Diagnosis of Biliary Strictures Using Probe-Based Confocal Laser Endomicroscopy under the Direct View of Peroral Cholangioscopy: Results of a Prospective Study (with Video)

Prospective assessment of probe-based confocal laser endomicroscopy under direct cholangioscopic visualization for biliary strictures that could not be definitively diagnosed using endoscopic retrograde cholangiopancreatography (with video)

The definitive diagnosis of patients with indeterminate biliary strictures remains challenging. Probe-based confocal laser endomicroscopy (pCLE) provides real-time histological assessment of bile duct tissues. Since no previous studies have evaluated the efficacy of pCLE under direct cholangioscopic visualization for biliary strictures that cannot be definitively diagnosed through endoscopic retrograde cholangiopancreatography using fluoroscopy, we prospectively assessed the feasibility and safety of this procedure in three cases. pCLE findings were obtained in three cases, providing accurate diagnoses. Additionally, no adverse event was reported. pCLE under direct cholangioscopic visualization for indeterminate biliary strictures might be feasible and safe, even though these strictures were not previously diagnosed using endoscopic retrograde cholangiopancreatography. Further studies with more cases are warranted to clarify the effectiveness of pCLE under direct cholangioscopic visualization.

Diagnostic accuracy of probe-based confocal laser endomicroscopy and tissue sampling by endoscopic retrograde cholangiopancreatography in indeterminate biliary strictures: a meta‑analysis

Probe-based confocal laser endomicroscopy (pCLE), also known as optical biopsy, is a new endoscopic technique that provides real-time magnification of 1000 × microscopic tissue information to diagnose indeterminate biliary strictures. Tissue sampling by endoscopic retrograde cholangiopancreatography (ERCP) is routinely performed to evaluate indeterminate biliary strictures. To evaluate the accuracy of pCLE and tissue sampling by ERCP in the diagnosis of indeterminate biliary strictures, 18 articles were included from 2008 to 2021 through Embase, PubMed, Web of Science, and Cochrane library databases. The summary estimates for the pCLE diagnosis of indeterminate biliary strictures were: sensitivity 0.88 (95% confidence interval (CI), 0.84-0.91); specificity 0.79 (95% CI 0.74-0.83); and Diagnostic Odds Ratio (DOR) 24.63 (95% CI 15.76-38.48). The summary estimates for tissue sampling by ERCP diagnosis for indeterminate biliary strictures were: sensitivity 0.54 (95% CI 0.49-0.59); specificity 0.96 (95% CI 0.94-0.98); and DOR 11.31 (95% CI 3.90-32.82). The area under the sROC curve of pCLE diagnosis of indeterminate biliary strictures is 0.90 higher than 0.65 of tissue sampling by ERCP. The pCLE is a better approach than tissue sampling by ERCP for the diagnosis of indeterminate biliary strictures by providing real-time microscopic images of the bile ducts.

Biliary Tree Diagnostics: Advances in Endoscopic Imaging and Tissue Sampling

The diagnostic approach to the biliary tree disorders can be challenging, especially for biliary strictures. Albeit the great diagnostic impact of endoscopic retrograde cholangiopancreatography (ERCP) which allows one to obtain fluoroscopic imaging and tissue sampling through brush cytology and/or forceps biopsy, a considerable proportion of cases remain indeterminate, leading to the risk of under/over treated patients. In the last two decades, several endoscopic techniques have been introduced in clinical practice, shrinking cases of uncertainties and improving diagnostic accuracy. The aim of this review is to discuss recent advances and emerging technologies applied to the management of biliary tree disorders through peroral endoscopy procedures.

Choledochoscopy: An update

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.

Current Status of Endoscopic Biliary Drainage in Patients with Distal Malignant Biliary Obstruction

Distal malignant biliary obstruction is caused by various malignant diseases that require biliary drainage. In patients with operable situations, preoperative biliary drainage is required to control jaundice and cholangitis until surgery. In view of tract seeding, endoscopic biliary drainage is the first choice. Since neoadjuvant therapies are being developed, the time to surgery is increasing, especially in pancreatic cancer cases. Therefore, it requires long stent patency. Recently, preoperative biliary drainage using self-expandable metal stents has been reported as a useful modality to secure long stent patency. In patients with unresectable distal malignant biliary obstruction, self-expandable metal stent is the first choice for maintaining long stent patency. Although there are many comparison studies between a covered and an uncovered self-expandable metal stent, their use is still controversial. Recently, endoscopic ultrasound-guided biliary drainage has been performed as an alternative treatment. The clinical success and stent patency are favorable. We should take into consideration that both endoscopic retrograde cholangiopancreatography-guided biliary drainage and endoscopic ultrasound-guided biliary drainage have advantages and disadvantages and chose the drainage method depending on the patient’s situation or the expertise of the endoscopist. Here, we discuss the current status of endoscopic biliary drainage in patients with distal malignant biliary obstruction.

Diagnostic Process Using Endoscopy for Biliary Strictures: A Narrative Review

The diagnostic process for biliary strictures remains challenging in some cases. A broad differential diagnosis exists for indeterminate biliary strictures, including benign or malignant lesions. The diagnosis of indeterminate biliary strictures requires a combination of physical examination, laboratory testing, imaging modalities, and endoscopic procedures. Despite the progress of less invasive imaging modalities such as transabdominal ultrasonography, computed tomography, and magnetic resonance imaging, endoscopy plays an essential role in the accurate diagnosis, including the histological diagnosis. Imaging findings and brush cytology and/or forceps biopsy under fluoroscopic guidance with endoscopic retrograde cholangiopancreatography (ERCP) are widely used as the gold standard for the diagnosis of biliary strictures. However, ERCP cannot provide an intraluminal view of the biliary lesion, and its outcomes are not satisfactory. Recently, peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound (EUS), and EUS-guided fine-needle aspiration have been reported as useful for indeterminate biliary strictures. Appropriate endoscopic modalities need to be selected according to the patient's condition, the lesion, and the expertise of the endoscopist. The aim of this review article is to discuss the diagnostic process for indeterminate biliary strictures using endoscopy.