American Society for Gastrointestinal Endoscopy guideline on role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: methodology and review of evidence

Diagnostic Efficacy of a Novel Rotating Brush for Endoscopic Sampling of Malignant Biliary Strictures: A Multicenter Prospective Study

INTRODUCTION

Although cytologic examination of biliary stricture brushings obtained by endoscopic retrograde cholangiopancreatography is commonly used for diagnosing malignant biliary strictures (MBSs), it has low sensitivity. Several new brushes have capabilities that are still being debated. We have developed a novel brush working from conventional back-and-forth movement to rotation in situ (RIS) that may be more efficient for MBS sampling. We aimed to compare the MBS detection sensitivity of our RIS brush with that of the conventional brush.

METHODS

In this multicenter prospective study, we enrolled patients who underwent endoscopic retrograde cholangiopancreatography for suspected MBSs involving biliary stricture brushings obtained using our RIS brush. The historical control group consisted of the 30-brushing arm of our previous randomized trial (patient inclusion, 2018-2020) that used the study design in the same centers and with the same endoscopists as were used in this study. The primary outcome was to compare the sensitivity and specificity of detecting MBSs by cytologic evaluation of biliary stricture brushings between the 2 groups.

RESULTS

We enrolled 155 patients in the intent-to-treat analysis. Using the same number of brushing cycles, the RIS brush showed a higher sensitivity than the conventional brush (0.73 vs 0.56, P = 0.003). In per-protocol population, the sensitivity was also higher in the RIS brush group than in the conventional brush group (0.75 vs 0.57, P = 0.002). Multivariate analysis revealed that the RIS brush was the only predictive factor for MBS detection. No significant differences were observed in procedure-related complications between the 2 groups.

DISCUSSION

The RIS brush was a promising tool for effective and safe MBS sampling and diagnosis. Further randomized studies are warranted to confirm our results (Chictr.org.cn, identifier: ChiCTR2100047270).

Role of endoscopic-ultrasound-guided biliary drainage with electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction

In this editorial, we discuss the article by Peng et al in the recent issue of the World Journal of Gastrointestinal Surgery, focusing on the evolving role of endoscopic-ultrasound-guided biliary drainage (EUS-BD) with electrocautery lumen apposing metal stent (LAMS) for distal malignant biliary obstruction. Therapeutic endoscopy has rapidly advanced in decompression techniques, with growing evidence of its safety and efficacy surpassing percutaneous and surgical approaches. While endoscopic retrograde cholangiopancreatography (ERCP) has been the gold standard for biliary decompression, its failure rate approaches 10.0%, prompting the exploration of alternatives like EUS-BD. This random-effects meta-analysis demonstrated high technical and clinical success of over 90.0% and an adverse event rate of 17.5%, mainly in the form of stent dysfunction. Outcomes based on stent size were not reported but the majority used 6 mm and 8 mm stents. As the body of literature continues to demonstrate the effectiveness of this technique, the challenges of stent dysfunction need to be addressed in future studies. One strategy that has shown promise is placement of double-pigtail stents, only 18% received the prophylactic intervention in this study. We expect this to improve with time as the technique continues to be refined and standardized. The results above establish EUS-BD with LAMS as a reliable alternative after failed ERCP and considering EUS to ERCP upfront in the same session is an effective strategy. Given the promising results, studies must explore the role of EUS-BD as first-line therapy for biliary decompression.

Still elusive: Developments in the accurate diagnosis of indeterminate biliary strictures

Indeterminate biliary strictures pose a significant diagnostic dilemma for gastroenterologists. Despite advances in endoscopic techniques and instruments, it is difficult to differentiate between benign and malignant pathology. A positive histological diagnosis is always preferred prior to high risk hepatobiliary surgery, or to inform other types of therapy. Endoscopic retrograde cholangiopancreatography with brushings has low sensitivity and despite significant improvements in instruments there is still an unacceptably high false negative rate. Other methods such as endoscopic ultrasound and cholangioscopy have improved diagnostic quality. In this review we explore the techniques available to aid accurate diagnosis of indeterminate biliary strictures and obtain accurate histology to facilitate clinical management.

Contributions of endoscopic ultrasonography-guided tissue acquisition (EUS-TA) to the diagnostics of biliary stricture and gallbladder lesions

Endoscopic ultrasonography (EUS) provides high spatial resolution and more detailed images than other diagnostic modalities. Furthermore, EUS-guided tissue acquisition (EUS-TA), such as EUS-guided fine needle aspiration or biopsy (EUS-FNA/FNB), is an indispensable tool in pancreaticobiliary disease diagnostics, supporting a conclusive pathological diagnosis. In this review, we evaluate the current status and the usefulness of EUS-TA for the diagnostics of the following biliary tract diseases: (A) biliary stricture diagnostics, (B) biliary tract cancer (BTC) itself, and (C) staging of advanced BTC. Previous reports have shown that EUS-FNA for biliary lesions is a safe procedure that is useful in differentiating biliary cancer from benign lesions and in the staging of BTC. On the other hand, the diagnostic performance of EUS-TA for bile duct lesions is reported to be similar to that of transpapillary biopsy. Overall, EUS-TA for biliary lesions may be a safe and effective method, but it should be performed with an understanding of the risk of serious adverse events such as bile leakage and peritoneal dissemination of cancer. It is recommended for distal biliary stricture lesions for which endoscopic retrograde cholangiopancreatography cannot confirm the diagnosis or gallbladder lesions if they do not require the needle to pass through the biliary lumen.