UNASSIGNED: It is still a challenging problem for clinicians to explore the nature of the indeterminate biliary strictures (IBSs). Approximately 20% of biliary strictures remain undetermined after a thorough preoperative assessment.
UNASSIGNED: Here, we present two cases of indeterminate biliary strictures patients, whose cross- sectional imaging and endoscopic examination were nondiagnostic. The patients underwent exploratory laparotomy finally and were confirmed as malignancy. We also reviewed the recent reports in literatures regarding the evaluation of IBSs.
UNASSIGNED: Given the majority of the biliary strictures are malignancy, preoperative differentiation between benign and malignant is critical for choosing the best therapeutic regimen. Thus, close follow-up, multiple multidisciplinary discussion, and prompt surgical exploration are necessary for some difficult diagnostic cases.

UNASSIGNED: Conventional peroral methods to visualize biliary strictures are not feasible in some patients with altered anatomy or biliary obstruction, and percutaneous transhepatic cholangioscopy can be used as an alternative procedure. This study aimed to retrospectively review the use of percutaneous transhepatic cholangiography using the SpyGlass DS technology (S-PTCS) during a 5-year period at a Danish tertiary referral centre.
UNASSIGNED: All patients who underwent S-PTCS at a single Danish tertiary referral centre between 2016 and 2021 were retrospectively analyzed. The visual, technical, and overall success rates of S-PTCS were analyzed, as well as the complication rate. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of S-PTCS were calculated.
UNASSIGNED: Twenty-two patients were included in the study. Visual, technical, and overall success of S-PTCS was achieved in 17/22, 22/22, and 21/22 patients, respectively. S-PTCS yielded a sensitivity of 83.3%, a specificity of 100%, a PPV of 100%, a NPV of 94.1%, and an accuracy of 95.4%. Complications occurred in 1/22 patients.
UNASSIGNED: S-PTCS is a safe modality, with high success rates, high predictive values, and a low rate of complications. This study suggests that S-PTCS is an alternative to conventional methods in patients with indeterminate biliary strictures where conventional methods were unfeasible.

OBJECTIVE: Characterization of indeterminate biliary strictures (IDBS) still represents a major challenge. Digital single-operator cholangioscopy (DSOC) could potentially overcome limits of conventional biopsy and brush sampling. The aim of this study was to compare diagnostic accuracy of visual evaluation and DSOC-guided biopsies to conventional trans-papillary sampling techniques and to evaluate the inter-observer agreement (IOA) on visual diagnosis.
METHODS: All consecutive patients undergoing DSOC-guided biopsy after conventional sampling techniques for IDBS during a six-year period were retrospectively evaluated. Final diagnosis was based on histological evaluation of the surgical specimen if available or a clinical follow-up of at least 6 months. For IOA, 20-second DSOC clips were retrospectively reviewed by 6 experts and 6 trainees and classified according to the Monaco Classification.
RESULTS: Thirty-five patients underwent DSOC for IDBS in the study period; 14 patients (F = 9) with a median age of 64 years (range 53-76) met the study aim. After DSOC, strictures location was changed in three patients (additional yield of 21.4 %). Intraductal DSOC-guided biopsy were technically successful in all cases, with an adequacy of 92.8 %. No adverse events were recorded. Final diagnosis was benign disease in five cases and cholangiocarcinoma in the others. For IOA, 29 videos were evaluated with almost perfect agreement for final diagnosis (kappa 0.871; agreement 93.1, p <0.001), although overall accuracy of DSOC visual finding was 73.6 % and 64.4 % for experts and trainees, respectively.
CONCLUSIONS: DSOC could improve diagnostic accuracy for IDBS, since it showed high sensitivity for visual finding and high specificity for DSOC guided-biopsy. Visual diagnosis seems reliable for diagnosis using the Monaco Classification.

Despite advances in cross-sectional imaging and endoscopic technology, bile duct strictures remain a challenging clinical entity. It is crucial to make an early determination of benign or malignant nature of biliary strictures. Early diagnosis not only helps with further management but also minimizes mortality and morbidity associated with delayed diagnosis. Conventional imaging and endoscopic techniques, particularly endoscopic retrograde cholangiopancreatography (ERCP) and tissue sampling techniques play a key in establishing a diagnosis. Indeterminate biliary strictures (IDBSs) have no definite mass on imaging or absolute histopathological diagnosis and often warrant utilization of multiple diagnostics to ascertain an etiology. In this review, we discuss possible etiologies, clinical presentation, diagnosis, and management of IDBSs. Based on available data and expert opinion, we depict an evidence based diagnostic algorithm for management of IDBSs. Areas of focus include use of traditional tissue sampling techniques such as ERCP with brush cytology, intraductal biopsies, fluorescence in situ hybridization and flow cytometry. We also describe the role of endoscopic ultrasound (EUS)-guided fine needle aspiration and biopsies, cholangioscopy, confocal laser endomicroscopy, and intraductal EUS in management of IDBSs.

Peroral cholangioscopy (POC) is an endoscopic procedure that allows direct intraductal visualization of the biliary tract. POC has emerged as a vital tool for indeterminate biliary stricture evaluation and treatment of difficult biliary stones. Over several generations of devices, POC has fulfilled additional clinical needs where other diagnostic or therapeutic modalities have been inadequate. With adverse event rates comparable to standard endoscopic retrograde cholangioscopy and unique technical attributes, the role of POC is likely to continue expand. In this frontiers article, we highlight the existing and growing clinical applications of POC as well as areas of ongoing research.

Choledochoscopy, or cholangioscopy, is an endoscopic procedure for direct visualization within the biliary tract for diagnostic or therapeutic purposes. Since its conception in 1879, many variations and improvements are made to ensure relevance in diagnosing and managing a range of intrahepatic and extrahepatic biliary pathologies. This ranges from improved visual impression and optical guided biopsies of indeterminate biliary strictures and clinically indistinguishable pathologies to therapeutic uses in stone fragmentation and other ablative therapies. Furthermore, with the evolving understanding of biliary disorders, there are significant innovative ideas and techniques to fill this void, such as nuanced instances of biliary stenting and retrieving migrated ductal stents. With this in mind, we present a review of the current advancements in choledo-choscopy with new supporting evidence that further delineates the role of choledochoscopy in various diagnostic and therapeutic interventions, complications, limitations and put forth areas for further study.

Peroral cholangioscopy (POC) provides minimally invasive, direct endoscopic visualization of the biliary ductal system for both diagnostic and therapeutic purposes. POC has benefited from a number of technologic advances since its first introduction several decades ago. These advances have led to improved utility and expanded functionality, making POC an integral part of managing various bile duct diseases and disorders. Over time, the clinical role of POC has expanded. Novel applications and capabilities are being increasingly appreciated and developed. This article provides an overview of the current state of POC, with a particular focus on digital single-operator cholangioscopy and its strengths, limitations, advances, and emerging applications.

OBJECTIVE: Evaluation of indeterminate biliary strictures remains challenging due to limited sensitivity of endoscopic tissue sampling. Biliary probe-based confocal laser endomicroscopy (pCLE) has shown promise to detect and exclude neoplasia. However, knowledge of whether individual inflammatory criteria are more prevalent in neoplasia compared to benign strictures is limited. The objective of this work is to improve diagnosis of neoplastic and inflammatory conditions using pCLE.
METHODS: The charts of all patients who underwent pCLE at a single referral center between 2009 and 2015 were reviewed. ERCP reports were reviewed for eleven Miami and Paris criteria. Primary outcome was the identification of neoplasia by histopathology (defined as high-grade dysplasia and/or adenocarcinoma). To model predictors of neoplasia, we fit a binary regression model incorporating data from pCLE operating criteria, pCLE impression, and PSC status.
RESULTS: 97 patients were identified. In the 27 patients with neoplasia, there was increasing number of Miami malignant criteria (Pearson r = 0.512, p < .001) while inflammatory criteria were less prevalent. 10% (5/51, p < .001) of patients with benign pCLE impression developed neoplasia, while 48% (22/46, p < .001) with suspicious pCLE impressions developed neoplasia. The binary regression model to predict neoplasia had a sensitivity of 83.3%, specificity of 92.5%, and overall accuracy 89.7%.
CONCLUSIONS: Presence of malignant criteria and absence of certain inflammatory criteria are more prevalent in patients with neoplasia. Our model, which weights individual imaging components, shows impressive sensitivity and specificity over prior prognostic efforts. Prospective studies will be required to evaluate this model.

BACKGROUND: Digital single-operator cholangioscopes (digital SOCs), equipped with an improved image quality, have been recently introduced.
OBJECTIVE: The aim of this study is to evaluate the safety and diagnostic and therapeutic efficacy of digital SOCs (Spyglass™ DS).
METHODS: Sixty-seven digital SOC procedures performed between 2015 and 2017 were retrospectively analyzed.
RESULTS: The most frequent indications for examination were indeterminate biliary strictures (61.2%) and biliary stone disease (23.9%). In 25 patients (37.3), visual findings predicted malignancy with a sensitivity of 88.9%, a specificity of 97.6%, a positive predictive value (PPV) of 96.0% and a negative predictive value (NPV) of 92.9%. For histological analysis, forceps biopsies were performed in 29 patients (43.2%). Compared with visual findings, forceps biopsies yield a lower diagnostic efficacy in diagnosing malignancy (sensitivity 62.5%, specificity 90.0%, PPV 90.9%, NPV 60.0%). Therapeutic interventions were performed in 19 patients with a technical success rate of 89.4%. Adverse events were observed in 17 patients (25.4%). Of these, 11 patients (16.4%) suffered from severe adverse events (pancreatitis, cholangitis or major bleeding), which led to a prolonged hospital stay.
CONCLUSIONS: Digital SOCs have excellent diagnostic and therapeutic efficacies, but are accompanied by high rates of adverse events; therefore, physicians should use digital SOCs in carefully selected cases.

BACKGROUND: Pre-operative evaluation of biliary strictures remains challenging. The dilemma that exists is how to balance the risk of failing to detect malignancy and the potential morbidity caused by unnecessary surgery in patients with benign etiologies. With emerging novel diagnostic modalities, this study aims to assess the efficacy of diagnostic techniques and facilitate a clinical approach to indeterminate biliary strictures. Areas covered: Conventional imaging modalities are crucial in identifying the location of a stricture and are helpful for choosing further diagnostic modalities. Utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS), is key in establishing a diagnosis. The emergence of novel diagnostic modalities, such as fluorescence in-situ hybridization (FISH), peroral cholangioscopy (POC), intraductal endoscopic ultrasound (IDUS) and confocal laser endomicroscopy (CLE), enhance the diagnostic yield in the evaluation of indeterminate biliary strictures. Expert commentary: More reliable and validated visual criteria for differentiating malignancy from benign biliary conditions, utilizing advanced imaging modalities such as POC and CLE, need to be established. It is of significance to further evaluate these novel diagnostic modalities through ongoing trials and to develop a diagnostic algorithm that reconciles cost-effectiveness with diagnostic accuracy.