Background/Objectives: Artificial intelligence (AI)-assisted endoscopic ultrasonography (EUS) diagnostic tools have shown excellent performance in diagnosing gastric mesenchymal tumors. This study aimed to assess whether incorporating clinical and endoscopic factors into AI-assisted EUS classification models based on digital image analysis could improve the diagnostic performance of AI-assisted EUS diagnostic tools. Methods: We retrospectively analyzed the data of 464 patients who underwent both EUS and surgical resection of gastric mesenchymal tumors, including 294 gastrointestinal stromal tumors (GISTs), 52 leiomyomas, and 41 schwannomas. AI-assisted classification models for GISTs and non-GIST tumors were developed utilizing clinical and endoscopic factors and digital EUS image analysis. Results: Regarding the baseline EUS classification models, the area under the receiver operating characteristic (AUC) values of the logistic regression, decision tree, random forest, K-nearest neighbor (KNN), and support vector machine (SVM) models were 0.805, 0.673, 0.781, 0.740, and 0.791, respectively. Using the new classification models incorporating clinical and endoscopic factors into the baseline classification models, the AUC values of the logistic regression, decision tree, random forest, KNN, and SVM models increased to 0.853, 0.715, 0.896, 0.825, and 0.794, respectively. In particular, the random forest and KNN models exhibited significant improvement in performance in Delong’s test (both p < 0.001). Conclusion: The diagnostic performance of the AI-assisted EUS classification models improved when clinical and endoscopic factors were incorporated. Our results provided direction for developing new AI-assisted EUS models for gastric mesenchymal tumors.

Background/Objectives: Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) is a promising tool for differentiating gastric subepithelial tumors (SETs). However, most published studies have mainly included gastrointestinal stromal tumors (GIST) and leiomyomas in the gastrointestinal tract, not limited to gastric SETs. This study evaluated the diagnostic performance of CH-EUS in gastric SETs encountered in clinical practice. Methods: We retrospectively analyzed 68 patients who underwent CH-EUS for gastric SETs between March 2021 and July 2025 at our institution. Gastric SETs were classified into benign (n = 27: ectopic pancreas, leiomyoma, schwannoma, glomus tumor, plexiform fibromyxoma, desmoid tumor, solitary fibrous tumor, and abscess) and GIST groups (n = 41). CH-EUS features, including arterial enhancement, irregular vessels, and diffuse enhancement, were assessed. Histopathological confirmation was obtained through EUS-guided fine-needle biopsy or endoscopic/surgical resection. Results: The GIST group showed significantly higher rates of arterial enhancement (95.1% vs. 74.1%, p = 0.024), irregular vessels (51.2% vs. 22.2%, p = 0.017), and diffuse enhancement (87.8% vs. 66.7%, p = 0.035) than the benign SETs. The diagnostic performance of arterial enhancement showed a sensitivity of 95.1% and specificity of 25.9%, while irregular vessels demonstrated a sensitivity of 51.2% and specificity of 77.8%, and diffuse enhancement showed a sensitivity of 87.8% and specificity of 33.3%. When combining ≥2 CH-EUS features, the sensitivity and specificity were 92.7% and 33.3%, respectively, with an overall accuracy of 69.1%. The presence of all three features yielded a specificity of 81.5% but a lower sensitivity (46.3%). Conclusions: CH-EUS exhibited a high sensitivity but low specificity in differentiating GISTs from various benign gastric SETs when using a combination of at least two CE-EUS features, including arterial enhancement, irregular vessels, and diffuse enhancement.

Background/Objectives: Endoscopic papillectomy (EP) is the preferred treatment for ampullary tumors because it has fewer side effects than surgical removal. This study retrospectively compared a new anchoring EP method (A-EP) with the conventional (C-EP) approach. Methods: Ninety-nine patients who underwent EP at a single medical institution between 2009 and 2021 were retrospectively reviewed. In all patients, the indications for EP were pathological adenoma with <10 mm of biliary invasion and a tumor diameter <30 mm on endoscopic ultrasonography. The exclusion criteria were antiplatelet/anticoagulant use, previous upper GI surgery, or prior biliary/pancreatic endoscopic therapy. One expert endoscopist performed the two types of EPs, A-EP and C-EP. Results: Sixty-two patients underwent A-EP, and 37 underwent C-EP. There were no significant differences in baseline characteristics, such as sex, age, tumor size, and ductal invasion on endoscopic ultrasound. The A-EP group had higher en bloc resection rates (95.2% vs. 78.4%, p = 0.010). Although the difference was not statistically significant, it tended towards fewer incidences of pancreatitis (p = 0.081) and duct stricture (p = 0.081). The recurrence rate was lower in the A-EP group (8.1% vs. 37.8%, p = 0.000). There were no significant differences between the two groups regarding the follow-up period (A-EP vs. C-EP, 725 vs. 1045 days, p = 0.109) or the days of recurrence (A-EP vs. C-EP, 341 vs. 562 days, p = 0.551). Conclusions: A-EP showed better outcomes than C-EP in terms of en bloc resection and recurrence rates, providing evidence for the efficacy of this novel EP method.

Proton pump inhibitors (PPIs) serve as the primary treatment for acid-related disorders, such as gastroesophageal reflux disease and peptic ulcer disease. Although PPIs are regarded as the first-line medication for acid suppression, they have notable limitations, including the need for acid-mediated activation, a short half-life and duration of action, and metabolic variability. Zastaprazan is a newly developed potassium-competitive acid blocker (P-CAB) that competitively and reversibly inhibits acid production and secretion. Like other P-CABs, zastaprazan exhibits pharmacodynamic and pharmacokinetic properties that differs significantly from those of PPIs. These differences offer potential advantages, such as rapid, robust, and long-standing acid suppression, the lack of CYP2C19 metabolism, and no need for conversion into an active form. Completed clinical trials of zastaprazan have demonstrated comparable or superior efficacy to that of PPIs for the healing of erosive esophagitis and gastric ulcers without concerning safety signals. Notably, in erosive esophagitis, zastaprazan 20 mg demonstrated faster healing at week 4 compared to esomeprazole 40 mg, whereas in gastric ulcers, zastaprazan 20 mg achieved a 100% healing rate at 8 weeks compared to 97.1% with lansoprazole 30 mg. Zastaprazan is approved in the Republic of Korea for the treatment of erosive esophagitis and gastric ulcer and is undergoing phase III clinical trials for the prevention of non-steroidal anti-inflammatory drug-induced peptic ulcer and the treatment of non-erosive reflux disease. In this review, we summarize and discuss the pharmacology, efficacy, and safety of zastaprazan in acid-related disorders.