Study Protocol for a Prospective Self-Controlled Trial on Success in Meeting Comprehensive Genomic Profiling Analysis Criteria for Specimens Obtained by Endoscopic Ultrasound-Guided Tissue Acquisition Using a 19G Needle from Primary and Metastatic Lesions in Pancreatic Cancer with Metastatic Lesions: The PRIMATE Study.

EUS-TA in unresectable pancreatic cancer requires not only a tissue diagnosis but also tissue collection in anticipation of comprehensive genomic profiling. However, the optimal puncture target remains controversial. Therefore, the Primary and Metastatic Lesions in Pancreatic Cancer (PRIMATE) study was designed to clarify the optimal target by comparing the success rates for meeting OncoGuide NCC Oncopanel (NOP) analysis criteria on pre-check primary and metastatic lesion specimens obtained during the same EUS-TA session in patients with invasive pancreatic ductal adenocarcinoma. In this ongoing prospective study, two specimens, each from primary and metastatic lesions, are obtained by EUS-TA (typically using a 19G fine-needle biopsy needle) in patients with invasive pancreatic ductal adenocarcinoma. The primary endpoint is the proportion of EUS-TA specimens that meet NOP analysis criteria during pre-check (i.e., tumor cellularity of ≥20% and a tissue area of ≥4 mm2), which are then compared between primary and metastatic lesions. This study has been approved by the National Cancer Center Institutional Review Board (Research No. 2022-168). The results of this study will be reported at an international conference and published in an international peer-reviewed journal. The trial registration number is UMIN 000048966.

Prospective multicenter surveillance study of branch-duct intraductal papillary mucinous neoplasm of the pancreas; risk of dual carcinogenesis.

BACKGROUND: The natural history of branch-duct intraductal papillary mucinous cystic neoplasms (BD-IPMNs) in the pancreas remains unclear. This study aimed to answer this clinical question by focusing on the development of concomitant pancreatic ductal adenocarcinomas (cPDAC). METHODS: The Japan Pancreas Society conducted a prospective multicenter surveillance study of BD-IPMN every six months for five years. The primary endpoints were progression of BD-IPMN, progression to high-grade dysplasia/invasive carcinoma (HGD/IC), and cPDAC. Factors predicting the progression of BD-IPMN to HGD/IC and development of cPDAC were also assessed as secondary endpoints. RESULTS: Among the 2104 non-operated patients, 348 (16.5 %) showed progression of primary BD-IPMN. Cumulative incidences of BD-IPMN with HGD/IC and cPDAC during the 5.17-year surveillance period were 1.90 % and 2.11 %, respectively, and standard incidence ratios of BD-IPMN with HGD/IC and cPDAC were 5.28 and 5.73, respectively. Of 38 cPDACs diagnosed during surveillance, 25 (65.8 %) were resectable. The significant predictive characteristics of BD-IPMN for progression to HGD/IC were larger cyst size (p = 0.03), larger main pancreatic duct size (p < 0.01), and mural nodules (p = 0.02). Significant predictive characteristics for the development of cPDAC were male sex (p = 0.03) and older age (p = 0.02), while the size of IPMN was not significant. CONCLUSION: Careful attention should be given to "dual carcinogenesis" during BD-IPMN surveillance, indicating the progression of BD-IPMN to HGD/IC and development of cPDAC distinct from BD-IPMN, although the establishment of risk factors that predict cPDAC development remains a challenge (UMIN000007349).

Diagnostic performance of EUS-guided tissue acquisition for solid pancreatic lesions ≤10 mm.

Background and Objectives: EUS tissue acquisition (EUS-TA) is the standard diagnostic method for solid pancreatic lesions (SPLs); however, there are few reports on EUS-TA results for SPLs ≤10 mm. Furthermore, given the recent advent of fine-needle biopsy, the current diagnostic accuracy of EUS-TA for SPLs ≤10 mm is unknown. This study aimed to evaluate the diagnostic accuracy and efficacy of EUS-TA for SPLs ≤10 mm. Methods: We retrospectively analyzed the data of 109 patients with SPLs ≤10 mm who underwent EUS-TA. All patients underwent rapid on-site specimen evaluation. Results: The median tumor diameter was 8 mm (range, 2.5-10 mm), and the technical success rate was 99.1% (108/109). Adverse events were observed in 3 patients (2.8%). The diagnostic performance was as follows: sensitivity, 90.1% (64/71); specificity, 97.3% (36/37); accuracy, 92.6% (100/108); positive predictive value, 98.5% (64/65); and negative predictive value, 83.7% (36/43). Multivariate analysis revealed that the number of punctures (odds ratio, 7.03; 95% confidence interval, 1.32-37.5; P = 0.023) and tumor type (odds ratio, 11.90; 95% confidence interval, 1.38-102.0; P = 0.024) were independent risk factors for inaccurate EUS-TA results. The diagnostic accuracy of EUS-TA for pancreatic ductal adenocarcinoma was 87.5% (14/16). No EUS-TA-related needle-tract seeding was observed in patients with pancreatic ductal adenocarcinoma during the observation period. Conclusions: EUS-TA for SPLs ≤10 mm showed adequate diagnostic accuracy and was safe for use with rapid on-site specimen evaluation in all cases.

Multicenter study comparing EUS-guided hepaticogastrostomy and ERCP for malignant biliary obstruction in patients with accessible papillae.

BACKGROUND: One advantage of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is that it is difficult for reflux cholangitis, caused by duodenal pressure increasing due to duodenal obstruction, to occur. In addition, since stent deployment is performed away from the malignant stricture site, longer stent patency than with endoscopic retrograde cholangiopancreatography (ERCP) may be obtained. However, no study has previously compared EUS-HGS and ERCP for patients without duodenal obstruction or surgically altered anatomy. The aim of the present study was to compare clinical outcomes between EUS-HGS and ERCP in normal anatomy patients without duodenal obstruction. METHOD: In the ERCP group, patients who initially underwent biliary drainage were included. In the EUS-HGS group, patients who underwent EUS-HGS due to failed biliary cannulation were included. Patients with an inaccessible papilla, such as with surgically altered anatomy or duodenal obstruction, were excluded. RESULTS: A total of 314 patients who underwent ERCP and EUS-HGS were enrolled in this study. Of the 314 patients, 289 underwent biliary stenting under ERCP guidance, and 25 patients underwent biliary stenting under EUS-HGS. After propensity score-matching analysis, the adverse event rate tended to be lower in the EUS-HGS group than in the ERCP group. Although overall survival was not significantly different between the EUS-HGS and ERCP groups (p = .228), stent patency was significantly longer in the EUS-HGS group (median 366.0 days) than in the ERCP group (median 76.5 days). CONCLUSIONS: EUS-HGS had a lower adverse event rate, shorter procedure time, and longer stent patency than ERCP in cases of normal anatomy without duodenal obstruction.

Comparison of stent patency between EUS-guided hepaticogastrostomy with bridging and endoscopic transpapillary biliary drainage for hilar obstruction.

Background and study aims Endoscopic ultrasound-guided hepaticogastrostomy with bridging between the left and right bile ducts is an alternative to endoscopic transpapillary drainage for malignant hilar biliary obstruction. We aimed to analyze the long-term stent patency of endoscopic ultrasound-guided hepaticogastrostomy with bridging. Patients and methods Patients who underwent endoscopic ultrasound-guided hepaticogastrostomy with bridging between April 2018 and July 2023 were retrospectively analyzed. We retrospectively compared the stent patency of these patients with that of the individuals who underwent endoscopic transpapillary drainage-multi-stenting using unmatched (entire) and propensity score-matched cohorts. Results Endoscopic ultrasound-guided hepaticogastrostomy with bridging had a technical success rate of 90% (18/20). Adverse events were minimal. The number of clinical success cases was 17 and 82 for endoscopic ultrasound-guided hepaticogastrostomy with bridging using metallic stent and endoscopic transpapillary drainage-multi-stenting, respectively. The recurrent biliary obstruction rate was 17.6% and 58.5% for endoscopic ultrasound-guided hepaticogastrostomy with bridging and endoscopic transpapillary drainage-multi-stenting, respectively; the median time to recurrent biliary obstruction (days) was significantly longer for endoscopic ultrasound-guided hepaticogastrostomy with bridging in the entire (not reached vs. 104, P =0.03) and propensity score-matched (183 vs. 79, P =0.05) cohorts. The non-recurrent biliary obstruction rate for endoscopic ultrasound-guided hepaticogastrostomy with bridging was 91.6% at 3 and 6 months and 57% at 12 months. Multivariate analyses revealed that endoscopic ultrasound-guided hepaticogastrostomy with bridging contributed to a lower recurrent biliary obstruction incidence (hazard ratio, 0.31, P =0.05) without significant difference. Conclusions Stent patency was significantly better for endoscopic ultrasound-guided hepaticogastrostomy with bridging. However, future prospective studies are needed.

A novel method of bilateral biliary decompression by EUS-guided hepaticogastrostomy with bridging stenting using the partial stent-in-stent method for reintervention of multiple metal stent failure.

Video 1A novel method of bilateral biliary decompression by EUS-guided hepaticogastrostomy with bridging stenting using the partial stent-in-stent method for reintervention of multiple metal stent failure.We report a case in which anterior and posterior drainage was performed using the partial stent-in-stent method via the transpapillary approach. The patient had a bismuth type IV biliary obstruction, but only the right hepatic lobe was drained due to obstruction of the left portal vein. For the recurrent stent dysfunction, the patient underwent placement of a plastic stent within an uncovered self-expanding metal stent to correct stent dysfunction. A 7F plastic stent inside a metal stent is shown.The patient later experienced stent failure and jaundice due to tumor progression and was admitted for plastic stent replacement. Neither imaging results nor symptoms suggested duodenal stenosis. The transpapillary approach was attempted first but was unsuccessful. Duodenoscopy was challenging to perform because of duodenal stenosis. Fluoroscopy confirmed the duodenal stenosis. The plastic stent was extracted using an upper endoscope. Multiple uncovered metal stents are shown (1 stent in the anterior bile duct and 2 stents in the posterior bile duct). Jaundice did not resolve despite plastic stent removal.The patient refused to undergo percutaneous biliary drainage, so a decision was made to perform an EUS-guided hepaticogastrostomy (HGS) instead. The left bile duct was observed in the stomach. The left bile duct was punctured with a 19-gauge FNA needle. A 0.025-inch hydrophilic guidewire was directed into the left bile duct. Enhancement of the bile duct showing malignant hilar biliary obstruction (bismuth IV) is seen. Insertion of the guide wire into the posterior bile duct is shown.The stent mesh was then dilated using a balloon dilator. However, there was difficulty inserting the catheter. Additional dilation was performed using a spiral dilator. This instrument is a tapered tip dilator that fits into 0.025-inch guidewires and is expandable to 7F. Insertion of a second guidewire with a larger caliber was done to straighten the bile duct and help stabilize stent insertion. A 0.035-inch hydrophilic guidewire into the posterior bile duct using a double-lumen cannula and insertion of a 0.025-inch hydrophilic guidewire into the anterior bile duct are shown.The stent mesh was then dilated using a spiral dilator. A metal stent was placed through the anterior bile duct at a steep angle. Insertion and deployment of the first uncovered self-expanding metal stent (8 × 60 mm) from the anterior bile duct into the left bile duct is shown. Multiple metal stents were implanted into the hilar area, and the new stent was placed using the partial stent-in-stent method to prevent overexpansion. Guidewire seeking the posterior bile duct from inside the deployed stent through the stent mesh is shown.The stent mesh was then dilated using a balloon dilator. Insertion and deployment of an uncovered self-expanding metal stent (8 × 60 mm) from the posterior bile duct to the left bile duct using the partial stent-in-stent method is shown. Enhancement of the bile duct shows drainage from the right bile duct. The fistula of the HGS was only dilated with the spiral dilator. The risk of bile leakage was low, so we decided to implant a plastic stent. A 7F × 15-cm plastic stent was placed from the posterior bile duct into the stomach. Anterior and posterior segment drainage by EUS-HGS with bridging stenting using the partial stent-in-stent method is shown, with left segment drainage by EUS-HGS with the plastic stent.We performed EUS-HGS on a patient with multiple metal stents in place. There were no adverse events, and total bilirubin levels were reduced by more than half within 2 weeks. Six months have passed without stent dysfunction.

Feasibility and safety of a novel plastic stent designed specifically for endoscopic ultrasound-guided pancreatic duct drainage.

Background and study aims Endoscopic ultrasound-guided pancreatic duct drainage (EUS-PD) is emerging as an effective alternative treatment for obstructive pancreatitis after unsuccessful endoscopic retrograde pancreatography (ERP). However, the high incidence of adverse events associated with EUS-PD (approximately 20%) remains an issue. Recently, we developed a novel plastic stent for EUS-PD, with a radiopaque marker positioned at approximately one-third of the length from the distal end of the stent and side holes positioned exclusively distal to the marker. This study aimed to evaluate the feasibility and safety of using this stent in EUS-PD. Patients and methods We retrospectively reviewed data from 10 patients who underwent EUS-PD with the novel plastic stent at the National Cancer Center Hospital between March 2021 and October 2023. Technical and clinical success, procedure times, adverse events (AEs), recurrent pancreatic duct obstruction (RPO), and time to RPO were assessed. Results Of the 10 patients, five had postoperative benign pancreaticojejunal anastomotic strictures and five had malignant pancreatic duct obstruction. The technical and clinical success rates were both 100% (10/10). An AE (self-limited abdominal pain) occurred in one patient (10.0%). Two patients (20.0%) died of their primary disease during the follow-up period (median, 44 days; range, 25-272 days). The incidence of RPO was 10.0% (1/10), and the 3-month non-RPO rate was 83.3%. Conclusions The novel plastic stent shows potential as a useful and safe tool in EUS-PD.

Efficacy of endoscopic ultrasound-guided gastroenterostomy using self-expandable metallic stent for afferent loop syndrome: A single-center retrospective study.

BACKGROUND AND AIM: Endoscopic ultrasound-guided gastroenterostomy is a procedure used to connect the stomach and dilated afferent loop using a stent under endoscopic ultrasound for afferent loop syndrome. However, the actual efficacy and safety of this procedure remain unclear. Therefore, this retrospective study aimed to evaluate the efficacy and safety of endoscopic ultrasound-guided gastroenterostomy using a laser-cut-type fully covered self-expandable metallic stent and an anchoring plastic stent for afferent loop syndrome. METHODS: Technical and clinical success rates, adverse events, recurrent intestinal obstruction rates, time to recurrent intestinal obstruction, and technical and clinical success rates of re-intervention were evaluated in intended patients who underwent endoscopic ultrasound-guided gastroenterostomy for afferent loop syndrome from October 2018 to August 2022. RESULTS: In 25 intended patients with afferent loop syndrome who intended endoscopic ultrasound-guided gastroenterostomy, the technical success rate was 100% (25/25), whereas the clinical success rate was 96% (24/25). Two patients experienced grade ≥ 3 early adverse events, including one with intra-abdominal abscess and one with hypotension. Both events were attributed to intestinal fluid leakage. No late adverse events were observed. The recurrent intestinal obstruction rate was 32% (8/25), and the median time to recurrent intestinal obstruction was 6.5 months (95% confidence interval: 2.8-not available). The technical and clinical success rates of re-intervention were both 100% (8/8). CONCLUSIONS: Endoscopic ultrasound-guided gastroenterostomy using a fully covered self-expandable metallic stent and an anchoring plastic stent is effective and safe as a treatment procedure for afferent loop syndrome.

Immune-related adverse event-associated sclerosing cholangitis due to immune checkpoint inhibitors: imaging findings and treatments.

OBJECTIVES: Immune-related adverse event-sclerosing cholangitis caused by treatment with immune checkpoint inhibitors is rare, and the diagnostic criteria and treatment strategy remain unclear. In this study, we confirmed the clinicopathological features of immune-related adverse event-sclerosing cholangitis and clarified its diagnosis and appropriate management. METHODS: We retrospectively evaluated 10 patients diagnosed with immune-related adverse event-sclerosing cholangitis and identified by electronic database searches. RESULTS: Blood tests revealed liver dysfunction with a predominance of biliary tract enzymes in all patients; however, jaundice was present in only one patient. Contrast-enhanced computed tomography revealed diffuse hypertrophy of the extrahepatic bile duct wall as the most frequent finding; however, endoscopic retrograde cholangiopancreatography showed various imaging features, such as the pruned-tree appearance of intrahepatic bile ducts, in all patients. Transpapillary bile duct biopsy showed inflammatory cell infiltration using immunostaining, with a predominance of cluster of differentiation 8-positive T cells in 63% of the cases. Initial steroid therapy was effective in two cases. Mycophenolate mofetil and tacrolimus were used in steroid-refractory cases. Although six patients showed improvements, all of the remaining patients died owing to immune-related adverse event-sclerosing cholangitis. CONCLUSIONS: Various bile duct imaging findings of immune-related adverse event-sclerosing cholangitis were revealed; transpapillary bile duct biopsy may be useful in the diagnosis of immune-related adverse event-sclerosing cholangitis. Despite the combination of multiple immunosuppressive agents, prognosis of immune-related adverse event-sclerosing cholangitis remains poor. Longer follow-up and larger clinical studies are necessary to establish its treatment strategy.

Drainage for fluid collections post pancreatic surgery and acute pancreatitis: similar but different?

Postoperative pancreatic fistulas (POPFs) are common adverse events that occur after pancreatic surgery. Endoscopic ultrasonography (EUS)-guided drainage (EUS-D) is a first-line treatment, similar to that for pancreatic fluid collection (PFCs) after acute pancreatitis. However, some POPFs do not develop fluid collections depending on the presence or location of the surgical drain, whereas others develop fluid collections, such as postoperative fluid collections (POPFCs). Although POPFCs are similar to PFCs, the strategy and modality for POPF management need to be modified according to the presence of fluid collections, surgical drains, and surgical type. As discussed for PFCs, the indications, timing, and selection of interventions or stents for EUS-D have not been fully elucidated for POPFs. In this review, we discuss the management of POPFs and POPFCs in comparison with PFCs due to acute pancreatitis and summarize the topics that should be addressed in future studies.

Factors Affecting Nonfunctioning Small Pancreatic Neuroendocrine Neoplasms and Proposed New Treatment Strategies.

BACKGROUND & AIMS: Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases of nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs. METHODS: In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the World Health Organization 2019 classification. Overall, 1490 patients met the eligibility criteria, and 1014 were included in the analysis cohort. RESULTS: In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate. CONCLUSIONS: NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

Multicenter validation study of a treatment selection MAP for pancreatic neuroendocrine tumors.

BACKGROUND: Somatostatin analogs, molecular-targeted agents and cytotoxic anticancer agents are available as therapeutic agents for the systemic treatment of pancreatic neuroendocrine tumors, and we have developed a first-line treatment selection MAP to enable selection of the optimal treatment strategy for pancreatic neuroendocrine tumors. The purpose of this study was to validate the usefulness of the treatment selection MAP. METHODS: Patients who had received systemic therapy for a pancreatic neuroendocrine tumor between January 2017 and December 2020 were compared according to whether they had been treated as recommended by the MAP (matched patients) or not (unmatched patients) to determine whether better outcomes were achieved by the matched patients. The primary endpoint was progression-free survival of the matched group and unmatched groups in the somatostatin analog, molecular-targeted agent and cytotoxic anticancer agents areas of the MAP. RESULTS: There were 41 (55%) MAP-matched patients in all areas among the 74 patients registered at seven hospitals. The MAP-matched rates were 100, 77 and 38% in the somatostatin analog area, molecular-targeted agent area and cytotoxic anticancer agents area, respectively. All of the unmatched patients had been selected for less intensive treatment. The median progression-free survival in the matched group and unmatched group in the molecular-targeted agent area of the MAP were 46.6 and 15.4 months, respectively, and a multivariate analysis identified MAP-matched (hazard ratio 0.18 [95% confidence interval: 0.04-0.87], P = 0.032) as the only significant independent favorable predictive factor. CONCLUSION: The usefulness of the MAP for treatment selection was validated in the molecular-targeted agent area of the MAP.

Incidence and factors associated with stent dysfunction and pancreatitis after gastroduodenal stenting for malignant gastric outlet obstruction.

Background and study aims Endoscopic gastroduodenal stent (GDS) deployment is currently a standard treatment for malignant gastric outlet obstruction (mGOO) in patients with limited life expectancy; however, stent dysfunction (SD) and complicated pancreatitis often occur after GDS deployment. We investigated incidence and contributing factors of SD and complicated pancreatitis. Patients and methods We retrospectively reviewed 203 patients who underwent initial GDS deployment for palliation of mGOO symptoms between October 2017 and July 2022, including 109 who underwent GDS deployment across the duodenal papilla (sub-cohort). Results SDs, including tumor ingrowth (n = 26), kinking (n = 14), and migration (n = 13), occurred in 68 patients (33.5%). Cumulative SD incidence was 41.1% (95% confidence interval, 32.6-49.4%). SD incidence increased to 0.4%, 0.16%, and 0.06% per day at < 8, 8-16, and>16 weeks, respectively. On multivariate analysis, Niti-S pyloric/duodenal stent deployment (sub-distribution hazard ratio [sHR] 0.26, P = 0.01) and survival length ≥ 90 days (sHR 2.5, P = 0.01) were respectively identified as favorable and risk factors significantly associated with SD. Pancreatitis developed in 14 patients (12.8%) in the sub-cohort, which had significantly higher parenchymal diameter ( P < 0.01) and lower main pancreatic duct (MPD) caliber ( P < 0.01) than the non-pancreatitis cohort. On multivariate analysis, MPD caliber < 3 mm independently predicted pancreatitis (odds ratio 6.8, P = 0.03). Conclusions Deployment of the Niti-S pyloric/duodenal stent, with conformability even for angulated strictures, significantly reduced the incidence of SD. Stent selection, life expectancy, and MPD caliber should be taken into consideration during decision-making for GDS deployment for mGOO.

Systematic review on surveillance for non-resected branch-duct intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: The management of branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) varies in existing guidelines. This study investigated the optimal surveillance protocol and safe discontinuation of surveillance considering natural history in non-resected IPMN, by systematically reviewing the published literature. METHODS: This review was guided by PRISMA. Research questions were framed in PICO format "CQ1-1: Is size criteria helpful to determine surveillance period? CQ1-2: How often should surveillance be carried out? CQ1-3: When should surveillance be discontinued? CQ1-4: Is nomogram predicting malignancy useful during surveillance?". PubMed was searched from January-April 2022. RESULTS: The search generated 2373 citations. After screening, 83 articles were included. Among them, 33 studies were identified for CQ1-1, 19 for CQ1-2, 26 for CQ1-3 and 12 for CQ1-4. Cysts <1.5 or 2 cm without worrisome features (WF) were described as more indolent, and most studies advised an initial period of surveillance. The median growth rate of cysts <2 cm ranged from 0.23 to 0.6 mm/year. Patients with cysts <2 cm showing no morphological changes and no WF after 5-years of surveillance have minimal malignancy risk of 0-2%. Two nomograms created with over 1000 patients had AUCs of around 0.8 and appear to be feasible in a real-world practice. CONCLUSIONS: For patients with suspected BD-IPMN <2 cm and no other WF, less frequent surveillance is recommended. Surveillance may be discontinued for cysts that remain stable during 5-year surveillance, with consideration of patient condition and life expectancy. With this updated surveillance strategy, patients with non-worrisome BD-IPMN should expect more streamlined management and decreased healthcare utilization.

Safety of biliary drainage with 6-mm metallic stent for preoperative obstructive jaundice in pancreatic cancer: PURPLE SIX STUDY.

BACKGROUND AND AIM: The 10-mm self-expandable metal stent (SEMS) is the standard for endoscopic transpapillary biliary drainage before pancreatic cancer surgery. However, the efficacy of stents thinner than 10 mm has not been adequately validated. Therefore, we aimed to evaluate the safety of a 6-mm fully covered SEMS (FCSEMS) for distal malignant biliary obstruction (DMBO) during preoperative chemotherapy for pancreatic cancer. METHODS: This was a single-arm, multicenter, prospective phase II study of endoscopic transpapillary initial biliary drainage for DMBO before pancreatic cancer surgery. The primary endpoint was stent-related adverse events, and the key secondary endpoint was the non-recurrent biliary obstruction (non-RBO) rate during the observation period for both resectable (R) and borderline resectable (BR) pancreatic cancers. RESULTS: The study enrolled 33 patients, among whom 32 received the study treatment. There were 23 and 9 cases of R and BR pancreatic cancers, respectively. The technical and clinical success rates were 97.0% and 90.1%, respectively. The stent-related adverse event rate was 3.1% (n = 1, acute pancreatitis) (95% confidential interval, 0.00-16.2), which met the criteria to be considered safe. The overall non-RBO rate during the observation period (median 96 days) was 78.1% (82.6% and 66.7% for R and BR pancreatic cancer cases, respectively). CONCLUSIONS: The 6-mm FCSEMS is an extremely safe metallic stent with a low stent-related adverse event rate of 3.1% for preoperative biliary drainage in pancreatic cancer. It is considered the optimal stent for preoperative biliary drainage in terms of the non-RBO rate. UMIN Clinical Trial Registry (UMIN-CTR 000041704).

EUS-guided hepaticogastrostomy versus EUS-guided hepaticogastrostomy with antegrade stent placement in patients with unresectable malignant distal biliary obstruction: a propensity score-matched case-control study.

BACKGROUND AND AIMS: EUS-guided hepaticogastrostomy (EUS-HGS) is a rescue procedure when ERCP fails. Peritonitis and recurrent biliary obstruction (RBO) are adverse events (AEs) associated with EUS-HGS. Antegrade stent placement across a malignant distal biliary obstruction (DBO) followed by EUS-HGS (EUS-HGAS) creates 2 biliary drainage routes, potentially reducing peritonitis and prolonging time to RBO (TRBO). We compared the outcomes of the 2 techniques. METHODS: Data of consecutive patients with malignant DBO who underwent attempted EUS-HGS or EUS-HGAS across 5 institutions from January 2014 to December 2020 were retrospectively analyzed. A matched cohort of patients was obtained using 1-to-1 propensity score matching. The primary outcome was TRBO, and secondary outcomes were AEs except for RBO and overall survival. RESULTS: Among 360 patients, 283 (176 and 107 in the HGS and HGAS groups, respectively) were eligible. The matched cohorts included 81 patients in each group. AEs developed in 10 (12.3%) and 15 (18.5%) patients (P = .38) in the HGS and HGAS groups, respectively. RBO occurred in 18 and 2 patients in the HGS and HGAS groups, respectively (P < .001). TRBO was significantly longer in the HGAS group (median, 194 days vs 716 days; hazard ratio, .050; 95% confidence interval, .0066-.37; P < .01). However, no significant differences occurred in overall survival between the groups (median, 97 days vs 112 days; hazard ratio, .97; 95% confidence interval, .66-1.4; P = .88). CONCLUSIONS: EUS-HGAS extended TRBO compared with EUS-HGS, whereas AEs, except for RBO and overall survival, did not differ. The longer TRBO of EUS-HGAS could benefit patients with longer life expectancy.

Viscosity and Characteristics of Malignant Ascites.

BACKGROUND/AIM: Malignant ascites is a common condition in patients with terminal cancer. Treatments, such as diuretics, percutaneous drainage of ascites, and abdominal vein shunting have been advocated. However, these treatments have not achieved sufficient palliative effects. Therefore, the development of innovative therapies is mandated, especially for new therapies that require the creation of a fluid simulation of malignant ascites. However, there have been no previous studies on the physical properties of malignant ascites, including viscosity, which are necessary for the development of such a fluid. Therefore, we prospectively investigated the physical properties of malignant ascites. PATIENTS AND METHODS: This single-center, prospective, observational study included 30 patients between November 2021 and January 2023. The primary endpoint was the viscosity of the malignant ascites, and the secondary endpoints included other viscosity studies, biochemical tests, and the presence of malignant cells in the ascites. RESULTS: The median viscosity was 1.105 mPa*S. The viscosity of malignant ascites tended to decrease with increasing temperature, which is common for liquids. Malignant ascites fluid containing malignant cells tended to be more viscous than ascites fluid without malignant cells; furthermore, albumin levels tended to be higher in the former than in the latter. CONCLUSION: Malignant ascites' median viscosity was 1.105 mPa*S. Correlation between viscosity and temperature showed a decreasing trend. These findings contribute valuable insights for future malignant ascites management and device development.