Diagnostic yield of EUS-guided FNA for malignant biliary stricture: a systematic review and meta-analysis

Endoscopic and novel approaches for evaluation of indeterminate biliary strictures

Indeterminate biliary strictures are defined as strictures which evade definitive diagnosis after endoscopic retrograde cholangiopancreatography (ERCP)-assisted sampling with brush cytology and/or forceps biopsy and pose significant clinical challenges. While most indeterminate biliary strictures are attributed to malignancies, up to one-third are benign strictures. False-negative and false-positive diagnoses lead to delayed or inappropriate treatment with untoward clinical consequences. Peroral cholangioscopy (POC) and single-operator cholangioscopy (SOC) have demonstrated superior diagnostic accuracy over traditional ERCP-based techniques through enhanced visualization and targeted biopsy. Endoscopic ultrasound (EUS)-guided tissue sampling also achieves superior sensitivity and diagnostic accuracy compared with ERCP-based tissue sampling. The 2025 ESGE guideline proposes an algorithm for optimizing the utilization of ERCP-based and EUS-guided tissue sampling and cholangioscopy with consideration of the stricture location. Furthermore, molecular diagnostic tools such as fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) enable the detection of chromosomal and genetic alterations commonly associated with biliary malignancies, thereby enhancing the sensitivity for malignancy. This review summarizes recent advances in the diagnostic work-up of indeterminate biliary strictures and emerging diagnostic strategies and modalities.

Diagnostic yields and clinical impact of endoscopic ultrasound-guided tissue acquisition for biliary lesions

BACKGROUND/PURPOSE

Diagnostic yields of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for biliary lesions have not been fully established due to limited evidence. We aimed to clarify the efficacy of EUS-TA for biliary lesions.

METHODS

Diagnostic yields and adverse event rates of EUS-TA for biliary lesions were evaluated. The subject cases were only limited to cases in which the biliary lesions itself was punctured. Diagnostic yields of endoscopic retrograde cholangiography (ERC)-guided biopsy/cytology performed within the same period were also evaluated to assess the additional effect of EUS-TA.

RESULTS

EUS-TA was attempted in 71 cases (28 hilar bile duct, 19 distal bile duct, 4 ampulla of Vater, and 20 gallbladder), and the final diagnosis was malignant in 54 cases (76.1%). The sensitivity, specificity, and accuracy of EUS-TA were 96.3% (52/54), 100% (17/17), and 97.2% (69/71), respectively. Adverse events were observed in one case (1.4%, peritonitis). The accuracy of ERC biopsy/cytology was 82.5% (212/257 cases); additional EUS-TA diagnosed 30 cases as malignant additionally and improved the accuracy (94.2%; 242/257 cases; p < .01).

CONCLUSIONS

EUS-TA is an accurate and safe diagnostic test for biliary lesions. The addition of EUS-TA may be considered when there is a suspicion of a false-negative ERC result.

EASL Clinical Practice Guidelines on the management of extrahepatic cholangiocarcinoma

Recent years have witnessed significant advances in the imaging, molecular profiling, and systemic treatment of cholangiocarcinoma (CCA). Despite this progress, the early detection, precise classification, and effective management of CCA remain challenging. Owing to recent developments and the significant differences in CCA subtypes, EASL commissioned a panel of experts to draft evidence-based recommendations on the management of extrahepatic CCA, comprising distal and perihilar CCA. Particular attention is given to the need for accurate classification systems, the integration of emerging molecular insights, and practical strategies for diagnosis and treatment that reflect real-world clinical scenarios.

Endoscopic diagnosis of immunoglobulin G4-related sclerosing cholangitis

Immunoglobulin G4 (IgG4)-related sclerosing cholangitis (IgG4-SC) is a distinct form of sclerosing cholangitis frequently associated with autoimmune pancreatitis and is recognized as a biliary manifestation of IgG4-related disease. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) are key diagnostic modalities for IgG4-SC. Cholangiocarcinoma and primary sclerosing cholangitis (PSC) are significant mimickers of IgG4-SC. ERCP is employed to evaluate narrowing of the bile duct, with cholangiograms of IgG4-SC classified into four types. This cholangiographic classification is crucial for differential diagnosis. Characteristic cholangiographic findings of IgG4-SC include diffuse or segmental strictures of the intrahepatic or extrahepatic bile ducts and intrahepatic strictures associated with autoimmune pancreatitis. ERCP is particularly useful for differentiating IgG4-SC from PSC because their cholangiographic features differ. EUS and intraductal ultrasonography (IDUS) are used to assess thickening of the bile duct wall. Characteristic IDUS findings in IgG4-SC include circular and symmetrical wall thickening, smooth outer and inner margins, and homogeneous internal echoes at stricture sites. Additionally, bile duct wall thickening at nonstricture sites is a typical IDUS feature of IgG4-SC. Bile duct biopsy is used to evaluate pathological findings, although its diagnostic yield for IgG4-SC is limited; its primary role is to exclude malignant biliary strictures. Duodenal papilla biopsy serves as a supplementary diagnostic tool for IgG4-SC. EUS and tissue acquisition also aid in diagnosing autoimmune pancreatitis as part of other organ involvement. Thus, endoscopic techniques play critical roles in the diagnosis of IgG4-SC.

Diagnostic work-up of bile duct strictures: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends the combination of endoscopic ultrasound-guided tissue acquisition (EUS-TA) and endoscopic retrograde cholangiopancreatography (ERCP)-based tissue acquisition as the preferred diagnostic approach for tissue acquisition in patients with jaundice and distal extrahepatic biliary stricture in the absence of a pancreatic mass. 2: ESGE suggests that brushing cytology should be completed along with fluoroscopy-guided biopsies, wherever technically feasible, in patients with perihilar biliary strictures. 3: ESGE suggests EUS-TA for perihilar strictures when ERCP-based modalities yield insufficient results, provided that curative resection is not feasible and/or when cross-sectional imaging has shown accessible extraluminal disease. 4: ESGE suggests using standard ERCP diagnostic modalities at index ERCP. In the case of indeterminate biliary strictures, ESGE suggests cholangioscopy-guided biopsies, in addition to standard ERCP diagnostic modalities. Additional intraductal biliary imaging modalities can be selectively used, based on clinical context, local expertise, and resource availability.

Diagnostic Approach to Biliary Strictures

Biliary strictures represent a narrowing of the bile ducts, leading to obstruction that may result from benign or malignant etiologies. Accurate diagnosis is crucial but challenging due to overlapping features between benign and malignant strictures. This review presents a comprehensive diagnostic approach that integrates biochemical markers, imaging modalities, and advanced endoscopic techniques to distinguish between these causes. Imaging tools such as ultrasound, MRI/MRCP, and CECT are commonly used, each with distinct advantages and limitations. Furthermore, endoscopic procedures such as ERCP and EUS are key in tissue acquisition, enhancing diagnostic accuracy, especially for indeterminate or complex strictures. Recent innovations, including artificial intelligence and new endoscopic techniques, hold promise in enhancing precision and reducing diagnostic challenges. This review emphasizes a multidisciplinary strategy to improve diagnostic pathways, ensuring timely management for patients with biliary strictures.

The past, present, and future of endoscopic management for biliary strictures: technological innovations and stent advancements

Biliary stricture can be induced by intrinsic narrowing and extrinsic compression, with the majority of cases being malignant. Clinically, distinguishing between benign and malignant biliary strictures remains a considerable challenge, and the ongoing disagreement over the optimal choice of biliary stents significantly influences treatment strategies and impacts patients' survival and prognosis. The utilization and advancement of endoscopic techniques have heightened the diagnostic sensitivity for biliary strictures. Concurrently, innovative technologies such as endoscopic ultrasound and magnetic compression anastomosis emerge as viable alternatives when endoscopic retrograde cholangiopancreatography (ERCP) is not an option, providing fresh insights for the clinical management of these patients. Traditional plastic and metal stents, characterized by their complex application and limited scope, have been unable to fully satisfy clinical needs. The introduction of novel stent varieties has notably improved this scenario, marking a considerable progression towards precision medicine. However, the clinical validation of the diverse stent materials available is incomplete. Hence, a thorough discussion on the present state and evolving trends of biliary stents is warranted.

Diagnostic efficacy of cytologic smear and pathologic histology in the differential diagnosis of distal biliary stricture via EUS-guided fine-needle aspiration

Background and Objectives

Distal biliary strictures (DBSs) can be caused by various malignancies, making accurate and early diagnosis crucial. Histopathology is the gold standard for diagnosis, with several methods available for tissue sampling. This study evaluates the performance of EUS-guided fine-needle aspiration (EUS-FNA) cytologic smears and histopathology in diagnosing suspected malignant DBSs.

Methods

A retrospective cohort study was conducted on patients who underwent EUS-FNA between January 2017 and January 2023 for DBSs. Demographic, imaging, procedural, and clinical data were collected. The diagnostic performance of EUS-FNA cytology, histology, and their combination was assessed in terms of sensitivity, specificity, positive predictive value, and negative predictive value. Subgroup analyses were conducted based on imaging and endoscopy characteristics.

Results

EUS-FNA for cytology had a sensitivity of 69.1% and specificity of 97.5%. EUS-FNA histology had a sensitivity of 76.4% and specificity of 99.1%. There was no difference in diagnostic efficacy between the two above (P > 0.05). Combining cytology and histology improved sensitivity to 82%. When 20 cases (6.8%) with histological slide failures were considered as negative, histologic sensitivity was 69.1%, completely consistent with cytology alone (P = 1). The presence of a mass shadow on computed tomography or magnetic resonance imaging was associated with higher cytologic diagnostic sensitivity compared with simple stenosis without a mass shadow (57.4% vs. 75.9%, P = 0.011). The larger the mass, the higher the cytologic diagnostic sensitivity. The radiologist's diagnostic imaging tendencies, that is, malignant, benign, and indeterminate, also affected cytologic diagnostic sensitivity (78.2% vs. 63.9% vs. 51.9%, P = 0.002). Furthermore, among our cohort of 118 patients diagnosed with benign DBSs, a notable subset of 33 individuals (28%) received a diagnosis of IgG4-related disease.

Conclusion

EUS-FNA histology combined with cytology was a reliable diagnostic method. There is no difference in diagnostic efficacy between EUS-FNA cytology and histology, irrespective of considering instances of histological slide failure. The presence of a mass shadow on computed tomography or magnetic resonance imaging and the size of the mass influenced the diagnostic efficacy of cytology. Additionally, IgG4-related diseases, accounting for a significant proportion of cases, were important in the differential diagnosis of these strictures.

Endoscopic Ultrasound and Intraductal Ultrasound in the Diagnosis of Biliary Tract Diseases: A Narrative Review

Endoscopic ultrasound (EUS) and intraductal ultrasound (IDUS) play very important roles in the field of biliary tract disease. Because of their excellent spatial resolution, the detection of small lesions and T- or N-staging of tumors have become possible. Additionally, contrast-enhanced EUS and the new imaging technique of detective flow imaging are reported to be useful for differential diagnosis. Furthermore, EUS-guided tissue acquisition is used not only for pathological diagnosis but also to collect tissue samples for cancer genome profiling. This review provides an overview of diagnosis utilizing the features and techniques of EUS and IDUS.

Performance evaluation of endoscopic ultrasonography needles: Experimental study

Background and study aims The relative procedural performance of needles for endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is unclear. The present study therefore compared six types of 22-gauge FNA/B needles using a bench simulator. Methods Resistance forces during needle puncture and removal, needle tip damage before and after procedure, leakage after puncture of mucinous cyst models, the shape of the puncture surface at the puncture site, amounts of samples extracted, ranges of needle deflection angles, and needle deformation after multiple procedures were compared using six types of needles. Results Maximum resistance forces during puncture and removal were highest for ProCore needles and lowest for Expect needles. None of the needles had damage after puncturing. SharkCore needles showed the highest amount of leakage, whereas FNA needles showed no leakage. The puncture tracts of FNA needles remained in the form of a flap at the puncture site, whereas FNB needles broke off the target material creating a hole. The target material removed was supplemented within the puncture needle. TopGain needles produced significantly larger samples than ProCore, EZShot3 Plus, and Expect needles. FNB needles produced larger and more core samples than FNA needles. EZShot3 Plus needles had the highest range of needle deflection angle using an elevator device and the lowest needle deformation after 20 punctures at full endoscopic angle and a full elevator. Conclusions The performance of the six needles differed in various ways. Understanding the characteristics of each needle may allow for selection of the appropriate needle for each situation.

Utility of Transpapillary Biopsy and Endoscopic Ultrasound-Guided Tissue Acquisition for Comprehensive Genome Profiling of Unresectable Biliary Tract Cancer

Tissue sampling in biliary tract cancer (BTC) is generally performed through transpapillary biopsy (TPB) or endoscopic ultrasound-guided tissue acquisition (EUS-TA). For the first time, we compared the suitability of specimens obtained using TPB and EUS-TA to determine the optimal tissue-sampling method for comprehensive genome profiling (CGP) analysis in patients with unresectable BTC (UR-BTC). Pathology precheck criteria for CGP analysis comprised the OncoGuide NCC Oncopanel System (NCCOP) and FoundationOne CDx (F1CDx). Seventy-eight patients with UR-BTC (35 TPB and 43 EUS-TA) were included. The NCCOP analysis suitability achievement rate was higher in EUS-TA specimens than in TPB specimens (34.9% vs. 8.6%, p = 0.007), whereas that of F1CDx was 0% in both groups. EUS-TA was identified as an independent factor that contributed to the suitability of the NCCOP analysis. The suitability of the NCCOP analysis of EUS-TA specimens showed a tendency to be higher for mass lesions (43.8% vs. 9.1%, p = 0.065), especially for target size ≥ 18.5 mm, and lower for perihilar cholangiocarcinoma (0% vs. 41.7%, p = 0.077). In TPB, papillary-type lesions (66.7% vs. 3.2%, p = 0.016) and peroral cholangioscopy-assisted biopsies (50.0% vs. 3.3%, p = 0.029) showed better potential for successful NCCOP analysis. EUS-TA is suitable for NCCOP analysis in UR-BTC and may be partially complemented by TPB.

Biliary fibrosis is an important but neglected pathological feature in hepatobiliary disorders: from molecular mechanisms to clinical implications

Fibrosis resulting from pathological repair secondary to recurrent or persistent tissue damage often leads to organ failure and mortality. Biliary fibrosis is a crucial but easily neglected pathological feature in hepatobiliary disorders, which may promote the development and progression of benign and malignant biliary diseases through pathological healing mechanisms secondary to biliary tract injuries. Elucidating the etiology and pathogenesis of biliary fibrosis is beneficial to the prevention and treatment of biliary diseases. In this review, we emphasized the importance of biliary fibrosis in cholangiopathies and summarized the clinical manifestations, epidemiology, and aberrant cellular composition involving the biliary ductules, cholangiocytes, immune system, fibroblasts, and the microbiome. We also focused on pivotal signaling pathways and offered insights into ongoing clinical trials and proposing a strategic approach for managing biliary fibrosis-related cholangiopathies. This review will offer a comprehensive perspective on biliary fibrosis and provide an important reference for future mechanism research and innovative therapy to prevent or reverse fibrosis.

Consensus statements on endoscopic ultrasound-guided tissue acquisition. Guidelines from the Asian Endoscopic Ultrasound Group

OBJECTIVES

This consensus was developed by the Asian EUS Group (AEG), who aimed to formulate a set of practice guidelines addressing various aspects of endoscopic ultrasound-guided tissue acquisition (EUS-TA).

METHODS

The AEG initiated the development of consensus statements and formed an expert panel comprising surgeons, gastroenterologists, and pathologists. Three online consensus meetings were conducted to consolidate the statements and votes. The statements were presented and discussed in the first two consensus meetings and revised according to comments. Final voting was conducted at a third consensus meeting. The Grading of Recommendations, Assessment, Development, and Evaluation system was adopted to define the strength of the recommendations and quality of evidence.

RESULTS

A total of 20 clinical questions and statements regarding EUS-TA were formulated. The committee recommended that fine-needle biopsy (FNB) needles be preferred over conventional fine-needle aspiration (FNA) needles for EUS-TA of subepithelial lesions. For solid pancreatic masses, rapid on-site evaluation is not routinely recommended when FNB needles are used. For dedicated FNB needles, fork-tip and Franseen-tip needles have essentially equivalent performance.

CONCLUSION

This consensus provides guidance for EUS-TA, thereby enhancing the quality of EUS-TA.

The additional value of the combined use of EUS and ERCP for the evaluation of unclear biliary strictures

OBJECTIVE

Assessing unclear biliary strictures is challenging. We analyzed the diagnostic performance of radiology, EUS, and ERCP.

METHODS

All patients referred for EUS and ERCP to assess an unclear biliary stricture were prospectively included. The data from radiology, EUS, ERCP, and tissue sampling were recorded. The diagnostic modalities were analyzed separately and in combination, with a focus on PSC.

RESULTS

Between 2013 and 2020, 78 patients were included; 31% had PSC. A cholangioscopy was not performed in this study. The final diagnosis indicated that the biliary stricture was benign in 62% of the patients and malignant in 38%. The differences among the modalities were numerical, not significant. The modalities showed an accuracy between 78 and 83% in all the patients and between 75 and 83% in the patients with PSC. The combination of radiology and EUS showed the highest sensitivity of 94% in all the patients and a sensitivity of 100% in PSC. Tissue sampling showed the highest specificity of 93% in all patients and 89% in PSC. In 22 cases with combined EUS, ERCP, and tissue sampling, the accuracy, sensitivity, and specificity were 82%, 70%, and 92%, respectively. Minor differences were observed between the intention-to-diagnose analysis and the per-protocol analysis. Adverse events were recorded in 4% of cases.

CONCLUSION

The combination of EUS and ERCP with tissue sampling seems to be useful and safe for excluding malignancy in unclear biliary strictures. In cases with a reduced suspicion of malignancy, radiology with an EUS may be sufficient.

A machine learning-based predictive model for biliary stricture attributable to malignant tumors: a dual-center retrospective study

Background

Biliary stricture caused by malignant tumors is known as Malignant Biliary Stricture (MBS). MBS is challenging to differentiate clinically, and accurate diagnosis is crucial for patient prognosis and treatment. This study aims to identify the risk factors for malignancy in all patients diagnosed with biliary stricture by Endoscopic Retrograde Cholangiopancreatography (ERCP), and to develop an effective clinical predictive model to enhance diagnostic outcomes.

Methodology

Through a retrospective study, data from 398 patients diagnosed with biliary stricture using ERCP between January 2019 and January 2023 at two institutions: the First People's Hospital affiliated with Jiangsu University and the Second People's Hospital affiliated with Soochow University. The study began with a preliminary screening of risk factors using univariate regression. Lasso regression was then applied for feature selection. The dataset was divided into a training set and a validation set in an 8:2 ratio. We analyzed the selected features using seven machine learning algorithms. The best model was selected based on the Area Under the Receiver Operating Characteristic (ROC) Curve (AUROC) and other evaluation indicators. We further evaluated the model's accuracy using calibration curves and confusion matrices. Additionally, we used the SHAP method for interpretability and visualization of the model's predictions.

Results

RF model is the best model, achieved an AUROC of 0.988. Shap result indicate that age, stricture location, stricture length, carbohydrate antigen 199 (CA199), total bilirubin (TBil), alkaline phosphatase (ALP), (Direct Bilirubin) DBil/TBil, and CA199/C-Reactive Protein (CRP) were risk factors for MBS, and the CRP is a protective factor.

Conclusion

The model's effectiveness and stability were confirmed, accurately identifying high-risk patients to guide clinical decisions and improve patient prognosis.

Endoscopic evaluation of indeterminate biliary strictures: Cholangioscopy, endoscopic ultrasound, or both?

Accurate and timely diagnosis of biliary strictures can be challenging. Because the diagnostic sensitivity and accuracy of standard endoscopic retrograde cholangiopancreatography-based tissue sampling for malignancy are suboptimal, additional endoscopic evaluation by cholangioscopy and/or endoscopic ultrasound (EUS) is often necessary to differentiate between malignant and benign biliary strictures to guide clinical management. While direct visualization by cholangioscopy and/or high-resolution imaging by EUS are often the first step in the evaluation of an indeterminate biliary stricture (IDBS), tissue diagnosis by cholangioscopy-guided biopsy and/or EUS-guided fine-needle tissue acquisition is the preferred modality to establish a diagnosis of malignancy. Because each modality has its own strengths and limitations, selection of cholangioscopy and EUS is best guided by the biliary stricture location and local expertise. Artificial intelligence-assisted diagnosis, biopsy forceps with improved design, contrast-enhanced EUS, and dedicated fine-needle biopsy devices are recent technological advances that may further improve the diagnostic performance of cholangioscopy and EUS in patients with IDBS.

Pancreaticobiliary Cytology Practice in 2021: Results of a College of American Pathologists Survey

CONTEXT.—

The College of American Pathologists (CAP) surveys provide national benchmarks of pathology practice.

OBJECTIVE.—

To investigate pancreaticobiliary cytology practice in domestic and international laboratories in 2021.

DESIGN.—

We analyzed data from the CAP Pancreaticobiliary Cytology Practice Supplemental Questionnaire that was distributed to laboratories participating in the 2021 CAP Nongynecologic Cytopathology Education Program.

RESULTS.—

Ninety-three percent (567 of 612) of respondent laboratories routinely evaluated pancreaticobiliary cytology specimens. Biliary brushing (85%) was the most common pancreaticobiliary cytology specimen evaluated, followed by pancreatic fine-needle aspiration (79%). The most used sampling methods reported by 235 laboratories were 22-gauge needle for fine-needle aspiration (62%) and SharkCore needle for fine-needle biopsy (27%). Cell block was the most used slide preparation method (76%), followed by liquid-based cytology (59%) for pancreatic cystic lesions. Up to 95% (303 of 320) of laboratories performed rapid on-site evaluation (ROSE) on pancreatic solid lesions, while 56% (180 of 320) performed ROSE for cystic lesions. Thirty-six percent (193 of 530) of laboratories used the Papanicolaou Society of Cytopathology System for Reporting Pancreaticobiliary Cytology in 2021. Among all institution types, significant differences in specimen volume, specimen type, ROSE practice, and case sign-out were identified. Additionally, significant differences in specimen type, slide preparation, and ROSE practice were found.

CONCLUSIONS.—

This is the first survey from the CAP to investigate pancreaticobiliary cytology practice. The findings reveal significant differences among institution types and between domestic and international laboratories. These data provide a baseline for future studies in a variety of practice settings.

Clinical utility of endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling of patients with biliary tract cancer, especially with intrahepatic cholangiocarcinoma

BACKGROUND/AIMS

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is a standard diagnostic method for biliary tract cancer (BTC), and samples obtained in this manner may be used for comprehensive genomic profiling (CGP). This study evaluated the utility of EUS-TA for CGP in a clinical setting and determined the factors associated with the adequacy of CGP in patients with BTC.

METHODS

CGP was attempted for 105 samples from 94 patients with BTC at the Aichi Cancer Center, Japan, from October 2019 to April 2022.

RESULTS

Overall, 77.1% (81/105) of the samples were adequate for CGP. For 22-G or 19-G fine-needle biopsy (FNB), the sample adequacy was 85.7% (36/42), which was similar to that of surgical specimens (94%, p=0.45). Univariate analysis revealed that 22-G or larger FNB needle usage (86%, p=0.003), the target primary lesions (88%, p=0.015), a target size ≥30 mm (100%, p=0.0013), and number of punctures (90%, p=0.016) were significantly positively associated with CGP sample adequacy.

CONCLUSIONS

EUS-TA is useful for CGP tissue sampling in patients with BTC. In particular, the use of 22-G or larger FNB needles may allow for specimen adequacy comparable to that of surgical specimens.

Combining brushing cytology with simultaneous vacuum aspiration in suspicious biliopancreatic malignancies: A multicenter propensity score-matched study (with video)

BACKGROUND

Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is a standard approach in diagnosing biliopancreatic strictures, with yet unsatisfying sensitivity.

AIMS

We brought additional simultaneous vacuum aspiration to brushing process and re-evaluate the diagnostic performance.

METHODS

This multi-centered retrospective study was conducted in three tertiary centers. Consecutive patients with biliopancreatic strictures were identified. The patients were divided into two arms: the conventional arm (CA) receiving general brushing approach, and the modified arm (MA) being treated with additional vacuum aspiration when performing bushing. The 1:1 propensity-score matching was implemented to tackle the selective biases.

RESULTS

A total of 555 patients were identified and 200 patient pairs (193 males, 207 females, with a mean age of 68.1 ± 13.1 years.) fell into the ultimate evaluation. A final diagnosis of malignant stricture was established in 243 patients. The diagnostic yield of the MA group was substantially better than that of the CA group, whether "suspicious malignancies" were considered malignancies or not. The rates of sensitivity, specificity and accuracy were 46.2%, 100%, 68.0% in the MA group, and 15.3%, 98.7%, and 47.0% in the CA group respectively.

CONCLUSIONS

Brushing accompanied by simultaneous vacuum aspiration at ERCP improves the diagnostic yield in suspicious biliopancreatic malignancies.

Case report: The diagnostic dilemma of indeterminate biliary strictures: report on two cases with a literature review

Background

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.

Case presentation

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.

Conclusions

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.

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma

A consensus meeting of national experts from all major national hepatobiliary centres in the country was held on May 26, 2023, at the Pakistan Kidney and Liver Institute & Research Centre (PKLI & RC) after initial consultations with the experts. The Pakistan Society for the Study of Liver Diseases (PSSLD) and PKLI & RC jointly organised this meeting. This effort was based on a comprehensive literature review to establish national practice guidelines for hilar cholangiocarcinoma (hCCA). The consensus was that hCCA is a complex disease and requires a multidisciplinary team approach to best manage these patients. This coordinated effort can minimise delays and give patients a chance for curative treatment and effective palliation. The diagnostic and staging workup includes high-quality computed tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography. Brush cytology or biopsy utilizing endoscopic retrograde cholangiopancreatography is a mainstay for diagnosis. However, histopathologic confirmation is not always required before resection. Endoscopic ultrasound with fine needle aspiration of regional lymph nodes and positron emission tomography scan are valuable adjuncts for staging. The only curative treatment is the surgical resection of the biliary tree based on the Bismuth-Corlette classification. Selected patients with unresectable hCCA can be considered for liver transplantation. Adjuvant chemotherapy should be offered to patients with a high risk of recurrence. The use of preoperative biliary drainage and the need for portal vein embolisation should be based on local multidisciplinary discussions. Patients with acute cholangitis can be drained with endoscopic or percutaneous biliary drainage. Palliative chemotherapy with cisplatin and gemcitabine has shown improved survival in patients with irresectable and recurrent hCCA.

The Role of Cholangioscopy in Biliary Diseases

Endoscopy plays a central role in diagnostic and therapeutic approaches to biliary disease in both benign and malignant conditions. A cholangioscope is an endoscopic instrument that allows for the direct exploration of the biliary tree. Over the years, technology has improved endoscopic image quality and allowed for the development of an operative procedure that can be performed during cholangioscopy. Different types of instruments are available in this context, and they can be used in different anatomical access points according to the most appropriate clinical indication. The direct visualization of biliary mucosa is essential in the presence of biliary strictures of unknown significance, allowing for the appropriate allocation of patients to surgery or conservative treatments. Cholangioscopy has demonstrated excellent performance in discriminating malignant conditions (such as colangiocarcinoma) from benign inflammatory strictures, and more recent advances (e.g., artificial intelligence and confocal laser endomicroscopy) could further increase its diagnostic accuracy. Cholangioscopy also plays a primary role in the treatment of benign conditions such as difficult bile stones (DBSs). In this case, it may not be possible to achieve complete biliary drainage using standard ERCP. Therapeutic cholangioscopy-guided lithotripsy allows for stone fragmentation and complete biliary drainage. Indeed, other complex clinical situations, such as patients with intra-hepatic lithiasis and patients with an altered anatomy, could benefit from the therapeutic role of cholangioscopy. The aim of the present review is to explore the most recent diagnostic and therapeutic advances in the roles of cholangioscopy in the management of biliary diseases.

A real-time interpretable artificial intelligence model for the cholangioscopic diagnosis of malignant biliary stricture (with videos)

BACKGROUND AND AIMS

It is crucial to accurately determine malignant biliary strictures (MBSs) for early curative treatment. This study aimed to develop a real-time interpretable artificial intelligence (AI) system to predict MBSs under digital single-operator cholangioscopy (DSOC).

METHODS

A novel interpretable AI system called MBSDeiT was developed consisting of 2 models to identify qualified images and then predict MBSs in real time. The overall efficiency of MBSDeiT was validated at the image level on internal, external, and prospective testing data sets and subgroup analyses, and at the video level on the prospective data sets; these findings were compared with those of the endoscopists. The association between AI predictions and endoscopic features was evaluated to increase the interpretability.

RESULTS

MBSDeiT can first automatically select qualified DSOC images with an area under the curve (AUC) of .963 and .968 to .973 on the internal testing data set and the external testing data sets, and then identify MBSs with an AUC of .971 on the internal testing data set, an AUC of .978 to .999 on the external testing data sets, and an AUC of .976 on the prospective testing data set, respectively. MBSDeiT accurately identified 92.3% of MBSs in prospective testing videos. Subgroup analyses confirmed the stability and robustness of MBSDeiT. The AI system achieved superior performance to that of expert and novice endoscopists. The AI predictions were significantly associated with 4 endoscopic features (nodular mass, friability, raised intraductal lesion, and abnormal vessels; P < .05) under DSOC, which is consistent with the endoscopists' predictions.

CONCLUSIONS

The study findings suggest that MBSDeiT could be a promising approach for the accurate diagnosis of MBSs under DSOC.

Endoscopic Ultrasound in the Diagnosis of Extrahepatic Cholangiocarcinoma: What Do We Know in 2023?

Extrahepatic cholangiocarcinoma (CCA) is a rare and aggressive type of cancer, presenting as a mass or as a biliary stricture. This review summarizes the utility of endoscopic ultrasound (EUS) in the detection, staging, and determination of the differential diagnosis, especially when no cause of bile duct dilatation is revealed by cross-sectional imaging. The EUS detection rate for distal CCAs is higher than that for the proximal CCAs. The accuracy of T staging varies between 60 and 80%, and vascular involvement is correctly assessed by conventional EUS. EUS-tissue acquisition from the primary tumors is reserved for unresectable or metastatic CCA, especially in distal strictures or mass CCAs. For proximal lesions, EUS could be performed as an adjunctive to ERCP sampling when the latter is inconclusive. EUS is not appropriate for assessing the malignant features of lymph nodes in CCAs. Lymph node EUS-tissue acquisition should be performed only if it changes the surgical decision. Perhaps the development of EUS-fine needle biopsy and the detection of molecular genetic alteration will increase the diagnostic yield in CCAs.

ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures

A biliary stricture is an abnormal narrowing in the ductal drainage system of the liver that can result in clinically and physiologically relevant obstruction to the flow of bile. The most common and ominous etiology is malignancy, underscoring the importance of a high index of suspicion in the evaluation of this condition. The goals of care in patients with a biliary stricture are confirming or excluding malignancy (diagnosis) and reestablishing flow of bile to the duodenum (drainage); the approach to diagnosis and drainage varies according to anatomic location (extrahepatic vs perihilar). For extrahepatic strictures, endoscopic ultrasound-guided tissue acquisition is highly accurate and has become the diagnostic mainstay. In contrast, the diagnosis of perihilar strictures remains a challenge. Similarly, the drainage of extrahepatic strictures tends to be more straightforward and safer and less controversial than that of perihilar strictures. Recent evidence has provided some clarity in multiple important areas pertaining to biliary strictures, whereas several remaining controversies require additional research. The goal of this guideline is to provide practicing clinicians with the most evidence-based guidance on the approach to patients with extrahepatic and perihilar strictures, focusing on diagnosis and drainage.

Advanced endoscopy meets molecular diagnosis of cholangiocarcinoma

Cholangiocarcinoma remains an aggressive and deadly malignancy that is often diagnosed late. Intrinsic tumour characteristics and the growth pattern of cancer cells contribute to the challenges of diagnosis and chemoresistance. However, establishing an early and accurate diagnosis, and in some instances identifying targetable changes, has the potential to impact survival. Primary sclerosing cholangitis, a chronic cholangiopathy prodromal to the development of a minority of cholangiocarcinomas, poses a particular diagnostic challenge. We present our diagnostic and theranostic approach to the initial evaluation of cholangiocarcinomas, focusing on extrahepatic cholangiocarcinoma. This involves a multipronged strategy incorporating advanced imaging, endoscopic methods, multiple approaches to tissue sampling, and molecular markers. We also provide an algorithm for the sequential use of these tools.

Identification of patients with malignant biliary strictures using a cholangioscopy-based deep learning artificial intelligence (with video)

BACKGROUND AND AIMS

Accurately diagnosing malignant biliary strictures (MBSs) as benign or malignant remains challenging. It has been suggested that direct visualization and interpretation of cholangioscopy images provide greater accuracy for stricture classification than current sampling techniques (ie, brush cytology and forceps biopsy sampling) using ERCP. We aimed to develop a convolutional neural network (CNN) model capable of accurate stricture classification and real-time evaluation based solely on cholangioscopy image analysis.

METHODS

Consecutive patients with cholangioscopy examinations from 2012 to 2021 were reviewed. A CNN was developed and tested using cholangioscopy images with direct expert annotations. The CNN was then applied to a multicenter, reserved test set of cholangioscopy videos. CNN performance was then directly compared with that of ERCP sampling techniques. Occlusion block heatmap analyses were used to evaluate and rank cholangioscopy features associated with MBSs.

RESULTS

One hundred fifty-four patients with available cholangioscopy examinations were included in the study. The final image database comprised 2,388,439 still images. The CNN demonstrated good performance when tasked with mimicking expert annotations of high-quality malignant images (area under the receiver-operating characteristic curve, .941). Overall accuracy of CNN-based video analysis (.906) was significantly greater than that of brush cytology (.625, P = .04) or forceps biopsy sampling (.609, P = .03). Occlusion block heatmap analysis demonstrated that the most frequent image feature for an MBS was the presence of frond-like mucosa/papillary projections.

CONCLUSIONS

This study demonstrates that a CNN developed using cholangioscopy data alone has greater accuracy for biliary stricture classification than traditional ERCP-based sampling techniques.

The role of endoscopic ultrasound-guided fine-needle aspiration/biopsy in the diagnosis of mediastinal lesions

Objective

Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB) is an accurate technique for sampling the pancreas and mediastinum. The aim of this study was to determine the value of EUS-FNA/FNB in the diagnosis of mediastinal lesions.

Methods

Data from 107 patients who underwent EUS-FNA/FNB for mediastinal lesions were evaluated.

Results

The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNA/FNB for mediastinal lesions were 92.00%, 100%, 100%, and 85%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNA for malignant mediastinal lesions were 92.00%, 100%, 100%, and 86.00%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNB for malignant mediastinal lesions were 92.00%, 100%, 100%, and 82.00%, respectively. Except for the discomfort caused by conventional gastroscopy, none of the patients had any complications, such as damage to surrounding large blood vessels or nerves.

Conclusion

EUS-FNA/FNB is an effective tool for diagnosing unknown mediastinal lesions, without any obvious complications.

An overview of extrahepatic cholangiocarcinoma: from here to where?

Extrahepatic cholangiocarcinoma (eCCA) contains perihilar cholangiocarcinoma and distal cholangiocarcinoma both of which can arise at any point of the biliary tree and originate from disparate anatomical sites. Generally, the incidence of eCCA is increasing globally. Though surgical resection is the principal treatment of choice for the early stages of eCCA, optimal survival remains restricted by the high risk of recurrence when most patients are present with unresectable disease or distant metastasis. Furthermore, both intra- and intertumoral heterogeneity make it laborious to determine molecularly targeted therapies. In this review, we mainly focused on current findings in the field of eCCA, mostly including epidemiology, genomic abnormalities, molecular pathogenesis, tumor microenvironment, and other details while a summary of the biological mechanisms driving eCCA may shed light on intricate tumorigenesis and feasible treatment strategies.

Current endoscopic approaches to biliary strictures

PURPOSE OF REVIEW

To summarize the current status and future perspectives of the endoscopic management of biliary strictures.

RECENT FINDINGS

In addition to conventional diagnostic modalities, such as cross-sectional imaging and endoscopic ultrasonography (EUS), per-oral cholangioscopy is helpful for indeterminate biliary strictures. It allows direct visualization of the biliary tract and targeted biopsy. For distal malignant biliary obstruction (MBO), a self-expandable metal stent (SEMS) via endoscopic retrograde cholangiopancreatography (ERCP) is a standard of care. EUS-guided biliary drainage (EUS-BD) is an emerging alternative to percutaneous transhepatic biliary drainage in cases with failed ERCP. EUS-BD is also an effective salvage option for perihilar MBO, which can not be managed via ERCP or percutaneous transhepatic biliary drainage. Preoperative drainage is necessary for most jaundiced patients as neoadjuvant chemotherapy is widely administered for resectable and borderline resectable pancreatic cancer, and a SEMS is preferred in this setting, too. For benign biliary strictures, a covered SEMS can improve stricture resolution and reduce the number of endoscopic sessions as compared to plastic stents.

SUMMARY

ERCP and EUS play a central role in the diagnosis and drainage for both malignant and benign biliary strictures.

Implementing precision medicine in endoscopy practice

In contrast to the "one-size-fits-all" approach, precision medicine focuses on providing health care tailored to individual variabilities. Implementing precision medicine in endoscopy practice involves selecting the appropriate procedures among the endoscopic armamentarium in the diagnosis and management of patients in a logical sequence, jointly considering the pretest probabilities of possible diagnoses, patients' comorbidities and preference, and risk-benefit ratio of the individual procedures given the clinical scenario. The aim of this review is to summarize evidence-supported strategies and measures that may enhance precision medicine in general endoscopy practice.

Future of Cholangioscopy

This article highlights the current status of cholangioscopy. In addition, the authors present their view on the future directions of cholangioscopy, including novel clinical applications, the need for technologic developments, and the expansion on the use of cholangioscopy in clinical practice. The authors envision that cholangioscopy will eventually become a conventional tool in the shelf of any biliary endoscopist. Future technologic improvements including optics, maneuverability, and full device accessories, plus the introduction of real-time artificial intelligence algorithms, will optimize the outcomes of cholangioscopy, but baseline proficiency in therapeutic endoscopic retrograde cholangiopancreatography will remain necessary for its successful utilization.

Brush Cytology, Forceps Biopsy, or Endoscopic Ultrasound-Guided Sampling for Diagnosis of Bile Duct Cancer: A Meta-Analysis

Endoscopic sampling is essential for tissue diagnosis of cholangiocarcinoma (CCA). To evaluate and compare the diagnostic sensitivities of endoscopic retrograde cholangiopancreatography-guided brush cytology biopsy, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with CCA. A comprehensive literature search through multiple databases was conducted for articles published between January 1995 and August 2020. The pooled rates of sensitivity for the diagnosis of CCA and of adverse events were compared among brushing, biopsy, brushing & biopsy, and EUS-FNA. In total, 1123 patients with CCA (32 studies), 719 patients (20 studies), 358 patients (13 studies), and 422 patients (17 studies) were tested by brushing, biopsy, brushing & biopsy, and EUS-FNA, respectively. The pooled diagnostic sensitivity was 56.0% (95% confidence interval (CI) 48.8-63.1%, I2 = 83.0%) with brushing, 67.0% (95% CI 60.2-73.5%, I2 = 72.5%) with biopsy, 70.7% (95% CI 64.1-76.8%, I2 = 42.7%) with brushing & biopsy, and 73.6% (95% CI 64.7-81.5%, I2 = 74.7%) with EUS-FNA. The diagnostic sensitivity was significantly lower for brushing than for biopsy, brushing & biopsy, or EUS-FNA. No significant difference was noted in diagnostic sensitivities among biopsy, brushing & biopsy, and EUS-FNA. Adverse events were comparable between the groups. Intraductal biopsy, brushing & biopsy, and EUS-FNA had comparable efficacy and safety for the diagnosis of CCA. Brushing was the least sensitive diagnostic tool compared with intraductal biopsy or EUS-FNA. Given the modest diagnostic sensitivities of intraductal biopsy and EUS-FNA in the diagnosis of CCA, further studies for complementing these techniques with biomarkers may be needed.

The Role of Cholangioscopy and EUS in the Evaluation of Indeterminate Biliary Strictures

Bile duct stenosis continues to present a diagnostic dilemma for clinicians. It is important to establish the benign or malignant nature of the stricture early in order to avoid any unnecessary delay in medical treatment or surgery. Tissue acquisition for histological diagnosis is particularly crucial when the initial diagnostic work up is inconclusive. The diagnostic yield from the conventional endoscopic retrograde cholangiopancreatography (ERCP) with brushing and biopsy is suboptimal. Patients with indeterminate biliary strictures (IDBSs) often require a multi-disciplinary diagnostic approach and additional endoscopic evaluation, including cholangioscopy and endoscopic ultrasound, before a final diagnosis can be reached. In this article, we discuss the recent endoscopic advancements in the diagnosis of biliary stricture with a focus on the roles of cholangioscopy and endoscopic ultrasound (EUS).

A new tool for bile duct tissue sampling: ex vivo clinical evaluation of intraductal cryobiopsy for cholangioscopy

Background and study aims  Indeterminate biliary strictures represent a major challenge in clinical diagnostics. Diagnostic yield of radiological, endoscopic imaging and histopathological diagnosis is insufficient. The cryobiopsy technique is a new method for tissue extraction already used in different clinical settings. The aim of this ex vivo clinical study was to investigate feasibility and tissue quality of cryobiopsy in the bile duct. Patients and methods  We included 14 patients who underwent pancreaticoduodenectomy. Bile duct samples were taken with either a new prototype cryoprobe or one of two forceps types. Results were analyzed for general feasibility, specimen size, histological assessability as well as representativity of retrieved tissue. Results  Feasibility of cholangioscopic forceps was poor compared to gastric biopsy forceps or cryobiopsy. Significantly larger tissue samples were obtained with cryobiopsy (5.6 ± 4.5 mm ² ) compared to gastric biopsy forceps (3.3 ± 5.1 mm ² , P  = 0.006). Furthermore, cryobiopsy was superior in histological assessment quality ( P  = 0.02) and concerning representativity ( P  = 0.03). Conclusions  Cryobiopsy in the bile duct is feasible and the quality of the obtained tissue is high. Further investigation of bile duct cryobiopsy in vivo is warranted.

Promising Genomic Testing for Biliary Tract Cancer Using Endoscopic Ultrasound-Guided Fine-Needle Aspiration/Biopsy Specimens

The undesired prognosis of biliary tract cancer is mainly attributed to the difficult detection of cancer lesions, including intraepithelial neoplasia and no standard examination for screening. In addition, pathological diagnosis of biliary stricture, whether it is malignant or benign, is not so easy, because of difficult optimal sampling by forceps biopsy and brush cytology, although various devices and methods for pathological diagnosis have been reported. Furthermore, we have to be careful about post-endoscopic retrograde cholangiography pancreatitis when we approach the biliary tract lesion via a transpapillary route. In order to improve the diagnostic accuracy, there have been several studies that indicate the feasibility and efficacy of genomic analysis for accurate diagnosis of biliary tract cancer by using pathological specimens, including endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB) samples. For efficient and precision medicine for patients with biliary tract cancer, future diagnosis and treatment should also be based on molecular and genetic analyses. In this article, we review and summarize the past knowledge and cutting edge of genomic testing for biliary tract cancer, using EUS-FNA/FNB specimens, and indicate some ingenuities in sample processing to promote effective clinical practice and future perspectives.

Digital Cholangioscopic Interpretation: When North Meets the South

BACKGROUND

Digital single-operator cholangioscopy (DSOC) (SpyGlass DS™, Boston Scientific, MA, USA) allows for high-definition imaging of the biliary tree. The superior visualization has led to the development of two different sets of criteria to evaluate and classify indeterminate biliary strictures: the Monaco criteria and the criteria in Carlos Robles-Medranda's publication (CRM). Our objective was to assess the interrater agreement (IA) of DSOC interpretation for indeterminate biliary strictures using the two newly published criteria.

METHODS

Forty de-identified DSOC video recordings were sent to 15 interventional endoscopists with experience in cholangioscopy. They were asked to score the videos based on the presence of Monaco Classification criteria: stricture, lesion, mucosal changes, papillary projections, ulceration, white linear bands or rings, and vessels. Next, they scored the videos using CRM criteria: villous pattern, polypoid pattern, inflammatory pattern, flat pattern, ulcerate pattern and honeycomb pattern. The endoscopists then diagnosed the recordings as neoplastic or non-neoplastic based on the criteria. Intraclass correlation (ICC) analysis was done to evaluate interrater agreement for both criteria set and final diagnosis.

RESULTS

Recordings of 26 malignant lesions and 14 benign lesions were scored. The IA using both the Monaco criteria and CRM criteria ranged from poor to excellent (range 0.1-0.76) and (range 0.1-0.62), respectively. Within the Monaco criteria, IA was excellent for lesion (0.75) and fingerlike papillary projections (0.74); good for tortuous vessels (0.7), mucosal features (0.62), uniform papillary projections (0.53), and ulceration (0.58); and fair for white linear bands (0.4). Within the CRM criteria, the IA was good for villous pattern (0.62), flat pattern (0.62), and honeycomb pattern; fair for ulcerated pattern (0.56), polypoid pattern (0.52) and inflammatory pattern (0.54). The diagnostic IA using Monaco criteria was good (0.65), while the diagnostic IA using CRM was fair (0.58). The overall diagnostic accuracy using the Monaco classification was 61% and CRM criteria were 57%.

CONCLUSION

The IOA and accuracy rate of DSOC using visual criteria from both Monaco Criteria and CRM are similar. However, some criteria from both sets suffer from poor IA, thus affecting the overall diagnostic accuracy. More formal training and refinements in visual criteria with additional validation are needed to improve diagnostic accuracy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02166099.

Endoscopic Ultrasound Plus Endoscopic Retrograde Cholangiopancreatography Based Tissue Sampling for Diagnosis of Proximal and Distal Biliary Stenosis Due to Cholangiocarcinoma: Results from a Retrospective Single-Center Study

Simple Summary

The diagnosis of cholangiocarcinoma depends on several factors, including growth pattern and location. Previous studies have evaluated the diagnostic accuracy of endoscopic retrograde cholangiopancreatography based tissue sampling and endoscopic ultrasound with either fine-needle aspiration or fine-needle biopsy, reporting values < 80% for each procedure. Here, we describe the performance of both methods in a group of patients with a stricture of the biliary tract suspicious for cholangiocarcinoma. Our analysis confirms the high diagnostic accuracy of the procedures when performed together in distinguishing between a primary malignant or benign biliary stenosis.

Abstract

Differentiating between benign and malignant biliary stenosis (BS) is challenging, where tissue diagnosis plays a crucial role. Endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling and endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) or biopsy (FNB) are used to obtain tissue specimens from BS. The aim of this retrospective study was to evaluate the diagnostic yield of EUS-FNA/B plus ERCP with brushing or forceps biopsy in BS. All endoscopic procedures performed in patients with BS at our gastroenterology unit were reviewed. The gold standard for diagnosis was histopathology of surgical specimens or the progression of the malignancy at radiological or clinical follow-up. A total of 70 endoscopic procedures were performed in 51 patients with BS. Final endoscopic diagnosis was reached in 96% of the patients and was malignant in 61.7% and benign in 38.3% of cases. Sensitivity, specificity, and diagnostic accuracy were 73.9%, 100%, and 80%, respectively, for EUS-FNA/B; 66.7%, 100%, and 82.5% for ERCP; and 83.3%, 100%, and 87.5% for both procedures carried out in the same session. The combination of EUS and ERCP tissue sampling seems to increase diagnostic accuracy in defining the etiology of BS. Performing both procedures in a single session reduces the time required for diagnostic work-up and optimizes resources.

Systematic review and meta-analysis of percutaneous transluminal forceps biopsy for diagnosing malignant biliary strictures

OBJECTIVES

To perform a systematic review and meta-analysis to determine the diagnostic performance of percutaneous transluminal forceps biopsy (PTFB) for differentiating malignant from benign biliary stricture.

METHODS

A comprehensive literature search of the PubMed, EMBASE, and Ovid MEDLINE databases was conducted to identify original articles published between January 2001 and January 2021 reporting the diagnostic accuracy of PTFB. A random-effects model was used to summarize the diagnostic odds ratio and other measures of accuracy.

RESULTS

Fourteen studies involving 1762 patients met the inclusion criteria and were included in the meta-analysis. The meta-analysis summary estimates of PTFB for diagnosis of malignant biliary strictures were as follows: sensitivity 81% (95% confidence interval [CI], 78-81%); specificity 100% (95% CI, 98-100%); diagnostic odds ratio 85.34 (95% CI, 38.37-189.81). The area under the curve of PTFB was 0.948 in the diagnosis of malignant biliary strictures. The diagnostic sensitivity was higher in intrinsic (85%) than in extrinsic (73%) biliary strictures. The pooled rate of all complications was 10.3% (95% CI, 7.0-14.2%), including a major complication rate of 3.1%.

CONCLUSION

These data demonstrate that PTFB is sensitive and highly specific for diagnosing malignancy in biliary strictures. PTFB should be incorporated into future guidelines for tissue sampling in biliary cancer, especially in cases with failed endoscopic management.

KEY POINTS

• PTFB had a good overall diagnostic performance for differentiating malignant from benign biliary strictures, with a meta-analysis summary estimate of 81% for sensitivity and 100% for specificity. • PTFB had higher sensitivity for cholangiocarcinoma (85%) than for other cancers (73%). • PTFB had a 100% technical success rate and a 10.3% rate for complications, including a 3.1% rate for major complications.

The Role Of Cytology In The Investigation And Management Of Pancreatobiliary Lesions With A Transition Towards A Standardised Reporting System: An Institutional Perspective

Pancreatobiliary pathology encompasses all benign and malignant disease within the pancreas and biliary tract; pancreatic cancer is currently the seventh leading cause of death worldwide accounting for approximately 466,000 deaths per annum. Cytology has been increasingly used in the physician's toolbox to provide an accurate, non-invasive and cost-effective modality for the diagnosis of pancreatobiliary lesions. The cytological appearance alone may be insufficient to establish the diagnosis and it is crucial for effective clinicopathological correlation in a multidisciplinary setting highlighting, the vital role of the pathologist to ensure effective and quality care. The advent of modern diagnostic techniques has allowed for a less invasive approach to tissue sampling which when combined with routine staining and specialised immunohistochemistry can help guide the diagnosis. The Papanicolaou Classification is comparable to the current C1-C5 system which will enable standardised reporting to help to improve communication with clinical colleagues and subsequent patient management and our article will discuss the criteria used by cytopathologists to determine the grade of both pancreatic and biliary lesions.

Endoscopic Ultrasound for the Diagnosis and Staging of Biliary Malignancy

Cholangiocarcinoma (CCA) is the most common neoplasm of the biliary tract. The biological behavior and prognosis of CCA vary depending on the tumor's location in the biliary tree, dictating a different diagnostic, and treatment approach. Establishing a diagnosis of CCA remains a challenge and up to 20% of biliary strictures can yield indeterminate results, despite extensive evaluation. Endoscopic ultrasound (EUS) has become an effective diagnostic tool, as it provides high-quality images of the bile duct and allows for the sampling of strictures in the same plane of view. In this chapter, we explore the utility of EUS as a diagnostic and staging tool for biliary cancers.

Improving Diagnostic Yield in Indeterminate Biliary Strictures

Indeterminate biliary strictures are defined as a narrowing of the bile duct that cannot be differentiated as malignant or benign after performing cross-sectional imaging and an ERCP. Identifying the etiology of a bile duct stricture is the single most important step in determining whether a complex and potentially morbid surgical resection is warranted. Due to this diagnostic and therapeutic dilemma, new technologies, laboratory tests, and procedures are emerging to solve this problem.

Endoscopic tissue sampling - Part 1: Upper gastrointestinal and hepatopancreatobiliary tracts. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that, where there is a suspicion of eosinophilic esophagitis, at least six biopsies should be taken, two to four biopsies from the distal esophagus and two to four biopsies from the proximal esophagus, targeting areas with endoscopic mucosal abnormalities. Distal and proximal biopsies should be placed in separate containers.Strong recommendation, low quality of evidence. 2: ESGE recommends obtaining six biopsies, including from the base and edge of the esophageal ulcers, for histologic analysis in patients with suspected viral esophagitis.Strong recommendation, low quality of evidence. 3: ESGE recommends at least six biopsies are taken in cases of suspected advanced esophageal cancer and suspected advanced gastric cancer.Strong recommendation, moderate quality of evidence. 4: ESGE recommends taking only one to two targeted biopsies for lesions in the esophagus or stomach that are potentially amenable to endoscopic resection (Paris classification 0-I, 0-II) in order to confirm the diagnosis and not compromise subsequent endoscopic resection.Strong recommendation, low quality of evidence. 5: ESGE recommends obtaining two biopsies from the antrum and two from the corpus in patients with suspected Helicobacter pylori infection and for gastritis staging.Strong recommendation, low quality of evidence. 6: ESGE recommends biopsies from or, if endoscopically resectable, resection of gastric adenomas.Strong recommendation, moderate quality of evidence. 7: ESGE recommends fine-needle aspiration (FNA) and fine-needle biopsy (FNB) needles equally for sampling of solid pancreatic masses.Strong recommendation, high quality evidence. 8: ESGE suggests performing peroral cholangioscopy (POC) and/or endoscopic ultrasound (EUS)-guided tissue acquisition in indeterminate biliary strictures. For proximal and intrinsic strictures, POC is preferred. For distal and extrinsic strictures, EUS-guided sampling is preferred, with POC where this is not diagnostic.Weak recommendation, low quality evidence. 9: ESGE suggests obtaining possible non-neoplastic biopsies before sampling suspected malignant lesions to prevent intraluminal spread of malignant disease.Weak recommendation, low quality of evidence. 10: ESGE suggests dividing EUS-FNA material into smears (two per pass) and liquid-based cytology (LBC), or the whole of the EUS-FNA material can be processed as LBC, depending on local experience.Weak recommendation, low quality evidence.

Role of Endoscopic Ultrasound in Liver Disease: Where Do We Stand?

As the burden of liver disease in the general populace steadily increases, so does the need for both advanced diagnostic and treatment options. Endoscopic ultrasound is a reliable diagnostic and therapeutic method that has an established role, foremost in pancreatobiliary pathology. This paper aims to summarize the growing role of endoscopic ultrasound in hepatology based on the search of the current literature. A number of applications of endoscopic ultrasound are reviewed, including both noninvasive methods and tissue acquisition in focal and diffuse liver disease, portal hypertension measurement, detection and management of gastric and esophageal varices, treatment of focal liver lesions and staging of pancreatobiliary malignancies, treatment of cystic and solid liver lesions, as well as liver abscess drainage. Both hepatologists and endoscopists should be aware of the evolving role of endoscopic ultrasound in liver disease. The inherent invasive nature of endoscopic examination limits its use to a targeted population identified using noninvasive methods. Endoscopic ultrasound is one the most versatile methods in gastroenterology, allowing immediate access with detection, sampling, and treatment of digestive tract pathology. Further expansion of its use in hepatology is immanent.

Biliary Strictures and Cholangiocarcinoma - Untangling a Diagnostic Conundrum

Cholangiocarcinoma is an uncommon and highly aggressive biliary tract malignancy with few manifestations until late disease stages. Diagnosis is currently achieved through a combination of clinical, biochemical, radiological and histological techniques. A number of reported cancer biomarkers have the potential to be incorporated into diagnostic pathways, but all lack sufficient sensitivity and specificity limiting their possible use in screening and early diagnosis. The limitations of standard serum markers such as CA19-9, CA125 and CEA have driven researchers to identify multiple novel biomarkers, yet their clinical translation has been slow with a general requirement for further validation in larger patient cohorts. We review recent advances in the diagnostic pathway for suspected CCA as well as emerging diagnostic biomarkers for early detection, with a particular focus on non-invasive approaches.

Tips and tricks for the diagnosis and management of biliary stenosis-state of the art review

Biliary stenosis may represent a diagnostic and therapeutic challenge resulting in a delay in diagnosis and initiation of therapy due to the frequent difficulty in distinguishing a benign from a malignant stricture. In such cases, the diagnostic flowchart includes the sequential execution of imaging techniques, such as magnetic resonance, magnetic resonance cholangiopancreatography, and endoscopic ultrasound, while endoscopic retrograde cholangiopancreatography is performed to collect tissue for histopathological/cytological diagnosis or to treat the stenosis by insertion of stent. The execution of percutaneous transhepatic drainage with subsequent biopsy has been shown to increase the possibility of tissue diagnosis after failure of the above techniques. Although the diagnostic yield of histopathology and imaging has increased with improvements in endoscopic ultrasound and peroral cholangioscopy, differential diagnosis between malignant and benign stenosis may not be easy in some patients, and strictures are classified as indeterminate. In these cases, a multidisciplinary workup including biochemical marker assays and advanced technologies available may speed up a diagnosis of malignancy or avoid unnecessary surgery in the event of a benign stricture. Here, we review recent advancements in the diagnosis and management of biliary strictures and describe tips and tricks to increase diagnostic yields in clinical routine.