Clinical utility of EUS before cholangioscopy in the evaluation of difficult biliary strictures

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.

Impact on follow-up strategies in patients with primary sclerosing cholangitis

BACKGROUND & AIMS

Evidence for the benefit of scheduled imaging for early detection of hepatobiliary malignancies in primary sclerosing cholangitis (PSC) is limited. We aimed to compare different follow-up strategies in PSC with the hypothesis that regular imaging improves survival.

METHODS

We collected retrospective data from 2975 PSC patients from 27 centres. Patients were followed from the start of scheduled imaging or in case of clinical follow-up from 1 January 2000, until death or last clinical follow-up alive. The primary endpoint was all-cause mortality.

RESULTS

A broad variety of different follow-up strategies were reported. All except one centre used regular imaging, ultrasound (US) and/or magnetic resonance imaging (MRI). Two centres used scheduled endoscopic retrograde cholangiopancreatography (ERCP) in addition to imaging for surveillance purposes. The overall HR (CI95%) for death, adjusted for sex, age and start year of follow-up, was 0.61 (0.47-0.80) for scheduled imaging with and without ERCP; 0.64 (0.48-0.86) for US/MRI and 0.53 (0.37-0.75) for follow-up strategies including scheduled ERCP. The lower risk of death remained for scheduled imaging with and without ERCP after adjustment for cholangiocarcinoma (CCA) or high-grade dysplasia as a time-dependent covariate, HR 0.57 (0.44-0.75). Hepatobiliary malignancy was diagnosed in 175 (5.9%) of the patients at 7.9 years of follow-up. Asymptomatic patients (25%) with CCA had better survival if scheduled imaging had been performed.

CONCLUSIONS

Follow-up strategies vary considerably across centres. Scheduled imaging was associated with improved survival. Multiple factors may contribute to this result including early tumour detection and increased endoscopic treatment of asymptomatic benign biliary strictures.

EASL Clinical Practice Guidelines on sclerosing cholangitis

Management of primary or secondary sclerosing cholangitis is challenging. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics including diagnostic methods, prognostic assessment, early detection of complications, optimal care pathways and therapeutic (pharmacological, endoscopic or surgical) options both in adults and children.

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.

International consensus statements for endoscopic management of distal biliary stricture

Distal biliary strictures (DBS) are common and may be caused by both malignant and benign pathologies. While endoscopic procedures play a major role in their management, a comprehensive review of the subject is still lacking. Our consensus statements were formulated by a group of expert Asian pancreatico-biliary interventional endoscopists, following a proposal from the Digestive Endoscopy Society of Taiwan, the Thai Association for Gastrointestinal Endoscopy, and the Tokyo Conference of Asian Pancreato-biliary Interventional Endoscopy. Based on a literature review utilizing Medline, Cochrane library, and Embase databases, a total of 19 consensus statements on DBS were made on diagnosis, endoscopic drainage, benign biliary stricture, malignant biliary stricture, and management of recurrent biliary obstruction and other complications. Our consensus statements provide comprehensive guidance for the endoscopic management of DBS.

The Diagnostic Dilemma of Malignant Biliary Strictures

The differential diagnosis for biliary strictures is broad. However, the likelihood of malignancy is high. Determining the etiology of a biliary stricture requires a comprehensive physical exam, laboratory evaluation, imaging, and ultimately tissue acquisition. Even then, definitive diagnosis is elusive, and many strictures remain indeterminant in origin. This literary review examines the diagnostic dilemma of biliary strictures and presents innovations in both histochemical and endoscopic techniques that have increased the diagnostic power of differentiating benign and malignant strictures. The field of tissue biopsy is revolutionizing with the advent of free DNA mutation profiling, fluorescence in situ hybridization (FISH), and methionyl t-RNA synthetase 1 (MARS 1), which allow for greater testing sensitivity. Endoscopic ultrasound, endoscopic retrograde cholangiopancreatography (ERCP), cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound build upon existing endoscopic technology to better characterize strictures that would otherwise be indeterminate in etiology. This review uses recent literature to insert innovative technology into the traditional framework of diagnostic methods for malignant biliary strictures.

Role of Endoscopy in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a progressive disease of the bile ducts that usually results in chronic liver disease often requiring liver transplantation. Endoscopy remains crucial to the care of these patients, although magnetic resonance cholangiopancreatography has replaced endoscopic retrograde cholangiopancreatography (ERCP) as the primary imaging modality for diagnosis. For detection of dysplasia or cholangiocarcinoma, ERCP with intraductal sampling remains compulsory. Moreover, dominant strictures play an important part in the disease development, and management by balloon dilatation or stenting could contribute to long-term prognosis. In addition, endoscopy offers management for adverse events such as bile leaks and anastomotic strictures after liver transplantation. Finally, the special phenotype of inflammatory bowel disease associated with PSC as well as the frequent occurrence of portal hypertension mandates close follow-up with colonoscopy and upper endoscopy. With the emergence of novel techniques, the endoscopist remains a key member of the multidisciplinary team caring for PSC patients.

Impact of peroral cholangioscopy on the management of indeterminate biliary conditions: a multicentre prospective trial

BACKGROUND AND AIMS

Single-operator cholangioscopy (SOC) can help diagnose biliopancreatic conditions. The impact of SOC on patient outcome has never been specifically addressed.

PATIENTS AND METHODS

Consecutive patients bearing indeterminate biliary strictures (IDBS), or primary sclerosing cholangitis (PSC) with suspected cholangiocarcinoma, were included. Patients with IDBS had at least one previous inconclusive endoscopic retrograde cholangio pancreatography (ERCP) + cytology. Primary endpoint was the difference in adequacy of management planned before and after SOC with regard to final diagnosis obtained after surgery or 24 months follow-up.

DESIGN

Prospective open-label multicentre trial.

RESULTS

61 patients were included (IDBS: 48; PSC: 13); 70.5% had a benign lesion (IDBS 66.7%, PSC 84.6%). The management adequacy rate was significantly higher after SOC than before SOC overall (p<10^-5), in IDBS (p<0.001) and PSC (p<0.05) patients. SOC induced changes in the management of the majority of patients in all groups (60.3%). The overall sensitivity of combined visual impression and biopsy ranged from 52% to 63.6% depending on investigator or independent expert rating (κ 0.92-0.96), whereas specificity, positive and negative predictive values of SOC were, respectively, 100%, 100% and 83.6%. Patient management observed at the end of follow-up was consistent with that anticipated after SOC in 88.5% overall.

CONCLUSION

Despite a moderate sensitivity for the diagnosis of malignancy, SOC has a dramatic impact on the management of patients with IDBS and PSC with suspected carcinoma. Cholangioscopy might be implemented in the workup of selected patients with challenging diagnosis, when a significant impact on outcome (essentially resection vs conservative management) is to be expected.

The interobserver agreement of optical features used to differentiate benign from neoplastic biliary lesions assessed at balloon-assisted cholangioscopy

BACKGROUND AND AIM

Balloon-assisted cholangioscopy allows mucosal assessment of the biliary tree with pediatric endoscopes. No validated optical criteria exist to differentiate benign from neoplastic biliary lesions. We aimed to identify, validate, and revalidate optical features differentiating benign from neoplastic biliary lesions. Furthermore, we aimed to determine whether cholangioscopic appearance allows endoscopists to accurately differentiate benign from neoplastic biliary lesions.

METHODS

Baseline: from 44 de-identified balloon-assisted cholangioscopy videos, a blinded investigator analyzed potential optical features distinguishing benign from neoplastic biliary lesions.

VALIDATION

during the initial "teaching phase," 20 endoscopists viewed video clips of 11 optical features identified in the baseline study. At the subsequent "test phase," 20 further video clips were assessed by the endoscopists blinded to clinical details and questionnaires completed for the presence or absence of optical features, favored diagnosis and diagnostic confidence. Revalidation: The six identified optical features from the validation study with at least moderate agreement were revalidated the same way 12 months later assessing 20 new lesions.

RESULTS

Baseline: 11 optical features were found to differentiate benign from neoplastic biliary lesions. Validation and revalidation: six optical features demonstrated at least moderate interobserver agreement (irregular margin, dark mucosa, adherent mucous, papillary projections, tubular, or branched/disorganized surface structures). Endoscopists correctly diagnosed lesions as benign in 89% and neoplastic in 83%. When highly confident, endoscopists correctly diagnosed 96% of benign and 87% neoplastic lesions.

CONCLUSIONS

Six features were validated and revalidated to differentiate benign from neoplastic biliary lesions. When highly confident with a diagnosis, endoscopists usually differentiate benign from neoplastic biliary lesions.

Review article: Asia-Pacific consensus recommendations on endoscopic tissue acquisition for biliary strictures

BACKGROUND

Pre-operative tissue diagnosis for suspected malignant biliary strictures remains challenging.

AIM

To develop evidence-based consensus statements on endoscopic tissue acquisition for biliary strictures.

METHODS

The initial draft of statements was prepared following a systematic literature review. A committee of 20 experts from Asia-Pacific region then reviewed, discussed, and modified the statements. Two rounds of independent voting were conducted to reach a final version. Consensus was considered to be achieved when 80% or more of voting members voted "agree completely" or "agree with some reservation."

RESULTS

Eleven statements achieved consensus. The choice of tissue sampling modalities for biliary strictures depends on the clinical setting, the location of lesion, and availability of expertise. Detailed radiological and endoscopic evaluation is useful to guide the selection of appropriate tissue acquisition technique. Standard intraductal biliary brushing and/or forceps biopsy is the first option when endoscopic biliary drainage is required with an overall (range) sensitivity and specificity of 45% (26%-72%) and 99% (98%-100%), and 48% (15%-100%) and 99% (97%-100%), respectively, in diagnosing malignant biliary strictures. Probe-based confocal laser endomicroscopy and fluorescence in situ hybridisation using 4 fluorescent-labelled probes targeting chromosomes 3, 7, 17 and 9p21 locus may be added to improve the diagnostic yield. Cholangioscopy-guided biopsy and EUS-guided tissue acquisition can be considered after prior negative conventional tissue sampling with an overall (range) sensitivity and specificity of 60% (38%-88%) and 98% (83%-100%), and 80% (46%-100%) and 97% (92%-100%), respectively, in diagnosing malignant biliary strictures.

CONCLUSION

These consensus statements provide evidence-based recommendations for endoscopic tissue acquisition of biliary strictures.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Clinical Assessment of Pancreatic Neoplasms

Accurate diagnosis and staging of pancreatic neoplasms is essential for surgical planning and identification of locally advanced and metastatic disease that is incurable by surgery. The ability to position the endoscopic ultrasonography (EUS) transducer close to the pancreas combined with the use of fine-needle aspiration enables the accurate diagnosis of pancreatic cysts and solid masses. EUS is also increasingly being used to procure core tissue for molecular analysis that facilitates personalized treatment of pancreatic cancer. Various therapeutic interventions can be undertaken under EUS guidance. This article focuses on the applications of EUS and endoscopic retrograde cholangiopancreatography in pancreatic neoplasms.

Usefulness of the single-operator cholangioscopy system SpyGlass in biliary disease: a single-center prospective cohort study and aggregated review

BACKGROUND AND STUDY AIM

Indeterminate biliary strictures and difficult bile duct stones remain clinically arduous and challenging situations. We aimed to evaluate the utility of the single-operator cholangioscopy (SOC)-system SpyGlass in both conditions in a single-center biliopancreatic interventional unit and in perspective of available aggregated literature.

METHODS

Usefulness of SOC was assessed for the above-mentioned indications by means of the combination of successful procedural completion, clinical success and incidence of procedure-related adverse events in our own prospective cohort from 3/2010 to 7/2014 and all available literature till 6/2015.

RESULTS

Our single-center cohort constituted of 84 patients undergoing SpyGlass either for indeterminate strictures (n = 45) or difficult stones (n = 39). In addition, a comprehensive literature review yielded 851 patients (from 15 series) for either stenosis (n = 646, 75.9 %) and difficult stones (n = 205, 24.1 %). In our series, overall procedural success amounted to 85.7 % (with 88.9 % for stenosis or 82.1 % for stones) compared to 90.7, 91.5 and 88.3 % in overall literature, respectively. Sensitivity, specificity and accuracy for visual diagnosis in our cohort added up to 83.3, 82.9 and 82.9 % compared to 90.8, 90.9 and 90.8 % in the pooled analysis. Respective figures for SOC-directed biopsies totaled 85.7, 100 and 95.7 % in our cohort and 72.4, 100 and 84 % overall. Overall procedure-related complications varied between 9.4 and 21.4 %.

CONCLUSIONS

The SOC-platform SpyGlass can be considered useful in the context of indeterminate biliary strictures and difficult-to-remove biliary stones. In both, SpyGlass-assisted intervention is associated with high procedural success and alters clinical outcome compared to conventional approaches with an acceptable safety profile.

The efficacy of peroral cholangioscopy for difficult bile duct stones and indeterminate strictures: a systematic review and meta-analysis

BACKGROUND AND STUDY AIMS

Current evidence supporting the efficacy of peroral cholangioscopy (POC) in the evaluation and management of difficult bile duct stones and indeterminate strictures is limited. The aims of this systematic review and meta-analysis were to assess the following: the efficacy of POC for the therapy of difficult bile duct stones, the diagnostic accuracy of POC for the evaluation of indeterminate biliary strictures, and the overall adverse event rates for POC.

PATIENTS AND METHODS

Patients referred for the removal of difficult bile duct stones or the evaluation of indeterminate strictures via POC were included. Search terms pertaining to cholangioscopy were used, and articles were selected based on preset inclusion and exclusion criteria. Quality assessment of the studies was completed with a modified Newcastle-Ottawa Scale. After critical literature review, relevant outcomes of interest were analyzed. Meta-regression was performed to examine potential sources of between-study variation. Publication bias was assessed via funnel plots and Egger's test.

RESULTS

A total of 49 studies were included. The overall estimated stone clearance rate was 88 % (95 % confidence interval [95 %CI] 85 % - 91 %). The accuracy of POC was 89 % (95 %CI 84 % - 93 %) for making a visual diagnosis and and 79 % (95 %CI 74 % - 84 %) for making a histological diagnosis. The estimated overall adverse event rate was 7 % (95 %CI 6 % - 9 %).

CONCLUSIONS

POC is a safe and effective adjunctive tool with endoscopic retrograde cholangiopancreatography (ERCP) for the evaluation of bile duct strictures and the treatment of bile duct stones when conventional methods have failed. Prospective, controlled clinical trials are needed to further elucidate the precise role of POC during ERCP.

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

BACKGROUND AND AIMS

EUS-guided FNA (EUS-FNA) is increasingly being used for tissue diagnosis of extrahepatic biliary strictures. The aim of this study was to determine the diagnostic yield of EUS-FNA in malignant biliary strictures.

METHODS

A comprehensive literature review was carried out by 2 reviewers for studies evaluating the accuracy of EUS-FNA in biliary stricture. A meta-analysis was performed to determine the pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio for EUS-FNA of extrahepatic biliary stricture. A Quality Assessment of Diagnostic Accuracy Studies questionnaire was used to assess the quality of the selected studies. Several sensitivity analyses were performed to assess the effect of the quality of the studies on the accuracy of the final results of the meta-analysis.

RESULTS

Twenty studies involving 957 patients met inclusion criteria and were included in the meta-analysis. The pooled sensitivity and specificity of EUS-FNA for diagnosis of malignant biliary stricture were 80% (95% confidence interval [CI], 74%-86%), and 97% (95% CI, 94%-99%), respectively. The pooled positive likelihood ratio was 12.35 (95% CI, 7.37-20.72), and the negative likelihood ratio was 0.26 (95% CI, 0.18-0.38). The pooled diagnostic odds ratio for diagnosing a malignant biliary stricture was 70.53 (95% CI, 38.62-128.82). The area under the receiver-operating characteristic curve was 0.97. Sensitivity analyses showed that the quality of the included studies did not affect the accuracy of the final results of the meta-analysis.

CONCLUSION

This meta-analysis demonstrates that EUS-FNA is sensitive and highly specific for diagnosing malignancy in biliary strictures. Further studies are needed to compare EUS--FNA with emerging methods including cholangioscopy-guided biopsy and laser endomicroscopy.

Advanced endoscopic imaging of indeterminate biliary strictures

Endoscopic evaluation of indeterminate biliary strictures (IDBSs) has evolved considerably since the development of flexible fiberoptic endoscopes over 50 years ago. Endoscopic retrograde cholangiography pancreatography (ERCP) was introduced nearly a decade later and has since become the mainstay of therapy for relieving obstruction of the biliary tract. However, longstanding methods of ERCP-guided tissue acquisition (i.e., biliary brushings for cytology and intraductal forceps biopsy for histology) have demonstrated disappointing performance characteristics in distinguishing malignant from benign etiologies of IDBSs. The limitations of these methods have thus helped drive the search for novel techniques to enhance the evaluation of IDBSs and thereby improve diagnosis and clinical care. These modalities include, but are not limited to, endoscopic ultrasound, intraductal ultrasound, cholangioscopy, confocal endomicroscopy, and optical coherence tomography. In this review, we discuss established and emerging options in the evaluation of IDBSs.

Cholangioscopy in liver disease

Since its introduction, cholangioscopy has been used diagnostically and therapeutically. The working channel size has increased, permitting direct visualization for tissue sampling and to guide application of lithotripsy for difficult stones. Cholangioscopy utilizes endoscope and catheter-based systems. The application of slim gastroscopes for direct cholangioscopy provides better image resolution than conventional systems. Cholangioscopy has proven effective in the management of large biliary stones and for the diagnosis and exclusion of biliary tumors. Commercially available cholangioscopes are fiberoptic; those with digital video technology remain in a prototype development phase. This review covers available cholangioscope technologies, indications, technique, efficacy, and complications.