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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. [ABSTRACT FROM AUTHOR]

Background/Aims Although early detection of intraductal neoplasms of the bile duct (IN-B) is crucial for the curative treatment of cholangiocarcinoma (CCA), current diagnostic modalities remain suboptimal. We aimed to evaluate whether disposable digital single-operator cholangioscopy (D-SOC) could be an effective tool for screening intraductal neoplasms of the bile duct in patients with bile duct stones. Methods Consecutive 181 patients who underwent D-SOC after endoscopic bile duct stone removal were enrolled. The primary outcome was the detection rate of intraductal neoplasms of the bile duct, and secondary outcomes were the technical success rates of D-SOC and D-SOC guided forceps biopsy, the diagnostic accuracy of D-SOC findings, adverse events, and the number of patients needed to screen to identify a single intraductal neoplasm. Results D-SOC was successfully performed in all patients, and 23 (13.5%) showed abnormal intraductal superficial lesions of the bile duct. The technical success rate of D-SOC guided forceps biopsy was 91.3% (21/23 patients). Pathological evaluation identified IN-Bs in 9 patients (42.9%) and benign lesions in 12 patients (57.1%); patients with IN-Bs were diagnosed with CCAs (n=2), intraductal papillary neoplasms of the bile duct (n=6), and adenomas with dysplasia (n=1). D-SOC findings afforded 87.5% sensitivity, 91.4% specificity, and 91.3% accuracy, respectively. Curative surgical resection was performed on 2 patients. Mild cholangitis occurred in 3 patients (1.7%) and was managed conservatively. The number of patients who needed to screen to detect a neoplastic bile duct lesion was calculated to be 20.1. Conclusion D-SOC can be a valuable tool for screening intraductal neoplasms of the bile duct, including CCAs, in patients with bile duct stones (NCT05600803). [ABSTRACT FROM AUTHOR]

Background/Aims Newly developed image-enhanced endoscopies such as texture and color enhancement imaging (TXI) and red dichromatic imaging (RDI) can improve the assessment of obscure ampullary lesions. We aimed to explore the usefulness of TXI and RDI compared to narrow-band imaging (NBI) in differentiating ampullary lesions. Methods Consecutive patients with suspected ampullary lesions underwent sequential endoscopic observation using white-light imaging, NBI, TXI-1, TXI-2, and RDI-3. After the detection and characterization of the ampullary lesions, the final diagnosis was confirmed through histologic findings from forceps biopsy, endoscopic papillectomy, and/or surgery. The evaluated outcomes included the detection rate of endoscopic features suggesting neoplasms and diagnostic accuracy. Results Among the 31 ampullary lesions, 4 (12.9%) were adenocarcinomas, 7 (22.6%) were adenomas, and 20 (64.5%) were benign. TXI-1 demonstrated superior capability compared to NBI in detecting discoloration (41.9% vs. 9.7%, p=0.023), dotted microvessels (35.5% vs. 6.5%, p=0.032), and irregularly dilated and tortuous vessels (38.7% vs. 9.7%, p=0.048). Although the intergroup difference was not significant, RDI-3 showed a trend toward superiority over NBI in evaluating irregular villous arrangements (38.7% vs. 22.6%, p=0.812). NBI outperformed both TXI-1 and RDI-3 in distinguishing the demarcation with normal villi (NBI vs. TXI-1, 45.2% vs. 12.9%, p=0.032; NBI vs. RDI-3, 45.2% vs. 9.7%, p=0.011). In the receiver operating characteristic curve analysis, the combined use of TXI and RDI showed significantly higher accuracy (0.91) than NBI alone (0.74, p=0.021). Conclusion TXI and RDI can enhance the characterization of ampullary lesions, providing a more accurate diagnosis when used in conjunction with NBI. [ABSTRACT FROM AUTHOR]

Background/Aims Although a long self-expandable metal stent (SEMS) with a sufficient intragastric portion is preferred for endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS), it can complicate endoscopic re-intervention for recurrent biliary obstruction (RBO). We evaluated the efficacy and safety of endoscopic re-intervention for RBO through the stent after EUS-HGS using a novel partially covered SEMS with an anchoring flange. Methods The covered SEMS featured a proximal uncovered portion measuring 1.5 cm in length and a resilient fold-back wide distal anchoring flange with a 2.0 cm diameter. Endoscopic re-interventions were performed through the stent lumen while the stent was in situ. The evaluated outcomes were the technical and clinical success of the endoscopic re-intervention, procedure time, and adverse events. Results In total, 35 re-interventions for RBO were performed in 19 patients. The overall technical and clinical success rates were 91.4% (32/35) and 85.7% (30/35). The re-intervention methods included stent cleaning (18.2%), additional HGS stent placement (33.3%), and antegrade stent placement (48.5%). Mild cholangitis occurred in 5.7% (2/35) of patients and was managed conservatively. Conclusion Various types of endoscopic re-interventions for RBO can be effectively and safely performed through the lumen of a new partially covered SEMS with an anchoring flange. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Although endoscopic retrograde cholangiopancreatography (ERCP) is a first-line diagnostic modality for suspected malignant biliary stricture (MBS), the diagnostic yield of ERCP-based tissue sampling is insufficient. Peroral cholangioscopy-guided forceps biopsy (POC-FB) and endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) are evolving as reliable diagnostic procedures for inconclusive MBS. This study aimed to evaluate the usefulness of a diagnostic approach using POC-FB or EUS-FNAB according to the stricture location in patients with suspected MBS.Methods: Consecutive patients diagnosed with suspected MBS with obstructive jaundice and/or cholangitis were enrolled prospectively. ERCP with transpapillary forceps biopsy (TPB) was performed initially. When malignancy was not confirmed by TPB, POC-FB using a SpyGlass direct visualization system or direct POC using an ultraslim endoscope was performed for proximal strictures, and EUS-FNAB was performed for distal strictures as a follow-up biopsy.Results: Among a total of 181 patients, initial TPB showed malignancy in 122 patients, and the diagnostic accuracy of initial TPB was 71.8 % (95 % confidence interval [CI] 65.3 % - 78.4 %]. Of the 59 patients in whom TPB was negative for malignancy, 32 had proximal biliary strictures and underwent successful POC. The remaining 27 patients had distal strictures and underwent successful EUS-FNAB. The accuracy of malignancy detection using POC-FB for proximal biliary strictures and EUS-FNAB for distal biliary strictures was 93.6 % (95 %CI 84.9 %-100 %) and 96.3 % (95 %CI 89.2 %-100 %), respectively. The overall diagnostic accuracy for the combination of TPB with either POC-FB for proximal strictures and EUS-FNAB for distal strictures was 98.3 % (95 %CI 95.9 %-100 %) and 98.4 % (95 %CI 95.3 %-100 %), respectively.Conclusions: An approach using POC-FB or EUS-FNAB according to the stricture location may be useful in the diagnosis of suspected MBS. [ABSTRACT FROM AUTHOR]

Background/Aims: Needle-knife precut fistulotomy (NK-F) is a well-known freehand technique for difficult biliary cannulation (DBC). Another approach involves the use of Iso-Tome®, a modified precutting device with an insulated needle tip to prevent direct thermal injury. This comparative study aimed to evaluate the efficacy of the Iso-Tome® precut (IT-P) compared to that of NK-F for DBC. Methods: Patients with a naïve papilla who underwent early IT-P or NK-F for DBC were enrolled. DBC was defined as failure to achieve selective biliary access by wire-guided cannulation despite 5 minutes of attempted cannulation, ≥5 papillary contacts, or a hooknose- shaped papilla. The primary endpoint was the primary technical success rate, which was based on a noninferiority model. Results: A total of 239 DBC cases were enrolled. The primary technical success rates were 74.7% (89/119) in the IT-P group and 91.6% (110/120) in the NK-F group (lower limit of 90% confidence interval, -0.23; p=0.927 for a noninferiority margin of 10%). The total technical success rates were 87.4% and 95.0%, respectively (p=0.038). The mean precutting times for successful biliary access were 11.2 minutes for IT-P and 7.3 minutes for NK-F (p<0.01). The procedure-related adverse event rates were 9.2% for IT-P and 5.8% for NK-F (p=0.318). The rates of post-endoscopic retrograde cholangiopancreatography pancreatitis were 4.2% and 2.5%, respectively (p=0.499). Conclusions: IT-P failed to exhibit noninferiority compared with NK-F regarding the primary technical success rate of DBC, but there was no difference in the frequency of adverse events. [ABSTRACT FROM AUTHOR]

Background/Aims: Presence of enhanced mural nodules, which can be visualized using computed tomography (CT), is one of high-risk stigmata in branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs). Conversely, the absence of enhanced mural nodules on preoperative imaging does not exclude malignant risk. The present study aimed to investigate other morphological features as predictors of malignancy in "pure" BD-IPMNs without enhanced mural nodules on CT. Methods: This retrospective study included 180 patients with surgically confirmed "pure" BD-IPMNs of the pancreas and no enhanced mural nodules on preoperative CT. The study was conducted at 15 tertiary referral centers throughout South Korea. Univariate and multivariate analyses were used to identify significant predictors of malignancy. Results: BD-IPMNs with low-grade (n=84) or moderate-grade (n=76) dysplasia were classified as benign; those with highgrade dysplasia (n=8) or invasive carcinoma (n=12) were classified as malignant. The multivariate analysis revealed that cyst size ≥30 mm (odds ratio, 8.6; p=0.001) and main pancreatic duct diameter ≥5 mm (odds ratio, 4.1; p=0.01) were independent risk factors for malignancy in "pure" BDIPMNs without enhanced mural nodules on CT. Endoscopic ultrasound detected enhanced mural nodules (6/82) that had been missed on CT, and two IPMNs with enhanced mural nodules were malignant. Conclusions: In patients with "pure" BD-IPMNs who have no enhanced mural nodules on CT, cyst size ≥30 mm and main pancreatic duct diameter ≥5 mm may be associated with malignancy. [ABSTRACT FROM AUTHOR]

Background/Aims: In suspected malignant biliary strictures (MBSs), the diagnostic yield of endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling is limited. Transpapillary forceps biopsy (TPB) under intraductal ultrasonography (IDUS) guidance is expected to improve the diagnostic accuracy in patients with indeterminate biliary strictures. We evaluated the usefulness of IDUS-guided TPB in patients with suspected MBS. Methods: Consecutive patients with suspected MBS were prospectively enrolled in the study. ERCP with IDUS was performed in all patients. Both conventional TPB and IDUS-guided TPB on fluoroscopy were performed in each patient. The primary outcome was the diagnostic accuracy of conventional TPB and IDUS-guided TPB. Results: The technical success rate of IDUS-guided TPB was 97.0% (65/67 patients). Of these 65 patients, the final diagnosis was malignancy in 61 patients (93.8%). On IDUS, the most common finding of IDUS was an intraductal infiltrating lesion in 29 patients (47.5%). The overall diagnostic accuracy was significantly higher using IDUS-guided TPB than that using conventional TPB (90.8% vs 76.9%, p=0.027). According to the subgroup analysis based on the tumor morphology, IDUS-guided TPB had a significantly higher cancer detection rate than conventional TPB for intraductal infiltrating lesions (89.6% vs 65.5%, p=0.028). Conclusions: IDUS-guided TPB appears to improve the accuracy of histological diagnosis in patients with MBS. [ABSTRACT FROM AUTHOR]

Background and study aims I-SCAN is a computed virtual chromoendoscopy (CVC) system designed to enhance surface and vascular patterns. In this study, we evaluated the usefulness of direct peroral cholangioscopy (POC) using I-SCAN compared with a conventional white-light image (WLI) to diagnose bile duct lesions. Patients and methods Patients with mucosal lesions in the bile duct detected during direct POC were enrolled prospectively. The quality of endoscopic visualization and the visual diagnosis were assessed using I-SCAN and WLI modes, respectively, during direct POC. Results A total of 20 patients (9 malignant and 11 benign lesions) underwent I-SCAN to evaluate lesions in the bile duct using direct POC. The quality of endoscopic visualization using direct POC with I-SCAN was significantly higher than that of WLI for surface structure (P = 0.04), surface microvascular architecture (P = 0.01), and margins (P = 0.02). Overall diagnostic accuracy of the visual diagnosis was not different between I-SCAN and WLI (90.0 % vs. 75.0 %; P = 0.20). Conclusion Direct POC using CVC by I-SCAN seems to be helpful for evaluating mucosal lesions of the bile duct, without the interference from bile.Clinical Trial Registration: UMIN000021009. [ABSTRACT FROM AUTHOR]

Background/Aims: Controversy still exists regarding the benefits of covered self-expandable metal stents (SEMSs) compared to uncovered SEMSs. We aimed to compare the patency and stent-related adverse events of partially covered SEMSs (PC-SEMSs) and uncovered SEMSs in unresectable malignant distal biliary obstruction. Methods: A total of 134 patients who received a PC-SEMS or uncovered SEMS for palliation of unresectable malignant distal biliary obstruction were reviewed retrospectively. The main outcome measures were stent patency, stent-related adverse events, and overall survival. Results: The median stent patency was 118 days (range, 3 to 802 days) with PC-SEMSs and 105 days (range, 2 to 485 days) with uncovered SEMSs (p=0.718). The overall endoscopic revision rate due to stent dysfunction was 36.6% (26/71) with PC-SEMSs and 36.5% (23/63) with uncovered SEMSs (p=0.589). Tumor ingrowth was more frequent with uncovered SEMSs (4.2% vs 19.1%, p=0.013), but migration was more frequent with PC-SEMSs (11.2% vs 1.5%, p=0.04). The incidence of stent-related adverse events was 2.8% (2/71) with PC-SEMSs and 9.5% (6/63) with uncovered SEMSs (p=0.224). The median overall survival was 166 days with PC-SEMSs and 168 days with uncovered SEMSs (p=0.189). Conclusions: Compared to uncovered SEMSs, PC-SEMSs did not prolong stent patency in unresectable malignant distal biliary obstruction. Stent migration was more frequent with PC-SEMSs. However, tumor ingrowth was less frequent with PC-SEMSs compared to uncovered SEMSs. [ABSTRACT FROM AUTHOR]

Background/Aims: Treatment for cholangitis without common bile duct (CBD) stones has not been established in patients with gallstones. We investigated the usefulness of endoscopic biliary drainage (EBD) without endoscopic sphincterotomy (EST) in patients diagnosed with gallstones and cholangitis without CBD stones by endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS). Methods: EBD using 5F plastic stents without EST was performed prospectively in patients with gallstones and cholangitis if CBD stones were not diagnosed by ERCP and IDUS. After ERCP, all patients underwent laparoscopic cholecystectomy. The primary outcomes were clinical and technical success. The secondary outcomes were recurrence rate of biliary events and procedure-related adverse events. Results: Among 187 patients with gallstones and cholangitis, 27 patients without CBD stones according to ERCP and IDUS received EBD using 5F plastic stents without EST. The stents were maintained in all patients until laparoscopic cholecystectomy, and recurrence of cholangitis was not observed. After cholecystectomy, the stents were removed spontaneously in 12 patients and endoscopically in 15 patients. Recurrence of CBD stones was not detected during the follow-up period (median, 421 days). Conclusions: EBD using 5F plastic stents without EST may be safe and effective for the management of cholangitis accompanied by gallstones in patients without CBD stones according to ERCP and IDUS. [ABSTRACT FROM AUTHOR]

Background and study aim: Endoscopic stent-instent (SIS) placement of multiple metal stents is technically demanding. In the present study, we explored the technical feasibility and efficacy of endoscopic deployment of a third metal stent to create a triple SIS placement in patients with a bilateral SIS configuration for inoperable high grade malignant hilar biliary stricture (HBS) that had failed clinically. Methods: Eighteen patients with histologically proven inoperable HBS underwent deployment of an additional third metal stent as a revisionary method after early clinical failure following technically successful bilateral SIS placement using cross-wired metal stents. The main outcome measures were the technical and clinical success rates, and adverse events. Results: The overall technical and clinical success rates were 88.9% (16/18) and 87.5% (14/16), respectively. The early and late complications were cholangitis (n=2) and cholecystitis (n=1). Stent occlusion developed in 35.7% (5/14) of patients in whom a third metal stent for revision of a bilateral SIS configuration was clinically successful. The median (range) times for stent patency and patient survival were 176 days (49-372) and 216 days (52-384), respectively. Conclusions: Endoscopic deployment of an additional third metal stent into a bilateral SIS configuration was technically feasible and effective in patients with inoperable high grade malignant HBS in whom bilateral SIS placement had failed clinically. [ABSTRACT FROM AUTHOR]

Background/Aims: The covered self-expandable metal stent (CMS) was developed to prevent tumor ingrowth-induced stent occlusion during the treatment of malignant biliary obstruction. However, complications such as cholecystitis, pancreatitis, and stent migration can occur after the endoscopic insertion of CMSs. The aim of the present study was to assess the efficacy and safety of a double-layered CMS (DCMS) for the management of malignant bile duct obstruction. Methods: DCMSs were endoscopically introduced into 59 patients with unresectable malignant extrahepatic biliary obstruction at four tertiary referral centers, and the patient medical records were retrospectively reviewed. Results: Both the technical and functional success rates were 100%. Procedure-related complications including pancreatitis, cholangitis, stent migration, and liver abscess occurred in five patients (8.5%). The median follow-up period was 265 days (range, 31 to 752 days). Cumulative stent patency rates were 68.2% and 40.8% at 6 and 12 months, respectively. At the final follow-up, the rate of stent occlusion was 33.9% (20/59), and the median stent patency period was 276 days (range, 2 to 706 days). Conclusions: The clinical outcomes of DCMSs were comparable to the outcomes previously reported for CMSs with respect to stent patency period and complication rates. [ABSTRACT FROM AUTHOR]

Background and Study Aim: The nonflared ends of fully covered, self-expandable, metal stents (FCSEMSs) may minimize stent-induced ductal injury. Suprapapillary intraductal placement of nonflared FCSEMSs for malignant biliary stricture might reduce duodenobiliary reflux and pancreatitis. The aim of this study was to evaluate the efficacy of a newly modified, nonflared FCSEMS for intraductal placement in patients with malignant biliary stricture.Patients and Methods: A total of 51 patients with nonhilar, extrahepatic, malignant biliary stricture were enrolled prospectively. The nonflared FCSEMS is 12 mm in diameter, and has a central saddle and a distal lasso of 7 cm in length. An FCSEMS was placed above the papilla in all patients, with the central saddle positioned at the stricture to prevent stent migration.Results: The technical and clinical success rates were 100 % and 98 %, respectively. Early adverse events occurred in one patient (2.0 %; mild pancreatitis). A total of 12 patients underwent surgery with curative intent, one of whom (8.3 %) experienced a postoperative adverse event. No stent migration occurred in any of the patients. Cholecystitis developed in one patient (2.0 %) as a late adverse event. Stent occlusion occurred in 44.7 % (17/38), and endoscopic removal of the stent was successful in 87.5 % of patients. The mean stent patency was 297 days (95 % confidence interval, 211 - 383).Conclusions: Intraductal placement of the nonflared FCSEMS, 12 mm in diameter, was feasible for the palliative and preoperative management of patients with malignant biliary stricture. Long-term follow-up and prospective comparative studies are needed to evaluate the usefulness of intraductal placement of this stent. [ABSTRACT FROM AUTHOR]

Fasciola hepatica infection may result in biliary obstruction with or without cholangitis in the chronic biliary phase. Because clinical symptoms and signs of F. hepatica are similar to other biliary diseases that cause bile duct obstruction, such as stones or bile duct malignancies, that are, in fact, more common, this condition may not be suspected and diagnosis may be overlooked and delayed. Patients undergoing endoscopic retrograde cholangiopancreatography or endoscopic ultrasonography for the evaluation of bile duct obstruction may be incidentally detected with the worm, and diagnosis can be confirmed by extraction of the leaf-like trematode from the bile duct. Intraductal ultrasonography (IDUS) can provide high-resolution cross-sectional images of the bile duct, and is useful in evaluating indeterminate biliary diseases. We present a case of biliary fascioliasis that was diagnosed using IDUS and managed endoscopically in a patient with acute cholangitis. [ABSTRACT FROM AUTHOR]

Newly introduced direct peroral cholangioscopy and the development of video choledochoscopes have enabled more defined observation of bile duct mucosal lesions with clearer images. Narrow-band imaging (NBI) is a unique endoscopic imaging technology that provides enhanced endoscopic images of surface mucosal structures and its superficial microvessels. Advanced cholangioscopy and NBI are expected to be useful for precise evaluation and correct diagnosis of biliary tract diseases. However, the diagnostic value of advanced bile duct imaging with cholangioscopy requires further evaluation. [ABSTRACT FROM AUTHOR]

Background/Aims: Various anatomical features of the biliary tree affect ability to remove difficult common bile duct (CBD) stones. In this study, we evaluated the clinical characteristics and outcomes of the endoscopic treatment of stones in stemware-shaped CBDs. Methods: Thirty-four patients with a stone and a stemware-shaped CBD who were treated at different tertiary referral centers from January 2008 to December 2012 were studied retrospectively. When stone removal failed, percutaneous or direct peroral cholangioscopic lithotripsy, endoscopic retrograde biliary drainage, or surgery was performed as a second-line procedure. Results: The overall success rate of the first-line procedure was 41.2%. Five of the 34 patients (14.7%) experienced procedure-related complications. No procedure-related mortality occurred. Mechanical lithotripsy was required to completely remove stones in 13 patients (38.2%). Conversion to a second-line procedure was required in 20 patients (58.8%). Mechanical lithotripsy was needed in 75% and 66.7% of those with a stone size of <1 cm or ≥1 cm, respectively. Stone recurrence occurred in two patients (9.1%) after 6 months and 27 months, respectively. Conclusions: The endoscopic treatment of stones in a stemware-shaped CBD is challenging. The careful assessment of difficult CBD stones is required before endoscopic procedures. [ABSTRACT FROM AUTHOR]

Cases of pancreatic ductal adenocarcinoma with multiple masses accompanying underlying pancreatic diseases, such as intraductal papillary mucinous neoplasm, have been reported. However, synchronous invasion without underlying pancreatic disease is very rare. A 61-year-old female with abdominal discomfort and jaundice was admitted to our hospital. Abdominal computed tomography (CT) revealed cancer of the pancreatic head with direct invasion of the duodenal loop and common bile duct. However, positron emission tomography-CT showed an increased standardized uptake value (SUV) in the pancreatic head and tail. We performed endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for the histopathologic diagnosis of the pancreatic head and the evaluation of the increased SUV in the tail portion of the pancreas, as the characteristics of these lesions could affect the extent of surgery. As a result, pancreatic ductal adenocarcinomas were confirmed by both cytologic and histologic analyses. In addition, immunohistochemical analysis of the biopsy specimens was positive for carcinoembryonic antigen and p53 in both masses. The two masses were ultimately diagnosed as pancreatic ductal adenocarcinoma, stage IIB, based on EUS-FNB and imaging studies. In conclusion, the entire pancreas must be evaluated in a patient with a pancreatic mass to detect the rare but possible presence of synchronous pancreatic ductal adenocarcinoma. Additionally, EUS-FNB can provide pathologic confirmation in a single procedure. [ABSTRACT FROM AUTHOR]

Background/Aims: It is sometimes difficult to incise the distal papillary roof (PR) completely in patients with choledocholiths and choledochoduodenal fistula (CDF). The Iso-Tome® (MTW-Endoskopie W. Haag KG), which is helpful in preventing electrical leakage, has good orientation capabilities and can be easily placed at the orifice of the CDF or ampulla of Vater (AV). We aimed to evaluate the efficacy of endoscopic sphincterotomy (ES) with the Iso-Tome® for cutting the distal PR. Methods: Between May 2003 and July 2012, 35 patients were analyzed retrospectively. The distal PR was cut downward and/or upward using the Iso-tome® until the pink intrapapillary mucosa was fully exposed. Downward incisions were performed from the opening of the CDF to the orifice of the AV; upward incisions were performed in reverse. Results: Spontaneous or artificial CDF occurred in four and 31 patients, respectively. The technical and therapeutic success rates were 94.3% (33/35) and 94.3% (33/35), respectively. There was no case of electrical damage to the pink intrapapillary mucosa. Adverse events occurred in 2.9% (1/35; 1, mild bleeding) of patients. Conclusions: The new technique of ES with the Iso-tome® is feasible and useful for effectively incising the distal PR in patients with CDF and choledocholiths. [ABSTRACT FROM AUTHOR]

Detection of tumors of the ampulla of Vater, including ampullary adenoma, has been improved by routine screening endoscopic procedures and imaging modalities. Endoscopic resection by endoscopic papillectomy is rapidly replacing classic surgical resection and is a less invasive procedure. Endoscopic resection can have a role not only in the final histopathologic diagnosis but also as a definite therapeutic option. However, the indications for endoscopic resection are not fully established, and endoscopic procedures are not standardized. Significant complications, including severe pancreatitis, intractable bleeding and duodenal perforation, are rare but can occur, especially in less experienced hands. Severe pancreatitis is the most feared complication, but it can be prevented by pancreatic duct stent insertion in most cases. However, in some cases, pancreatic stenting can be challenging after resection. Incomplete resections are sometimes performed to avoid complications. Endoscopic surveillance is also important for identifying and managing remnant adenomatous tissue or recurrent lesions. Further technical development is needed to expand the indications for this procedure, minimize complications and ensure a high success rate. [ABSTRACT FROM AUTHOR]

The article looks at studies on technological developments in endoscopic retrograde cholangiopancreatography (ERCP) that were presented at the 2014 Digestive Disease Week in Chicago, Illinois. Retrospective results of prophylactic rectal indomethacin with pancreatic duct stenting were presented. Impact of probe-based confocal laser endomicroscopy on patients with indetermine biliary structures was reported.

Amyloidosis is characterized by the abnormal deposition of extracellular amyloid fibrils. Cases involving amyloid light-chain amyloidosis in the small intestine have been reported infrequently in Korea. Here, we report a case of localized light chain protein amyloidosis in the small intestine. Esophagogastroduodenoscopy, push enteroscopy, and capsule endoscopy revealed submucosal tumor-like lesions, multiple shallow ulcers, and several erosions in the distal duodenum and jejunum. An endoscopic biopsy established the diagnosis of amyloidosis. In through an immunohistochemical analysis, the presence of lambda light chain protein was detected. The patient had no evidence of an underlying clonal plasma cell disorder or additional organ involvement. Therefore, we concluded that the patient had localized amyloidosis of the small intestine. [ABSTRACT FROM AUTHOR]

Background Numerous clinical trials to improve the success rate of biliary access in difficult biliary cannulation (DBC) during ERCP have been reported. However, standard guidelines or sequential protocol analysis according to different methods are limited in place. We planned to investigate a sequential protocol to facilitate selective biliary access for DBC during ERCP. Methods This prospective clinical study enrolled 711 patients with naïve papillae at a tertiary referral center. If wire-guided cannulation was deemed to have failed due to the DBC criteria, then according to the cannulation algorithm early precut fistulotomy (EPF; cannulation time > 5 min, papillary contacts > 5 times, or hook-nose-shaped papilla), double-guidewire cannulation (DGC; unintentional pancreatic duct cannulation ⩾ 3 times), and precut after placement of a pancreatic stent (PPS; if DGC was difficult or failed) were performed sequentially. The main outcome measurements were the technical success, procedure outcomes, and complications. Results Initially, a total of 140 (19.7%) patients with DBC underwent EPF (n = 71) and DGC (n = 69). Then, in DGC group 36 patients switched to PPS due to difficulty criteria. The successful biliary cannulation rate was 97.1% (136/140; 94.4% [67/71] with EPF, 47.8% [33/69] with DGC, and 100% [36/36] with PPS; P < 0.001). The mean successful cannulation time (standard deviation) was 559.4 (412.8) seconds in EPF, 314.8 (65.2) seconds in DGC, and 706.0 (469.4) seconds in PPS (P < 0.05). The DGC group had a relatively low successful cannulation rate (47.8%) but had a shorter cannulation time compared to the other groups due to early switching to the PPS method in difficult or failed DGC. Post-ERCP pancreatitis developed in 14 (10%) patients (9 mild, 1 moderate), which did not differ significantly among the groups (P = 0.870) or compared with the conventional group (P = 0.125). Conclusions Based on the sequential protocol analysis, EPF, DGC, and PPS may be safe and feasible for DBC. The use of EPF in selected DBC criteria, DGC in unintentional pancreatic duct cannulations, and PPS in failed or difficult DGC may facilitate successful biliary cannulation. [ABSTRACT FROM AUTHOR]

Copyright © 2021 Korean Society of Gastrointestinal Endoscopy 147 Of all patients with symptomatic gallbladder stones, 10-20% are diagnosed with concomitant common bile duct (CBD) stones. The American Society for Gastrointestinal Endoscopy (ASGE) guidelines of 2010 recommended stratification of the CBD stone risk, determined by baseline biochemical tests and abdominal ultrasonography (US), when considering ERCP. As diagnostic imaging methods with good performance for CBD stones emerge, the criteria for high-risk CBD stones should include only those cases where the CBD stone is objectively identified using imaging tests. [Extracted from the article]

Background and study aims: Endoscopic retrograde cholangiopancreatography (ERCP)-related duodenal perforation is rare but can cause high mortality. Our aim was to assess the clinical outcomes of these events. Method: A total of 59 patients who were diagnosed as having ERCP-related duodenal perforation at six institutions between 2000 and 2007 were enrolled in this multicenter retrospective study. We evaluated complications and mortality associated with ERCP-related duodenal perforation according to injury detection time (IDT), peritoneal irritation signs (PIS), systemic inflammation signs (SIS), and treatment modality in these patients. Results: Of the 59 patients, 41 (69.5 %) and 18 (30.5 %) underwent medical and surgical treatment, respectively. Duodenal perforation-related death was observed in five patients, who had received medical therapy (n=2) and surgical therapy (n=3). Among medically treated patients, seven patients (17.1 %) underwent endoscopic clipping immediately after the injury; surgery was not required as a salvage therapy and there were no complications or deaths among these patients. The remaining 34 patients received antibiotics combined with therapeutic fasting and intravenous hydration. Duodenal perforation-related complications depended significantly on IDT (P=0.0001), treatment modality (P=0.008), PIS (P=0.003), and SIS (P=0.010). The duodenal perforation- related mortality was significantly related to IDT (P=0.008) and PIS (P=0.001). Conclusions: IDT, PIS, and SIS appear to be important prognostic factors following ERCP-related duodenal perforation. Medical therapy can be suggested as an initial treatment strategy for ERCP-related duodenal perforation, and if possible, endoscopic clipping is strongly recommended. However, surgical treatment should be considered if the perforation is not expected to seal spontaneously, or if the continuing leakage causes PIS or SIS. [ABSTRACT FROM AUTHOR]

Background and study aims: After endoscopic papillectomy, pancreatic duct stenting is important in preventing pancreatitis, but duct cannulation can be difficult following conventional snare resection. Pancreatic duct wire-guided endoscopic snaring before resection can reduce the post-procedure stenting failure rate. We evaluated the usefulness of this approach. Patients and methods: Pancreatic duct wire-guided endoscopic papillectomy was performed in 72 patients with ampullary adenoma. The snare loop was passed over a guide wire inserted into the pancreatic duct. After resection, a pancreatic stent was immediately placed along or alongside the guide wire. Results: Pancreatic duct stentingwas successful in all patients after endoscopic papillectomy. Postprocedure pancreatitis occurred in 6/72 (8 %), but was mild and resolved with conservative treatment. Complete endoscopic resection of ampullary adenoma was achieved in 65/72 (90 %), with en bloc resection in 60/72 (83 %). There was no procedure-associated mortality. Follow-up (mean 23.7 months) showed recurrence in 5/65 (8 %) who had undergone complete resection. Conclusions: Pancreatic duct wire-guided endoscopic snare papillectomy for ampullary adenoma effectively facilitated pancreatic duct stenting to prevent severe post-procedure pancreatitis. [ABSTRACT FROM AUTHOR]

Background: Self-expandable metallic stents (SEMS) of varying designs and materials have been developed to reduce complications, but few comparative data are available with regard to the type of stent and the stent manufacturer. We analyzed the success rates and complication rates, according to stent type (uncovered vs. covered stent) and individual stent manufacturer, in malignant colorectal obstruction. Methods: From November 2001 to August 2008, 103 patients were retrospectively included in this study: four types of uncovered stents in 73 patients and two types of covered stents in 30 patients. The SEMS was inserted into the obstructive site by using the through-the-scope method. Results: Technical and clinical success rates were not different between stent type or among stent manufacturers: 100 and 100% ( p = ns) and 100 and 96.6% ( p > 0.05), respectively, in uncovered and covered stents. Stent occlusion and migration rates were 12.3 and 3.3% ( p = 0.274) and 13.7 and 16.7% ( p = 0.761), respectively, in uncovered and covered stents, and 11.1, 5, and 9% ( p = 0.761) and 25.9, 15, and 0% ( p = 0.037) in Wallstent, Niti-S, and Bonastent uncovered stents, respectively. Conclusions: The placement of SEMS is an effective and safe treatment for patients with malignant colorectal obstruction. Although minor differences in outcome were detected according to the type and the manufacturer of the stents, no statistically significant difference was observed, except in stent migration among the stent manufacturer. [ABSTRACT FROM AUTHOR]

The authors reflect on the viability of the endoscopic ultrasound (EUS)-guided bile duct drainage to replace the traditional endoscopic retrograde cholangiopancreatography (ERCP). They compare EUS studies that use self-expanding metallic stent in treatment of patients with distal malignant biliary obstruction. The authors believe that replacement of the conventional ERCP-guided transpapillary bile duct drainage could only be possibly with standardized echoendoscope and specialized stents.

OBJECTIVES:Intracorporeal lithotripsy must be used under direct visual control with an additional endoscope in order to ensure safety and precise targeting during the removal of difficult-to-extract bile duct stones using conventional methods. The currently available “mother–baby” scope system has several disadvantages. We evaluated the feasibility and efficacy of direct peroral cholangioscopy (POC) using an ultra-slim upper endoscope for electrohydraulic lithotripsy (EHL) or laser lithotripsy (LL) for the treatment of difficult-to-extract bile duct stones.METHODS:A total of 18 patients who were unsuccessfully treated for common bile duct (CBD) stones using conventional endoscopy, including mechanical lithotripsy (ML), underwent EHL or LL under intraductal balloon-guided direct POC using an ultra-slim upper endoscope. The balloon catheter was used to maintain access while an ultra-slim upper endoscope was advanced directly into the bile duct. EHL or LL was performed until it became possible to capture the fragmented stones in a basket. Endoscopic removal of stone fragments by duodenoscopy was attempted in the same session.RESULTS:The overall success rate of bile duct clearance by lithotripsy under direct POC by a single endoscopist was 88.9% (16 of 18). Stone fragmentation under direct POC was successfully performed in nine patients using EHL and in seven patients using LL. The average number of treatment sessions required to complete stone removal was 1.6. ML was performed to complete stone removal in 5 of 18 (27.8%) patients. Procedure-related complications were not observed.CONCLUSIONS:Lithotripsy with EHL or LL under direct POC involving the use of an ultra-slim endoscope by a single endoscopist seems to be an effective and safe treatment for select patients with difficult-to-extract CBD stones. [ABSTRACT FROM AUTHOR]

Background and Aim: Little is known about the role of platelet-derived growth factor (PDGF) in biliary fibrosis in the setting of bacterial colonization of the biliary tree. We therefore sought to investigate whether exposure to bacterial lipopolysaccharide (LPS) alters PDGF isoform and receptor expression in cultured rat common bile duct fibroblasts (CBDF) and normal rat cholangiocytes (NRC). Methods: Collagen content in cells and media was assessed by colorimetric assay and gel electrophoresis. mRNA levels of PDGF-A and -B, and PDGF-Receptors (PDGF-R) α and β were measured by relative quantitative real-time PCR. Protein levels of PDGF-AA, AB and BB were measured by ELISA, and PDGF-Rα and PDGF-Rβ by Western blot. Results: In CBDF, LPS increased total soluble collagen synthesis and secretion. PDGF-Rα and β mRNA and protein were also increased by LPS treatment in CBDF. Lipopolysaccharide treatment elicited an increase in PDGF-A and -B mRNA levels in CBDF. In NRC, levels of PDGF-A mRNA increased in a dose-dependent fashion following LPS treatment, whereas PDGF-B mRNA showed no response. PDGF-AA secretion was higher by CBDF than by NRC. PDGF-BB levels were also higher in CBDF than in NRC. While PDGF-BB levels did not respond to LPS treatment in CBDF, there was a dose-dependent response of this isoform to LPS in NRC. Intracellular and secreted PDGF-AB increased with LPS treatment in NRC. Conclusions: These results support a model in which chronic bacterial colonization of the biliary tree induces fibrosis through PDGF-dependent mechanisms. [ABSTRACT FROM AUTHOR]

The article investigated the separation of three binary hydrogen mixture in a methyltriethoxysilane-templating silica composite α-alumina (MTES)-templating silica membrane. The study examined H2/N2, H2/CO2 and H2/CH4 to determine the role of molecular size and structure and the adsorption affinity in membrane separation. It revealed that it was difficult to predict the separation factor using the one-component permeation ratio.

OBJECTIVES: Difficult diagnoses and a lack of effective therapy complicate biliary tract malignancies. Interleukin-6 (IL-6) is a human bile duct epithelium growth factor correlated with tumor burden. We evaluated the usefulness of serum IL-6 in the diagnosis of primary BDC and measured changes in serum IL-6 levels following photodynamic therapy (PDT). METHODS: We prospectively measured serum IL-6 levels in patients with BDC (N = 26: 14 patients treated with PDT, 12 with biliary drainage alone), hepatocelluar carcinoma (HCC, N = 26), and healthy adults (N = 23). Serum IL-6 levels were measured by an enzyme-linked immunosorbent assay. Patients with clinical conditions known to increase IL-6 levels were excluded. RESULTS: IL-6 was detected in all patients with BDC and HCC, and in 6 of 23 healthy adults. Median and mean levels of IL-6 were higher in patients with BDC than in both other groups ( P < 0.001). Using a 25.8 pg/mL cutoff, IL-6 provided a diagnostic sensitivity of 73% and a specificity of 92%; positive and negative predictive values were 83% and 87%, respectively. Serum levels of IL-6 were correlated with tumor burden in BDC patients. One month after treatment of BDC with PDT, the mean IL-6 level decreased significantly from 282.1 ± 121.8 to 38.2 ± 9.9 pg/mL ( P= 0.008). CONCLUSIONS: Serum IL-6 concentration is a useful addition to the available tests for the differential diagnosis of BDC, and serves as a marker for monitoring the response to treatment of BDC with PDT. [ABSTRACT FROM AUTHOR]

Background and Aim: Esophageal motor abnormalities including ineffective esophageal motility (IEM) and visceral hypersensitivity have been frequently observed in patients with gastroesophageal reflux. The aim of this study was to observe the incidences of hypersensitivity to acid infusion and motor abnormalities in non-erosive reflux disease (NERD) compared with erosive esophagitis. Methods: We performed upper GI endoscopy, an acid perfusion test and esophageal manometry on 113 NERD patients and 37 erosive esophagitis patients. Results: The frequency of acid sensitization was 69.9% in NERD and 67.6% in erosive esophagitis. The frequency of esophageal motor abnormality in patients with erosive esophagitis (48.6%) was higher than in patients with NERD (25.7%, P = 0.014). The most frequent esophageal motor abnormality was IEM. The frequency of IEM was 15.9% in NERD patients, 42.9% in Los Angeles grade A, 53.8% in Los Angeles grade B and 66.7% in Los Angeles grade C esophagitis (χ2 = 16.67, P < 0.0001). Conclusion: Our results suggest that no difference exists between visceral hypersensitivity in patients with NERD and those with erosive esophagitis, and that IEM occurs in NERD as well as erosive esophagitis patients. The occurrence of IEM is associated with the endoscopic severity of gastroesophageal reflux disease. [ABSTRACT FROM AUTHOR]

Background/Aims: No reliable nationwide clinical data about chronic pancreatitis (CP) was available in Korea. The etiology and clinical features of CP were investigated using a multicenter nationwide study. Methods: 814 cases of CP were enrolled retrospectively over the past 4 years at 13 hospitals. The following data were obtained from all patients: etiology, symptoms, complications, and surgery. Result: Alcohol (64.3%) was the major cause of CP and idiopathic CP (20.8%) was the second most common form. Mean patient age was 50.6 years and the male:female ratio was 6:1 (24:1 for alcoholic CP vs. 2:1 in idiopathic CP, p < 0.001). Diabetes (31.6%), pseudocysts (28.4%), biliary stricture (13.9%), and pancreatic ascites (6.6%) were the main complications. Of these, diabetes (35 vs. 26%) and pseudocyst (33.7 vs. 21.9%) were more frequent in alcoholic than in idiopathic CP. Pancreatic cancer developed in 25 patients (3.1%) during follow-up and their mean age was 59.1 years. Conclusions: In Korea, alcohol is the most common etiology of CP. Moreover, diabetes and pseudocysts are frequent complications, especially in alcoholic CP, and pancreatic cancer development is not infrequent. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The adsorption kinetics and equilibria of CO2 in commercial zeolite 4A and CaX pellets were theoretically and experimentally studied by a gravimetric method in the range of 273–313 K and 0.0–0.8 atm. The diffusion mechanism of an adsorbate into a pellet is composed of micropore and macropore diffusion due to the bidisperse structure of the pellet. When one diffusion mechanism played a more important role than the other in determining the overall diffusion rate, the diffusion rate was estimated by the nonisothermal monodisperse diffusion model (NMDM). However, when the combined effects of both mechanisms controlled the overall adsorption kinetics, the experimental uptake was analyzed by the nonisothermal bidisperse diffusion model (NBDM). The CO2 diffusion in zeolite 4A pellets was controlled by micropore diffusion within the experimental pressure and temperature ranges. However, both macropore and micropore diffusion contributed to CO2 diffusion in the zeolite CaX pellet. The overall CO2 diffusion rate in zeolite CaX became faster as pressure increased mainly due to its highly favorable isotherm in the zeolite CaX. The micropore diffusion time constant of CO2 in the zeolite CaX pellet was approximately one hundred times greater than that in the zeolite 4A pellet. In addition, the activation energy of micropore diffusion of CO2 diffusion in the zeolite CaX pellet was smaller than that in the zeolite 4A pellet. In this study, the dimensionless parameter, γ, indicating the relative importance of macropore and micropore diffusion, was modified to consider non-zero coverage as an initial condition for each step in the gravimetric method. When γ is greater than 100, the overall adsorption rate is controlled by macropore diffusion. However, in cases where γ is less than 0.1, micropore diffusion is the dominant mechanism in the overall adsorption rate. In the case of a system with γ between these values, both macropore and micropore diffusion contributed to the overall diffusion rate. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 57-year-old man who has undergone endoscopic retrograde cholangiopancreatography (ERCP) for multiple bile duct and gallbladder stones. The case outlines various endoscopic techniques that have been introduced for removing a proximally migrated pancreatic stent. It also notes the delayed removal following insertion of an additional stent that can help to make more space for inserting removal devices.

Evaluation of: Coté GA, Singh S, Bucksot LG et al. Association between volume of endoscopic retrograde cholangiopancreatography at an academic medical center and use of pancreatobiliarytherapy. Clin. Gastroenterol. Hepatol. 10(8), 920-924 (2012). Many patients have pancreatobiliary diseases involving complications and comorbidities. This study shows the trends in the use of endoscopic retrograde cholangiopancreatography (ERCP) at an academic medical center from 1994 to 2009. During that time, the use of ERCPs for the treatment of bile duct stones reached a plateau and those for the treatment of pancreas divisum showed a decline. However, endoscopic therapy for benign biliary stricture and management for obstructive chronic pancreatitis increased during this period. There was a trend toward greater use of therapeutic ERCP for bile duct stenting involving metal stents and for pancreatic therapeutics. In that same period, there was an increase in the proportion of patients who had undergone unsuccessful ERCP at various other centers. Consequently, at academic medical centers, ERCP has become an increasingly complex intervention. Increasing numbers of patients with comorbidities, complications and history of failed ERCPs are being referred to academic centers to receive endotherapy. [ABSTRACT FROM AUTHOR]

Electrohydraulic lithotripsy is a very useful method for fragmenting biliary stones and it can be used for endoscopic removal of difficult biliary stones. Acute afferent loop syndrome induced by enterolith is very rare, and surgical treatment is the usual choice for this condition. We describe a patient with acute afferent loop syndrome, which was induced by an enterolith after a Billroth II gastrectomy. We used electrohydraulic lithotripsy to endoscopically remove the enterolith. [ABSTRACT FROM AUTHOR]

Background/Aims Intraductal papillary neoplasm of bile duct (IPNB) is a precursor of invasive carcinoma. However, it can be miss or underdiagnosed by cross-sectional imaging studies and/or cholangiography. Recently, as single operator peroral cholangioscopy (SO-POC) which is easy to maneuver in high image quality has been developed, SO-POC are emerging as one of the diagnostic methods of bile duct diseases. In this study, we evaluated the usefulness of SO-POC for diagnosis and management of IPNB. Methods Data from consecutive patients undergoing SO-POC and diagnosed as IPNB were analyzed. SO-POC was performed with direct POC using an ultra-slim endoscope and/or SpyGlass direct visualization system. All POC findings were reviewed by two experienced investigators. All of IPNB cases were diagnosed as IPNB according to the criteria of World Health Organization 2010 by one expert pathologist. Results A total of 30 patients with IPNB diagnosed by POCs was analyzed. In 16 patients (53.3%), IPNB was not observed in computed tomography and SO-POC was performed for the evaluation of dilated bile duct (n=7) and management of stones (n=7). In 17 patients (56.7%), direct POC with narrow band image and/or I-SCAN was used for evaluation of IPNB. Irregular tortuous and dilated vessels (p=0.012) was found to be significantly associated with invasiveness. POC-guided target biopsy was performed technically successful in all patient. In 11 patients (36.7%), management plan was changed after confirmation of IPNB extent by POC.Background/Aims Intraductal papillary neoplasm of bile duct (IPNB) is a precursor of invasive carcinoma. However, it can be miss or underdiagnosed by cross-sectional imaging studies and/or cholangiography. Recently, as single operator peroral cholangioscopy (SO-POC) which is easy to maneuver in high image quality has been developed, SO-POC are emerging as one of the diagnostic methods of bile duct diseases. In this study, we evaluated the usefulness of SO-POC for diagnosis and management of IPNB. Methods Data from consecutive patients undergoing SO-POC and diagnosed as IPNB were analyzed. SO-POC was performed with direct POC using an ultra-slim endoscope and/or SpyGlass direct visualization system. All POC findings were reviewed by two experienced investigators. All of IPNB cases were diagnosed as IPNB according to the criteria of World Health Organization 2010 by one expert pathologist. Results A total of 30 patients with IPNB diagnosed by POCs was analyzed. In 16 patients (53.3%), IPNB was not observed in computed tomography and SO-POC was performed for the evaluation of dilated bile duct (n=7) and management of stones (n=7). In 17 patients (56.7%), direct POC with narrow band image and/or I-SCAN was used for evaluation of IPNB. Irregular tortuous and dilated vessels (p=0.012) was found to be significantly associated with invasiveness. POC-guided target biopsy was performed technically successful in all patient. In 11 patients (36.7%), management plan was changed after confirmation of IPNB extent by POC. Conclusions SO-POC is useful to detect the IPNB which was not observed by cross-sectional imaging studies and decide the management plan of IPNB. [ABSTRACT FROM AUTHOR]