicking subepithelial lesions that were observed for ＞2 years revealed that many lesions enlarged over time with the development of central depression. Infiltration beyond the muscularis propria was observed in 11 patients, and lymph node metastasis was observed in four patients. Our findings suggest that early histological diagnosis and prompt lesion resection are important in cases of gastric cancer mimicking subepithelial lesions.

Abdominal aortic injuries associated with PEG is rare. Here, we encountered a case of abdominal aortic perforation caused by needle puncture during PEG, successfully treated with emergency endovascular aortic repair (EVAR). A 76-year-old woman with multiple system atrophy underwent PEG for dysphagia using the standard introducer method. During trocar insertion, the needle tip inadvertently reached the posterior wall of the stomach. Shortly postoperatively, the patient experienced hemorrhagic shock. Computed tomography revealed retroperitoneal hematoma and contrast extravasation from the abdominal aorta, confirming iatrogenic aortic injury as the bleeding source. The patient was successfully treated with emergency EVAR, and her condition stabilized. This case highlights the importance of recognizing structures anterior and posterior to the stomach during PEG. It is important to thoroughly review preoperative imaging findings and select the PEG technique based on individual risk factors.

A 52-year-old woman underwent pancreaticoduodenectomy 29 months earlier for a hypervascular tumor in the pancreatic head that was diagnosed as a neuroendocrine tumor（G1）. During surgery, portal vein injury occurred, necessitating portal vein resection and reconstruction. Postoperatively, portal vein thrombosis led to a hemorrhagic ulcer at the choledochojejunostomy site, making it impossible to continue anticoagulation. Portal vein stenosis worsened gradually. The patient presented to the emergency department with hematemesis. Contrast-enhanced computed tomography revealed biliary variceal bleeding due to cavernous transformation of the portal vein. To reduce portal hypertension and control the bleeding, partial splenic artery embolization was performed. After the procedure, the patient experienced no bleeding recurrence, and the clinical course was uneventful.

A modified introducer method for percutaneous endoscopic gastrostomy（PEG）effectively prevents peristomal infection and tumor seeding. However, conventional bumper-type catheters are limited by physical resistance and potential tissue trauma during insertion and removal. This article describes a minimally invasive approach using a next-generation device, which features a unique insertion mechanism that encapsulates the bumper within a gelatin capsule to maintain a streamlined profile. For removal, it employs low-resistance mechanism that collapses the bumper into a thin silicone membrane upon extracting a shape-memory nickel-titanium ring. During placement, a single-step dilator simplifies tract dilation, whereas a peel-away sheath prevents axis misalignment and gastric wall injury, ensuring smooth insertion. During replacement, removal of the internal wire allows for atraumatic extraction without scraping the fistulous tract. Furthermore, reinsertion using a dedicated obturator over a guidewire minimizes misplacement risk. By minimizing invasiveness from initial placement to subsequent replacement, this system standardizes the procedure and reduces reliance on operator experience. This innovative approach contributes significantly to alleviating patient discomfort and enhancing medical safety during enteral access.

Endoscopic ultrasonography (EUS) provides high spatial resolution and is widely used for pancreatic disease evaluation. Although conventional EUS interpretation relies heavily on operator judgment, contrast-enhanced EUS (CE-EUS) and elastography offer more reproducible assessments and greater diagnostic confidence. CE-EUS uses the second-generation contrast agent Sonazoid to assess microvascular flow by resonating microbubbles at specific acoustic pressures. In pancreatic disease, it detects lesions based on vascularity and characterizes them by flow volume and distribution. It helps distinguish tumor nodules from mucous clots in intraductal papillary mucinous neoplasms, identifies small pancreatic cancers missed by standard EUS, and detects liver metastases. Enhancement patterns aid in the differential diagnosis of hypoenhancement in pancreatic cancer, isoenhancement in mass-forming pancreatitis, and hyperenhancement in neuroendocrine tumors. Blood flow assessment can guide EUS-guided fine-needle aspiration. Elastography evaluates tissue stiffness without biopsy and includes strain elastography (SE) and shear-wave elastography (SWE). SE measures relative stiffness from tissue deformation under compression and is useful for assessing malignancy risk of pancreatic tumors and predicting postoperative pancreatic fistulas. SWE measures absolute stiffness from shear-wave velocity and is effective for diagnosing chronic and autoimmune pancreatitis. These techniques provide complementary information. Selecting the appropriate method based on clinical need can improve the diagnostic accuracy and assist in management decisions for pancreatic diseases.

Objectives: Sessile serrated lesions (SSLs) pose a risk of carcinoma, necessitating endoscopic resection. Conventional endoscopic mucosal resection (EMR) often fails to achieve complete resection for intermediate-sized SSLs. Although underwater EMR (UEMR) is being increasingly used for colon polyps, its efficacy for SSLs remains unclear. This study evaluated the complete resection rate of UEMR for intermediate-sized SSLs.

Methods: This prospective, single-arm, observational study was conducted at two institutions. Patients with endoscopically diagnosed intermediate-sized SSLs (10-20mm) were enrolled. UEMR was performed, and specimens were histologically assessed. Post-UEMR lesions were closely examined, and biopsies were taken to check for residuals. Follow-up colonoscopy was performed 1 year later to evaluate recurrence. The primary end-point was the complete resection rate, defined as no residual in biopsy specimens. The secondary end-points were the rates of R0 resection, en bloc resection, recurrence, adverse events, and factors regarding procedural difficulty.

Results: In total, 103 patients with 133 lesions were consecutively identified. Twenty-seven cases with 30 lesions were excluded by criteria; 103 endoscopically diagnosed SSLs were enrolled. The median postresection lesion size was 12mm (range 8-23). The R0 and en bloc resection rates were 61% and 91%, respectively. The overall complete resection rate was 97% (95% confidence interval 91.8-99.0%). Follow-up colonoscopy in 87 lesions showed no recurrence. Only one patient (1%) experienced delayed bleeding. Snaring difficulty was significantly associated with piecemeal resection.

Conclusion: The complete resection rate of UEMR for intermediate-sized SSLs was acceptable. UEMR may become a standard treatment for intermediate-sized SSLs.

Trial registration: The study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN) under the identifier UMIN 00041171.

The author interviewed opinion leaders at international conferences held in 2025 to examine their views on Japan’s role and contributions to the global community. The interviews focused on two key topics: （1）the potential contributions of Japanese endoscopic medicine to global healthcare and future expectations, and（2）the projected state of endoscopic medicine over the next decade. Analysis of the responses demonstrated broad consensus among the experts. First, major technological advances are expected in emerging fields, including endoscopic artificial intelligence, robotics, and inter-organ therapy. Second, Japan should preserve and further strengthen its position as a global leader by capitalizing on its established strengths in technical expertise, education, and research. Third, Japan must continue providing high-quality evidence to the international community, supported by its extensive clinical data and advanced medical practices. Fourth, physicians from Asian countries expressed strong expectations for Japan to assume a leading role in endoscopic education, clinical research, and technological innovation. Endoscopic medicine is advancing globally at an unprecedented rate. To maintain its central role and continue contributing to the advancement of global healthcare, Japan must build on its longstanding traditions, pursue continuous innovation, and implement strategic initiatives informed by a broader global perspective.