Background/Aims: Fully covered self-expandable metallic stents (FCSEMSs) are used widely for the preoperative biliary drainage of pancreatic cancer because of their low recurrent biliary obstruction (RBO) rates. On the other hand, concerns about non-RBO adverse events (AEs), such as pancreatitis, have led to ongoing debate over the optimal stent. Therefore, this study aimed to clarify the clinical outcomes of preoperative biliary drainage using plastic stents (PSs) and FCSEMSs for patients with pancreatic cancer undergoing neoadjuvant chemotherapy (NAC). Methods: This study retrospectively reviewed consecutive patients (between June 2012 and September 2024) who underwent NAC following biliary drainage using either PSs or FCSEMSs and who were followed up until the decision for or against a surgical resection was made. Results: Forty-seven patients were included (PS, n=33; FCSEMS, n=14). The RBO rate was not significantly different (39% vs. 7.1%, p=0.081), whereas the time to RBO was significantly longer in the FCSEMS group (126 days vs. not reached, p=0.046). Non-RBO AEs were observed more frequently in the FCSEMS group (15% vs. 43%, p=0.061). The rate of overall AEs, including RBO and non-RBO AEs, was similar between the two groups (45% vs. 43%, p=1.000). Subgroup analysis between the PS ≥10 Fr (n=27) and FCSEMS groups showed no significant differences. Conclusions: Large-diameter PSs may be an alternative in selected patients at high risk of non-RBO AEs, including post-ERCP pancreatitis, but attention should be paid to the risk of RBO.

ABSTRACT Objectives Endoscopic ultrasound‐guided hepaticogastrostomy (EUS‐HGS) is usually performed for unresectable malignant distal biliary obstruction (MDBO) when endoscopic retrograde cholangiopancreatography‐guided biliary stenting with fully covered self‐expandable metallic stents (EBS‐MSs) fails. We aimed to clarify the clinical outcomes of EUS‐HGS with plastic stents (HGS‐PSs) compared to EBS‐MS. Methods We retrospectively reviewed patients who underwent either HGS‐PS with or without antegrade stenting using MS (AS‐MS) or EBS‐MS as initial biliary drainage for unresectable MDBO between January 2017 and July 2024. Results A total of 27 patients were included in the HGS‐PS group, and 128 patients were included in the EBS‐MS group. Median procedure time was significantly shorter for the HGS‐PS group (24 vs. 39 min, p < 0.001), and the incidence of adverse events was comparable (22% vs. 32%, p = 0.365). The HGS‐PS group had a significantly higher recurrent biliary obstruction (RBO) rate (48% vs. 26%, p = 0.002) and shorter time to RBO (TRBO) (169 vs. 341 days, p = 0.001). After propensity score matching, no significant differences were observed in either the RBO rate or TRBO. Subgroup analyses showed that TRBO was comparable between the HGS‐PS with AS‐MS and EBS‐MS groups (273 vs. 341 days, p = 0.609). Conclusions Although TRBO tended to be shorter for HGS‐PS compared to EBS‐MS, the addition of AS‐MS to HGS‐PS led to comparable TRBO, suggesting that this combination may be a viable alternative. Clinical Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.

Background/Aims: The treatment of cystic duct confluence stones often requires peroral cholangioscopy (POCS)-guided lithotripsy. This study evaluated the efficacy of endoscopic treatment for cystic duct confluence stones and identified predictive factors for the need for POCS-guided lithotripsy. Methods: This retrospective cohort study included 38 patients with cystic duct confluence stones treated endoscopically between September 2007 and December 2023. The primary outcome was the rate of complete stone removal. Secondary outcomes included the number of sessions, total procedure time, adverse events, and predictive factors for POCS-guided lithotripsy. Results: The complete stone removal rate was 100%. POCS-guided lithotripsy was required in 50% of the cases. The mean number of sessions needed for stone removal was 2.05. The mean procedure time was 93.9 minutes. The incidence of adverse events was 13%. Multivariate analysis showed that a minor axis length of the stone relative to the distal bile duct diameter greater than 1.2 was an independent predictive factor for requiring POCS-guided lithotripsy. Conclusions: Endoscopic treatment is highly effective for cystic duct confluence stones. However, POCS-guided lithotripsy was necessary when the minor axis of the stone relative to the distal bile duct diameter exceeded 1.2.

BACKGROUND/AIMS:The factors affecting the detection rate of lymphoplasmacytic sclerosing pancreatitis (LPSP) using endoscopic ultrasound-guided tissue acquisition (EUS-TA) in patients with type 1 autoimmune pancreatitis (AIP) have not been thoroughly studied. Therefore, we conducted a retrospective study to identify the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. METHODS:Fifty patients with AIP were included in this study, and the primary outcome measures were the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. RESULTS:Multivariate analysis identified the use of fine needle biopsy (FNB) needles as a significant predictive factor for LPSP detection (odds ratio, 15.1; 95% confidence interval, 1.62-141; ¬¬p=0.017). The rate of good-quality specimens (specimen adequacy score ≥4) was significantly higher for the FNB needle group than for the fine needle aspiration (FNA) needle group (97% vs. 56%; p<0.01), and the FNB needle group required significantly fewer needle passes than the FNA needle group (median, 2 vs. 3; p<0.01). CONCLUSIONS:The use of FNB needles was the most important factor for the histological confirmation of LPSP using EUS-TA in patients with type 1 AIP.

A 56-year-old woman with high-grade or invasive intraductal papillary mucinous neoplasm (IPMN) underwent 3 pancreatic surgeries for initial and recurrent IPMN lesions. Immunostaining and genetic analyses of all lesions revealed a consistent mutation in KRAS and loss of serine/threonine kinase 11 (STK11), indicating the same origin of these lesions and the possibility of intraductal dissemination. Other immunostaining findings, such as mucin expression and a high Ki-67 labeling index, were consistent among all the lesions and supported their malignant potential. IPMNs with loss of STK11 may benefit from tailored follow-up of the remnant pancreas due to their high likelihood of recurrence through intraductal spread.

Background/Aims In patients undergoing endoscopic extraction of common bile duct stones (CBDs) and subsequent cholecystectomy, CBDs sometimes recur during the preoperative and perioperative periods. In this study, the incidence and risk factors for CBDs recurrence were investigated. Methods A total of 245 patients (mean age: 66 years; 138 men) who underwent cholecystectomy within 180 days of CBDs extraction between October 2017 and June 2023 were included. Recurrence was defined as the detection of the CBDs during the preoperative or perioperative period using imaging modalities such as computed tomography or re-endoscopic retrograde cholangiopancreatography, regardless of the presence of cholangitis. Results CBDs recurrence occurred in 4.1% of the patients (10/245). The median time to recurrence was 40 days. Preoperative recurrence was observed in nine patients, and only one patient had postoperative recurrence. Multivariate analysis identified cystic duct stones as the only significant risk factor for CBDs recurrence (hazard ratio, 15.6; 95% confidence interval, 3.7–66; p<0.001). Conclusions The risk of CBDs recurrence after endoscopic extraction during the pre and perioperative periods is high in patients with cystic duct stones. Prophylactic biliary stenting may be considered in high-risk patients.

Background/Aims: Plastic stent placement is required when biliary stones cannot be completely removed during the initial endoscopic retrograde cholangiopancreatography (ERCP). Although double half-pigtail plastic stents (DHPs) help prevent stent migration, their clinical utility has not yet been evaluated. Methods: We retrospectively reviewed data from 221 patients who underwent DHP placement for acute calculous cholangitis (ACC) between January 2015 and March 2024. Patient without complete stone removal during initial ERCP were included. Clinical success, adverse events, recurrent biliary obstruction (RBO), and time to RBO (TRBO) were compared in 21 patients treated with straight plastic stents (STs) under similar conditions. Results: Clinical success was achieved in 99% of patients in the DHP group and 95% of the ST group (p=0.13). Adverse event rates were comparable between groups. During follow-up, the DHP group had significantly lower stent occlusion (2% vs. 20%, p<0.01) and migration rates (4% vs. 15%, p=0.02), leading to a lower RBO rate (5% vs. 35%, p<0.01). The median TRBO was significantly longer in the DHP group (585 vs. 247 days, p<0.01). Conclusions: DHPs had comparable efficacy to STs, with significantly fewer stent-related adverse events. This may be a potential option for biliary drainage in ACC.

Objectives:Cholangioscopy-guided mapping biopsy (CMB) is performed for preoperative evaluation of extrahepatic cholangiocarcinoma. The aim of this study was to evaluate the usefulness of CMB using a SpyBite Max and to determine the effectiveness of multiple biopsy strokes from the same site. Methods:Between August 2020 and October 2022, 21 patients with extrahepatic cholangiocarcinoma were enrolled in this prospective observational study. The primary outcome was the rate of site-based successful biopsies, which was defined as the acquisition of epithelium-containing material appropriate for diagnosing benignity/malignancy from each site. The cumulative success rate of obtaining appropriate materials increased by increasing biopsy strokes from 1 to 4. Results:The cholangioscope could be advanced to all 80 target sites. The overall adequate specimen rate was 67% (142/212). The overall rate of site-based successful biopsies was 83% (66/80). The cumulative success rate of obtaining appropriate materials did not significantly improve by increasing the number of biopsy strokes from 1 (81%) to 4 (86%). Conclusions:The biopsy material was obtained for 83% of the required sites. However, repetitive biopsy strokes for the same site did not improve the rate of site-based successful biopsy. This study was registered in UMIN (UMIN000041530).

We present the case of a 54-year-old woman who was diagnosed with intraductal papillary neoplasm of the bile duct (IPNB) in the remnant intrapancreatic bile duct, 37 years after surgery for congenital biliary dilatation. Endoscopic ultrasonography revealed a papillary, low-echoic mass in the intrapancreatic bile duct, and peroral cholangioscopy revealed a papillary mucosa. A pancreaticoduodenectomy was performed, and the patient was pathologically diagnosed with type 1 pancreatobiliary-type IPNB with associated invasive carcinoma. As a similar atypical epithelium was identified in the pancreatic duct, it was suggested that the IPNB extended longitudinally to the pancreatic duct through the common channel.

Objective Surgery is recommended for large pedunculated gallbladder polyps (PGPs), which measure 10 mm or more in size, because they tend to be neoplastic polyps (NPs), such as adenomas and adenocarcinomas. However, after resection, they are often found to be non-neoplastic polyps (non-NPs). This study aimed to evaluate the usefulness of plain computed tomography (CT) in distinguishing NPs from non-NPs. Methods Of the 80 patients who underwent cholecystectomy for PGPs ≥10 mm between January 2008 and February 2021, 46 who underwent plain and contrast-enhanced CT (CE-CT) before resection were included in this study. We retrospectively assessed the polyp detection rate (PDR) using CT and calculated the difference in the CT values between PGPs and the surrounding bile. Results Twenty-one patients had NPs (12 adenomas, 5 carcinomas in adenoma, and 4 adenocarcinomas). The others were non-NPs (24 cholesterol polyps and one hyperplastic polyp). The PDR using plain CT was significantly higher in the NP group than in the non-NP group (38% (8/21) vs. 0% (0/25), p <0.01). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of NPs were 38%, 100%, 100%, 66%, and 72%, respectively. The difference in the CT values between PGPs and the surrounding bile was significantly larger in the NP group than in the non-NP group (14.12 ± 11.38 HU, 5.04 ± 6.15 HU, p <0.01). Conclusions PGPs detected using plain CT had a high probability of being NPs. Plain CT is therefore considered to be useful for differentiating NPs from non-NPs.

Background and study aims Because more than a few patients have intraductal papillary mucinous neoplasms of the pancreas (IPMNs) with mural nodules (MNs) that are benign, clinical plans should be determined by using histocytological specimens especially, for patients with high risk for surgery or with a small MN. Patients and methods This study included 27 patients to evaluate the efficacy of peroral pancreatoscopy using a SpyGlass DS system (POPS-DS) for patients with MN-positive IPMN, mainly focusing on the ability of POPS-DS to detect malignancy. Results Biopsy specimens obtained under POPS-DS guidance could be used for histological evaluation of all patients with MNs in the main pancreatic duct and 67% of the patients with MNs in the branch ducts, whereas fluid specimens collected during POPS-DS could be used for histocytological evaluation for all patients. For the 13 patients who underwent surgery just after POPS-DS, the sensitivity, specificity, and accuracy of POPS-DS to detect malignancy were 89%, 100%, and 92%, respectively. For the 12 patients who underwent surveillance without surgery, the cumulative 3-year progression rates for nine benign IPMNs and three malignant ones determined using POPS-DS were 0% and 100%, respectively. However, the sensitivity of POPS to detect IPMN epithelium in the resection margin was 20%. Only one patient developed procedure-related pancreatitis (mild). Conclusions POPS-DS could be used to accurately detect malignancy in patients with MN-positive IPMN. Therefore, histocytological evaluation using POPS-DS can contribute to selection of patients for whom surgery would be appropriate.

Background/Aims: Endoscopic biliary drainage using self-expandable metallic stents (SEMSs) for malignant biliary strictures occasionally induces acute cholecystitis (AC). This study evaluated the efficacy of prophylactic gallbladder stents (GBS) during SEMS placement. Methods: Among 158 patients who underwent SEMS placement for malignant biliary strictures between January 2018 and March 2023, 30 patients who attempted to undergo prophylactic GBS placement before SEMS placement were included. Results: Technical success was achieved in 21 cases (70.0%). The mean diameter of the cystic duct was more significant in the successful cases (6.5 mm vs. 3.7 mm, p<0.05). Adverse events occurred for 7 patients (23.3%: acute pancreatitis in 7; non-obstructive cholangitis in 1; perforation of the cystic duct in 1 with an overlap), all of which improved with conservative treatment. No patients developed AC when the GBS placement was successful, whereas 25 of the 128 patients (19.5%) without a prophylactic GBS developed AC during the median follow-up period of 357 days (p=0.043). In the multivariable analysis, GBS placement was a significant factor in preventing AC (hazard ratio, 0.61; 95% confidence interval, 0.37-0.99; p=0.045). Conclusions: GBS may contribute to the prevention of AC after SEMS placement for malignant biliary strictures.

Background/Aims: We aimed to investigate (1) promising clinical findings for the recognition of focal type autoimmune pancreatitis (FAIP) and (2) the impact of endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-TA) on the diagnosis of FAIP.Methods: Twenty-three patients with FAIP were involved in this study, and 44 patients with resected pancreatic ductal adenocarcinoma (PDAC) were included in the control group.Results: (1) Multivariate analysis revealed that homogeneous delayed enhancement on contrast-enhanced computed tomography was a significant factor indicative of FAIP compared to PDAC (90% vs. 7%, p=0.015). (2) For 13 of 17 FAIP patients (76.5%) who underwent EUS-TA, EUS-TA aided the diagnostic confirmation of AIPs, and only one patient (5.9%) was found to have AIP after surgery. On the other hand, of the six patients who did not undergo EUS-TA, three (50.0%) underwent surgery for pancreatic lesions.Conclusions: Homogeneous delayed enhancement on contrast-enhanced computed tomography was the most useful clinical factor for discriminating FAIPs from PDACs. EUS-TA is mandatory for diagnostic confirmation of FAIP lesions and can contribute to a reduction in the rate of unnecessary surgery for patients with FAIP.

Abstract Objectives Optimal stents for preoperative biliary drainage (PBD) for patients with possible resectable pancreatic cancer remain controversial, and risk factors for post‐endoscopic retrograde cholangiopancreatography pancreatitis (PEP), followed by PBD, are unknown. In this study, the efficacy and safety of fully covered self‐expandable metallic stents (FCSEMSs) and plastic stents (PSs) were compared, and the risk factors for PEP, followed by PBD, were investigated for patients with pancreatic cancer. Methods Consecutive patients with pancreatic cancer who underwent PBD between April 2005 and March 2022 were included. We retrospectively evaluated recurrent biliary obstruction, adverse events (AEs), and postoperative complications for FCSEMS and PS groups and investigated the risk factors for PEP. Results A total of 105 patients were included. There were 20 patients in the FCSEMS group and 85 patients in the PS group. For the FCSEMS group, the rate of recurrent biliary obstruction (0% vs. 25%, p = 0.03) was significantly lower. There was no difference in AE between the two groups. No significant differences were observed in the overall postoperative complications, but the volume of intraoperative bleeding was larger for the PS group than it was for the FCSEMS group (p < 0.001). From multivariate analysis, being female and lack of main pancreatic duct dilation were independent risk factors for pancreatitis (odds ratio, 5.68; p = 0.028; odds ratio, 4.91; p = 0.048). Conclusions FCSEMSs are thought to be preferable to PSs for PBD due to their longer time to recurrent biliary obstruction. Being female and the lack of main pancreatic duct dilation were risk factors for PEP.

We report the first case of bile duct mixed neuroendocrine–non-neuroendocrine neoplasm (MiNEN) that had a mucinous carcinoma component. An 88-year-old man with biliary obstruction was diagnosed as having distal bile duct cancer using imaging examinations and endoscopic biopsy. The patient received the best supportive care without surgical resection for 13 months until death. An autopsy revealed a bulky mass involving the distal bile duct and multiple metastases in intra-abdominal lymph nodes, the liver, and the lungs. The primary cancer was microscopically diagnosed as a MiNEN, which consisted of mucinous adenocarcinoma and large cell-type neuroendocrine carcinoma (NEC) components. Metastatic lesions in the liver and lungs were composed of only NEC with rich extracellular mucin without adenocarcinoma cells. Using electron microscopy and immunohistochemistry, it was proved that all NEC cells in both primary and metastatic lesions had amphicrine features. On the basis of pathological findings, we thought that the MiNEN was initially derived from a mucinous adenocarcinoma that dedifferentiated to amphicrine NEC cells with mucin production.

Objectives: A difficult step in endoscopic ultrasound (EUS)-guided drainage procedures is dilation of the puncture tract before stent deployment. The efficacy and safety of a novel spiral dilator, Tornus ES, for EUS-guided drainage were investigated in this study. Methods: This study was conducted as a prospective, single-arm, observational study at Sendai City Medical center. Dilation of the puncture tract using a spiral dilator was attempted for all EUS-guided drainage cases. The primary outcome was the technical success rate which was defined as successful stent placement in the puncture tract. Secondary outcomes were the success rate of dilation using a spiral dilator, procedure time, and adverse events related to the procedures. Results: A total of 10 patients were enrolled between January and March 2022. Seven patients underwent EUS-guided biliary drainage (hepaticogastrostomy for six and hepaticojejunostomy for one), and the remaining three patients underwent EUS-guided gallbladder drainage. The technical success rate and the success rate of dilation using a spiral dilator were both 100%. The mean procedure time was 27 min. No adverse events related to the procedure occurred in all cases. Conclusions: Dilation of the puncture tract using a spiral dilator was effective and safe and might make it easier to perform EUS-guided drainage.

An 80-year-old woman with acute cholangitis was referred to our hospital due to difficult biliary canulation. Computed tomography (CT) detected a stone with a diameter of 8 mm in the common bile duct (CBD) and a perihepatic biloma in the right hepatic lobe with a maximum diameter of approximately 14 cm [Figure 1a]. Although the CBD stone was endoscopically removed, her abdominal symptom did not improve. By using re-examination of CT, the biloma was found to become larger and cover much of the surface of the right hepatic lobe [Figure 1b], and percutaneous drainage via the hepatic parenchyma for the huge biloma was considered to be difficult. Thus, we planned to perform EUS-guided transluminal drainage on the biloma. Under EUS guidance from the duodenal bulbus, the biloma was visualized beyond the right hepatic lobe and was punctured by using a 19-gauge needle (EZ shot 3 plus: Olympus Co., Tokyo, Japan) with taking care not to puncture visible hepatic vessels by using Color Doppler imaging [Figure 2]. A 0.025-inch guidewire was advanced into the inside of the biloma through the needle, and then a 6-Fr endoscopic nasobiliary drainage (ENBD) catheter (Gadelius Medical K.K., Tokyo, Japan) was inserted into the biloma after dilatation of the hepaticoduodenostomy route with a 7 Fr catheter [Figure 3]. Over a 1-day period after the procedure, approximately 700 ml of bilious fluid drained from the ENBD catheter, and her symptoms disappeared. Finally, the regression of the biloma was confirmed using CT after EUS-guided drainage [Figure 4a and b].Figure 1: Computed tomography images showing a huge biloma lateral to the right hepatic lobe on admission (a) and 10 days after ERCP (b)Figure 2: Under EUS guidance from the duodenal bulbus, the biloma was visualized beyond the right hepatic lobe (arrowhead) and was punctured with a 19 G needleFigure 3: Fluoroscopic image of EUS-guided drainage with a 6-Fr endoscopic nasobiliary drainage catheterFigure 4: Follow-up computed tomography images showing resolution of the biloma before discharge (a) and 2 months after discharge (b)Percutaneous drainage is widely used for symptomatic bilomas,[1] whereas EUS-guided transluminal drainage for those in the left hepatic lobe has recently been reported.[2,3] In addition, EUS-guided drainage can be the alternative to the percutaneous one for selected patients with symptomatic bilomas in the right hepatic lobe [Video 1]. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Background/Aims: This study aimed to clarify the efficacy and safety of pancreatic duct lavage cytology combined with a cell-block method (PLC-CB) for possible pancreatic ductal adenocarcinomas (PDACs).Methods: This study included 41 patients with suspected PDACs who underwent PLC-CB mainly because they were unfit for undergoing endoscopic ultrasonography-guided fine needle aspiration. A 6-Fr double lumen catheter was mainly used to perform PLC-CB. Final diagnoses were obtained from the findings of resected specimens or clinical outcomes during surveillance after PLC-CB.Results: Histocytological evaluations using PLC-CB were performed in 87.8% (36/41) of the patients. For 31 of the 36 patients, final diagnoses (invasive PDAC, 12; pancreatic carcinoma in situ, 5; benignancy, 14) were made, and the remaining five patients were excluded due to lack of surveillance periods after PLC-CB. For 31 patients, the sensitivity, specificity, and accuracy of PLC-CB for detecting malignancy were 94.1%, 100%, and 96.8%, respectively. In addition, they were 87.5%, 100%, and 94.1%, respectively, in 17 patients without pancreatic masses detectable using endoscopic ultrasonography. Four patients developed postprocedural pancreatitis, which improved with conservative therapy.Conclusions: PLC-CB has an excellent ability to detect malignancies in patients with possible PDACs, including pancreatic carcinoma in situ.