Comparison of disposable digital single-operator cholangioscopy versus direct peroral cholangioscopy for the diagnosis of intraductal superficial lesions of the bile duct.

BACKGROUND AND AIMS: Disposable digital single-operator cholangioscopy (D-SOC) and direct peroral cholangioscopy (D-POC) using an ultraslim endoscope are established POC modalities for the diagnosis and treatment of various biliary diseases. We compared the usefulness of D-SOC and D-POC for the diagnosis of intraductal superficial lesions of the bile duct (ISL-Bs). METHODS: In total, 38 consecutive patients with suspected biliary diseases who underwent both D-SOC and D-POC were enrolled. The primary outcome was the detection rate of the ISL-Bs, and the secondary outcomes were the technical success of POC and POC-guided forceps biopsy sampling (POC-FB), procedure time, visualization quality, and tissue adequacy. RESULTS: D-SOC had a higher technical success rate than D-POC but without a statistically significant difference (100% vs. 92.1%, P = 0.248). D-POC had a marginally higher ISL-B detection rate (34.2% vs. 28.9%, P = 0.683) and significantly higher visualization quality (P = 0.033). The mean procedure time was significantly shorter with D-SOC (11.00 ± 1.34 vs. 19.03 ± 2.95 min, P < 0.001). The technical success rate of POC-FB and tissue adequacy did not differ between the two techniques (D-SOC vs. D-POC: 81.8% vs. 84.6%, P = 0.693 and 77.8% vs. 90.9%, P = 0.566). CONCLUSIONS: Our results demonstrate that both POC systems are safe and useful for the detection, characterization, and diagnosis of minute ISL-Bs. While D-SOC displayed a shorter procedure time and a tendency for higher technical success rate, D-POC provided superior visualization quality, allowing detailed observation of the surface structure and microvascular patterns.

Impact of temperature-controlled endobiliary radiofrequency ablation for inoperable hilar cholangiocarcinoma: A propensity score-matched analysis.

Background and study aims Endobiliary radiofrequency ablation (RFA) can be an effective palliative treatment, but few studies have evaluated its outcomes for malignant obstruction in the hilar bile duct, which has a thin wall and complex duct-vascular contacts. We evaluated the efficacy and safety of temperature-controlled endobiliary RFA, which can reduce the risk of unintentional thermal injury by maintaining the temperature of the ablation segment, in the treatment of inoperable hilar cholangiocarcinoma (CCA). Patients and methods After propensity score matching, 64 patients with inoperable hilar CCA were categorized to the RFA + stent group (endobiliary RFA with stenting; n=32) or stent-only group (stenting only; n=32). The evaluated outcomes were the median time to recurrent biliary obstruction (RBO), overall survival (OS), and adverse events (AEs). Results Technical success was achieved in all patients. The clinical success rate was 93.8% in the RFA + stent group and 87.5% in the stent-only group ( P =0.672). The median time to RBO was 242 days in the RFA + stent group and 168 days in the stent-only group ( P =0.031). The median OS showed a non-significant tendency to be higher in the RFA + stent group (337 versus 296 days; P =0.260). Overall AE rates were comparable between the two groups (12.5% vs 9.4%, P =1.000). Conclusions Temperature-controlled endobiliary RFA resulted in favorable stent patency without increasing the rate of AEs but it did not significantly increase OS in patients with inoperable hilar CCA (Clinical trial registration number: KCT0008576).

Quality Indicators of Endoscopic Retrograde Cholangiopancreatography in Korea.

Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure that requires significant experiences and skills and has various procedure-related complications, some of which can be severe and even result in the death of patients. Expanding ERCP availability has the advantage of increasing accessibility for patients. However, ERCP poses a substantial risk if performed without proper quality management. ERCP quality management is essential for both ensuring safe and successful procedures and meeting the social demands for enhanced healthcare competitiveness and quality assurance. To address these concerns, the Korean Pancreatobiliary Association established a task force to develop ERCP quality indicators (QIs) tailored to the Korean medical environment. Key questions for five pre-procedure, three intra-procedure, and four post-procedure measures were formulated based on a literature search related to ERCP QIs and a comprehensive clinical review conducted by experts. The statements and recommendations regarding each QI item were selected through peer review. The developed ERCP QIs were reviewed by external experts based on the latest available evidence at the time of development. These domestically tailored ERCP QIs are expected to contribute considerably to improving ERCP quality in Korea.

Usefulness of Direct Peroral Cholangioscopy Using a Multibending Ultraslim Endoscope for the Management of Intrahepatic Bile Duct Lesions (with Videos).

Background/Aims: : Peroral cholangioscopy (POC) has been used to assess intrahepatic duct (IHD) lesions but with a limited role. A new multibending (MB) ultraslim endoscope has been designed to improve POC performance. We evaluated the usefulness of POC using the MB ultraslim endoscope for the management of IHD lesions. Methods: : Between March 2017 and March 2020, 22 patients underwent direct POC using the MB ultraslim endoscope for IHD lesions documented by previous imaging or cholangiopancreatography. The primary outcome was technical success of POC, and secondary outcomes were technical success of POC-guided interventions, median procedure time, and POC-related adverse events. Results: : The technical success rate for POC using the MB ultraslim endoscope for IHD lesions was 95.5% (21/22). Free-hand insertion was successful in 95.2% (20/21). The overall technical success rate for POC-guided intervention was 100% (21/21), including nine diagnostic and 12 therapeutic procedures (eight direct stone removal and four intraductal lithotripsies). The median procedure time was 29 minutes (range, 9 to 79 minutes). There were no procedure-related adverse events. Conclusions: : Direct POC using the MB ultraslim endoscope allows direct visualization of IHD lesions and may be useful for diagnosis and therapeutic management in selected patients.

Preliminary feasibility study of a new partially covered self-expandable metal stent with an anchoring flange for EUS-guided hepaticogastrostomy (with videos).

BACKGROUND AND AIMS: EUS-guided hepaticogastrostomy (EUS-HPG) has a risk of serious procedural adverse events (AEs), but few dedicated devices for EUS-HPG are available. We evaluated the feasibility of a new partially covered self-expandable metal stent (PCSEMS) with an anchoring flange for EUS-HPG. METHODS: The feasibility of a stent featuring a proximal radiopaque uncovered portion 1.5 cm in length and a distal anchoring flange 20 mm in diameter was evaluated in consecutive patients undergoing EUS-HPG for unresectable malignant biliary obstruction. Primary outcomes were the technical and clinical success of EUS-HPG, and secondary outcomes were AEs, recurrent biliary obstruction (RBO), reintervention for RBO, and the technical feasibility of peroral cholangioscopy (POC) through the stent in situ. RESULTS: EUS-HPG was performed in 24 patients with unresectable malignant biliary obstruction. The technical and clinical success rates of EUS-HPG were 100% (24/24) and 91.7% (22/24), respectively. AEs developed after EUS-HPG in 8.3% of patients (2/24, cholangitis). RBO developed in 29.2% of patients (7/24), with a median cumulative time to RBO of 6.7 months. The causes of RBO were sludge formation (n = 4), hyperplasia at an uncovered portion (n = 2), and nonocclusive cholangitis (n = 1). Reintervention for RBO had a 100% success rate (7/7), and POC through the stent in situ was technically feasible in 7 of 8 patients with a stent diameter of 10 mm. CONCLUSIONS: EUS-HPG with a new PCSEMS can alleviate malignant biliary obstruction after failed ERCP. The novel stent evaluated in this study may prevent stent-related AEs, including stent migration, and allow advanced endoscopic interventions through the HPG route.

Comparison between three types of needles for endoscopic ultrasound-guided tissue acquisition of pancreatic solid masses: a multicenter observational study.

It is debatable which needle has clear superiority of diagnostic performance in endoscopic ultrasound (EUS)-guided fine needle biopsy (FNB) of solid pancreatic masses. This study aimed to compare the performance of three needles and determine the variables that affect diagnostic accuracy. From March 2014 to May 2020, 746 patients with solid pancreatic masses who underwent EUS-FNB using three types of needles (Franseen needle, Menghini-tip needle, and Reverse-bevel needle) were retrospectively reviewed. Multivariate analysis using a logistic regression model was used to identify factors related to diagnostic accuracy. There were significant differences between the groups regarding the procurement rate of the histologic and optimal quality cores (Franseen vs. Menghini-tip vs. Reverse-bevel: 98.0% [192/196] vs. 85.8% [97/113] vs. 91.9% [331/360], P < 0.001 and 95.4% [187/196] vs. 65.5% [74/113] vs. 88.3% [318/360], P < 0.001, respectively). The sensitivity and accuracy using histologic samples were 95.03% and 95.92% for Franseen, 82.67% and 88.50% for Menghini-tip, and 82.61% and 85.56% for Reverse-bevel needles, respectively. In direct comparison between the needles using histologic samples, the Franseen needle showed significantly superior accuracy than the Menghini-tip (P = 0.018) and Reverse-bevel needles (P < 0.001). Multivariate analysis indicated that tumor size ≥ 2 cm (odds ratio [OR] 5.36, 95% confidence interval [CI] 3.40-8.47, P < 0.001) and fanning technique (OR 1.70, 95% CI 1.00-2.86, P = 0.047) were significantly associated with an accurate diagnosis. EUS-FNB using the Franseen needle enables the acquisition of a larger and more adequate histologic core tissue and achieves an accurate histological diagnosis when using the fanning technique.

Detection and endoscopic classification of intraductal neoplasms of the bile duct by peroral cholangioscopy with narrow-band imaging (with videos).

BACKGROUND AND AIMS: Indirect diagnostic modalities are unsatisfactory for detecting intraductal neoplasm of the bile duct (IN-B), which can be detected by peroral cholangioscopy (POC) with narrow-band imaging (NBI). We investigated the POC findings of IN-B and developed a feasible endoscopic classification system. METHODS: Four hundred seventy-one patients who underwent direct POC from April 2008 to July 2020 were enrolled. Intraductal superficial lesions of the bile duct (ISL-Bs) were classified according to surface structure and microvascular pattern on POC with NBI and correlated to histologic findings after POC-guided forceps biopsy sampling (POC-FB) or surgery. The primary outcome was the detection rate of IN-Bs, and the secondary outcomes were the associations of POC findings with IN-B, technical success rates of POC and POC-FB, and adverse events. RESULTS: Direct POC was successful in 458 of 471 patients (97.2%). Among the patients, 131 (27.8%) exhibited ISL-Bs. The technical success rate of POC-FB was 94.7% (124/131). Among the 124 patients who underwent POC-FB, IN-B was revealed in 54 (43.5%), for a detection rate of 11.8% (54/458). Papillary lesions (P = .041), nodular lesions (P = .044), and irregularly or regularly dilated and tortuous vessels (P = .004 and P = .006, respectively) were POC findings associated with IN-B. The area under the receiver-operating characteristic curve of the novel classification system was .899. CONCLUSIONS: POC with NBI can be useful for the detection of IN-Bs. Our novel classification system based on both surface structure and microvascular pattern may allow differentiation of IN-B from ISL-Bs.

Comparison of the long-term outcomes between proximal and distal IgG4-related sclerosing cholangitis: A multicenter cohort study.

BACKGROUND AND AIMS: Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is considered a biliary manifestation of IgG4-related diseases. However, there has been a controversy on the clinical outcomes according to the location of the involved bile duct. We therefore compared the clinical outcomes and long-term prognosis of IgG4-SC with proximal bile duct involvement (proximal IgG4-SC) and IgG4-SC with distal bile duct involvement (distal IgG4-SC). METHODS: We reviewed the data of patients with IgG4-SC that were prospectively collected at 10 tertiary centers between March 2002 and October 2020. Clinical manifestations, outcomes, association with autoimmune pancreatitis (AIP), steroid-responsiveness, and relapse of IgG4-SC were evaluated. RESULTS: A total of 148 patients (proximal IgG4-SC, n = 59; distal IgG4-SC, n = 89) were analyzed. The median age was 65 years (IQR, 56.25-71), and 86% were male. The two groups were similar in terms of jaundice at initial presentation (51% vs 65%; P = 0.082) and presence of elevated serum IgG4 (66% vs 70%; P = 0.649). The two groups showed significant differences in terms of steroid-responsiveness (91% vs 100%; P = 0.008), association with AIP (75% vs 99%; P = 0.001), and occurrence of liver cirrhosis (9% vs 1%; P = 0.034). During a median follow-up of 64 months (IQR, 21.9-84.7), the cumulative relapse-free survival was significantly different between the two groups (67% vs 79% at 5 years; P = 0.035). CONCLUSIONS: Relapse of IgG4-SC frequently occurred during follow-up. Proximal IgG4-SC and distal IgG4-SC had different long-term outcomes in terms of steroid-responsiveness, occurrence of liver cirrhosis, and recurrence. It may be advantageous to determine the therapeutic and follow-up strategies according to the location of bile duct involvement.

EUS-guided tissue acquisition using a novel torque technique is comparable with that of the fanning technique for solid pancreatic lesions: A multicenter randomized trial.

BACKGROUND: The torque and fanning techniques allow for multiple areas within pancreatic lesions to be targeted using different maneuvers and can, hence, enhance diagnostic outcomes. We compared the diagnostic performance of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) for pancreatic masses using the torque and fanning techniques. METHODS: This multicenter randomized trial enrolled a total of 160 consecutive patients who underwent EUS-FNB for solid pancreatic tumors using either the torque or fanning technique. Three passes were permitted for each lesion, and the technique sequence was randomly assigned as either torque first or fanning first with the standard technique as a reference. RESULTS: The median quality score of the histological samples was significantly higher in the torque and fanning group than in the standard group (p < .001). Furthermore, the torque technique provided improved sensitivity of 93.38% and accuracy of 94.30%. The standard technique provided diagnostic sensitivity of 68.84% and accuracy of 72.96%, while the fanning technique showed sensitivity of 91.85% and accuracy of 93.04%. CONCLUSIONS: The new torque technique enables the acquisition of better-quality samples and can potentially increase the diagnostic outcomes in the EUS-FNB of pancreatic solid masses, with the same recommendations as those for the fanning technique.

National Survey Regarding the Management of Difficult Bile Duct Stones in South Korea.

Background/Aims: This study aimed to investigate the patterns of preferred endoscopic procedure types and techniques for managing difficult common bile duct (CBD) stones in South Korea. Methods: The Committee of Policy and Quality Management of Korean Pancreatobiliary Association (KPBA) conducted a survey containing 19 questions. Both paper and online surveys were carried out; with the paper survey being conducted during the 2019 Annual Congress of KPBA and the online survey being conducted through Google Forms from April 2020 to February 2021. Results: The response rate was approximately 41.3% (86/208). Sixty-two (73.0%) worked at tertiary hospitals or academic medical centers, and 60 (69.7%) had more than 5 years of endoscopic retrograde cholangiopancreatography experience. The preferred size criteria for large CBD stones were 15 mm (40.6%), 20 mm (31.3%), and 30 mm (4.6%). For managing of large CBD stones, endoscopic papillary large balloon dilation after endoscopic sphincterotomy was the most preferred technique (74.4%). When performing procedures in those with bleeding diathesis, 64 (74.4%) respondents favored endoscopic papillary balloon dilation (EPBD) alone or EPBD with small endoscopic sphincterotomy. Fifty-five respondents (63.9%) preferred the doubleguidewire technique when faced with difficult bile duct cannulation in patients with periampullary diverticulum. In surgically altered anatomies, cap-fitted forward viewing endoscopy (76.7%) and percutaneous transhepatic cholangioscopy (48.8%) were the preferred techniques for Billroth-II anastomosis and total gastrectomy with Roux-en-Y anastomosis, respectively. Conclusions: Most respondents showed unifying trends for the management of difficult CBD stones. The current practice patterns could be used as basic data for clinical quality improvements in the management of difficult CBD stones.

A novel bipolar electrocautery-enhanced delivery system with a lumen-apposing metal stent for EUS-guided drainage: A porcine study.

BACKGROUND: An electrocautery-enhanced delivery system with a lumen-apposing metal stent (LAMS) is available for one-step endoscopic ultrasound-guided transmural drainage (EUS-TD). Bipolar electrosurgery has several potential clinical advantages, including reduced collateral thermal damage, enhanced hemostasis, and no requirement for a return electrode plate. In this study, we compared the technical feasibility and safety of a newly developed bipolar electrocautery-enhanced delivery system with a conventional delivery system for EUS-TD using a LAMS in a porcine model. METHOD: Ten days before the study, 12 mini pigs underwent common bile duct ligation for EUS-guided gallbladder drainage. Transenteric puncture was performed, followed by placement of a guidewire. In six pigs, a bipolar electrocautery-enhanced delivery system with LAMS (Hot SPAXUS) was inserted over the guidewire and advanced into the gallbladder, without prior dilation of the tract, by applying a bipolar cut current. In the remaining six pigs, a conventional delivery system with LAMS (Cold SPAXUS) was inserted after tract dilatation using a cystotome. The stent was removed after 4 weeks. RESULTS: In all pigs, the stent was successfully inserted and deployed in the gallbladder without adverse events. The mean procedure time of EUS-TD was significantly lower in the Hot SPAXUS group than that of the Cold SPAXUS group (mean ± standard deviation: 188.7 ± 5.2 vs 449.5 ± 97.5 s, P = .0019). Stent migration was not observed, and all stents were removed successfully. CONCLUSIONS: Endoscopic ultrasound-guided transmural drainage using a bipolar electrocautery-enhanced LAMS is feasible for reducing the procedure time while maintaining the high success rate and safety of conventional LAMS.

Feasibility of Cholangioscopy Using Multibending Ultra-Slim Endoscope Through a Lumen-Apposing Metal Stent for Choledochoduodenostomy.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS) guided choledochoduodenostomy using a lumen-apposing metal stent (LAMS) allows access to the biliary system with a sufficiently large diameter stent. However, an appropriate endoscope for this purpose is required. We evaluated the feasibility of per-oral cholangioscopy (POC) using a multibending ultra-slim endoscope through a LAMS for EUS-guided choledochoduodenostomy. METHODS: Twelve patients who underwent EUS-guided choledochoduodenostomy, followed by POC via a LAMS, were enrolled. POC was performed with an multibending ultra-slim endoscope. The primary outcome was technical success, defined as examination of both hepatic ducts and either the distal common bile duct or stricture site within 10 min. The types of intervention and adverse events were also assessed. RESULTS: Technical success was achieved in all cases with the multibending ultra-slim endoscope. Narrow-band imaging endoscopy was performed in five cases (41.7%) and POC-guided targeted biopsy was performed in three cases (25.0%). Stone extraction during POC was performed in two patients (16.7%) and foreign body removal from the intrahepatic duct was performed in one patient. One patient underwent additional metal stent insertion under direct visualization. After POC, no stent migration or severe adverse events were seen in any case. CONCLUSIONS: POC using a multibending ultra-slim endoscope for diagnostic or therapeutic purposes can be performed effectively and safely through a LAMS after EUS-guided choledochoduodenostomy.

Current Practice Patterns of Endoscopic Ultrasound-Guided Tissue Sampling for Pancreatic Solid Mass in Korea: Outcomes of a National Survey.

Background/Aims: Although endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) are widely used for tissue acquisition of pancreatic solid mass, the optimal strategy of this procedure has not been established yet. The aim of this nationwide study was to investigate the current practice patterns of EUS-FNA/FNB for pancreatic solid mass in Korea. Methods: The Policy-Quality Management of the Korean Pancreatobiliary Association (KPBA) developed a questionnaire containing 22 questions. An electronic survey consisting of the questionnaire was distributed by e-mail to members registered to the KPBA. Results: A total of 101 respondents completed the survey. Eighty respondents (79.2%) performed preoperative EUS-FNA/FNB for operable pancreatic solid mass. Acquire needles (60.4%) were used the most, followed by ProCore needles (47.5%). In terms of need size, most respondents (>80%) preferred 22-gauge needles regardless of the location of the mass. Negative suction with a 10-mL syringe (71.3%) as sampling technique was followed by stylet slow-pull (41.6%). More than three needle passes for EUS-FNA/FNB was performed by most respondents (>80%). The frequency of requiring repeated procedure was significantly higher in respondents with a low individual volume (<5 per month, p=0.001). Prophylactic antibiotics were routinely used in 39 respondents (38.6%); rapid on-site pathologic evaluation was used in 6.1%. Conclusions: According to this survey, practices of EUS-FNA/FNB for pancreatic solid mass varied substantially, some of which differed considerably from the recommendations present in existing guidelines. These results suggest that the development of evidence-based quality guidelines fitting Korean clinical practice is needed to establish the optimal strategy for this procedure.

Efficacy and safety of direct peroral cholangioscopy using a new multibending ultra-slim endoscope for the management of biliary diseases.

BACKGROUND/PURPOSE: Compared with currently available duodenoscopy-assisted systems, direct peroral cholangioscopy (DPOC) using an ultra-slim endoscope is limited by technical difficulties. The multibending (MB) ultra-slim endoscope was introduced as a dedicated cholangioscope for DPOC to challenge the technical problem. We retrospectively analyzed the clinical utility of DPOC using an MB endoscope with free-hand insertion into the bile duct in patients with biliary diseases. METHODS: A total of 145 patients who underwent DPOC using an MB endoscope were analyzed. The primary outcome was the technical success rate of DPOC using the free-hand insertion of the MB endoscope. The secondary outcomes were the technical success rates of DPOC-guided diagnostic and therapeutic interventions, the diagnostic accuracy of DPOC-guided target biopsy, and adverse events related to DPOC. RESULTS: Free-hand biliary insertion of a MB endoscope for DPOC was technically successful in 133 patients (91.7%). DPOC-guided target biopsy was successful in 36 of 38 patients (94.7%) and had a diagnostic accuracy of 91.7% (95% confidence interval, 82.6-100). Sixty-nine therapeutic interventions were performed; technical success was achieved in 65 (94.2%). No severe adverse events were observed. CONCLUSIONS: The MB ultra-slim endoscope was technically effective to perform a DPOC including various diagnosis and therapeutic interventions without device assistance. MB endoscope is considered to contribute to expanding a role of DPOC in diagnosis and treatment of diverse biliary tract diseases.

Efficacy of narrow-band imaging during peroral cholangioscopy for predicting malignancy of indeterminate biliary strictures (with videos).

BACKGROUND AND AIMS: Direct peroral cholangioscopy (POC) can be useful when combined with narrow-band imaging (NBI) to explore the etiologies of indeterminate biliary strictures. We evaluated the efficacy of NBI compared with that of conventional white-light imaging (WLI) during POC diagnosis of indeterminate biliary strictures. METHODS: Consecutive patients with indeterminate biliary strictures were enrolled from 2016 to 2019. The primary outcome was diagnostic accuracy, and secondary outcomes were technical success, adverse events, and visualization quality when predicting malignancy. RESULTS: Seventy-one patients underwent direct POC under NBI during targeted biopsy sampling. The strictures were successfully explored and adequate biopsy samples obtained in 67 of 71 patients (94.4%). In terms of visual impression, WLI and NBI afforded 75.0% and 87.5% sensitivity, 82.9 and 91.4% specificity, and 82.8 and 91.3% accuracy, respectively. The areas under the WLI and NBI receiver-operating characteristic curves were .80 and .96 (P = .01). Under NBI, the visualization quality of surface structures, microvessels, and lesional margins was higher than that under conventional WLI (P < .05). CONCLUSIONS: Direct POC under NBI effectively and accurately predicts malignancies of indeterminate biliary strictures. NBI effectively illuminated surface structures, microvessels, and lesional margins.

Utility of Direct Peroral Cholangioscopy Using a Multibending Ultraslim Endoscope for Difficult Common Bile Duct Stones.

Background/Aims: Treatment options for difficult bile duct stones are limited. Direct peroral cholangioscopy (POC)-guided lithotripsy may be an option. A newly developed multibending (MB) ultraslim endoscope has several structural features optimized for direct POC. We evaluated the utility of direct POC using an MB ultraslim endoscope for lithotripsy in patients with difficult bile duct stones. Methods: Twenty patients with difficult bile duct stones, in whom stone removal using conventional endoscopic methods, including mechanical lithotripsy, had failed were enrolled from March 2018 to August 2019. Direct POC-guided lithotripsy was performed by electrohydraulic lithotripsy or laser lithotripsy. The primary outcome was complete ductal clearance, defined as the retrieval of all bile duct stones after lithotripsy confirmed by balloon-occluded cholangiography and/or direct POC. Results: The technical success rate of direct POC was 100% (20/20), and the free-hand insertion rate was 95% (19/20). Direct POC-guided lithotripsy, attempted by electrohydraulic lithotripsy in nine patients (45%) and laser lithotripsy in 11 patients (55%), was successful in 95% (19/20) of the patients. Complete ductal clearance after direct POC-guided lithotripsy was achieved in 95% (19/20) of patients. Patients required a median of 2 (range, 1-3) endoscopic retrograde cholangiopancreatography sessions for complete stone removal. Adverse event was observed in one patient (5%) with hemobilia and was treated conservatively. Conclusions: Direct POC using an MB ultraslim endoscope was safe and effective for lithotripsy in patients with difficult bile duct stones.