Therapeutic endoscopic ultrasonography (EUS) procedures using the forward-viewing convex EUS (FV-EUS) have been reviewed based on the articles reported to date. The earliest reported procedure is the drainage of pancreatic pseudocysts using FV-EUS. However, the study on drainage of pancreatic pseudocysts focused on showing that drainage is possible with FV-EUS rather than leveraging its features. Subsequently, studies describing the characteristics of FV-EUS have been reported. By using FV-EUS in EUS-guided choledochoduodenostomy, double punctures in the gastrointestinal tract can be avoided. In postoperative modified anatomical cases, using the endoscopic function of FV-EUS, procedures such as bile duct drainage from anastomosis, pancreatic duct drainage from the afferent limb, and abscess drainage from the digestive tract have been reported. When a perpendicular puncture to the gastrointestinal tract is required or when there is a need to insert the endoscope deep into the gastrointestinal tract, FV-EUS is considered among the options.

Background/Aims: Non-invasive tissue sampling from the lower intra-abdominal and pelvic cavity is challenging. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in this situation is not well-established because of the limitations of the curved linear-array echoendoscopy-EUS for colonic insertion. The aim of this study was to report our institutional experience of transcolonic EUS-FNA using forward-viewing therapeutic linear echoendoscopy-EUS (FV-EUS) in combination with fluoroscopic guidance. Methods: Medical records of 13 patients who underwent transcolonic EUS-FNA of extracolonic lesions using FV-EUS in combination with fluoroscopic guidance at Aichi Cancer Center Hospital, Nagoya, Japan from June 2015 to November 2018 were retrospectively reviewed. Results: Using FV-EUS under fluoroscopic guidance, the FNA procedure could be performed successfully in all patients (100% technical success), with a median procedure time of 31 minutes. The sensitivity, specificity, and accuracy of EUS-FNA for detecting malignant lesions in this study were 91%, 100%, and 92%, respectively. There were no adverse events associated with the EUS-FNA procedure. Conclusions FV-EUS in combination with fluoroscopic guidance is an easy, safe, and effective technique for FNA of extracolonic lesions in the lower abdomen.

Probe-based confocal laser endomicroscopy is an endoscopic technique that enables in vivo histological evaluation using fluorescent pigment. The ability to diagnostically differentiate between benign and malignant biliary disease using the “CholangioFlexTM”, a dedicated biliary device, has been reported. However, the Miami and Paris classifications, used as diagnostic criteria, mainly evaluate findings in the submucosa, and visualizing the epithelium as the main site of lesions remains difficult. To address this problem, we verified the imaging findings and diagnostic ability of three types of probes: CholangioFlexTM, GastroFlexTM, and AlveoFlexTM. With GastroFlexTM, the clear mucosal epithelium was observed, and differential diagnoses as benign/malignant could be made based on epithelial findings. GastroFlexTM may be a good first-choice probe for probe-based confocal laser endomicroscopy of biliary diseases, and a new diagnostic classification based on bile duct epithelial findings may provide useful criteria independent of the Miami or Paris classifications.

Chronic pancreatitis (CP) is pathologically characterized by the loss of exocrine pancreatic parenchyma, irregular fibrosis, cellular infiltration, and ductal abnormalities. Diagnosing CP objectively is difficult because standard diagnostic criteria are insufficient. The change of parenchymal hardness is the key factor for the diagnosis and understanding of the severity of CP. The ultrasonography (US) or endoscopic ultrasonography (EUS) elastography have been used to diagnose pancreatic diseases. Both strain elastography (SE) and shear wave elastography are specific diagnostic techniques for measuring tissue hardness. Most previous studies were conducted with SE. There are three methods of interpreting SE; the method of recognizing the patterns in SE distribution images in the region of interest, the method of using strain ratio to compare the hardness of adipose tissue or connective tissue with that of the lesion, and the method of evaluating the hardness distribution of a target by histogram analysis. These former two methods have been used primarily for neoplastic diseases, and histograms analysis has been used to assess hardness distribution in the evaluation of CP. Since the hardness of the pancreas increases with aging, it is necessary to consider the age in the diagnosis of pancreatic disorders using US or EUS elastography.

Background/Aims: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is essential for the diagnosis of pancreatic cancer. The feasibility of comprehensive genomic profiling (CGP) using samples obtained by EUS-TA has been under recent discussion. This study aimed to evaluate the utility of EUS-TA for CGP in a clinical setting. Methods: CGP was attempted in 178 samples obtained from 151 consecutive patients with pancreatic cancer at the Aichi Cancer Center between October 2019 and September 2021. We evaluated the adequacy of the samples for CGP and determined the factors associated with the adequacy of the samples obtained by EUS-TA retrospectively. Results: The overall adequacy for CGP was 65.2% (116/178), which was significantly different among the four sampling methods (EUS-TA vs. surgical specimen vs. percutaneous biopsy vs. duodenal biopsy, 56.0% [61/109] vs. 80.4% [41/51] vs. 76.5% [13/17] vs. 100.0% [1/1], respectively; p=0.022). In a univariate analysis, needle gauge/type was associated with adequacy (22 G fine-needle aspiration vs. 22 G fine-needle biopsy [FNB] vs. 19 G-FNB, 33.3% (5/15) vs. 53.5% (23/43) vs. 72.5% (29/40); p=0.022). The sample adequacy of 19 G-FNB for CGP was 72.5% (29/40), and there was no significant difference between 19 G-FNB and surgical specimens (p=0.375). Conclusions To obtain adequate samples for CGP with EUS-TA, 19 G-FNB was shown to be the best in clinical practice. However, 19 G-FNB was not still sufficient, so further efforts are required to improve adequacy for CGP.

Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS) is widely performed not only as an alternative to transpapillary biliary drainage, but also as primary drainage for malignant biliary obstruction. For anatomical reasons, this technique carries an unavoidable risk of mispuncturing intrahepatic vessels. We report a technique for troubleshooting EUS-guided portal vein coiling to prevent bleeding from the intrahepatic portal vein after mispuncture during interventional EUS. EUS-HGS was planned for a 59-year-old male patient with unresectable pancreatic cancer. The dilated bile duct (lumen diameter, 2.8 mm) was punctured with a 19-gauge needle, and a guidewire was inserted. After bougie dilation, the guidewire was found to be inside the intrahepatic portal vein. Embolizing coils were placed to prevent bleeding. Embolization coils were successfully inserted under stabilization of the catheter using a double-lumen cannula with a guidewire. Following these procedures, the patient was asymptomatic. Computed tomography performed the next day revealed no complications.

Background/Aims: Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common and serious complication of endoscopic retrograde cholangiopancreatography. To prevent this event, a unique precutting method, termed opening window fistulotomy, was performed in patients with a large infundibulum as the primary procedure for biliary cannulation, whereby a suprapapillary laid-down H-shaped incision was made without touching the orifice. This study aimed to assess the safety and feasibility of this novel technique. Methods: One hundred and ten patients were prospectively enrolled in this study. Patients with a papillary roof size ≥10 mm underwent opening window fistulotomy for primary biliary access. In addition, the incidence of complications and success rate of biliary cannulation were evaluated. Results: The median size of the papillary roof was 6 mm (range, 3–20 mm). Opening window fistulotomy was performed in 30 patients (27.3%), none of whom displayed PEP. Duodenal perforation was recorded in one patient (3.3%), which was resolved by conservative treatment. The cannulation rate was high (96.7%, 29/30 patients). The median duration of biliary access was 8 minutes (range, 3–15 minutes). Conclusions Opening window fistulotomy demonstrated its feasibility for primary biliary access by achieving great safety with no PEP complications and a high success rate for biliary cannulation.

Background/Aims: Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using oblique-view EUS in patients with a surgically altered anatomy (SAA) of the upper gastrointestinal tract is limited because of difficult scope insertion due to the disturbed anatomy. This study aimed to investigate the efficiency of forward-view (FV)-EUS in performing FNA in patients with a SAA. Methods: We retrospectively investigated 32 patients with a SAA of the upper gastrointestinal tract who visited Aichi Cancer Center Hospital in Nagoya, Japan, between January 2014 and December 2020. We performed-upper gastrointestinal EUS-FNA using FV-EUS combined with fluoroscopic imaging to confirm tumor recurrence or to make a decision before chemotherapy or after a failure of diagnosis by radiology. Results: We successfully performed EUS-FNA in all studied patients (100% technical success), with the specificity, sensitivity, and accuracy of 100%, 87.5%, and 87.8%, respectively, with no complications. Conclusions EUS-FNA using FV-EUS combined with fluoroscopic imaging is an effective and safe technique for tissue acquisition in patients with a SAA.

Benign biliary stricture (BBS) is a complication of chronic pancreatitis (CP). Despite endoscopic biliary stenting, some patients do not respond to treatment, and they experience recurrent cholangitis. We report two cases of CP with refractory BBS treated using endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) fistula creation. A 50-year-old woman and a 60-year-old man both presented with obstructive jaundice secondary to BBS due to alcoholic CP. They underwent repeated placement of a fully covered self-expandable metal stent for biliary strictures. However, the strictures persisted, causing repeated episodes of cholangitis. Therefore, an EUS-CDS was performed. The stents were eventually removed and the patients became stent-free. These fistulas have remained patent without cholangitis for more than 2.5 years. Fistula creation using EUS-CDS is an effective treatment option for BBS.

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) through ducts B2 or B3 is effective in most patients with biliary obstruction, because B2 and B3 commonly join together. However, in some patients, B2 and B3 do not join each other due to invasive hilar tumors; therefore, single-route drainage is insufficient. Here, we investigated the feasibility and efficacy of EUS-HGS through both B2 and B3 simultaneously in seven patients. We decided to perform EUS-HGS through both B2 and B3 to achieve adequate biliary drainage because these two ducts were separate from each other. Here, we report a 100% technical and overall clinical success rate. Early adverse effects were closely monitored. Minimal bleeding was reported in one patient (1/7) and mild peritonitis in one patient (1/7). None of the patients experienced stent dysfunction, fever, or bile leakage after the procedure. EUS-HGS through both B2 and B3 simultaneously is safe, feasible, and effective for biliary drainage in patients with separated ducts.