Yousuke Nakai

The University of Tokyo | Todai · Department of Gastroenterology

Walled‐off necrosis (WON) develops as local complications after acute necrotizing pancreatitis. Although less invasive interventions such as endoscopic ultrasonography (EUS)‐guided drainage and endoscopic necrosectomy are selected over surgical interventions, delayed and step‐up interventions are still preferred to avoid procedure‐related adverse e...

Excess body weight may modulate the progression of various cancer types. The prognostic relevance of body mass index (BMI) has not been fully examined in patients with biliary tract cancer. Using a single-institutional cohort of 360 patients receiving gemcitabine-based chemotherapy for advanced biliary tract cancer, we examined the association of B...

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 o...

Background/Objective: Interventional endoscopic ultrasound (I-EUS) is technically difficult and has risks of severe adverse events due to the scarcity of dedicated endoscopes and tools. A new EUS scope was developed for I-EUS and was modified to increase the puncture range, reduce the blind area, and overcome guidewire difficulties. We evaluated th...

Aim Comprehensive genomic profiling (CGP) test for solid tumors is now increasingly utilized in clinical practice, especially in pancreatobiliary cancer, and specimens obtained by endoscopic ultrasound‐guided tissue acquisition (EUS‐TA) are often submitted for tissue‐based CGP test. In this study, we evaluated the feasibility of EUS‐TA using a 22‐g...

Objective To examine whether long-term surveillance of intraductal papillary mucinous neoplasms (IPMNs) leads to early diagnosis and better clinical outcomes of pancreatic ductal adenocarcinomas (PDACs) developing concomitantly with IPMNs. Summary Background Data Long-term image-based surveillance is recommended for patients with low-risk IPMNs. H...

Background and aim Balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is an emerging procedure for pancreatobiliary diseases in patients with surgically altered anatomy. However, data on BE-ERCP for hepatolithiasis after hepaticojejunostomy (HJS) are still limited. Methods Stone removal success, adverse events and...

We herein present the first known case of bacteremia caused by Kluyvera georgiana in a 67-year-old female undergoing chemotherapy for recurrent pancreatic cancer. The patient underwent choledochojejunotomy and thereafter developed ascending cholangitis. The diagnosis of K. georgiana was confirmed using matrix-assisted laser desorption/ionization ti...

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....

Studies have demonstrated a prognostic role of sarcopenia (i.e., loss of skeletal muscle volume and functionality) in patients with various cancer types. In patients with biliary tract cancer, the quantity and quality of skeletal muscles and their serial changes have not been fully investigated in relation to survival outcomes. We identified 386 pa...

Objective Current guidelines recommend long-term image-based surveillance for patients with low-risk intraductal papillary mucinous neoplasms (IPMNs). This simulation study aimed to examine the comparative cost-effectiveness of continued versus discontinued surveillance at different ages and define the optimal age to stop surveillance. Design We c...

471 Background: CCA represents ~3% of all gastrointestinal malignancies globally; it is particularly prevalent in Asian countries. Additionally, FGFR2 gene fusions occur in ~13% of intrahepatic CCA cases. Tasurgratinib (E7090) is an orally available selective inhibitor of FGFR 1–3; the recommended dose is 140 mg per day per the dose-escalation part...

Objectives The local renin-angiotensin system promotes angiogenesis and proliferation via vascular endothelial growth factor or epidermal growth factor receptor expression. In this study, we aimed to evaluate the impact of angiotensin system inhibitors (ASIs) on long-term outcomes in patients undergoing surgical resection of pancreatic ductal adeno...

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 outcome...

Objective We aimed to elucidate the feasibility of surveillance of patients with mucinous cystic neoplasm (MCN). Methods We performed a retrospective, multi-institutional study of 328 patients who underwent surgery for MCN at 18 Japanese institutions. Patients with MCN were divided into an immediate surgery group and a surveillance group, which un...

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Objectives For preoperative biliary drainage (PBD) of malignant hilar biliary obstruction (MHBO), current guidelines recommend endoscopic nasobiliary drainage (ENBD) due to the higher risk of cholangitis after endoscopic biliary stenting (EBS) during the waiting period before surgery. However, few studies have supported this finding. Therefore, we...

Objectives No comprehensive study has examined short‐ and long‐term adverse outcomes of endoscopic ultrasound (EUS)‐guided treatment of pancreatic fluid collections (PFCs) including walled‐off necrosis (WON) and pseudocysts. Methods In a multi‐institutional cohort of 357 patients receiving EUS‐guided treatment of PFCs (228 with WON and 129 with ps...

Background: Endoscopic self-expandable metal stent (SEMS) placement is a current mainstay for malignant gastric outlet obstruction (GOO), but symptomatic recurrence due to initial SEMS dysfunction commonly occurs. We aimed to compare the safety and effectiveness of second SEMS for recurrent GOO (RGOO). Methods: Between April 2006 and December 2022,...

Interstitial lung disease (ILD) is an adverse event associated with gemcitabine administration. Gemcitabine plus nab-paclitaxel, which is now a first-line chemotherapy regimen for pancreatic cancer (PC), may increase the risk of ILD; however, large-scale clinical data on this are limited. Thus, this study aimed to elucidate the incidence and risk f...

Background and aims: Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed for management of pancreatobiliary diseases; however, post-ERCP pancreatitis (PEP) remains as an unsolved problem. Although various risk factors for PEP have been reported, the prediction of PEP remains controversial. This study aimed to develop a predic...

Background: Trajectories of serological and morphological signatures have not been documented in pancreatic carcinogenesis related to intraductal papillary mucinous neoplasms (IPMNs). Methods: Using a prospective cohort of 3437 IPMN patients, we identified 100 IPMN patients who developed pancreatic carcinomas during long-term surveillance. We ex...

Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is widely used for the pathological diagnosis of solid pancreatic lesions but in cases with obstructive jaundice, transpapillary sampling can be performed during endoscopic retrograde cholangiopancreatography with transpapillary biliary stent placement. Thus, it is still con...

Background Studies have demonstrated a prognostic role of sarcopenia (i.e., loss of skeletal muscle volume and functionality) in patients with various cancer types. In patients with biliary tract cancer, the quantity and quality of skeletal muscles and their serial changes have not been fully investigated in relation to survival outcomes. Methods...

Abstract Alterations in KRAS, CDKN2A (p16), TP53, and SMAD4 genes have been major drivers of pancreatic carcinogenesis. The clinical course of patients with pancreatic cancer in relation to these driver alterations has not been fully characterised in large populations. We hypothesised that pancreatic carcinomas with different combinations of KRAS m...

4011 Background: L-type amino acid transporter 1 (LAT1, SLC7A5) is overexpressed in cancer cells leading to aggressive proliferation and lymphatic metastases. LAT1 sustains energy resources by supplying essential amino acids to the TCA cycle in chemotherapy-resistant cancer cells. LAT1 is a documented marker of poor prognosis. In a placebo-controll...

Aims: Endoscopic management of unresectable hilar malignant biliary obstruction (HMBO) is technically challenging, and effectiveness of stent-in-stent using large-cell, metal stents was reported. A new, large-cell stent with a 6-Fr tapered delivery system was recently developed. The aim of this study is to compare clinical outcomes of this slim-de...

Background With the increasing popularity of endoscopic ultrasound (EUS)-guided transmural interventions, walled-off necrosis (WON) of the pancreas is increasingly managed via non-surgical endoscopic interventions. However, there has been an ongoing debate over the appropriate treatment strategy following the initial EUS-guided drainage. Direct end...

Pancreatic fluid collections (PFCs) typically develop as local complications of acute pancreatitis and complicate the clinical course of acute pancreatitis patients with potentially fatal clinical outcomes. Interventions are required in cases of symptomatic walled-off necrosis (matured PFC with necrosis) and pancreatic pseudocysts (matured PFC with...

Background: Endoscopic-ultrasound-guided gastrojejunostomy (EUS-GJ) can be a new alternative for patients with malignant afferent loop syndrome (MALS). However, a fully covered self-expandable metal stent (FCSEMS) has not been well investigated in this setting. Methods: This is a multicenter retrospective cohort study. Consecutive patients that...

Background and aims: Endoscopic ultrasound (EUS)-guided interventions currently serve as first-line treatment for symptomatic pancreatic fluid collections (PFCs) but require high-level expertise and multidisciplinary care. Hospital caseload has not been fully examined in relation to clinical outcomes of patients with endoscopically managed PFCs....

Background and objectives: EUS-guided hepaticogastrostomy (EUS-HGS) is an effective salvage procedure when conventional endoscopic transpapillary biliary drainage is difficult or fails. However, the risk of stent migration into the abdominal cavity has not been resolved completely. In this study, we evaluated a newly developed partially covered se...

Objective: We aimed to examine the factors contributing to radiation exposure exceeding the DRL of the transnasal ileus tube placement in this post hoc analysis from the cohort of the REX-GI study. Methods: Patients with transnasal ileus tubes were enrolled in the rex-gi study from may 2019 to december 2020. We investigated the endoscope inserti...

Objectives: We surveyed and reported low protective equipment usage and insufficient knowledge among endoscopy-fluoroscopy departments in Japan in 2020. Two years later, we conducted a follow-up survey of doctors, nurses, and technologists in Japan. Methods: We conducted a questionnaire survey on radiation protection from May to June 2022. The p...

Background/aims: Mechanical properties (MPs) and axial and radial force (AF and RF) may influence the efficacy and complications of self-expandable metallic stent (SEMS) placement. We measured the MPs of various SEMSs and examined their influence on the SEMS clinical ability. Methods: We evaluated the MPs of 29 types of 10-mm SEMSs. RF was measu...

Acute pancreatitis is an acute inflammatory process of the pancreas that is becoming an increasingly common clinical issue. The most frequent underlying etiologies include gallstones and chronic alcohol use, which account for more than two-thirds of cases. We recently experienced a rare case of acute myeloid leukemia (AML) presenting with recurrent...

Purpose Patients with pancreatic cancer often have cancer cachexia at diagnosis. Recent studies suggested that loss of skeletal muscle mass was related to cancer cachexia, which hindered continuance of chemotherapy and could be one of prognostic factors in pancreatic cancer, however the association remains unclear in patients receiving gemcitabine...

Background & aims: Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation. Methods: Among 3,610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2,829 IPMN patients...

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis due to the difficulty of its diagnosis. Because human satellite II (HSATII) RNA, a satellite repeat RNA, is highly and specifically expressed in human PDAC, the serum HSATII RNA level may be a biomarker of PDAC. To measure the serum HSATII RNA level with high sensitivity and reproducibili...

494 Background: LAT1 is a transporter ( SLC7A5) of L-type amino acid. Overexpression in cancer cells supports aggressive proliferation. High expression of LAT1 in tumor specimens has been identified as a predictor of poor prognosis in patients with various cancer types, including BTC. The efficacy and safety of nanvuranlat (JPH203), a first-in-clas...

Aims: This study aimed to evaluate the effectiveness and safety of stenting with a flexible braided self-expandable metal stent (SEMS) for unresectable malignant gastric outlet obstruction (GOO). Methods: Palliative stenting was prospectively carried out at seven university hospitals between October 2017 and August 2020. All procedures were perf...

Background and aims: There is a lack of biliary epithelial molecular markers for primary sclerosing cholangitis (PSC). We analyzed candidates from disease susceptibility genes identified in recent genome-wide association studies. Methods: Expression was quantified using immunohistochemistry in biliary epithelia in liver biopsy samples from patients...

The molecular subtypes of pancreatic cancer (PC), either classical/progenitor-like or basal/squamous-like, are currently a major topic of research because of their direct association with clinical outcomes. Some transcription factors (TFs) have been reported to be associated with these subtypes. However, the mechanisms by which these molecular sign...

Background: With the increasing popularity of endoscopic ultrasound (EUS)-guided transmural interventions, walled-off necrosis (WON)of the pancreas is increasingly managed via non-surgical endoscopic interventions. However, there has been an ongoing debate over the appropriate treatment strategy following the initial EUS-guided drainage. Endoscopic...

Given the promising activity and tolerability of FOLFIRINOX as a second-line treatment for advanced biliary tract cancer (BTC), it can be an attractive first-line treatment option as well. This is a single-arm, open-label, multicenter phase II study to evaluate the safety and efficacy of FOLFIRINOX as a first-line treatment for patients with advanc...

Pancreatic fluid collections (PFCs) commonly develop as complications of acute pancreatitis and ductal disruption due to chronic pancreatitis. In the revised Atlanta classification, PFCs were classified based on the presence of necrosis and duration following the onset of acute pancreatitis. Interventions are required in cases of symptomatic pancre...

Background The appropriate method of preoperative endoscopic biliary drainage (EBD) for cholangiocarcinoma with hilar biliary obstruction remains controversial. The inside-stent technique is a method of placing plastic stents entirely inside the bile duct. Several studies of patients with unresectable stage have reported longer stent patency compar...

Objectives: Interventions for necrotizing pancreatitis are generally postponed until 4 weeks after the onset of acute pancreatitis, but there remains controversy about whether we should always wait >4 weeks or can intervene early when necessary. This meta-analysis was conducted to evaluate treatment outcomes of necrotizing pancreatitis according t...

Purpose: Given the promising activity and tolerability of FOLFIRINOX as a second-line treatment for advanced biliary tract cancer (BTC), it can be an attractive first-line treatment option as well. Materials and Methods: This is a single-arm, open-label, multicenter phase II study to evaluate the safety and efficacy of FOLFIRINOX as a first-line tr...

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with only a few effective therapeutic options. A characteristic feature of PDAC is its unique tumor microenvironment (TME), termed desmoplasia, which shows extensive fibrosis and extracellular matrix deposition, generating highly hypoxic and nutrient-deprived conditions within the...

Pancreatic cancers related to intraductal papillary mucinous neoplasms (IPMN) include IPMN-derived carcinomas and concomitant carcinomas. Data from our institution shows that the cumulative incidence of pancreatic cancer was 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. The standardized incidence ratio of pancreatic cancer was 10.8. T...

Background: Covered self-expandable metal stent (cSEMS) for gastric outlet obstruction (GOO) had been developed to overcome tumor ingrowth but prone to be associated with an increased risk of migration. Clinical impact of the novel large-bore cSEMS for malignant GOO remains unclear. Methods: A total of 117 patients undergoing endoscopic cSEMS pl...

Objective: Noninvasive intraductal papillary mucinous neoplasms (IPMNs) theoretically do not metastasize. The purpose of this study is to preoperatively distinguish invasive carcinomas associated with IPMN from noninvasive IPMN. Methods: A total of 131 patients who underwent surgical resection for IPMN were retrospectively analyzed to identify t...

Purpose of review: To summarize the current status and future perspectives of the endoscopic management of biliary strictures. Recent findings: In addition to conventional diagnostic modalities, such as cross-sectional imaging and endoscopic ultrasonography (EUS), per-oral cholangioscopy is helpful for indeterminate biliary strictures. It allows...

Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed for malignant hilar biliary obstruction (MHBO). On the contrary, patients with surgically altered anatomy traditionally undergo percutaneous transhepatic biliary drainage due to difficulty in performing ERCP. Recently, endoscopic ultrasound guided biliary drainage (EUS-BD) ha...

Macroautophagy (hereafter autophagy) is a catabolic process through which cytosolic components are captured in the autophagosome and degraded in the lysosome. Autophagy plays two major roles: nutrient recycling under starvation or stress conditions and maintenance of cellular homeostasis by removing the damaged organelles or protein aggregates. In...

KRAS mutation is a major driver of pancreatic carcinogenesis and will likely be a therapeutic target. Due to lack of sensitive assays for clinical samples of pancreatic cancer with low cellularity, KRAS mutations and their prognostic association have not been fully examined in large populations. In a multi-institutional cohort of 1,162 pancreatic c...

This Editorial refers to the article by M. Kitano et al., p 307–316 of the issue DEN 34:2.

Objectives: Proton pump inhibitors (PPIs) are widely prescribed medications for gastric acid-induced diseases. Despite the effectiveness of PPIs, recent evidence suggested an increased risk of various bacterial infections in PPI users. The current study was conducted to evaluate the risk of biliary infection after endoscopic biliary stent placemen...

Objectives: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) plays a crucial role in the diagnosis of pancreatic tumors. The present study aimed to investigate the current status of needle tract seeding (NTS) after EUS-TA of pancreatic tumors based on a nationwide survey in Japan. Methods: Patients who underwent surgical resection of pri...

Bckground and objectives: EUS-guided cystogastrostomy is a well-established advanced endoscopic technique with a steep-learning curve which necessitates an ex-vivo simulator that would allow for adequate training. The aim of this study is to evaluate the feasibility of the model in allowing training for EUS-guided cystogastrostomy using lumen-appo...