Few studies have compared the diagnostic utility of endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) and endoscopic retrograde cholangiopancreatography (ERCP) tissue sampling for extrahepatic cholangiocarcinoma (ECC). We evaluated the efficacy and safety of EUS-FNA for diagnosing ECC compared with ERCP tissue sampling. Patients who underwent EUS-FNA or ERCP tissue sampling to differentiate ECC from benign biliary disease were enrolled retrospectively between October 2011 and March 2017. We evaluated diagnostic performances of EUS-FNA and ERCP tissue sampling based on pathological evaluation. We compared adverse events in EUS-FNA and ERCP tissue sampling. We enrolled 73 patients with biliary disease and performed EUS-FNA and ERCP in 19 and 54 patients, respectively. Sensitivity, specificity, and accuracy of ERCP tissue sampling were 76.0%, 100%, and 88.9%, respectively, and for EUS-FNA these were 81.8%, 87.5%, and 84.2%, respectively. Statistical values of ERCP tissue sampling and EUS-FNA were not significantly different. The adverse event frequency of EUS-FNA was significantly lower than that of ERCP tissue sampling (0% vs. 25.9%, p = 0.033). The diagnostic ability of EUS-FNA for ECC is similar to that of ERCP tissue sampling. EUS-FNA is a safer tissue sampling modality than ERCP for evaluating biliary disease.

Laser-based photodynamic endoscopic diagnosis (LPDED) is a type of endoscopic diagnosis that uses the fluorescence caused by the photochemical reaction that occurs when a fluorescent substance is irradiated by a light of a specific wavelength. Although 5-aminolevulinic acid (5-ALA) can detect early gastric cancer (EGC) during LPDED, there is an unresolved issue of the differences in fluorescence intensity among histopathological types of gastric cancer. Thus, the aim of the present study was to assess whether protoporphyrinogen oxidase (PPOX), involved in the activation of protoporphyrin IX, can affect the fluorescence intensity in EGC. Thirty-three gastric tumor lesions in 30 patients were assessed by LPDED using a prototype endoscope equipped with a blue laser ray to cause excitation following oral 5-ALA administration. The tumors were then resected by endoscopic submucosal dissection or laparoscopic surgery. PPOX expression was examined immunohistochemically in the excised specimens. To explore the mechanisms of histopathological diversity in PPOX and coproporphyrinogen oxidase (CPOX) expression of EGC, immunohistochemical analysis was performed using 75 surgically resected specimens of diverse EGCs. Among the 33 lesions, 26 tumors were detectable by LPDED, whereas seven were undetectable. Between the LPDED-positive and negative groups, there was a significant difference in histopathology. The expression of PPOX was higher in tubular adenocarcinoma (tub) than in signet-ring cell carcinoma (sig). There were significant differences in PPOX and CPOX expression scores of the surgically resected specimens among tub, poorly differentiated adenocarcinoma (por), and sig. PPOX protein expression could be involved in the fluorescence intensity of LPDED in EGC, possibly reflecting histopathological features.

Background/Aims: The Japan Gastroenterological Endoscopy Society (JGES) has published guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment. These guidelines classify endoscopic ultrasound-guided biliary drainage (EUS-BD) as a high-risk procedure. Nevertheless, the bleeding risk of EUS-BD in patients undergoing antithrombotic therapy is uncertain. Therefore, this study aimed to assess the bleeding risk in patients undergoing antithrombotic therapy.Methods: This single-center retrospective study included 220 consecutive patients who underwent EUS-BD between January 2013 and December 2018. We managed the withdrawal and continuation of antithrombotic agents according to the JGES guidelines. We compared the bleeding event rates among patients who received and those who did not receive antithrombotic agents.Results: A total of 18 patients (8.1%) received antithrombotic agents and 202 patients (91.8%) did not. Three patients experienced bleeding events, with an overall bleeding event rate of 1.3% (3/220): one patient was in the antithrombotic group (5.5%) and two patients were in the non-antithrombotic group (0.9%) (p=0.10). All cases were moderate. The sole thromboembolic event (0.4%) was a cerebral infarction in a patient in the non-antithrombotic group.Conclusions: The rate of EUS-BD-related bleeding events was low. Even in patients receiving antithrombotic therapy, the bleeding event rates were not significantly different from those in patients not receiving antithrombotic therapy.

Background: Peroral cholangioscopy (POCS) has become a widely-used technique in diagnosing indeterminate biliary strictures, enabling optical viewing of the biliary system and targeted biopsies under direct vision. The diagnostic utility of the new endoscopic scraper, Trefle^®, for extrahepatic cholangiocarcinoma (ECC) has also been reported. However, the diagnostic utility of POCS-guided and Trefle^®-assisted tissue acquisition for ECC has never been compared empirically. We evaluated the efficacy and safety of Trefle^®-assisted tissue acquisition for diagnosing ECC compared with POCS-guided tissue sampling. Methods: Patients who underwent Trefle^®-assisted tissue acquisition or POCS-guided forceps biopsy to differentiate ECC from benign biliary disease between April 2014 and March 2018 were enrolled retrospectively. We evaluated the diagnostic performance of Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy based on pathological evaluation. We also compared adverse events associated with Trefle^®-assisted tissue acquisition with those of POCS-guided forceps biopsy. Results: We enrolled 34 patients with biliary disease and performed Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy in 14 and 20 patients, respectively. Sensitivity, specificity, and accuracy of Trefle^®-assisted tissue acquisition were 87.5%, 83.3%, and 85.7%, respectively, and for POCS-guided forceps biopsy, these were 90.0% each. Statistical values of Trefle^®-assisted tissue acquisition and POCS-guided tissue acquisition were not significantly different. There were no significant differences in the occurrence of adverse events between the Trefle^®-assisted tissue acquisition and the POCS-guided forceps biopsy (35.7% vs. 25.0%, p = 0.770). Compared with patients who underwent POCS procedure, endoscopic sphincterotomy was performed for fewer patients who underwent Trefle^®-assisted tissue acquisition (p < 0.001). Conclusions: The diagnostic ability of Trefle^®-assisted tissue acquisition for ECC is similar to that of POCS-guided tissue acquisition. Trefle^®-assisted tissue acquisition might also help to preserve the sphincter of Oddi and its digestive function.

Peroral cholangioscopy (POCS) is believed to be effective in treating intrahepatic stones; however, reports on its efficacy are few. We reviewed the results of intrahepatic stones treated with fluoroscopic guidance or POCS. This study included 26 patients who underwent endoscopic treatment for intrahepatic stones at our institution between January 2017 and December 2021. We retrospectively evaluated the procedure time and adverse events in the first session and the rate of complete stone removal. Complete stone removal was achieved in 92% (24/26); POCS was required in 16 of 26 (62%) procedures and the complete stone removal was achieved in 15 of 16 (94%) of these procedures. The POCS group had a significantly longer procedure time than the fluoroscopy group. Cholangitis incidence was high; however, no difference was noted between patients with and without POCS, and all cases were mild and treated conservatively. Endoscopic treatment for intrahepatic stones may lead to an increase in the incidence of cholangitis, requires specialized devices such as a cholangioscope, and should be performed in an established institution by experienced staff. POCS is useful for intrahepatic stones formed upstream of the stenosis and intrahepatic stones piled in the bile duct.

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.