横山 健介

BACKGROUND AND AIMS: Stenosis at pancreaticojejunal (PJ) anastomosis is a recognized adverse event after pancreaticoduodenectomy. Although double-balloon endoscopic retrograde cholangiopancreatography (DB-ERCP) can be used for management, this procedure is often technically challenging. METHODS: We describe a case in which complete obstruction of PJ anastomosis was successfully treated by identifying the anastomosis with contrast injection through a standard injection needle. RESULTS: Pancreatography was performed by puncturing the area suspected to be the anastomosis with a 25-gauge injection needle. After pancreatography, the anastomosis was dilated using a balloon catheter, and endoscopic nasopancreatic duct drainage was placed. No adverse events occurred. CONCLUSIONS: After DB-ERCP, pancreatic duct dilatation improved. Pancreatography and treatment of PJ anastomotic obstruction can be performed safely by puncturing the anastomotic site with an injection needle.

With accompanying video, Sakurai and colleagues described a peroral direct cholangioscopy technique using a double-balloon enteroscope to treat bile duct stones after Billroth II gastrectomy. Direct insertion of the enteroscope into the bile duct eliminated scope exchange, enabling precise device manipulation, broader accessory selection, and shorter procedure time.

BACKGROUND: IgG4-related disease is a rare autoimmune disorder characterised by tissue infiltration of IgG4-positive plasma cells, storiform fibrosis, elevated serum IgG4 concentrations, and increased risk of tumour complications. Previous genetic studies have implicated FCGR2B and HLA loci in susceptibility to IgG4-related disease; however, most relied on microarray-based genotyping and imputation, which have limited resolution in highly polymorphic and structurally complex regions. This study aimed to investigate genetic susceptibility to IgG4-related disease using comprehensive genomic variant analysis, including low-frequency and structural variants not readily captured by microarrays. METHODS: We conducted a genome-wide association study using whole-genome sequencing data in a two-set, subtype-stratified case-control design in the Japanese population. Set 1 included samples (cases) from patients with IgG4-related disease from 50 hospitals across Japan participating in the Japanese IgG4-related disease Working Consortium (recruited between Oct 27, 2008, and March 3, 2016) and previously sequenced Japanese population control samples. Set 2 included samples (cases) from patients with IgG4-related disease from eight hospitals of the Consortium (recruited between Aug 12, 2021, and Dec 20, 2023) and previously sequenced healthy individuals residing in the Tokyo metropolitan area (controls). No specific inclusion or exclusion criteria were applied to either cases and controls. We used whole-genome sequencing at depths of 15× or 30× using HiSeqX and NovaSeq platforms (Illumina; San Diego, CA, USA) to enable the inclusion of previously uncaptured single nucleotide polymorphisms and direct analysis of HLA amino acid residues. We investigated complement component 4 copy number variations using short-read sequencing data and established read-depth-based typing methods. People with lived experience of IgG4-related disease were not involved in the study. FINDINGS: This whole-genome sequencing study comprised of 2 sets. Set 1 included 646 patient samples (172 [26·6%] were female, 474 [73·4%] were male, and the mean age was 64·4 years [SD 11·4]) and 2254 population controls (1348 [59·8%] were female and 906 [40·2%] were male). Set 2 included 223 patient samples (78 [35·0%] were female, 145 [65·0%] were male, and the mean age was 63·5 years [10·9]) and 405 population controls (65 [16·0%] were female and 340 [84·0%] were male). All individuals were of Hondo Japanese ancestry. The average IgG4 concentration at diagnosis was 653·1 mg/dL (SD 596·3) in Set 1 and 543·5 mg/dL (603·5) in Set 2. We validated the FCGR2B (p=9·8 × 10-11) region as the susceptibility locus for IgG4-related disease. PTCH1 (p=3·8 × 10-8) and long non-coding RNA LOC102724227 were found to be specific susceptibility loci for Mikulicz's disease. We also confirmed the association between the HLA amino acid residue DRB1-GB-7 (p=1·1 × 10-19) with IgG4-related disease and identified two additional residues, A-GA2-9 (p=4·1 × 10-6) and DQB1-GB-82 (p=4·7 × 10-9), that were significantly associated with IgG4-related disease. In the joint-association analysis of complement component 4 copy number variation, C4A showed a protective association with IgG4-related disease (β=-0·127, p=7·9 × 10-3), whereas C4B was associated with an increased risk (β=0·151, p=1·9 × 10-2). A low level of linkage disequilibrium (r2<0·15) was observed between the C4A and C4B alleles and the identified HLA amino acid residues in the main island Japanese population. INTERPRETATION: C4 copy number variation, in addition to HLA and FCGR2B, was found to be a distinct genetic factor associated with IgG4-related disease susceptibility, illustrating the complex polygenic nature of the disease. Furthermore, the identification of PTCH1 and the long non-coding RNA LOC102724227 as Mikulicz's disease-specific susceptibility loci suggests that genetic heterogeneity might underlie the clinical diversity of IgG4-related disease, particularly with respect to the affected organs. FUNDING: The Japanese Ministry of Health, Labour, and Welfare, the Japanese Agency of Medical Research and Development, the Kyoto University Grant for Top Global University Japan Project, and the Kyoto University Division of Graduate Studies SPRING Program.

A 50-year-old man was diagnosed with type 1 autoimmune pancreatitis (AIP) following endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and a histopathological examination. After six months of untreated follow-up, the serum IgG4 level decreased, and the diffuse pancreatic enlargement improved; however, a pancreatic head mass became apparent. EUS-FNA of this mass revealed pancreatic ductal adenocarcinoma (PDAC) with IgG4-positive plasma cells. In addition, the resected specimen revealed PDAC, without any features of AIP. After pancreatoduodenectomy, AIP did not recur. The development of AIP in this case could be related to paraneoplastic syndrome.

OBJECTIVES: This study assessed factors influencing the complete removal and recurrence of bile duct stones in patients with surgically altered anatomy (SAA) undergoing double-balloon endoscopy-assisted endoscopic retrograde cholangiography (DBERC). METHODS: A retrospective analysis of 289 patients with SAA treated for biliary stones with DBERC at Jichi Medical University Hospital (January 2007 to December 2022) was conducted. Evaluation of factors impacting complete stone removal was performed in 257 patients with successful bile duct cannulation. Logistic and Cox proportional hazards regression models were used to compute the odds ratios (ORs) and hazard ratios (HRs) at 95% confidence intervals (CIs). RESULTS: Of 257 patients, 139 (54.0%) and 209 (81.3%) achieved initial and complete removal, respectively. Recurrence occurred in 55 (21.4%) patients. Factors associated with initial complete stone removal included cholangitis (P < 0.01, OR 0.48, 95% CI 0.27-0.83), number of stones (P < 0.01, OR 0.31, 95% CI 0.18-0.54), and largest stone diameter (P < 0.01, OR 0.37, 95% CI 0.20-0.67). The size of the largest stone was associated with complete removal (P = 0.01, OR 0.24, 95% CI 0.13-0.76). Recurrence was associated with cholangitis (P = 0.046, HR 0.54, 95% CI 0.29-0.99), congenital biliary dilatation (P = 0.01, HR 2.65, 95% CI 1.21-5.80), and number of stones (P = 0.02, HR 1.96, 95% CI 1.12-3.41). CONCLUSIONS: Successful complete bile stone removal in patients with SAA depends on the stone diameter and number. Stone recurrence is influenced by the number of stones and history of congenital biliary dilatation.

Endoscopic ultrasonography (EUS) is an important diagnostic technique to accurately diagnose diseases originating from organs near the gastrointestinal tract. EUS-guided fine-needle aspiration (FNA) has improved the histopathological diagnosis. EUS-FNA has been further developed over a long period of 40 years. The history of the development of endosonographic scopes, ultrasonographic observation systems, puncture needles, and puncture methods will provide a springboard for future development.

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

A 66-year-old man diagnosed with immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) with diffuse intrahepatic bile duct stenosis and elevated serum IgG4 levels was referred for a further examination because of elevated serum carbohydrate antigen 19-9 levels despite treatment with corticosteroids. An umbilical nodule was found on a physical examination and a biopsy showed adenocarcinoma. Although several imaging studies revealed no changes from prior studies, bile cytology collected by endoscopic retrograde cholangiopancreatography showed adenocarcinoma. Consequently, the patient was diagnosed with cholangiocarcinoma resembling IgG4-SC after detecting an umbilical metastasis, also known as Sister Mary Joseph's nodule.

Video 1A metalic wire removed by endoscopic submucosal dissection using the pocket-creation method.

BACKGROUND: /Objectives: This study aimed to evaluate the usefulness of three-dimensional (3D) immunohistochemistry for the Ki67 index of small tissue specimens of pancreatic neuroendocrine tumor (PanNET). METHODS: Clinicopathological materials from 17 patients with PanNET who underwent surgical resection at Jichi Medical University Hospital were analyzed. We compared the Ki67 index of endoscopic ultrasonography-fine-needle aspiration biopsy (EUS-FNAB) specimens, surgical specimens, and small tissue specimens hollowed from paraffin blocks of surgical specimens that were substituted for EUS-FNAB specimens ("sub-FNAB"). The sub-FNAB specimens were optically cleared using LUCID (IlLUmination of Cleared organs to IDentify target molecules) and analyzed using 3D immunohistochemistry. RESULTS: The median Ki67 index in FNAB, sub-FNAB, and surgical specimens with conventional immunohistochemistry were 1.2% (0.7-5.0), 2.0% (0.5-14.6), and 5.4% (1.0-19.4), respectively. The median Ki67 index in sub-FNAB specimens with tissue clearing was calculated separately using the total number of cells on multiple images ("multiple slice"), with the image of the fewest positive cells ("coldspot"), and with the image of most positive cells ("hotspot"), which were 2.7% (0.2-8.2), 0.8% (0-4.8), and 5.5% (2.3-12.4), respectively. PanNET grade evaluated for the hotspot of the surgical specimens was significantly more consistent with those of the hotspot than multiple images of sub-FNAB specimens (16/17 vs. 10/17, p = 0.015). Hotspot evaluation using 3D immunohistochemistry of the sub-FNAB specimens showed agreement with the assessment of the surgical specimens (Kappa coefficient: 0.82). CONCLUSIONS: Tissue clearing and 3D immunohistochemistry for the Ki67 index can potentially improve the preoperative evaluation of EUS-FNAB specimens of PanNET in routine clinical practice.

During balloon enteroscopy-assisted endoscopic retrograde cholangiography, the minimal water exchange method facilitates reaching the site and prevents pneumobilia, hepatic portal venous gas, and air embolism. However, the water may mix with bile or blood, obscuring the visual field. Yokoyama and colleagues demonstrate how the gel immersion method helps overcome this problem.

Endoscopic ultrasound can be useful for obtaining detailed diagnostic images for pancreatic disease. Contrast-enhanced harmonic endoscopic ultrasound has allowed to demonstrate not only microvasculature but also real perfusion imaging using second-generation contrast agents. Furthermore, endoscopic ultrasound fine-needle aspiration cytology and histology have become more ubiquitous; however, the risk of dissemination caused by paracentesis has yet to be resolved, and the application of less invasive contrast-enhanced endoscopic ultrasound for the differential diagnosis of pancreatic tumors has been anticipated. Contrast-enhanced harmonic endoscopic ultrasound can contribute to the differential diagnosis of pancreatic tumors.

Autoimmune pancreatitis (AIP), which is characterized by pancreatic enlargement and irregular narrowing of the main pancreatic duct, is difficult to differentiate from malignancy. The irregular narrowing of the pancreatic duct, which can be detected via endoscopic retrograde cholangiopancreatography, is a characteristic feature of AIP; however, distinguishing between localized AIP and pancreatic cancer based on pancreatic duct imaging is difficult. This study overviews the efficacy of endoscopic ultrasound (EUS)-guided pancreatic sampling for the histopathological diagnosis of AIP. Recent enhancements in needle biopsy methodologies and technologies have contributed to improvement in the diagnostic efficacy of this technique. The guidance provided in this study for the histological diagnosis of AIP is anticipated to further advance in the histopathological diagnosis of AIP using EUS-guided pancreatic sampling.

Balloon enteroscopy-assisted endoscopic retrograde cholangiography (BEA-ERC) is useful and feasible in adults with pancreatobiliary diseases, but its efficacy and safety have not been established in pediatric patients. We compared the success rate and safety of BEA-ERC between adults and pediatric patients. This single-center retrospective study reviewed 348 patients (pediatric: 57, adult: 291) with surgically altered gastrointestinal anatomies who underwent BEA-ERC for biliary disorders from January 2007 to December 2019. The success rate of reaching the anastomosis or duodenal papilla was significantly lower in pediatric patients than in adult patients (66.7% vs. 88.0%, p < 0.01). The clinical success rate was also significantly lower in pediatric patients (64.9% vs. 80.4%, p = 0.014). The rate of adverse events was significantly higher in pediatric patients than in adults (14.2% vs. 7.7%, p = 0.037). However, if the anastomotic sites were reached in pediatric patients, the treatment was highly successful (97.3%). The time of reaching target site was significantly longer in pediatric patients than in adult patients. This study shows that BEA-ERC in pediatric patients is more difficult than that in adult patients. However, in patients where the balloon enteroscope was advanced to the anastomosis, clinical outcomes comparable to those in adults can be achieved.

The number of new cases of pancreatic ductal adenocarcinoma is increasing with a cumulative total of 495,773 cases worldwide, making it the fourteenth most common malignancy. However, it accounts for 466,003 deaths per year and is the seventh leading cause of cancer deaths. Regional differences in the number of patients with pancreatic ductal adenocarcinoma appear to reflect differences in medical care, as well as racial differences. Compared to the prevalence of other organ cancers in Japan, pancreatic ductal adenocarcinoma ranks seventh based on the number of patients, eighth based on morbidity, and fourth based on the number of deaths, with a continuing increase in the mortality rate. Risk factors for developing pancreatic ductal adenocarcinoma include family history, genetic disorders, diabetes, chronic pancreatitis, and intraductal papillary mucinous neoplasms. An issue that hinders improvement in the prognosis of patients with pancreatic ductal adenocarcinoma is the development of a strategy to identify patients with these risk factors to facilitate detection of the disease at a stage when intervention will improve survival.

Autoimmune pancreatitis (AIP) is characterized by enlargement of the pancreas and irregular narrowing of the main pancreatic duct. It is often associated with IgG4-related sclerosing cholangitis (IgG4-SC), in which the bile duct narrows. Although characteristic irregular narrowing of the pancreatic duct caused by endoscopic retrograde cholangiopancreatography is noted in AIP, it is difficult to differentiate between localized AIP and pancreatic carcinoma based on imaging of the pancreatic duct. While stenosis of the bile duct in IgG4-SC is characterized by longer-length stenosis than in cholangiocarcinoma, differentiation based on bile duct imaging alone is challenging. Endoscopic ultrasound (EUS) can characterize hypoechoic enlargement of the pancreas or bile duct wall thickening in AIP and IgG4-SC, and diagnosis using elastography and contrast-enhanced EUS are being evaluated. The utility of EUS-guided fine needle aspiration for the histological diagnosis of AIP has been reported and is expected to improve diagnostic performance for AIP. Findings in the bile duct wall from endoscopic retrograde cholangiopancreatography followed by intraductal ultrasonography are useful in differentiating IgG4-SC from cholangiocarcinoma. Diagnoses based on endoscopic ultrasonography play a central role in the diagnosis of AIP.

Background and study aims  Tumor seeding after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is rare. A 53-year-old man underwent transesophageal EUS-FNA for diagnosis of a 6-cm mass in the mediastinum as seen by computed tomography (CT). Four weeks later, repeat CT scan revealed a mass in the esophageal wall. Upper gastrointestinal endoscopy confirmed a lesion in the mid-esophagus, which was biopsied and found to be consistent with needle tract seeding after EUS-FNA. Tumor seeding in the gastrointestinal wall or peritoneum after EUS-FNA is rare, but may adversely affect the prognosis. Indications for EUS-FNA must be carefully considered.