Intraductal ultrasound for the evaluation of patients with biliary strictures and no abdominal mass on computed tomography

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

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for the diagnosis of malignancy in patients with biliary strictures of undetermined etiology. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses the role of fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS in the diagnosis of malignancy in patients with biliary strictures. In the endoscopic workup of these patients, we suggest the use of fluoroscopic-guided biopsy sampling in addition to brush cytology over brush cytology alone, especially for hilar strictures. We suggest the use of cholangioscopic and EUS-guided biopsy sampling especially for patients who undergo nondiagnostic sampling, cholangioscopic biopsy sampling for nondistal strictures and EUS-guided biopsy sampling distal strictures or those with suspected spread to surrounding lymph nodes and other structures.

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.

Endoscopic management of perihilar cholangiocarcinoma

Endoscopic management for perihilar cholangiocarcinoma (PHCC) is evolving toward more accurate diagnosis and safer drainage. In imaging, it is important to diagnose the entire lesion using multidetector-row computed tomography to determine resectability and optimal surgical planning, followed by local diagnosis using endoscopic retrograde cholangiopancreatography. Video peroral cholangioscopy and probe-based confocal laser endomicroscopy have been newly introduced as diagnostic imaging methods and are being applied clinically. In transpapillary forceps biopsy for PHCC diagnosis, the location in the bile duct (for mapping biopsy) and the number of biopsy samples should be determined depending on resectability, the morphological type, and future surgical planning. Preoperative drainage has shifted from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage given the possibility of seeding metastasis. In addition, considering potential patient discomfort from a nasal tube, the usefulness of the placement of a plastic stent above the papilla (inside stent) as a bridging therapy for surgery has been reported. For drainage of unresectable PHCC, the improved prognosis due to advances in chemotherapy has necessitated a strategy that accounts for reintervention. Thus, in addition to uncovered self-expandable metallic stents (SEMS), exchangeable slim fully covered SEMS and inside stents have started to be used. In addition to the conventional transpapillary approach, an endoscopic ultrasonography-guided approach has been introduced, and a combination of both methods has also been proposed. To improve the quality of life and prognosis of PHCC patients, endoscopists need to understand and be able to use the various methods of endoscopic management for PHCC.

Multidisciplinary Approach to Indeterminate Biliary Strictures

Biliary strictures that remain unclassified after cross-sectional imaging and endoscopic retrograde cholangiopancreatography-based tissue sampling are defined as indeterminate biliary strictures (IDBS). A substantial proportion of biliary strictures fall into this category due to low sensitivity of brush cytology and intraductal biopsy. Over last few decades, several modalities have emerged for the evaluation of IDBS. Of these, cholangioscopy and endosonography are the frontrunners and have cemented their place for the evaluation of IDBS. Both of these modalities are widely available, and therefore, biliary strictures that remain uncharacterized after their utilization represent IDBS in the current era.

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.

Biliary Tree Diagnostics: Advances in Endoscopic Imaging and Tissue Sampling

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

Biliary endoscopy in the management of primary sclerosing cholangitis and its complications

Primary sclerosing cholangitis (PSC) is a chronic, idiopathic, cholestatic liver disease characterized by inflammation and fibrosis of the intrahepatic and/or extrahepatic bile ducts. It can affect individuals of all age groups and gender, has no established pharmacotherapy, and is associated with a variety of neoplastic (e.g. cholangiocarcinoma) and non-neoplastic (e.g. dominant strictures) hepatobiliary complications. Given these considerations, endoscopy plays a major role in the care of patients with PSC. In this review, we discuss and provide updates regarding endoscopic considerations in the management of hepatobiliary manifestations and complications of PSC. Where evidence is limited, we suggest pragmatic approaches based on currently available data and expert opinion.

Prospective Comparison of Intraductal Ultrasonography-Guided Transpapillary Biopsy and Conventional Biopsy on Fluoroscopy in Suspected Malignant Biliary Strictures

Background/Aims

In suspected malignant biliary strictures (MBSs), the diagnostic yield of endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling is limited. Transpapillary forceps biopsy (TPB) under intraductal ultrasonography (IDUS) guidance is expected to improve the diagnostic accuracy in patients with indeterminate biliary strictures. We evaluated the usefulness of IDUS-guided TPB in patients with suspected MBS.

Methods

Consecutive patients with suspected MBS were prospectively enrolled in the study. ERCP with IDUS was performed in all patients. Both conventional TPB and IDUS-guided TPB on fluoroscopy were performed in each patient. The primary outcome was the diagnostic accuracy of conventional TPB and IDUS-guided TPB.

Results

The technical success rate of IDUS-guided TPB was 97.0% (65/67 patients). Of these 65 patients, the final diagnosis was malignancy in 61 patients (93.8%). On IDUS, the most common finding of IDUS was an intraductal infiltrating lesion in 29 patients (47.5%). The overall diagnostic accuracy was significantly higher using IDUS-guided TPB than that using conventional TPB (90.8% vs 76.9%, p=0.027). According to the subgroup analysis based on the tumor morphology, IDUS-guided TPB had a significantly higher cancer detection rate than conventional TPB for intraductal infiltrating lesions (89.6% vs 65.5%, p=0.028).

Conclusions

IDUS-guided TPB appears to improve the accuracy of histological diagnosis in patients with MBS.

A combined bile and urine proteomic test for cholangiocarcinoma diagnosis in patients with biliary strictures of unknown origin

BACKGROUND

Detection of cholangiocarcinoma (CC) remains a diagnostic challenge particularly in patients with primary sclerosing cholangitis (PSC). We recently established diagnostic peptide marker models in bile and urine to detect CC. Our aim was to combine both models to reach a higher diagnostic accuracy of CC diagnosis.

METHODS

Bile (BPA) and urine (UPA) proteome analysis by capillary electrophoresis mass spectrometry was performed in a case-control phase II study on 87 patients (36 CC including 13 with CC on top of PSC, 33 PSC and 18 other benign disorders). A logistic regression model with both analyses was developed and subsequently validated in a prospective cohort of 45 patients.

RESULTS

In the retrospective study, single BPA and UPA showed sensitivities of 83 and 89 % and specificities of 80 and 86 % with an area under the curve (AUC) value of 0.85 and 0.93. If CC was defined as positive UPA and BPA the combination resulted in a sensitivity of 72 % and a specificity of 96 %. The logistic regression model resulted in an increase in sensitivity to 92 % at 84 % specificity with an AUC of 0.96. Applied to the prospective study cohort, the logistic regression model was superior in its sensitivity (94%) and specificity (76%) over single BPA (63% sensitivity, 69% specificity) and UPA (81% sensitivity, 72% specificity) with an AUC of 0.84.

CONCLUSION

Our logistic regression model enables CC diagnosis with a higher accuracy than currently available diagnostic tools leading potentially to an earlier diagnosis.

Intraductal Ultrasonography without Radiocontrast Cholangiogramin Patients with Extrahepatic Biliary Disease

BACKGROUND/AIMS

Intraductal ultrasonography (IDUS) has been performed as an adjunct to endoscopic retrograde cholangiography (ERC) during radiocontrast cholangiography (RC). Radiation exposure during RC poses a health risk to both patients and examiners. We evaluated the feasibility of IDUS without RC in various extrahepatic biliary diseases.

METHODS

IDUS was performed with the insertion of an IDUS probe from the papilla of Vater to the confluent portion of the common hepatic duct without fluoroscopy. The technical success rate and procedure-related complications were evaluated retrospectively.

RESULTS

Wire-guided IDUS without RC was performed in 105 patients. The mean age was 66.5 years, and 50 (47.6%) were male. The IDUS diagnoses included choledocholithiasis (73, 69.5%), benign biliary stricture (11, 10.5%), choledocholithiasis with biliary pancreatitis (9, 8.6%), bile duct cancer (5, 4.8%), pancreatic cancer (1, 0.9%), and others (6, 5.7%). After IDUS, 66 (62.8%) underwent stone removal, 19 (18.1%) underwent biliary drainage, and 7 (6.6%) underwent brush cytology and biopsy. No significant complications such as perforation or severe pancreatitis occurred.

CONCLUSIONS

IDUS without RC was a feasible and safe approach in patients with various extrahepatic biliary diseases. We anticipate a potentially important role of IDUS in various ERC procedures because it lacks the hazards of RC.

Evaluation and management of intrahepatic and extrahepatic cholangiocarcinoma

Cholangiocarcinomas are rare biliary tract tumors that are often challenging to diagnose and treat. Cholangiocarcinomas are generally categorized as intrahepatic or extrahepatic depending on their anatomic location. The majority of patients with cholangiocarcinoma do not have any of the known or suspected risk factors and present with advanced disease. The optimal evaluation and management of patients with cholangiocarcinoma requires thoughtful integration of clinical information, imaging studies, cytology and/or histology, as well as prompt multidisciplinary evaluation. The current review focuses on recent advances in the diagnosis and treatment of patients with cholangiocarcinoma and, in particular, on the role of endoscopy, surgery, transplantation, radiotherapy, systemic therapy, and liver-directed therapies in the curative or palliative treatment of these individuals. Cancer 2016;122:1349-1369. © 2016 American Cancer Society.

Evaluation of indeterminate biliary strictures

Biliary strictures frequently present a diagnostic challenge during pre-operative evaluation to determine their benign or malignant nature. A variety of benign conditions, such as primary sclerosing cholangitis (PSC) and IgG4-related sclerosing cholangitis, frequently mimic malignancies. In addition, PSC and other chronic biliary diseases increase the risk of cholangiocarcinoma and so require ongoing vigilance. Although traditional methods of evaluation including imaging, detection of circulating tumour markers, and sampling by endoscopic ultrasound and endoscopic retrograde cholangiopancreatography have a high specificity, they suffer from low sensitivity. Currently, up to 20% of biliary strictures remain indeterminate after pre-operative evaluation and necessitate surgical intervention for a definitive diagnosis. The discovery of novel biomarkers, new imaging modalities and advanced endoscopic techniques suggests that a multimodality approach might lead to better diagnostic accuracy.

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.

Diagnosing Biliary Malignancy

The most common malignant causes of biliary strictures are pancreatic cancer and cholangiocarcinoma. Differentiating between malignant and benign causes of biliary strictures has remained a clinical challenge. Endoscopic retrograde cholangiopancreatography (ERCP) remains the mainstay and first-line method of tissue diagnosis but has a poor diagnostic yield. This article reviews the causes of biliary strictures, the initial clinical evaluation of biliary obstruction, the diagnostic yield of ERCP-based sampling methods, the role of newer tools in the armamentarium for evaluating strictures, and ways to address the ongoing challenge of stricture evaluation in patients with primary sclerosing cholangitis.

Endoscopic diagnosis of cholangiocarcinoma: From endoscopic retrograde cholangiography to bile proteomics

Cholangiocarcinoma (CCA) is the second most common primary liver cancer. In clinical practice, the diagnosis remains challenging and often requires endoscopic approaches. Endoscopic retrograde and percutaneous transhepatic cholangiography are the first-line endoscopic procedures for the evaluation of indeterminate bile duct strictures. Tissue acquisition via brush cytology and forceps biopsies allows the cytological and/or histological confirmation of the disease. Due to the low sensitivity of these techniques, repetitive examinations and/or alternative approaches are required. Cholangioscopy, endoscopic and intraductal ultrasound and confocal laser endomicroscopy are additional methods which can be applied for the diagnosis of CCA. Particularly, new experimental approaches like bile and urine proteomic analyses show promising results which have to be evaluated prospectively for further integration in diagnostic algorithms.

Triple modality testing by endoscopic retrograde cholangiopancreatography for the diagnosis of cholangiocarcinoma

OBJECTIVES

Brush cytology has a low sensitivity for the diagnosis of cholangiocarcinoma. This study aimed to compare the standard approach (brush cytology) with a triple modality approach utilizing brush cytology, forceps biopsy and fluorescence in situ hybridization in terms of sensitivity and specificity for the diagnosis of cholangiocarcinoma.

METHODS

In a retrospective study at a single academic center, 50 patients underwent triple modality testing. Additionally, 61 patients underwent brush cytology alone. Intervention was endoscopic retrograde cholangiopancreatography with brush cytology, fluorescence in situ hybridization, and forceps biopsy. The main outcome measures included sensitivity, specificity, positive predictive value and negative predictive value.

RESULTS

Overall, 50 patients underwent triple tissue sampling, and 61 patients underwent brush cytology alone. Twenty-two patients were eventually diagnosed with cholangiocarcinoma. Brush cytology had a sensitivity of 42%, specificity of 100%, positive predictive value of 100% and negative predictive value of 88%. Triple tissue sampling had an overall sensitivity of 82%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 87%. Within the triple test group, brush cytology had a sensitivity of 27%, forceps biopsy had a sensitivity of 50%, and fluorescence in situ hybridization analysis had a sensitivity of 59%.

CONCLUSIONS

A triple modality approach results in a marked increase in sensitivity for the diagnosis of cholangiocarcinoma compared with single modality testing such as brush cytology and should be considered in the evaluation of indeterminate or suspicious biliary strictures.

Bile proteome in health and disease

The study of bile proteins could improve the understanding of physiological processes involved in the regulation of the hepato-biliary system. Researchers have tried for years to investigate the bile proteome but, until recently, only a few tens of proteins were known. The advent of proteomics, availing of large-scale analytical devices paired with potent bioinformatic resources, lately allowed the identification of thousands of proteins in bile. Nevertheless, the knowledge of their role in the hepato-biliary system still represents almost a "blank page in the book of physiology." In this review, we first guide the reader through the historical phases of the analysis of bile protein content, emphasizing the recent progresses achieved through the use of proteomic techniques. Thereafter, we deeply explore the involvement of bile proteins in health and disease, with a particular focus on the discovery of biomarkers for biliary tract malignancies.

Biliary strictures: diagnostic considerations and approach

Biliary strictures present a diagnostic challenge, especially when no etiology can be ascertained after laboratory evaluation, abdominal imaging and endoscopic retrograde cholangiopancreatography (ERCP) sampling. These strictures were traditionally classified as indeterminate strictures, although with advances in endoscopic techniques and better understanding of hepato-biliary pathology, more are being correctly diagnosed. The implications of missing a malignancy in patients with biliary strictures—and hence delaying surgery—are grave but a significant number of patients (up to 20%) undergoing surgery for suspected biliary malignancy can have benign pathology. The diagnostic approach to these patients involves detailed history and physical examination and depends on the presence or absence of jaundice, level of obstruction, and presence or absence of a mass lesion. While abdominal imaging helps to find the level of obstruction and provides a ‘road map' for further endoscopic investigations, tissue diagnosis is usually needed to make decisions on management. Initially ERCP was the only modality to investigate these strictures but now, with the development of endoscopic ultrasound with fine needle aspiration and the availability of newer techniques such as intraductal ultrasound, single-operator cholangioscopy and confocal laser endomicroscopy, the diagnostic approach to biliary strictures has changed significantly. In this review, we will focus on the decision-making process for patients with biliary strictures and discuss the key decision points that should dictate further diagnostic investigations at each step.

Endoscopic ultrasonography for inflammatory distal biliary stricture: Analysis of 165 cases

AIM: To explore the value of endoscopic ultrasonography (EUS) in the treatment of inflammatory distal biliary stricture.

METHODS: The clinical data for 165 patients with inflammatory distal biliary stricture who underwent EUS from March 2010 to March 2013 were retrospectively analyzed.

RESULTS: A total of 256 EUS treatments were performed in 165 patients. Endoscopic retrograde cholangiopancreatography (ERCP) and EUS were selected based on the clinical condition. Endoscopic nasobiliary drainage and/or endoscopic retrograde biliary drainage were separately used. Clinical symptoms were relieved and hepatic function was improved in all patients. Bile duct pressure was reduced. The success rate of ERCP was 98.8%. The rate of complications was 4.84% (8/165). Three patients developed post-ERCP hyperamylasemia, 3 patients developed mild cholangeitis, and 2 patients developed acute pancreatitis. During a follow-up period of 1-37 mo (average, 17.8 mo ± 5.3 mo), no stricture recurrence was found. Stents were removed in 121 cases, but stent replacement was required in another 29 cases.

CONCLUSION: Endoscopic ultrasonography is a safe, effective and mini-invasive method for inflammatory distal biliary stricture.

Advanced techniques for endoscopic biliary imaging: cholangioscopy, endoscopic ultrasonography, confocal, and beyond

Cholangioscopy, endosonography, and confocal microscopy represent important technologies that expand biliary imaging beyond a level previously realized by noninvasive modalities (ultrasonography, computed tomography, and magnetic resonance cholangiopancreatography) and endoscopic retrograde cholangiopancreatography. Endoscopic ultrasonography has shown efficacy for the evaluation of indeterminate biliary strictures; however, this modality seems most reliable for distal bile duct abnormalities and in the setting of a moderate to high pretest probability for malignancy. Further refinement of these technologies, validation of their respective diagnostic criteria, and study within the context of comparative, randomized trials are needed and will contribute greatly to expedient patient care.

Endoscopic evaluation of bile duct strictures

Differentiating between malignant and benign bile duct strictures is often challenging. Endoscopic retrograde cholangiopancreatography with brush cytology and/or endobiliary forceps biopsy is routinely performed. Advanced cytologic methods such as fluorescence in situ hybridization or digital image analysis increases the sensitivity of cytology. Endoscopic ultrasonography enables detailed examination of tissues surrounding the bile duct stricture and offers the advantage of fine-needle aspiration. Intraductal ultrasonography enables detailed evaluation of bile duct wall layers, and cholangioscopy offers direct visualization of the bile duct lesions. Novel techniques of probe-based confocal laser endomicroscopy and optical coherence tomography have introduced the era of in vivo histology.

Diagnosis of distal cholangiocarcinoma after the removal of choledocholithiasis

Background and Aim. Distal cholangiocarcinoma associated with choledocholithiasis has not been reported, and the causal relationship remains to be established. We evaluated diagnosis of distal cholangiocarcinoma diagnosed after the removal of choledocholithiasis. Patients and Methods. We assigned 9 cases of cholangiocarcinoma with choledocholithiasis to Group A. As a control group, 37 patients with cholangiocarcinoma without choledocholithiasis were assigned to Group B. Results. Abdominal pain at admission is the only significant difference between Group A and Group B (P = 0.001). All patients in Group A had gall bladder stones, compared with 7 patients (19%) in Group B (P < 0.01). Of the 9 patients in Group A, endoscopic retrade cholangiopancreatography (ERCP) detected normality in 2 patients (22%) and abnormalities in 7 patients (78%). Of the 32 patients in Group B, ERCP detected normality in 4 patients (13%) and abnormalities in 28 patients (88%) (P = 0.597). Intraductal ultrasonography (IDUS) detected a tumor in 8 patients in Group A, while in Group B, IDUS detected normality in 1 patient (3%) and tumors in 29 patients (97%) (P = 1.000). Conclusions. IDUS after stone removal may potentially help in the detection of unexpected tumors. Therefore, we believe that IDUS after stone removal will lead to improve outcome and prognosis.

Current endoscopic approach to indeterminate biliary strictures

Biliary strictures are considered indeterminate when basic work-up, including transabdominal imaging and endoscopic retrograde cholangiopancreatography with routine cytologic brushing, are non-diagnostic. Indeterminate biliary strictures can easily be mischaracterized which may dramatically affect patient’s outcome. Early and accurate diagnosis of malignancy impacts not only a patient’s candidacy for surgery, but also potential timely targeted chemotherapies. A significant portion of patients with indeterminate biliary strictures have benign disease and accurate diagnosis is, thus, paramount to avoid unnecessary surgery. Current sampling strategies have suboptimal accuracy for the diagnosis of malignancy. Emerging data on other diagnostic modalities, such as ancillary cytology techniques, single operator cholangioscopy, and endoscopic ultrasonography-guided fine needle aspiration, revealed promising results with much improved sensitivity.

Pancreatico-biliary endoscopic ultrasound: A systematic review of the levels of evidence, performance and outcomes

Our aim was to record pancreaticobiliary endoscopic ultrasound (EUS) literature of the past 3 decades and evaluate its role based on a critical appraisal of published studies according to levels of evidence (LE). Original research articles (randomized controlled trials, prospective and retrospective studies), meta-analyses, reviews and surveys pertinent to gastrointestinal EUS were included. All articles published until September 2011 were retrieved from PubMed and classified according to specific disease entities, anatomical subdivisions and therapeutic applications of EUS. The North of England evidence-based guidelines were used to determine LE. A total of 1089 pertinent articles were reviewed. Published research focused primarily on solid pancreatic neoplasms, followed by disorders of the extrahepatic biliary tree, pancreatic cystic lesions, therapeutic-interventional EUS, chronic and acute pancreatitis. A uniform observation in all six categories of articles was the predominance of LE III studies followed by LE IV, IIb, IIa, Ib and Ia, in descending order. EUS remains the most accurate method for detecting small (< 3 cm) pancreatic tumors, ampullary neoplasms and small (< 4 mm) bile duct stones, and the best test to define vascular invasion in pancreatic and peri-ampullary neoplasms. Detailed EUS imaging, along with biochemical and molecular cyst fluid analysis, improve the differentiation of pancreatic cysts and help predict their malignant potential. Early diagnosis of chronic pancreatitis appears feasible and reliable. Novel imaging techniques (contrast-enhanced EUS, elastography) seem promising for the evaluation of pancreatic cancer and autoimmune pancreatitis. Therapeutic applications currently involve pancreaticobiliary drainage and targeted fine needle injection-guided antitumor therapy. Despite the ongoing development of extra-corporeal imaging modalities, such as computed tomography, magnetic resonance imaging, and positron emission tomography, EUS still holds a leading role in the investigation of the pancreaticobiliary area. The major challenge of EUS evolution is its expanding therapeutic potential towards an effective and minimally invasive management of complex pancreaticobiliary disorders.

Endoscopic retrograde cholangioscopy and advanced biliary imaging

Developments in endoscopic retrograde cholangioscopy provide multiple new advanced methods of biliary imaging. Cholangioscopy provides direct visualization of epithelium with white light as well as advanced modalities, such as narrow band imaging and autofluorescence. In vivo histologic images can be achieved with confocal endomicroscopy. Cross-sectional imaging is also possible with intraductal ultrasonography and optical coherence tomography. This article describes these advanced imaging techniques, which can be used together to assist in the diagnosis of biliary strictures and lesions.

[Klatskin tumors: rational diagnostics and staging]

Klatskin tumors continue to be a challenge for diagnostic assessment and staging due to their longitudinal tumor growth along the perihilar bile ducts. Therefore the rate of non-resectable tumors remains relatively stable despite modern imaging and endoscopic techniques. This article reviews the current diagnostic methods for preoperative staging and the significance for predicting resectability.

Endoscopic management of hilar cholangiocarcinoma

Hilar cholangiocarcinoma has a poor prognosis and surgery remains the only curative option. However, few patients are diagnosed at a curable stage and palliative therapies are, therefore, mandatory. Endoscopy could have a useful role in the work-up of patients with hilar cholangiocarcinoma who are unsuitable for surgery. Endoscopic retrograde cholangiopancreatography provides an opportunity to collect specimens for cytological or histological diagnosis, yet is often nondiagnostic. Other techniques, including fluorescence in situ hybridization, confocal laser endomicroscopy and endoscopic ultrasonography, are now improving the accuracy of tissue diagnosis. This Review presents an overview of the diagnostic and therapeutic role of endoscopic procedures in the management of hilar cholangiocarcinoma. The use of such procedures in guiding the therapeutic management of patients with hilar cholangiocarcinoma is discussed, and the relative success of endoscopic stenting as the main palliative therapy for obstructive jaundice (a common complication of hilar cholangiocarcinoma) is described. The potential role of photodynamic therapy as a palliative treatment for patients with hilar cholangiocarcinoma is also outlined.

Efficacy of intraductal ultrasonography in the diagnosis of non-opaque choledocholith

AIM: To evaluate the efficacy of intraductal ultrasonography (IDUS) in the diagnosis of non-opaque, common bile duct stones.

METHODS: A total of 183 patients (102 males, mean age 73 years; 81 females, mean age 70 years) with suspected common bile duct stones diagnosed through abdominal computed tomography (CT), magnetic resonance imaging (MRI), and abdominal Type-B ultrasound were included in the study. The diagnosis was confirmed through endoscopic retrograde cholangiopancreatography (ERCP) followed by IDUS.

RESULTS: A total of 183 patients with suspected common bile duct (CBD) stones were included in the study as follows: 36 patients with high-density CBD stones, 68 patients with sand-like stones, 44 patients with low-density stones, 21 patients with ampullary cancer, and 14 patients with pancreatic cancer. Conventional imaging revealed 124 cases of choledochectasia, and only 36 cases of suspected CBD stones; ERCP revealed 145 cases of CBD stones with three missed diagnoses. IDUS revealed 148 cases of CBD stones, 21 cases of ampullary tumors, and 14 cases of pancreatic cancer.

CONCLUSION: IDUS was more effective in the diagnosis of bile duct stones than ERCP, upper abdominal CT or upper abdominal MRI.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension.

Discrimination between sclerosing cholangitis-associated autoimmune pancreatitis and primary sclerosing cholangitis, cancer using intraductal ultrasonography

BACKGROUND AND AIM

Differentiation of sclerosing cholangitis-associated autoimmune pancreatitis (SC-AIP), primary sclerosing cholangitis (PSC) and cancer of the hilar part of the bile duct (CHB) has been challenging. The aim of the present study was to evaluate characteristic intraductal ultrasonography (IDUS) features that could be used to discriminate SC-AIP from PSC and CHB.

METHODS

Six patients with SC-AIP, 10 patients with PSC and 12 patients with CHB were identified. We reviewed the following bile duct features observed using IDUS to determine their usefulness for differentiating SC-AIP from PSC and CHB: presence of symmetrical wall thickness, wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar.

RESULTS

IDUS results (SC-AIP, PSC, CHB) were as follows: wall thickness (mm), 3.7±0.9, 2.6 ±0.9, 2.8±0.0.6; presence of symmetrical wall thickness, 100% (6/6), 20% (2/10), 8.3% (1/12); presence of homogeneous internal foci, 100% (6/6), 10% (1/10), 8.3% (1/12); and presence of lateral mucosal lesions continuous to the hilar, 83.3% (5/6), 40%(4/10), 25% (3/12). Symmetrical wall thickness of the bile duct, homogeneous internal foci and lateral mucosal lesions continuous to the hilar were detected significantly more often among the patients with SC-PSC than among the patients with PSC or CHB (P<0.05).

CONCLUSIONS

IDUS findings, such as symmetrical wall thickness, presence of homogeneous internal foci and presence of lateral mucosal lesions continuous to the hilar can facilitate the differential diagnosis of SC-AIP from PSC and CHB.

Cholangiocarcinoma: an endoscopist's perspective

The incidence of cholangiocarcinoma is on the rise. This may be related in part to higher detection rates secondary to sophisticated endoscopic modalities. These tumors pose a significant diagnostic dilemma. High index of suspicion, careful interpretation of serum markers and utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography and endoscopic ultrasound, help to establish the diagnosis. Imaging modalities are crucial in the evaluation of these tumors. They help to define the extent of the native lesion, which may dictate its resectability, as well as evaluate for metastasis. Therapeutic options are somewhat limited, short of surgical resection. Newer chemotherapeutic agents, as well as endoscopy-targeted therapy, may improve the overall treatment success rate, although experience is somewhat limited at this time. Endoscopic intervention is essential for palliation.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are rare malignancies that arise from the biliary epithelium. Intrahepatic CCAs usually present as mass lesions that are asymptomatic or cause nonspecific systemic symptoms such as fatigue, fever, and weight loss. Hilar and extrahepatic tumors most commonly present with jaundice, though cholangitis also can be seen. Tumor markers such as carbohydrate antigen 19-9 and carcinoembryonic antigen have been used to diagnose CCA, but these are nonspecific and may be elevated in infection, inflammation, or any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) has been used for the diagnosis and management of CCA for many years. This article summarizes the data regarding the application of ERCP in the diagnosis and management of CCA.

Are the echogenicities on intraductal ultrasonography really biliary microlithiasis?

BACKGROUND

Intraductal ultrasonography (IDUS) is a useful procedure for diagnosing microlithiasis in the bile duct but it is not easy to differentiate between tiny echogenicity and real microlithiasis. We compared the echogenicity seen on IDUS and the findings of bile microscopy (BM) of bile that was collected in the common bile duct (CBD) to determine whether the echogenicity seen on IDUS is real microlithiasis.

METHODS

This prospective study involved a total of 30 patients who experienced biliary pain (n = 11), acute cholecystitis (n = 11) or indeterminate pancreatitis (n = 8) without a filling defect or obstruction in the bile duct. IDUS was performed during endoscopic retrograde cholangiopancreatography (ERCP), followed by bile aspiration for BM. Endoscopic sphincterotomy (EST) was performed if definite echogenic materials were observed on IDUS.

RESULTS

Of the 30 patients, 23 (77%) had echogenic materials visible in the CBD on IDUS. Of these 23 patients, 13 (57%) were found to have biliary crystals by BM. The size of the echogenic materials was the only significant factor associated with BM positivity. Using the receiver operating curve, the optimal size of the echogenicity to differentiate real microlithiasis was 1.4 mm.

CONCLUSIONS

Optimal concordance between IDUS and BM was observed when the size of the microlithiasis was greater than 1.4 mm; under these conditions the sensitivity and specificity were 71% and 75%, respectively. This information may be useful when deciding whether to perform endoscopic sphincterotomy.

Intraductal ultrasonography combined with percutaneous transhepatic cholangioscopy for the preoperative evaluation of longitudinal tumor extent in hilar cholangiocarcinoma

BACKGROUND AND AIM

In hilar cholangiocarcinoma, an accurate assessment of preoperative resectability is important to optimize surgical resection. We investigated the accuracy of the combination of intraductal ultrasonography (IDUS) and percutaneous transhepatic cholangioscopy (PTCS) for evaluating longitudinal extent in hilar cholangiocarcinoma.

METHODS

Patients diagnosed with hilar cholangiocarcinoma underwent multidetector computed tomography (MDCT) and magnetic resonance cholangiography (MRC) for tumor staging and Bismuth type. Percutaneous transhepatic biliary drainage was performed at the left or right bile duct of the liver section that was anticipated to be preserved in the surgical treatment. After tract dilation, PTCS with cholangioscope-directed biopsy and IDUS were sequentially performed to evaluate Bismuth type. Surgical treatment was executed according to tumor staging and longitudinal tumor extent. Postoperative histological Bismuth types were compared to preoperative Bismuth types based on MDCT, MRC, PTCS with biopsy, and IDUS.

RESULTS

From June 2006 to November 2008, 25 patients with hilar cholangiocarcinoma were enrolled, with 20 of these patients evaluable. The accuracy of MDCT, MRC, PTCS with biopsy, and IDUS for the evaluation of Bismuth type was 80%, 84.2%, 90%, and 85.0%, respectively, in 20 patients, and 82.4%, 82.4%, 94.1%, and 88.2%, respectively, in 18 patients with Bismuth type IIIa, IIIb, or IV cancer. The accuracy of the combination of IDUS and PTCS with biopsy was 95% in 20 patients, and 100% in 18 with Bismuth type IIIa, IIIb, or IV cancer.

CONCLUSIONS

The combination of IDUS and PTCS with biopsy was highly accurate for assessing Bismuth type and may help in the identification of an optimal surgical plan for the treatment of hilar cholangiocarcinoma, especially in Bismuth type IIIa, IIIb, or IV.

Endoscopic ultrasonography can diagnose distal biliary strictures without a mass on computed tomography

AIM: To assess the diagnostic ability of endoscopic ultrasonography (EUS) for evaluating causes of distal biliary strictures shown on endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), even without identifiable mass on computed tomography (CT).

METHODS: The diagnostic ability of EUS was retrospectively analyzed and compared with that of routine cytology (RC) and tumor markers in 34 patients with distal biliary strictures detected by ERCP or MRCP at Dokkyo Medical School Hospital from December 2005 to December 2008, without any adjacent mass or eccentric thickening of the bile duct on CT that could cause biliary strictures. Findings considered as benign strictures on EUS included preservation of the normal sonographic layers of the bile duct wall, irrespective of the presence of a mass lesion. Other strictures were considered malignant. Final diagnosis of underlying diseases was made by pathological examination in 18 cases after surgical removal of the samples, and by clinical follow-up for > 10 mo in 16 cases.

RESULTS: Seventeen patients (50%) were finally diagnosed with benign conditions, including 6 “normal” subjects, while 17 patients (50%) were diagnosed with malignant disease. In terms of diagnostic ability, EUS showed 94.1% sensitivity, 82.3% specificity, 84.2% positive predictive value, 93.3% negative predictive value (NPV) and 88.2% accuracy for identifying malignant and benign strictures. EUS was more sensitive than RC (94.1% vs 62.5%, P = 0.039). NPV was also better for EUS than for RC (93.3% vs 57.5%, P = 0.035). In addition, EUS provided significantly higher sensitivity than tumor markers using 100 U/mL as the cutoff level of carbohydrate antigen 19-9 (94.1% vs 53%, P = 0.017). On EUS, biliary stricture that was finally diagnosed as malignant showed as a hypoechoic, irregular mass, with obstruction of the biliary duct and invasion to surrounding tissues.

CONCLUSION: EUS can diagnose biliary strictures caused by malignant tumors that are undetectable on CT. Earlier detection by EUS would provide more therapeutic options for patients with early-stage pancreaticobiliary cancer.

Differential diagnosis and treatment of biliary strictures

Biliary tract strictures present both diagnostic and therapeutic challenges to clinicians. Advances in imaging and endoscopic techniques have improved our ability to differentiate between benign and malignant lesions. Intraductal ultrasonography (IDUS), using an endoscopic approach, has the potential to aid in separating benign and malignant biliary lesions. In a series of 93 patients, a majority of whom had cancer, we found that IDUS had a sensitivity and specificity of 89.7% and 84%, respectively, for diagnosing biliary strictures. However, benign strictures associated with untreated autoimmune pancreatitis and/or the intrapancreatic portion of the distal common bile duct could not be easily distinguished from malignant strictures. Direct visualization of biliary mucosa using a percutaneous transhepatic endoscopic approach also helps separate benign from malignant biliary strictures. Further, the ability to obtain multiple directed biopsies using a percutaneous approach also increases diagnostic accuracy. A final advantage of the percutaneous approach is that once a suitable sized tract has been established, biliary strictures and stents can be placed. IDUS and percutaneous biliary endoscopy are promising new modalities for the diagnosis and treatment of biliary strictures.

Intraductal ultrasonography (IDUS) for the diagnosis of biliopancreatic diseases

Intraductal ultrasonography (IDUS) is an imaging modality having unique characteristics and suitable for imaging of a narrow ductal cavity, its wall and the neighbouring structures. As IDUS uses high-frequency ultrasound (12-30MHz), its image quality is very high within approximately 2-cm range of radius. The bile duct and the pancreatic duct, therefore, are good targets for the assessment by IDUS. Biliopancreatic IDUS is mainly performed through the papilla of Vater in the same session as endoscopic retrograde cholangiopancreatography (ERCP). Biliary IDUS is possible through the percutaneous transhepatic route as well. Not many comparative studies on biliopancreatic IDUS have been published. Gallbladder IDUS as well as most pancreatic IDUS are still at the level of clinical research. Constant delineation of Oddi's sphincter with the improvement of instruments will expand the use of IDUS for the assessment of the papilla of Vater lesions.

Clinical application of intraductal ultrasound during endoscopic retrograde cholangiopancreatography

Intraductal ultrasound (IDUS) used during endoscopic retrograde cholangiopancreatography (ERCP) can facilitate reliable evaluation of biliary and pancreatic disorders. The smaller diameter, flexibility, and the image quality offered by IDUS devices makes them ideal for evaluating a variety of difficult biliary and pancreatic diseases, especially in undefined strictures, luminal filling defects, and ampullary neoplasms. This article examines the numerous possible roles for IDUS in the evaluation of biliary and pancreatic conditions, as well as in ampullary neoplasms. IDUS is a simple, easy to learn, and safe technique that should be considered an integral tool in the therapeutic endoscopist's armamentarium.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

Several advances in diagnosis, treatment and palliation of cholangiocarcinoma (CC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. CC is a relatively rare tumor and the main risk factors are: chronic inflammation, genetic predisposition and congenital abnormalities of the biliary tree. While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down. The only curative treatment for CC is surgical resection with negative margins. Liver transplantation has been proposed only for selected patients with hilar CC that cannot be resected who have no metastatic disease after a period of neoadjuvant chemo-radiation therapy. Magnetic resonance imaging/magnetic resonance cholangiopancreatography, positron emission tomography scan, endoscopic ultrasound and computed tomography scans are the most frequently used modalities for diagnosis and tumor staging. Adjuvant therapy, palliative chemotherapy and radiotherapy have been relatively ineffective for inoperable CC. For most of these patients biliary stenting provides effective palliation. Photodynamic therapy is an emerging palliative treatment that seems to provide pain relief, improve biliary patency and increase survival. The clinical utility of other emerging therapies such as transarterial chemoembolization, hepatic arterial chemoinfusion and high intensity intraductal ultrasound needs further study.

Evaluation of malignant and benign bile duct strictures by intraductal ultrasonography

AIM: To determine whether intraductal ultrasonography (IDUS) is of assistance in distinguishing benign from malignant biliary strictures.

METHODS: Sixty-seven patients (all were followed up for 12-36 mo) with biliopancreatic obstruction who underwent the examination of ERCP and IDUS from January 2006 to January 2007 were analyzed, and the difference of imaging diagnosis was compared and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of IDUS were calculated.

RESULTS: Malignant strictures (37 patients) were confirmed histopathologically and benign stricture (30 patients) was confirmed based on negative pathology plus extended clinical follow-up. Sensitivity, specificity, positive predictive values, negative predictive values and accuracy of IDUS for malignant bile duct strictures were 89.2%, 77.4%, 82.5%, 88.9% and 85.1%.

CONCLUSION: Intraductal ultrasonography is safe and is of high value in differentiating benign from malignant biliary strictures.

Are there roles for intraductal US and saline solution irrigation in ensuring complete clearance of common bile duct stones?

BACKGROUND

Persistent small common bile duct (CBD) stones after endoscopic sphincterotomy (EST) and stone extraction may be a nidus for stone growth and could be detected by intraductal US (IDUS). CBD saline solution irrigation may flush out residual stones.

OBJECTIVES

Our purpose was to determine the frequency of residual CBD stones after EST and basket/balloon extraction by using IDUS and to assess the effectiveness of saline solution irrigation in clearing remnant CBD stones.

DESIGN

Prospective study.

SETTING

General Hospital Singapore.

PATIENTS

Seventy patients (mean age 62 years, 51% male) were recruited.

INTERVENTIONS

In the presence of CBD stones, EST and stone extraction were performed, followed by IDUS. If residual stones were detected, a catheter was inserted into the proximal CBD, saline solution irrigation performed, and IDUS repeated.

MAIN OUTCOME MEASUREMENTS

(1) The frequency of residual stones detected by IDUS after EST and basket/balloon extraction and (2) the effect of saline solution irrigation in clearing residual CBD stones.

RESULTS

Cholangiogram showed CBD stones in 38 of 70 patients (median 1 [range 1-5], mean size 7.6 mm [range 3.0-12.0 mm]). IDUS showed CBD stones in 32 of 32 with normal cholangiogram (median 2 [range 1-8], mean size 2.6 mm [range 0.9-7.2 mm]). After EST and stone extraction, IDUS showed persistent stones in 28 of 70 (median: 2 [range 1-5], mean size 2.2 mm [range 1.1-4.6 mm]). The CBD was irrigated with a mean of 48 mL of saline solution. Repeat IDUS showed persistent CBD stones in 2 of 70, and these were flushed out by further saline solution irrigation.

LIMITATIONS

Single-center study.

CONCLUSION

IDUS detected small residual CBD stones that persisted after EST and basket/balloon extraction. Saline solution irrigation appeared useful in clearing residual small stones.

Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUS-guided biopsy is also emphasized, including the addition of molecular marker techniques.