Hirotoshi Ishiwatari

Background and Objectives: Pathological diagnosis of autoimmune pancreatitis (AIP) is essential for selecting the appropriate treatment strategy. Although macroscopic on-site evaluation (MOSE) can reduce the number of needle passes during EUS-guided tissue acquisition (EUS-TA) in pancreatic neoplasms, its utility in AIP remains unclarified. We investigated the utility of MOSE in diagnosing AIP using EUS-TA-derived specimens. Methods: We conducted a retrospective study of patients with type 1 AIP who underwent EUS-TA using fine-needle biopsy needles. Macroscopic visible core (MVC) length was measured using MOSE, and histological diagnosis was evaluated following the International Consensus Diagnostic Criteria. The correlation between MVC length and diagnostic yield, histological features, and tissue volume was assessed. Results: Thirty-eight lesions of 36 patients were included. Among these, 32 had definite AIP and four had probable AIP. Level 1 and 1 or 2 histologies were identified in 47% and 90% of lesions, respectively. Longer MVC length was associated with a higher level 1 histology detection rate ( P < 0.01), with 22 mm as the optimal cutoff (area under the curve = 0.80; 95% confidence interval = 0.65–0.95). Specimens with MVC ≥22 mm (75%) had a significantly higher level 1 histology detection rate than those with MVC P < 0.001). MVC length positively correlated with tissue area ( r = 0.789, P < 0.001) and independently affected level 1 histology detection (odds ratio = 11.2, P < 0.01). Conclusion: MVC length ≥22 mm is a practical indicator of adequate tissue quality for the histological diagnosis of AIP. Therefore, MOSE may help determine the number of needle passes during EUS-TA in patients with AIP.

Mapping biopsy (MB) aids in diagnosing superficial mucosal spread of biliary tract cancer. However, conventional MB is technically challenging, which can reduce the diagnostic yield. This study aimed to assess the usefulness of MB using the newly developed Endosheather (ES) (Piolax, Tokyo, Japan). We retrospectively analyzed data from patients who had biliary tract cancer with hilar biliary obstruction and underwent MB. Outcome measures included the overall technical success rate, quality of specimens, impact of MB results on the treatment strategy, and adverse events (AEs), which were compared between the conventional (Conv) group and the ES group. A total of 91 patients were included. The overall technical success rate was significantly higher in the ES group (92%, 43/47) than in the Conv group (59%, 26/44) (P < 0.05). The rate of samples containing both biliary epithelium and stromal tissue was significantly higher in the ES group than in the Conv group (77% [67/87] vs. 47% [32/68]; P < 0.05). MB results affected the treatment strategy in one patient (2.3%) in the Conv group and five patients (11%) in the ES group (P = 0.11). There was no significant difference between the two groups in terms of AEs. MB using ES significantly improved technical success and specimen quality, providing valuable information for preoperative assessment of patients with biliary tract cancer.

In patients with perihilar cholangiocarcinoma (PHC) and obstructive jaundice undergoing planned major hepatectomy, preoperative biliary drainage of the future liver remnant is recommended, typically via endoscopic plastic stents (PSs [1] [2] [3] [4]). When endoscopic retrograde cholangiopancreatography (ERCP) is technically difficult, endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) serves as a rescue procedure [5]; however, PS placement via EUS-HGS typically drains only the left hepatic duct. We report a case of bilateral drainage achieved via EUS-HGS using a novel PS with a side hole at the tip ([Fig. 1] and [Video 1]). An 84-year-old woman with jaundice was referred to our hospital. Contrast-enhanced computed tomography (CT) revealed bismuth type 3a PHC ([Fig. 2]), and central bisectionectomy was recommended based on the remnant liver volume. ERCP was performed to drain the future liver remnant (the left and posterior sectoral ducts). Although the anterior sectoral duct was cannulated, the posterior and left sectoral ducts could not be accessed ([Fig. 3]). EUS-guided rendezvous was then attempted via puncture of the segment 2 bile duct using a 19-gauge FNA needle; however, guidewire advancement into the common bile duct failed. Nevertheless, the posterior sectoral duct was reached. To drain both ducts, a 7 Fr, 14-cm ADFlap stent (Century Medical, Tokyo, Japan) was deployed, with its tip in the posterior sectoral duct and the side hole aligned with the left hepatic duct, enabling effective bilateral drainage ([Fig. 4]). The patient experienced no postoperative complications. Jaundice improved, and follow-up CT confirmed decompression of both ducts ([Fig. 5]). Although surgical resection was initially considered, conservative management was chosen by the patient. No further drainage was required during the 5-month follow-up period. This case highlights the potential of a novel PS design in EUS-HGS to achieve bilateral drainage in complex PHC. Although feasible, this approach should be considered carefully, and its clinical role requires further evaluation in future studies. Endoscopy_UCTN_Code_TTT_1AS_2AH Article published online: 26 February 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Endoscopic ultrasound‐guided biliary drainage (EUS‐BD) is used when biliary drainage using endoscopic retrograde cholangiopancreatography fails. Recently, it has been adopted as a primary biliary drainage method, and its indications have expanded. Since EUS‐BD can cause adverse events (AEs), such as bile leakage and stent migration, which do not occur in endoscopic retrograde cholangiopancreatography, endoscopists need to be well‐versed in its management and preventive techniques. EUS‐BD includes several procedures, such as EUS‐guided choledochoduodenostomy (EUS‐CDS), EUS‐guided hepaticogastrostomy (EUS‐HGS), EUS‐guided antegrade stenting (EUS‐AS), and EUS‐guided rendezvous (EUS‐RV). A recent meta‐analysis reported that the overall AE rate of EUS‐BD was 13.7% (EUS‐CDS, 11.9%; EUS‐HGS, 15.5%; EUS‐AS, 9.9%; and EUS‐RV, 8.8%). Among various EUS‐BD techniques, EUS‐CDS and EUS‐HGS are the most frequently reported. Tubular self‐expandable metal stents have been traditionally used in EUS‐CDS; however, lumen‐apposing metal stents have recently gained popularity. A systematic review showed that the rates of early AEs were similar between self‐expandable metal stents and lumen‐apposing metal stents; however, stent maldeployment was more problematic with lumen‐apposing metal stents. Although tubular self‐expandable metal stents are used in EUS‐HGS, stent maldeployment remains a serious issue, and available devices and technical tips for preventing this AE should be well understood. Furthermore, AEs, such as sepsis, cholangitis, and bleeding, can occur, and strategies to mitigate these risks are essential. In this narrative review, we discussed AEs related to EUS‐BD with a focus on management options and strategies for prevention.

Endoscopic ultrasound-guided rendezvous (EUS-RV) is a rescue technique employed when biliary access during endoscopic retrograde cholangiopancreatography (ERCP) fails [1] [2] [3] [4]. However, EUS-RV is challenging due to the bile leakage risk, which can result in fluid collection between the liver and gastrointestinal tract. We report successful EUS-RV rescue using a self-expandable metal stent (SEMS) with an ultra-slim delivery system ([Video 1]). A 69-year-old woman developed obstructive jaundice secondary to pancreatic tail cancer. Computed tomography revealed hilar biliary obstruction and intrahepatic bile duct dilation caused by a metastatic tumor. ERCP was initially attempted; however, biliary cannulation failed, prompting same-session EUS-RV. Duodenal puncture was not feasible due to a non-dilated extrahepatic bile duct; therefore, a transgastric approach was adopted. Because the intrahepatic bile duct in segment 2 was less dilated, the dilated duct in segment 3 was punctured using a 19-gauge needle ([Fig. 1]). A 0.025-inch guidewire was inserted but failed to pass through the hilar biliary obstruction, even when a hydrophilic guidewire was used owing to the highly angulated left hepatic duct ([Fig. 2]). A double-guidewire technique using a double-lumen cannula was employed [5]. However, bile leakage occurred during catheter exchange, and fluid collection was observed between the liver and stomach, complicating the procedure ([Fig. 3]). We decided to convert the patient to hepaticogastrostomy. Owing to the anticipated technical difficulty in inserting a metal stent with a conventional 8-Fr delivery system without dilation devices such as a cautery dilator or balloon catheter, we selected a fully covered SEMS with a 5.9-Fr delivery system (8-mm × 12-cm HANAROSTENT; M.I. Tech, Seoul, Korea). This facilitated smooth stent insertion, and hepaticogastrostomy was successfully completed ([Fig. 4]). The patient developed peritonitis, which resolved with conservative treatment. Her total bilirubin levels decreased, and no further biliary drainage was required. Endoscopy_UCTN_Code_TTT_1AS_2AH Article published online: 18 September 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

We are grateful to the authors of the Letter to the Editor for their thoughtful and constructive comments regarding our recent article, “Benefits of macroscopic on-site evaluation in endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling. ” We appreciate this opportunity to respond to the points raised, which we address below. Our study primarily aimed to identify an optimal specimen collection method for FoundationOne CDx (F1CDx) using endoscopic ultrasound-guided tissue acquisition (EUS-TA), ensuring sufficient material for comprehensive genomic profiling. Received: 13 July 2025 Accepted: 01 August 2025 Article published online: 14 August 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany