1.Endoscopic Technology for Diagnosis of Biliary Stricture with a Focus on Peroral Cholangioscopy: Challenges in Peroral Cholangioscopy-Based Management
Ko TOMISHIMA ; Hiroyuki ISAYAMA ; Toshio FUJISAWA ; Yusuke TAKASAKI ; Taito FUKUMA ; Sho TAKAHASHI ; Shigeto ISHII
Korean Journal of Pancreas and Biliary Tract 2026;31(2):42-53
Biliary strictures arise from diverse benign and malignant etiologies, and accurate differentiation is pivotal for prognosis and treatment selection. Conventional endoscopic retrograde cholangiopancreatography (ERCP)-based sampling (brush cytology and forceps biopsy) suffers from limited sensitivity despite high specificity, leaving a substantial proportion as indeterminate biliary strictures. Peroral cholangioscopy (POCS) enables direct intraductal visualization and targeted biopsies, thereby enhancing diagnostic yield. This review summarizes technological evolution from fiber-optic mother–baby systems to digital single-operator cholangioscopy and direct POCS, as well as the integration of image-enhanced endoscopy and emerging wide-channel scopes. Visual criteria for malignancy—tumor vessels, irregular granular or papillary/villous patterns, and friability—achieve high sensitivity and interobserver reliability with proposed classifications (Monaco, Mendoza). For cholangiocarcinoma, POCS-guided mapping biopsies precisely assess longitudinal intraepithelial tumor spread, informing R0 surgical planning. Randomized trials indicate higher or at least comparable sensitivity of POCS-guided biopsies relative to ERCP sampling, while novel forceps and larger working channels increase specimen size and reduce the number of biopsies. Artificial intelligence (AI) applied to POCS images shows promise for real-time risk stratification and improved targeting. Therapeutically, POCS guides intraductal lithotripsy with high clearance rates, and facilitates management in surgically altered anatomy in concert with endoscopic ultrasound-guided biliary drainage or transendosonographically/ guided created route procedure. Adverse events, chiefly pancreatitis and cholangitis, warrant attention to intraductal pressure control and CO2 insufflation. POCS has established an essential role in the diagnostic algorithm for biliary strictures; future advances will likely come from enhanced imaging, AI assistance, and next-generation digital cholangioscopes with larger biopsy devices.
2.Evaluation of the mechanical properties of current biliary self-expandable metallic stents: axial and radial force, and axial force zero border
Wataru YAMAGATA ; Toshio FUJISAWA ; Takashi SASAKI ; Rei ISHIBASHI ; Tomotaka SAITO ; Shuntaro YOSHIDA ; Shizuka NO ; Kouta INOUE ; Yousuke NAKAI ; Naoki SASAHIRA ; Hiroyuki ISAYAMA
Clinical Endoscopy 2023;56(5):633-649
Background/Aims:
Mechanical properties (MPs) and axial and radial force (AF and RF) may influence the efficacy and complications of self-expandable metallic stent (SEMS) placement. We measured the MPs of various SEMSs and examined their influence on the SEMS clinical ability.
Methods:
We evaluated the MPs of 29 types of 10-mm SEMSs. RF was measured using a conventional measurement device. AF was measured using the conventional and new methods, and the correlation between the methods was evaluated.
Results:
A high correlation in AFs was observed, as measured by the new and conventional manual methods. AF and RF scatterplots divided the SEMSs into three subgroups according to structure: hook-and-cross-type (low AF and RF), cross-type (high AF and low RF), and laser-cut-type (intermediate AF and high RF). The hook-and-cross-type had the largest axial force zero border (>20°), followed by the laser-cut and cross types.
Conclusions
MPs were related to stent structure. Hook-and-cross-type SEMSs had a low AF and high axial force zero border and were considered safest because they caused minimal stress on the biliary wall. However, the increase in RF must be overcome.
3.Feasibility of Endoscopic Papillary Large Balloon Dilation in Patients with Difficult Bile Duct Stones without Dilatation of the Lower Part of the Extrahepatic Bile Duct.
Yuji FUJITA ; Akito IWASAKI ; Takamitsu SATO ; Toshio FUJISAWA ; Yusuke SEKINO ; Kunihiro HOSONO ; Nobuyuki MATSUHASHI ; Kentaro SAKAMAKI ; Atsushi NAKAJIMA ; Kensuke KUBOTA
Gut and Liver 2017;11(1):149-155
BACKGROUND/AIMS: There is no consensus for using endoscopic papillary large balloon dilation (EPLBD) in patients without dilatation of the lower part of the bile duct (DLBD). We evaluated the feasibility and safety of EPLBD for the removal of difficult bile duct stones (diameter ≥10 mm) in patients without DLBD. METHODS: We retrospectively reviewed the records of 209 patients who underwent EPLBD for the removal of bile duct stones from October 2009 to July 2014. Primary outcomes were the clearance rate and additional mechanical lithotripsy. Secondary outcomes were the incidence of complications and recurrence rate. RESULTS: Fifty-seven patients had DLBD (27.3%), and 152 did not have DLBD (72.7%). There were no significant differences in the overall success rate or the use of mechanical lithotripsy. Success rate during the first session and procedure time were better in the DLBD than the without-DLBD group (75.7% vs 66.7%, 48.1±23.0 minutes vs 58.4±31.7 minutes, respectively). As for complications, there were no significant differences in the incidence of pancreatitis, perforation or bleeding after endoscopic retrograde cholangiopancreatography. The recurrence rate did not differ significantly between the two groups. CONCLUSIONS: EPLBD is a useful and safe method for common bile duct stone removal in patients without DLBD.
Bile Ducts*
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Bile Ducts, Extrahepatic*
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Bile*
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Cholangiopancreatography, Endoscopic Retrograde
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Common Bile Duct
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Consensus
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Dilatation*
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Hemorrhage
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Humans
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Incidence
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Lithotripsy
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Methods
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Pancreatitis
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Recurrence
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Retrospective Studies
4.Which Is Crucial, Strengthen the Foundation or Building the Dream House?.
Hiroyuki ISAYAMA ; Yousuke NAKAI ; Toshio FUJISAWA
Gut and Liver 2017;11(4):453-454
No abstract available.
Dreams*

Result Analysis
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