Successful Surgical Resection of Pancreatic Arteriovenous Malformation Complicated by Acute Pancreatitis: A Case Report.

A 73-year-old man presented with left hypochondral pain. Dynamic computed tomography (CT) revealed abnormal vessels surrounding the pancreas, leading to a suspected diagnosis of pancreatic arteriovenous malformation (PAVM). At the time of the initial examination, dynamic CT revealed mild acute pancreatitis, and PAVM was diagnosed based on the findings of dynamic CT. Although repeated abdominal pain was observed after the improvement of pancreatitis, distal pancreatectomy was performed. At >1 year after surgery, no recurrence of PAVM was observed. Surgical resection should be considered in patients with symptomatic PAVM.

WONDER-02: plastic stent vs. lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic pseudocysts-study protocol for a multicentre randomised non-inferiority trial.

BACKGROUND: Endoscopic ultrasound (EUS)-guided transluminal drainage has become a first-line treatment modality for symptomatic pancreatic pseudocysts. Despite the increasing popularity of lumen-apposing metal stents (LAMSs), plastic stents may resolve non-necrotic fluid collections effectively with lower costs and no LAMS-specific adverse events. To date, there has been a paucity of data on the appropriate stent type in this setting. This trial aims to assess the non-inferiority of plastic stents to a LAMS for the initial EUS-guided drainage of pseudocysts. METHODS: The WONDER-02 trial is a multicentre, open-label, non-inferiority, randomised controlled trial, which will enrol pancreatic pseudocyst patients requiring EUS-guided treatment in 26 centres in Japan. This trial plans to enrol 80 patients who will be randomised at a 1:1 ratio to receive either plastic stents or a LAMS (40 patients per arm). In the plastic stent group, EUS-guided drainage will be performed using two 7-Fr double pigtail stents. In the LAMS group, the treatment will be performed in the same way except for LAMS use. The step-up treatment will be performed via endoscopic and/or percutaneous procedures at the trial investigator's discretion. The primary endpoint is clinical success, which is defined as a decrease in a pseudocyst size to ≤ 2 cm and an improvement in inflammatory indicators (i.e. body temperature, white blood cell count, and serum C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, pseudocyst recurrence, and medical costs. DISCUSSION: The WONDER-02 trial will investigate the efficacy and safety of plastic stents compared to a LAMS in EUS-guided treatment of symptomatic pancreatic pseudocysts with a particular focus on the non-inferior efficacy of plastic stents. The findings will help establish a new treatment algorithm for this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT06133023 registered on 9 November 2023. UMIN000052647 registered on 30 October 2023. jRCT1032230444 registered on 7 November 2023.

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).

Implantation cyst appearing more than 30 years after gastrectomy.

Implantation cyst is often reported to be a delayed complication after colorectal surgery. This report presents a 70-year-old man undergoing gastrectomy 33 years earlier for an acute gastric ulcer. His endoscopic finding showed a submucosal tumor about 20 mm in diameter at the gastro-jejunal anastomosis. Endoscopic ultrasonography showed that the tumor was a cystic mass that was continuous from the third layer, but there were no existences of internal substantial nodules, indicating that the tumor was diagnosed as implantation cyst. This is the first report showing that implantation cyst can occur at gastro-jejunal anastomosis. We should take into account the occurrence of implantation cyst, when we encounter a submucosal tumor at gastro-jejunal anastomosis after surgery even if a long period has passed.

Diagnosis of pancreatic malignancies using an overnight-stored pancreatic juice cell block specimen.

BACKGROUND AND AIMS: Pancreatic juice cytology is useful for diagnosing pancreatic duct strictures and cystic lesions. However, some cases cannot be diagnosed using cytology. This study aimed to evaluate the utility of the overnight-stored pancreatic juice cell block (CB) method for diagnosing pancreatic disease. METHODS: This retrospective study included 32 patients who presented with pancreatic duct strictures or cystic lesions between 2018 and 2024. The sensitivity, specificity, and accuracy of the CB method and single/multiple pancreatic juice cytology were compared to evaluate the utility of the CB. RESULT: An endoscopic nasopancreatic drainage tube was placed in the main pancreatic duct, and pancreatic juice was collected to create a CB specimen. The median amount of pancreatic juice collected was 180(30-200) mL, and the median number of cytological examinations was three(2-8). Of the 32 cases, 13 were malignant, and 19 were benign (non-malignant). The sensitivity was significantly higher for the CB method (62 %) than for single cytology(15 %, P = 0.0414), and there was no significant difference between CB and multiple cytology(54 %, P = 1.0). The specificity and accuracy were not significantly different between the CB method and single or multiple cytology. When multiple cytology and CB were combined, sensitivity improved to 77 %. The pathological findings of the CB specimens were similar to the surgical specimens, including immunohistochemistry. CONCLUSION: The overnight-stored pancreatic juice CB method was more effective than single cytology, with similar sensitivities to multiple cytology and can also be used for immunohistochemistry. The pancreatic juice CB method is useful for pancreatic juice assessment.

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.

Advances and efficacy in specimen handling for endoscopic ultrasound-guided fine needle aspiration and biopsy: A comprehensive review.

Endoscopic ultrasound-guided fine needle aspiration and biopsy have significantly evolved since they offer a minimally invasive approach for obtaining pathological specimens from lesions adjacent to or within the intestine. This paper reviews advancements in endoscopic ultrasound-guided fine needle aspiration and biopsy techniques and devices, emphasizing the importance of handling specimens for diagnostic accuracy. Innovations of fine needle biopsy needles with features like side holes and Franseen shapes have enhanced histological sampling capabilities. Techniques for specimen handling, including rapid on-site evaluation and macroscopic on-site evaluation, play pivotal roles in assessing sample adequacy, thereby influencing diagnostic outcomes. The utility of artificial intelligence in augmenting rapid on-site evaluation and macroscopic on-site evaluation, although still in experimental stages, presents a promising avenue for improving procedural efficiency and diagnostic precision. The choice of specimen handling technique is dependent on various factors including endoscopist preference, procedure objectives, and available resources, underscoring the need for a comprehensive understanding of each method's characteristics to optimize diagnostic efficacy and procedural safety.

Evaluating optimal bilateral biliary stenting in endoscopic reintervention after initial plastic stent dysfunction for unresectable malignant hilar biliary obstruction: Retrospective cross-sectional study.

OBJECTIVES: The placement of plastic stents (PS), including intraductal PS (IS), is useful in patients with unresectable malignant hilar biliary obstruction (UMHBO) because of patency and ease of endoscopic reintervention (ERI). However, the optimal stent replacement method for PS remains unclear. METHODS: This retrospective study included 322 patients with UMHBO. Among them, 146 received PS placement as initial drainage (across-the-papilla PS [aPS], 54; IS, 92), whereas 75 required ERI. Eight bilateral aPS, 21 bilateral IS, and 17 bilateral self-expandable metallic stent (SEMS) placements met the inclusion criteria. Rates of technical and clinical success, adverse events, recurrent biliary obstruction (RBO), time to RBO (TRBO), overall survival, and secondary ERI were compared. RESULTS: There were no significant intergroup differences in rates of technical or clinical success, adverse events, RBO occurrence, or overall survival. The median TRBO was significantly shorter in the aPS group (47 days) than IS (91 days; P = 0.0196) and SEMS (143 days; P < 0.01) groups. Median TRBO did not differ significantly between the IS and SEMS groups (P = 0.44). On Cox multivariate analysis, the aPS group had the shortest stent patency (hazard ratio 2.67 [95% confidence interval 1.05-6.76], P = 0.038). For secondary ERI, the median endoscopic procedure time was significantly shorter in the IS (22 min) vs. SEMS (40 min) group (P = 0.034). CONCLUSIONS: Bilateral IS and SEMS placement featured prolonged patency after first ERI. Because bilateral IS placement is faster than SEMS placement and IS can be removed during secondary ERI, it may be a good option for first ERI.

Pretherapeutic factors predicting conversion surgery in unresectable pancreatic ductal adenocarcinoma: A retrospective study.

Recently, conversion surgery (CS) has been reported to improve the prognosis in patients with unresectable pancreatic ductal adenocarcinoma (UR-PDAC) with a favorable response to intense chemotherapy or chemoradiotherapy. However, few pretherapeutic parameters predict the attainability of CS in patients with UR-PDAC. The present study aimed to explore the pretherapeutic predictors for the attainability of CS in patients with UR-PDAC. The present study retrospectively evaluated 130 patients with UR-PDAC treated at Gifu University Hospital (Gifu, Japan) from January 2015 to December 2021. Survival analysis was performed using the Simon and Makuch-modified Kaplan-Meier method. The hazard ratio (HR) was estimated using a time-varying Cox regression model. The association between each predictor and CS was evaluated using the univariate analysis and age-adjusted Fine-Gray sub-distribution hazard model. The bootstrap bias-corrected area under the receiver operating characteristic curve analysis for predicting CS was used to assess the cut-off values for each predictor. The cumulative incidence rate was calculated with CS as the outcome when divided into two groups based on the cut-off value of each pretherapeutic predictor. Among the 130 patients included in the analysis, only 14 (11%) underwent CS. The median survival time was significantly longer in patients who underwent CS compared with patients without CS (56.3 vs. 14.1 months; P<0.001). The age-adjusted Fine-Gray sub-distribution hazard regression showed that the total protein (TP) [HR 2.81, 95% confidence interval (CI) 1.19-6.65; P=0.018], neutrophil-to-lymphocyte ratio (NLR) (HR 0.53, 95% CI 0.31-0.90; P=0.020), and lymphocyte-to-monocyte ratio (LMR) (HR 1.28, 95% CI 1.07-1.53; P=0.006) were significantly associated with CS. Moreover, TP ≥6.8, NLR <2.84 and LMR ≥3.87 were associated with a higher cumulative incidence of CS. In conclusion, pretherapeutic TP, NLR and LMR are clinically feasible biomarkers for predicting the attainability of CS in patients with UR-PDAC.

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.

Protocol for a Multi-Center Confirmatory Trial to Evaluate the Differential Diagnostic Performance of Contrast-Enhanced Ultrasonography Using Perflubutane in Patients with a Pancreatic Mass: A Multicenter Prospective Study.

For pancreatic masses, an evaluation of their vascularity using contrast-enhanced ultrasonography can help improve their characterization. This study was designed to evaluate the utility and safety of contrast-enhanced transabdominal ultrasonography (CE-TUS) and endoscopic ultrasonography (CE-EUS) in the diagnosis of pancreatic masses including solid or cystic masses. This multi-center comparative open-label superiority study is designed to compare Plain (P)-TUS/EUS alone with P-TUS/P-EUS plus CE-TUS/CE-EUS. Three hundred and one patients with a total of 232 solid pancreatic masses and 69 cystic masses were prospectively enrolled. The primary endpoints are to compare the diagnostic accuracy between P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for both the TUS and EUS of solid pancreatic masses, and to compare the diagnostic accuracy between P-EUS alone and P-EUS plus CE-EUS in cystic pancreatic masses. The secondary endpoints are to compare the diagnostic sensitivity and specificity of P-TUS/P-EUS alone and P-TUS/P-EUS plus CE-TUS/CE-EUS for pancreatic solid/cystic masses, and the accuracy of P-TUS alone and P-TUS plus CE-TUS for pancreatic cystic masses. Other secondary endpoints included comparing the diagnostic sensitivity, specificity, and accuracy of CE-TUS, CE-EUS and CE-computed tomography (CT) for solid/cystic pancreatic masses. The safety, degree of effective enhancement, and diagnostic confidence obtained with CE-TUS/CE-EUS will also be assessed.

Early versus delayed EUS-guided drainage for postoperative pancreatic fluid collections: a systematic review and meta-analysis.

BACKGROUND: Postoperative pancreatic fluid collections (POPFCs) are common adverse events (AEs) after pancreatic surgery and may need interventions. Endoscopic ultrasound (EUS)-guided drainage for POPFCs is increasingly reported, but its appropriate timing has not been fully elucidated. The aim of this meta-analysis was to evaluate treatment outcomes of POPFCs according to the timing of EUS-guided drainage. METHODS: Using PubMed, Embase, Web of Science, and the Cochrane database, we identified clinical studies published until December 2022 with data comparing outcomes of early and delayed EUS-guided drainage for POPFCs. We pooled data on AEs, mortality, and technical and clinical success rates, using the random-effects model. RESULTS: From 1415 papers identified in the initial literature search, we identified 6 retrospective studies, including 128 and 107 patients undergoing early and delayed EUS-guided drainage for POPFCs. The threshold of early and delayed drainage ranged from 14 to 30 days. Distal pancreatectomy was the major cause of POPFCs, ranging from 44 to 100%. The pooled odds ratio (OR) for AEs was 0.81 (95% confidence interval [CI] 0.40-1.64, P = 0.55) comparing early to delayed drainage. There was no procedure-related mortality. Technical success was achieved in all cases and a pooled OR of clinical success was 0.60 (95% CI 0.20-1.83, P = 0.37). CONCLUSION: POPFCs can be managed by early EUS-guided drainage without an increase in AEs.

Development of Pancreatic Cancer during the Follow-up of Autoimmune Pancreatitis: A Report of Two Cases.

Autoimmune pancreatitis (AIP) is considered to have a good steroid response and is recognized as a disease with a favorable prognosis. However, it has been reported that patients with AIP have malignant diseases. We herein report two cases of pancreatic cancer during the follow-up of AIP, in which both patients died of pancreatic cancer. Patients with AIP may be at a high risk of malignant diseases, including pancreatic cancer, and medium- to long-term follow-up may be necessary.

Pancreatic Metastases from Renal Cell Carcinoma Showing Atypical Imaging Findings.

A 59-year-old man receiving sunitinib chemotherapy for postoperative recurrence of renal cell carcinoma (RCC) metastases was found to have multiple metastases on contrast-enhanced computed tomography (CECT). CECT revealed a typical hyperdense enhanced nodule in the arterial phase of the stomach and head and tail of the pancreas. However, in the uncinate process of the pancreas, CECT revealed an atypical image and a hypodense enhanced nodule in each phase. Both lesions were finally pathologically diagnosed as clear cell carcinoma. Treatment-modified pancreatic metastases from RCC may present with nonspecific images; therefore, caution is required when deciding on treatment strategies.

Endoscopic ultrasound-guided fine-needle aspiration for pancreatic cystic lesions: a comprehensive review.

Advancements in diagnostic radiology have amplified the incorporation of these techniques into routine clinical practice. Concurrently, the frequency of incidentally identifying pancreatic cystic lesions (PCLs) has surged. PCLs encompass diverse categories contingent upon their origin. Among them, branch duct-intraductal papillary mucinous neoplasms (BD-IPMN) and mucinous cystic neoplasms (MCN) are categorized as mucinous cystic lesions that have malignant potential. Even solid neoplasms occasionally show cystic degeneration. Therefore, precise differential PCL diagnosis is crucial to optimize clinical management strategies and detect malignant transformations. Endoscopic ultrasound (EUS) affords comprehensive visualization of the pancreas with high-resolution ultrasound, complemented by fine-needle aspiration (FNA) under real-time EUS guidance, which is a minimally invasive procedure for obtaining pathological samples. This synergy has established EUS and EUS-FNA as vital procedures in the management of PCLs, enabling differentiation of PCLs. Cyst fluid analysis has played a pivotal role in deciding the optimal management strategy. The efficacy of cytological analysis is limited by scant cytologic material. The "string sign" test evaluates fluid viscosity, and its simplicity warrants initial consideration. Amylase and tumor markers, such as CEA, have been studied, but they yield varied sensitivity and specificity. Glucose and genetic mutations (KRAS, GNAS) exhibit promise, while comprehensive genomic profiling underscores genetic insights. Through-the-needle biopsy and needle-based confocal laser endomicroscopy also show high diagnostic yield. EUS-FNA, however, entails risks like infection and needle tract seeding, emphasizing the need for proper utilization. Pancreatic cyst fluid analysis augments diagnostic accuracy and informs clinical decisions, making it a valuable adjunct to imaging.

Comparison of unilateral and bilateral intraductal plastic stent placement for unresectable malignant hilar biliary obstruction: A propensity score-matched cohort analysis.

BACKGROUND: Although intraductal plastic stent (IS) placement is an effective treatment for unresectable malignant hilar biliary obstruction (UMHBO), the effectiveness of unilateral and bilateral IS drainage remains controversial. This retrospective study investigated the effectiveness of bilateral IS placement for UMHBO using the propensity score matching method. METHODS: Patients who underwent transpapillary endoscopic stenting for UMHBO were analyzed for technical and clinical success, adverse events, and time to recurrent biliary obstruction (TRBO). RESULTS: A total of 321 patients were enrolled in the study with 27 patients in each unilateral and bilateral IS group in the propensity score-based cohort. Technical success was 100%, while clinical success was 93% and 96% in the unilateral and bilateral IS groups, respectively (p = 1.0). Cholecystitis occurred in 4% and 7%, respectively (p = 1.0). The median TRBO was shorter in the unilateral group (129 [5-383] days) than that in the bilateral group (226 [16-563] days) (p = .0281). Bilateral IS placement was an independent long TRBO factor (hazard ratio [HR] 0.46; 95% confidence interval [CI]: 0.21-0.97; p = .041). CONCLUSIONS: Unilateral and bilateral IS placement had high technical and clinical success rates in primary stent placement. However, bilateral IS placement showed a longer TRBO. Bilateral IS placement may be a good option for initial UMHBO drainage.

Improvement of Rectal Prolapse Using an Over-the-scope Clip System.

Rectal prolapse is typically treated surgically, and internal therapy has not been reported. We encountered a case of rectal prolapse that improved with an over-the-scope clip system (OTSC). An 81-year-old woman complaining of anorectal pain underwent colonoscopy, and rectal prolapse was observed prior to colonoscopy. Unfortunately, rectal perforation occurred while attempting endoscopic reversal. The OTSC system was used to close the rectal perforation and subsequently improved her rectal prolapse, probably because the rectal wall was anchored to the retroperitoneum. This is the first report to show that rectal prolapse can be endoscopically improved and that an OTSC system might be a viable alternative method for managing inoperable rectal prolapse.

Comparison of covered self-expandable metallic stents with 12-mm and 10-mm diameters for unresectable malignant distal biliary obstructions: a prospective randomized trial.

BACKGROUND AND AIMS: Covered self-expandable metallic stents have longer patency than uncovered self-expandable metallic stents for unresectable malignant distal biliary obstruction because of the prevention of tumor ingrowth, and they are removable during reintervention. One main cause of recurrent biliary obstruction in covered self-expandable metallic stents is sludge formation, which can be prevented by using large-bore stents. We evaluated the treatment results of 12-mm and 10-mm covered self-expandable metallic stents for unresectable malignant distal biliary obstructions using a randomized controlled trial. METHODS: This study was conducted between May 2016 and January 2019 and included 81 consecutive patients with unresectable malignant distal biliary obstruction. The primary endpoint was the rate of nonrecurrent biliary obstruction at 6 months after stent placement. RESULTS: The primary endpoint in the 12-mm group was significantly higher than that in the 10-mm group (P = .0369). Therefore, the median time to recurrent biliary obstruction was 172 days in the 12-mm group and 120 days in the 10-mm group. The median time to recurrent biliary obstruction in the 12-mm group was significantly longer than that in the 10-mm group (P = .0168). Using the 12-mm covered self-expandable metallic stents and receiving chemotherapy were factors affecting the rate of recurrent biliary obstruction in the multivariate analysis. CONCLUSIONS: The 12-mm covered self-expandable metallic stents provide a longer time to recurrent biliary obstruction than do 10-mm covered self-expandable metallic stents for managing unresectable malignant distal biliary obstruction. (Clinical trial registration number: UMIN000016911.).