Influence of stricture dilation and repeat brushing on the cancer detection rate of brush cytology in the evaluation of malignant biliary obstruction

Implementing Massive Parallel Sequencing into Biliary Samples Obtained through Endoscopic Retrograde Cholangiopancreatography for Diagnosing Malignant Bile Duct Strictures

Despite advancements in radiologic, laboratory, and pathological evaluations, differentiating between benign and malignant bile duct strictures remains a diagnostic challenge. Recent developments in massive parallel sequencing (MPS) have introduced new opportunities for early cancer detection and management, but these techniques have not yet been rigorously applied to biliary samples. We prospectively evaluated the Oncomine Comprehensive Assay (OCA) and the Oncomine Pan-Cancer Cell-Free Assay (OPCCFA) using biliary brush cytology and bile fluid obtained via endoscopic retrograde cholangiopancreatography from patients with bile duct strictures. The diagnostic performance of MPS testing was assessed and compared to the pathological findings of biliary brush cytology and primary tissue. Mutations in TP53, BRAF, CTNNB1, SMAD4, and K-/N-RAS identified in biliary brush cytology samples were also detected in the corresponding bile fluid samples from patients with extrahepatic cholangiocarcinoma. These mutations were also identified in the bile fluid samples, but with variant allele frequencies lower than those in the corresponding biliary brush cytology samples. In control patients diagnosed with gallstones, neither the biliary brush cytology samples nor the bile fluid samples showed any pathogenic mutations classified as tier 1 or 2. Our study represents a prospective investigation into the role of MPS-based molecular testing in evaluating bile duct strictures. MPS-based molecular testing shows promise in identifying actionable genomic alterations, potentially enabling the stratification of patients for targeted chemotherapeutic treatments. Future research should focus on integrating OCA and OPCCFA testing, as well as similar MPS-based assays, into existing surveillance and management protocols for patients with bile duct strictures.

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Possibility of Cell Block Specimens from Overnight-Stored Bile for Next-Generation Sequencing of Cholangiocarcinoma

The identification of anticancer therapies using next-generation sequencing (NGS) is necessary for the treatment of cholangiocarcinoma. NGS can be easily performed when cell blocks (CB) are obtained from bile stored overnight. We compared NGS results of paired CB and surgically resected specimens (SRS) from the same cholangiocarcinoma cases. Of the prospectively collected 64 bile CBs from 2018 to 2023, NGS was performed for three cases of cholangiocarcinoma that could be compared with the SRS results. The median numbers of DNA and RNA reads were 95,077,806 [CB] vs. 93,161,788 [SRS] and 22,101,328 [CB] vs. 24,806,180 [SRS], respectively. We evaluated 588 genes and found that almost all genetic alterations were attributed to single-nucleotide variants, insertions/deletions, and multi-nucleotide variants. The coverage rate of variants in SRS by those found in CB was 97.9-99.2%, and the coverage rate of SRS genes by CB genes was 99.6-99.7%. The NGS results of CB fully covered the variants and genetic alterations observed in paired SRS samples. As bile CB is easy to prepare in general hospitals, our results suggest the potential use of bile CB as a novel method for NGS-based evaluation of cholangiocarcinoma.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

DISCUSSION

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

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.

Use of catheter-based cholangioscopy in the diagnosis of indeterminate stenosis: a multicenter experience

BACKGROUND

Direct bile ducts visualization through cholangioscopy has gained popularity due to its better diagnostic accuracy than a standard ERCP in indeterminate biliary stricture.

METHODS

We aimed to review our catheter-based cholangioscopy interventions in patients with indeterminate biliary stenosis, using the SpyGlass Direct Visualization System (SDVS) and summarize our experience in terms of procedures and results. We collected 25 consecutive patients with indeterminate biliary stricture over 3 years.

RESULTS

The overall procedural success in our cohort amounted to 96% (24/25). If we focus on the diagnostic procedures, the ability to merely visualize the region of interest/lesion and perform biopsy of the lesion was possible in 96% (24/25) In our cohort localization in the common bile duct (P=0.03; 95% CI: 0.27-0.96) was found as positive determining factor for diagnosis. Sensitivity, specificity and accuracy for visual diagnosis by SDVS in our cohort were 100, 83.3 and 96%, respectively. The use of biopsy or obtaining a histological diagnosis to assist in identifying patients with malignant stenosis, to exclude malignancy and to correctly classify diagnosed patients resulted in a sensitivity of 100%, a specificity of 73% with an overall accuracy of 94.4%. Only a mild adverse event (cholangitis, treated conservatively) occurred.

CONCLUSIONS

Today, the SDVS should be considered essential in diagnosing indeterminate biliary strictures, since the procedure is associated with high procedural success in terms of diagnostic accuracy, alters clinical outcome in over 80% of considered insolvable cases, with an acceptable safety profile.

Multicenter randomized trial comparing diagnostic sensitivity and cellular abundance with aggressive versus standard biliary brushing for bile duct stenosis without mass syndrome

BACKGROUND : The diagnosis of cholangiocarcinoma in patients with a biliary stricture without mass syndrome can be obtained by biliary brushing with a sensitivity of ~50 %. We performed a multicenter randomized crossover trial comparing the aggressive Infinity brush with the standard RX Cytology Brush. The aims were to compare sensitivity for cholangiocarcinoma diagnosis and cellularity obtained. METHODS : Biliary brushing was performed consecutively with each brush, in a randomized order. Cytological material was studied with blinding to the brush type used and order. The primary end point was sensitivity for cholangiocarcinoma diagnosis; the secondary end point was the abundance of cellularity obtained with each brush, with cellularity quantified in order to determine if one brush strongly outperformed the other. RESULTS : 51 patients were included. Final diagnoses were cholangiocarcinoma (n = 43; 84 %), benign (n = 7; 14 %), and indeterminate (n = 1; 2 %). Sensitivity for cholangiocarcinoma was 79 % (34 /43) for the Infinity brush versus 67 % (29/43) for the RX Cytology Brush (P = 0.10). Cellularity was rich in 31/51 cases (61 %) with the Infinity brush and in 10/51 cases (20 %) with the RX Cytology Brush (P < 0.001). In terms of quantification of cellularity, the Infinity brush strongly outperformed the RX Cytology Brush in 28/51 cases (55 %), while the RX Cytology Brush strongly outperformed the Infinity brush in 4/51 cases (8 %; P < 0.001). CONCLUSIONS : This randomized crossover trial showed that the Infinity brush is not significantly more effective than the RX Cytology Brush for biliary stenosis without mass syndrome in terms of sensitivity for cholangiocarcinoma diagnosis, but does offer a significantly higher abundance of cellularity.

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.

Histological assessment of new cholangioscopy-guided forceps in ERCP biliary stricture sampling: a blinded comparative study

Background and study aims  Obtaining quality tissue during ERCP biliary stricture sampling is of paramount importance for a timely diagnosis. While single-operator cholangioscopy (SOC)-guided biopsies have been suggested to be the superior biliary tissue acquisition modality given direct tissue visualization, less is known about the specimen histological quality. We aimed to analyze the specimen quality of SOC biopsies and compare the new generation forceps with prior "legacy" forceps. Patients and methods  Patients who underwent SOC from January 2017-August 2021 for biliary sampling were reviewed. In February 2020, the SOC-guided biopsy forceps were changed from legacy SpyBite to the SpyBite Max forceps (max). Specimens were assessed by blinded pathologists for crush artifact (none, mild, or severe) and gross size (greatest dimension in mm). Crush artifact and gross size were compared between the two groups. The diagnostic performance characteristics for cholangiocarcinoma (CCA), were assessed in an exploratory fashion. Results  Eighty-one patients (max = 27, legacy = 54) with similar baseline characteristics were included in this study. On blinded pathological assessment, 58 % had crush artifact, without significant differences between the two groups (Max 63 % vs. Legacy 56 %; P  = 0.64). A similar mean specimen size was found (max 3 mm vs. legacy 3.2 mm; P  = 0.24). The overall prevalence of CCA was 40 %. The sensitivity, specificity, positive predictive value, and negative predictive value of the entire cohort using a combination of cytology, fluorescence in situ hybridization, and SOC-guided biopsies were 78.1 %, 91.8 %, 86.2 %, and 86.5 %, respectively. No difference between legacy or max groups was found. Conclusions  A high rate of crush artifact was found in SOC-guided biopsy specimens. Further investigation regarding proper biopsy technique and handling is necessary to increase the diagnostic yield with SOC-guided biopsies.

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.

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.

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.

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.

Fluoroscopy-guided shaped endobiliary biopsy at endoscopic retrograde cholangiography can accurately diagnose biliary neoplasia: Results from a large cohort

Background and study aims  The sensitivity of using standard endobiliary forceps biopsy to diagnose neoplastic biliary lesions remains low. We have developed a unique biopsy approach, termed fluoroscopy-guided, shaped endobiliary biopsy (FSEB), in which the biopsy forceps are modified to improve diagnostic yield. In this study, we evaluate the diagnostic characteristics of FSEB for endobiliary lesions at endoscopic retrograde cholangiography (ERC). Patients and methods  Consecutive patients undergoing FSEB between 1/2001 and 12/2014 were retrospectively enrolled. The identification of neoplastic lesions with FSEB, was the primary endpoint. The gold standard of neoplasia was histopathology, cytology or surgical histopathology. The benign cases were followed up for one year. Results  A total of 204 patients undergoing 250 biopsy sessions by FSEB were analyzed. Per-patient analysis was performed and FSEB showed 81.1 % sensitivity and 88.2 % accuracy. FSEB detection of proximal biliary lesions was more sensitive (91.1 % vs 73.2 %, P  < 0.01) and accurate (94.9 % vs 82.2 %, P  < 0.01) compared to distal lesions. No complications from FSEB were reported. Conclusions  FSEB shows high accuracy for diagnosis of neoplasia in biliary strictures, especially for proximal lesions. Future prospective randomized controlled studies are merited to further validate the role of FSEB as the first-line sampling tool for evaluation of biliary neoplasm.

Endoscopic Evaluation of Biliary Strictures: Current and Emerging Techniques

The diagnosis of biliary strictures in clinical practice can be challenging. Discriminating between benign and malignant biliary strictures is important to prevent the morbidity and mortality associated with incorrect diagnoses. Missing a malignant biliary stricture may delay surgery, resulting in poor prognostic outcomes. Conversely, it has been demonstrated that approximately 20% of patients who undergo surgery for suspected biliary malignancies have a benign etiology on histopathology. Traditional tissue sampling using endoscopic retrograde cholangiography does not always produce a definitive diagnosis, with a considerable proportion of cases remaining as indeterminate biliary strictures. Recent advances in endoscopic techniques have the potential to improve the diagnostic and prognostic accuracy of biliary strictures.

Present and future role of endoscopic retrograde cholangiography in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare, inflammatory cholestatic liver disease that causes biliary strictures which can lead to secondary complications. About 30-50% of PSC patients develop dominant strictures (DS) in the biliary tree, which are both the cause of jaundice and bacterial cholangitis as well as predilection spots for development of neoplastic development. Cancer is the most common cause of death in PSC. A central concern is to distinguish malignant from benign strictures, which eventually is done by invasive methods to obtain a brush cytology or biopsy sample, in most cases via endoscopic retrograde cholangiography-pancreatography (ERCP). Since medical therapies, like ursodesoxycholic acid or immunosuppressive drugs have no proven effect, therapeutic ERCP has become the primary management strategy to improve symptoms and in some patients may slow down disease progression. This article aims at outlining the current and emerging methods in ERCP in PSC patients.

Optimal tissue sampling during ERCP and emerging molecular techniques for the differentiation of benign and malignant biliary strictures

Patients with cholangiocarcinoma have poor survival since the majority of patients are diagnosed at a stage precluding surgical resection, due to locally irresectable tumors and/or metastases. Optimization of diagnostic strategies, with a principal role for tissue diagnosis, is essential to detect cancers at an earlier stage amenable to curative treatment. Current barriers for a tissue diagnosis include both insufficient tissue sampling and a difficult cyto- or histopathological assessment. During endoscopic retrograde cholangiopancreatography, optimal brush sampling includes obtaining more than one brush within an individual patient to increase its diagnostic value. Currently, no significant increase of the diagnostic accuracy for the new cytology brush devices aiming to enhance the cellularity of brushings versus standard biliary brush devices has been demonstrated. Peroral cholangioscopy with bile duct biopsies appears to be a valuable tool in the diagnostic work-up of indeterminate biliary strictures, and may overcome current technical difficulties of fluoroscopic-guided biopsies. Over the past years, molecular techniques to detect chromosomal instability, mutations and methylation profiling of tumors have revolutionized, and implementation of these techniques on biliary tissue during diagnostic work-up of biliary strictures may be awaited in the near future. Fluorescence in situ hybridization has already been implemented in routine diagnostic evaluation of biliary strictures in several centers. Next-generation sequencing is promising for standard diagnostic care in biliary strictures, and recent studies have shown adequate detection of prevalent genomic alterations in KRAS, TP53, CDKN2A, SMAD4, PIK3CA, and GNAS on biliary brush material. Detection of DNA methylation of tumor suppressor genes and microRNAs may evolve over the coming years to a valuable diagnostic tool for cholangiocarcinoma. This review summarizes optimal strategies for biliary tissue sampling during endoscopic retrograde cholangiopancreatography and focuses on the evolving molecular techniques on biliary tissue to improve the differentiation of benign and malignant biliary strictures.

Aspiration fluid cytology during single operator cholangioscopy with targeted biopsy to improves the diagnostic yield in indeterminate biliary strictures

INTRODUCTION

Sensitivities of various sampling methods to detect malignant biliary strictures remain suboptimal. Irrigation during digital single operator cholangioscopy (dSOC) is done routinely for visualization of the duct. The aim of this study was to evaluate improvement of the sensitivity for detecting malignant biliary strictures when adding aspiration fluid cytology (AFC) from the irrigated fluid during cholangioscopy to cholangioscopic biopsy (CBx).

METHODS

We conducted a retrospective analysis of patients at a tertiary medical center who underwent CBx for evaluation of their biliary strictures. We included patients who had aspiration of fluid from the bile duct after CBx and were sent for cytology from January 2017 to October 2017. Diagnosis was made on the basis of final pathology or follow-up over 9 months.

RESULTS

Fifty-six patients had CBx obtained, out of which 35 patients had AFC in conjunction. Twenty-two (62%) patients were male and the average age was 65 years. Considering atypical cells as benign, the sensitivity, specificity, positive and negative predictive values (PPV, NPV) for CBx were 62.5%, 100%, 100%, and 76% respectively. When CBx combined with AFC, the above statistics went up to 81.25%, 100%, 100%, and 86.36% respectively. When atypical cells were considered malignant, the sensitivity, specificity, PPV and NPV for CBx were 81.25%, 84.21%, 81.25%, 84.21% and increased to 93.75%, 78.94%, 78.94%, and 93.75% respectively after adding AFC results.

CONCLUSION

For patients with biliary stricture, addition of AFC dSOC guided biopsies, significantly improves the sensitivity for detecting malignancy.

Intraductal Tissue Sampling Device Designed for the Biliary Tract

Clinical sampling of tissue that is read by a pathologist is currently the gold standard for making a disease diagnosis, but the few minimally invasive techniques available for small duct biopsies have low sensitivity, increasing the likelihood of false negative diagnoses. We propose a novel biopsy device designed to accurately sample tissue in a biliary stricture under fluoroscopy or endoscopic guidance. The device consists of thin blades organized around the circumference of a cylinder that are deployed into a cutting annulus capable of comprehensively sampling tissue from a stricture. A parametric study of the device performance was done using finite element analysis; this includes the blade deployment under combined axial compression and torsion followed by an axial 'cutting' step. The clinical feasibility of the device is determined by considering maximum deployment forces, the radial expansion achieved and the cutting stiffness. We find practical parameters for the device operation to be an overall length of 10 mm and a diameter of 3.5 mm for a [Formula: see text] blade thickness, which allow the device to be safely deployed with a force of 10N and achieve an expansion over 3x its original diameter. A model device was fabricated with these parameters and a [Formula: see text] thickness out of a NiTi superalloy and tested to validate the performance. The device showed strong agreement with an equivalent numerical model, reaching a peak force within 2% of that predicted numerically and fully recovering after compression to 20% of its length. Clinical and Translational Impact Statement -This pre-clinical research conceptually demonstrates a novel expandable device to biopsy tissue in narrow strictures during an ERCP procedure. It can greatly improve diagnostic tissue yield compared to existing methods.

Assessment of different modalities for repeated tissue acquisition in diagnosing malignant biliary strictures: A two-center retrospective study

OBJECTIVE

Various modalities are applied for pathological diagnosis of malignant biliary strictures (MBS), including brush cytology (BC), forceps biopsy (FB) and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). We aimed to assess the value of these modalities in a repeated tissue acquisition process for biliary strictures with initially inconclusive pathological outcomes.

METHODS

Patients who were suspected of having MBS and underwent a BC in two large teaching hospitals were retrospectively included. The sensitivity, specificity, positive and negative predictive values, and accuracy of the initial and repeated BC, FB and EUS-FNA were analyzed. Their performances were compared to determine which modality was superior in repeated tissue acquisition.

RESULTS

In total, 476 patients were included. The sensitivity, specificity and accuracy in diagnosing MBS for the initial BC were 30.3%, 100% and 55.0%, respectively. Altogether 39, 27 and 44 patients underwent a repeat BC, FB and EUS-FNA, respectively. The sensitivity for repeated BC, FB and EUS-FNA was 41.2%, 61.1% and 44.4%, respectively, whereas their specificity all reached 100%. When comparing diagnostic accuracy, none of the modalities was superior (74.4% vs 74.1% vs 54.5%, P = 0.173). In the repeated process, one patient who underwent BC and two underwent FB developed mild pancreatitis.

CONCLUSIONS

Repeated tissue acquisition achieves a conclusive diagnosis of MBS in nearly half patients who have an initially inconclusive cytological diagnosis. None of the tissue acquisition methods is significantly superior in the repeated process.

Comparison of the Diagnostic Performance of Novel Slim Biopsy Forceps with Conventional Biopsy Forceps for Biliary Stricture: A Multicenter Retrospective Study

Novel slim biopsy forceps provide some technical advantages to facilitate a more accurate diagnosis, although we are not aware of any comparative studies. Therefore, we compared tissue acquisition and diagnostic accuracy between novel slim biopsy forceps and conventional biopsy forceps in cases with a biliary stricture. We reviewed 341 patients who underwent endoscopic retrograde cholangiopancreatography for the histological confirmation of biliary stricture at two tertiary hospitals between 2013 and 2020. The primary endpoint was the forceps’ diagnostic accuracies. We included 276 patients who underwent biopsy using the novel forceps (n = 130) or conventional forceps (n = 146). The novel forceps provided 81.7% sensitivity, 100.0% specificity, positive-predictive value (PPV) of 100.0%, and negative-predictive value (NPV) of 57.8%, with an accuracy of 85.4% when the diagnosis by endobiliary biopsy included suspected or positive malignancy. The conventional forceps provided 61.7% sensitivity, 100.0% specificity, PPV of 100.0%, and NPV of 36.1%, with an accuracy of 68.5%. Only novel forceps use was significantly associated with an accurate diagnosis (odds ratio: 2.70, 95% confidence interval: 1.52–5.00). There were no significant inter-group differences in the procedure-related rates of adverse events. Endobiliary biopsy using novel forceps offered better diagnostic performance and more acceptable procedure-related adverse events than conventional forceps.

Transpapillary tissue sampling of biliary strictures: balloon dilatation prior to forceps biopsy improves sensitivity and accuracy

The early and definitive diagnosis of malignant bile duct stenoses is essential for a timely and adequate therapy. However, tissue sampling with transpapillary brush cytology (BC) or forceps biopsy (FB) remains challenging. With this study, we aimed to compare the effectiveness and safety of different tissue sampling modalities (BC, FB without/after previous balloon dilatation). Standardized database research identified all patients, who underwent endoscopic retrograde cholangiography with BC and/or FB for indeterminate bile duct stenosis between January 2010 and April 2018 and with a definitive diagnosis. 218 patients were enrolled (149 cases with malignant and 69 with benign disease). FB had a significant higher sensitivity than BC (43% vs. 16%, p < 0.01). Prior balloon dilatation of the stenosis improved the sensitivity of FB from 41 to 71% (p = 0.03), the NPV from 36 to 81% (p < 0.01) and the accuracy from 55 to 87% (p < 0.01). The complication rates did not differ significantly between the modalities. In our center FB turned out to be the diagnostically more effective procedure. Balloon dilatation of the stenosis before FB had a significant diagnostic benefit and was not associated with a higher complication rate.

Cytomorphologic characteristics of next-generation sequencing-positive bile duct brushing specimens

INTRODUCTION

Cytology of bile duct brushings (BDBs) is a specific, but insensitive, test for malignancy. Next-generation sequencing (NGS) of BDBs has recently been shown to improve sensitivity. We analyzed the cytologic features of NGS-positive (NGS⁺) and NGS-negative (NGS^-) BDBs and correlated the morphology with the presence of mutations.

MATERIALS AND METHODS

A total of 96 BDBs were analyzed for 29 cytologic features by 2 pathologists who were unaware of the original diagnosis and NGS results. Clinicopathologic follow-up was used to determine the patient outcomes (ie, benign, low-grade neoplasm, malignant [carcinoma/high-grade dysplasia]).

RESULTS

We analyzed 74 NGS⁺ BDBs from 66 patients and 22 NGS^- BDBs from 22 patients. During follow-up, 58 of 66 NGS⁺ patients (88%) had malignancy compared with 0% of NGS^- patients (P < 0.001). Fewer than 50% of the malignant cases had been interpreted as malignant on cytology; however, 100% had demonstrated mutations using NGS. Within the NGS⁺ cases, 53% showed late mutations (TP53, SMAD4, and CDKN2A) supportive of a high-risk stricture. Significant morphologic differences were seen in the background appearance, presence of single cells, architectural disarray, nucleomegaly, anisonucleosis, irregular nuclear borders, increased nuclear/cytoplasmic ratio, nuclear hyperchromasia, nucleoli, abnormal groups, clusters, and/or single cells, and overall impression. Naked nuclei, nucleomegaly, anisonucleosis, and coarse chromatin were more common in BDBs with late mutations than in those with KRAS/GNAS (Kirsten rat sarcoma viral oncogene homolog/guanine nucleotide binding protein, α-stimulating complex locus) mutations only. Cytology had a sensitivity of 16% and a specificity of 100% for malignancy. In contrast, NGS had a sensitivity of 100% and a specificity of 73%. Late mutations were 100% specific for malignancy compared with mutations in KRAS/GNAS only, of which 69% were malignant.

CONCLUSIONS

We found significant overlap in the cytomorphologic features between neoplastic and non-neoplastic BDBs, and more than one half of cancer cases had been interpreted as "nonmalignant" on cytology. NGS showing late mutations was 100% specific for malignancy. Adding genetic testing to BDB cytology would be a valuable ancillary test for the detection of malignancy, and reflex testing should be considered.

Challenging biliary strictures: pathophysiological features, differential diagnosis, diagnostic algorithms, and new clinically relevant biomarkers - part 1

It is frequently challenging to make the correct diagnosis in patients with biliary strictures. This is particularly important as errors may have disastrous consequences. Benign-appearing strictures treated with stents may later be revealed to be malignant and unnecessary surgery for benign strictures carries a high morbidity rate. In the first part of the review, the essential information that clinicians need to know about diseases responsible for biliary strictures is presented, with a focus on the most recent data. Then, the characteristics and pitfalls of the methods used to make the diagnosis are summarized. These include serum biomarkers, imaging studies, and endoscopic modalities. As tissue diagnosis is the only 100% specific tool, it is described in detail, including techniques for tissue acquisition and their yields, how to prepare samples, and what to expect from the pathologist. Tricks to increase diagnostic yields are described. Clues are then presented for the differential diagnosis between primary and secondary sclerosing cholangitis, IgG4-related sclerosing cholangitis, cholangiocarcinoma, pancreatic cancer, autoimmune pancreatitis, and less frequent diseases. Finally, algorithms that will help to achieve the correct diagnosis are proposed.

Efficacy of digital single-operator cholangioscopy and factors affecting its accuracy in the evaluation of indeterminate biliary stricture

BACKGROUND AND AIMS

Indeterminate biliary stricture remains a significant diagnostic challenge. The current method of ERCP with bile duct brush cytology has substantial room for improvement. We aimed to determine the efficacy of a digital single-operator cholangioscopy (DSOC) in evaluation of indeterminate biliary stricture.

METHODS

An observational cohort study was conducted among the patients who underwent DSOC for the indication of indeterminate biliary stricture at a tertiary academic medical center. The outcomes of interests were the accuracy of DSOC in visual interpretation and bile duct sample and identification of any factor(s) that could influence its effectiveness.

RESULTS

One hundred five patients were included. The overall accuracy of DSOC in visual interpretation was 89.5%, whereas the accuracy of bile duct sample was 83.2%. The sensitivities of visual impression and bile duct sample were 89.1% and 69.8% and their specificities were 90% and 97.9%, respectively. The degree of endoscopists' experience with fewer than 25 cases and the severity of hyperbilirubinemia negatively impacted the accuracy of DSOC. Among 55 patients with definitive diagnosis of malignant stricture, the sensitivity of combined intraductal forceps biopsy sampling and brush cytology was 80.6%, whereas the sensitivity of brush cytology alone was 47.1%.

CONCLUSIONS

DSOC augments ERCP in evaluating indeterminate biliary stricture. The acquisition of intraductal forceps biopsy samples should be a requisite in evaluation of indeterminate biliary stricture with DSOC. Discovery of modifiable factors such as the degree of endoscopists' expertise and the severity of hyperbilirubinemia, which can influence the accuracy of DSOC, warrants further studies on patient preprocedure optimization and an endoscopic training program that will cultivate procedural competency.

Integrating next-generation sequencing to endoscopic retrograde cholangiopancreatography (ERCP)-obtained biliary specimens improves the detection and management of patients with malignant bile duct strictures

OBJECTIVE

Despite improvements in imaging, serum CA19-9 and pathological evaluation, differentiating between benign and malignant bile duct strictures remains a diagnostic conundrum. Recent developments in next-generation sequencing (NGS) have opened new opportunities for early detection and management of cancers but, to date, have not been rigorously applied to biliary specimens.

DESIGN

We prospectively evaluated a 28-gene NGS panel (BiliSeq) using endoscopic retrograde cholangiopancreatography-obtained biliary specimens from patients with bile duct strictures. The diagnostic performance of serum CA19-9, pathological evaluation and BiliSeq was assessed on 252 patients (57 trainings and 195 validations) with 346 biliary specimens.

RESULTS

The sensitivity and specificity of BiliSeq for malignant strictures was 73% and 100%, respectively. In comparison, an elevated serum CA19-9 and pathological evaluation had sensitivities of 76% and 48%, and specificities of 69% and 99%, respectively. The combination of BiliSeq and pathological evaluation increased the sensitivity to 83% and maintained a specificity of 99%. BiliSeq improved the sensitivity of pathological evaluation for malignancy from 35% to 77% for biliary brushings and from 52% to 83% for biliary biopsies. Among patients with primary sclerosing cholangitis (PSC), BiliSeq had an 83% sensitivity as compared with pathological evaluation with an 8% sensitivity. Therapeutically relevant genomic alterations were identified in 20 (8%) patients. Two patients with ERBB2-amplified cholangiocarcinoma received a trastuzumab-based regimen and had measurable clinicoradiographic response.

CONCLUSIONS

The combination of BiliSeq and pathological evaluation of biliary specimens increased the detection of malignant strictures, particularly in patients with PSC. Additionally, BiliSeq identified alterations that may stratify patients for specific anticancer therapies.

The ideal technique for processing SpyBite tissue specimens: a prospective, single-blinded, pilot-study of histology and cytology techniques

Background and study aims  Diagnostic sensitivity for indeterminate biliary lesions remains suboptimal. Cytology techniques may mitigate the impediment of small cholangioscopic specimens. Our primary aim was to compare cell block cytology (CB) with standard histology for foregut SpyBite (SB) specimens. Our secondary aim was to assess CB in biliary SB biopsies. Patients and methods  This was a two-phase prospective pilot study. In phase one, a prospective pilot study, foregut SB specimens from three sites (4 per site per patient per processing technique) were allocated to CB or histology, and assessed by a single, blinded pathologist. The gold standard comprised two standard forceps (CFB) histological specimens per site per patient. Specimen ease of processing, size and number, adequacy for diagnosis and artefact were evaluated. In phase two, CB was used for consecutive patients with indeterminate biliary lesions, and compared with phase one CB results. Results  In phase one, 240 SB foregut biopsies were performed in 10 patients, 227 specimens recorded by pathologist. Specimen origin was identified in 100 % and 97 % of histology and CB batches respectively. Specimens were significantly larger in the histology group (2.02 mm vs 1.49 mm, P  < 0.05). There was a trend to less crush artifact with CB, and no difference in processing difficulty. In phase two, 11 patients (63.0 ±12.7 years, 91 % female) underwent SpyGlass (SG) assessment of suspected indeterminate stricture (n = 8) or mass (n = 3), and six underwent SB. All CB specimens were adequate for diagnosis. Specimen parameters were not significantly different from luminal CB outcomes. Conclusions  In this pilot study, cell block cytology showed similar results as histological analysis of SpyBite specimens in the analysis of biliary stricture.

Brush Cytology Performance for the Assessment of Biliopancreatic Strictures

INTRODUCTION

Brush cytology is commonly used during endoscopic retrograde cholangiopancreatography for the diagnostic evaluation of biliopancreatic strictures. However, since the overall sensitivity of brush cytology is poor, the exclusion of malignancy is difficult. Recognition of factors related to the patient, technique or lesion may help improve the diagnostic yield of brush cytology. The objective of this study was to evaluate the diagnostic yield of brush cytology in the assessment of biliopancreatic strictures and identify predictive factors associated with a positive diagnosis of malignancy.

METHODS

Retrospective study that evaluated all consecutive patients that underwent brush cytology for the investigation of biliopancreatic strictures in a tertiary center, between January 2012 and January 2018.

RESULTS

One hundred and sixty-five patients that underwent 182 procedures were included. A diagnosis of malignancy was confirmed in 110 patients (66.7%), of whom 62 had positive brush cytology (sensitivity 53.7%, specificity 98.5%, accuracy 69.8%). On the multivariate analysis, age ≥68 years (OR 4.83, 95% CI 1.04-22.37) and lesions suspicious of metastasis on cross-sectional imaging (OR 8.58, 95% CI 1.70-43.38) were independently associated with a positive result. Subanalysis of the patients presenting with these two factors (n = 26) revealed an increase in the diagnostic yield (sensitivity 80.8%).

CONCLUSION

Age ≥68 years and lesions suspicious of metastasis on cross-sectional imaging are independent factors associated with a positive result. Patient selection taking these factors into account may increase the diagnostic yield of brush cytology.

Analysis of microRNA expression in brush cytology specimens improves the diagnosis of pancreatobiliary cancer

BACKGROUND/OBJECTIVES

Malignant pancreatobiliary strictures are in many cases clinically indistinguishable and present a major problem to endoscopy specialists. Intraductal sampling procedures such as brush cytology are commonly used for diagnosis with a sensitivity that is low for a diagnostic test used in daily clinical practice. MicroRNA (miR) alterations detected in many cancers are disease-specific, which can be utilized in clinical applications. The aim of the present study was to analyze whether determination of miR expression levels in intraductal brush cytology specimens is a feasible approach to improve the diagnosis of pancreatobiliary cancer.

METHODS

Brush cytology specimens have been collected during endoscopic retrograde cholangio-pancreatography (ERCP) and analyzed by routine cytology and ancillary miR assays. Total RNA was extracted using the miRNeasy Mini Kit and the expression of miRs frequently dysregulated in pancreatobiliary cancer (miR-16, miR-21, miR-196a, miR-221) were analyzed by quantitative real-time PCR using RNU6B as internal control.

RESULTS

Routine cytology resulted in no false positive diagnoses, however, the combined sensitivity remained at 53.8%. Expression (ΔCt values) of miR-16 (p = 0.0039), miR-196a (p = 0.0003) and miR-221 (p = 0.0049) showed a clear statistical significance between malignant and benign pancreatobiliary specimens (n = 35). Malignancy could be detected combining routine cytology and the miR-196a single marker expression levels with a sensitivity of 84.6% (92.9% in biliary strictures) with no false positives.

CONCLUSIONS

The results offer the first direct demonstration that microRNAs are readily detectable in brush cytology specimens obtained during ERCP, and have the potential to help the cytological diagnosis of pancreatobiliary malignancy.

Cholangioscopy: seeing to believe, seeing to know, seeing to cure

Endoscopic retrograde cholangiopancreatography (ERCP) remains the gold standard for the diagnosis and treatment of biliopancreatic disorders, and over one million ERCP procedures are performed each year worldwide. ERCP has always been performed by a group of courageous endoscopists who on a daily basis managed to develop its full diagnostic and therapeutic potential over the technique's 50 years of lifespan, always making the most of radiographic images, ever secretly dreaming of directly viewing the banned, consigned-to-oblivion territory.

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.

Modern work-up and extended resection in perihilar cholangiocarcinoma: the AMC experience

AIM

Perihilar cholangiocarcinoma (PHC) is a challenging disease and requires aggressive surgical treatment in order to achieve curation. The assessment and work-up of patients with presumed PHC is multidisciplinary, complex and requires extensive experience. The aim of this paper is to review current aspects of diagnosis, preoperative work-up and extended resection in patients with PHC from the perspective of our own institutional experience with this complex tumor.

METHODS

We provided a review of applied modalities in the diagnosis and work-up of PHC according to current literature. All patients with presumed PHC in our center between 2000 and 2016 were identified and described. The types of resection, surgical techniques and outcomes were analyzed.

RESULTS AND CONCLUSION

Upcoming diagnostic modalities such as Spyglass and combinations of serum biomarkers and molecular markers have potential to decrease the rate of misdiagnosis of benign, inflammatory disease. Assessment of liver function with hepatobiliary scintigraphy provides better information on the future remnant liver (FRL) than volume alone. The selective use of staging laparoscopy is advisable to avoid futile laparotomies. In patients requiring extended resection, selective preoperative biliary drainage is mandatory in cholangitis and when FRL is small (< 50%). Preoperative portal vein embolization (PVE) is used when FRL volume is less than 40% and optionally includes the left portal vein branches to segment 4. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) as alternative to PVE is not recommended in PHC. N2 positive lymph nodes preclude long-term survival. The benefit of unconditional en bloc resection of the portal vein bifurcation is uncertain. Along these lines, an aggressive surgical approach encompassing extended liver resection including segment 1, regional lymphadenectomy and conditional portal venous resection translates into favorable long-term survival.

Outcomes of Different Methods for Analysis of Biliary Brush Cytology and of Factors Associated with Positive Diagnosis in an Age-Dependent Retrospective Review

Background and Aims

Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is the most frequently used strategy for obtaining a tissue sample from an indeterminate biliary stricture. A recent study reported that age is a factor associated with positive yields, but further analysis of how age influences the results was lacking. We aimed to evaluate clinical effectiveness of biliary cytology and prognostic factors for a positive outcome, especially age.

Methods

This study was a single-center, retrospective, clinical study of 77 consecutive patients who underwent brush cytology during ERCP to obtain a diagnosis of an indeterminate biliary stricture. We compared 2 routine cytology techniques: A (smear); B (centrifugation of the cytological material collected and the cut-off brush + cell block when sufficient amount of material was available). The data were collected aiming to compare the accuracy of the different techniques used and the prognostic factors affecting the outcome, with a particular focus on age. The yield for brush cytology was compared with the gold standard defined as either definitive histology or the long-term clinical course.

Results

The overall accuracy of the 2 used methods was 75.3%. Sensitivity was 52.5%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 66.1%. Although not statistically significant, there was a trend toward accuracy for method B compared with method A (80.4 vs. 65.4%; p = 0.153). Multiple logistic regression analysis showed that younger age was the only independent prognostic factor associated with a positive diagnosis (OR 0.95; 95% CI 0.90-0.99; p = 0.039). Receiver operating characteristic curves for age yielded an area under the curve value of 68.2%. On the basis of the Youden index, 69 years was found to be the optimal cutoff for age.

Conclusions

In this series, the accuracy of routine biliary brush cytology was not equal for all methods and ages; in particular, younger patients (below 69 years) tended to have a higher probability of a correct diagnosis.

Evaluation of novel slim biopsy forceps for diagnosis of biliary strictures: Single-institutional study of consecutive 360 cases (with video)

AIM

To evaluate the feasibility and reliability of endoscopic transpapillary bile duct biopsy for the diagnosis of biliary strictures.

METHODS

A total of 360 patients (241 men) who underwent endoscopic retrograde cholangiopancreatography for biliary strictures with biopsy from April 2012 to March 2016 at Tokyo Medical University Hospital were retrospectively reviewed. This study was approved by our Institutional Review Board (No. 3516). Informed consent was obtained from all individual participants included in this study. The biopsy specimens were obtained using a novel slim biopsy forceps (Radial Jaw 4P, Boston Scientific, Boston, MA, United States).

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 69.6%, 100%, 100%, 59.1%, and 78.8%, respectively. The sensitivity was 75.6% in bile duct cancer, 64% in pancreatic cancer, 61.1% in gallbladder cancer, and 57.1% in metastasis. In bile duct cancer, a lower sensitivity was observed for perihilar bile duct stricture (68.7%) than for distal bile duct stricture (83.1%). In terms of the stricture lengths of pancreatic cancer, gallbladder cancer, and metastasis, a longer stenosis resulted in a better sensitivity. In particular, there was a significant difference between pancreatic cancer and gallbladder cancer (P < 0.05). One major complication was perforation of the extrahepatic bile duct with bile leakage.

CONCLUSION

Endoscopic transpapillary biopsy alone using novel slim biopsy forceps is feasible and reliable, but restrictive. Biopsy should be performed in consideration of the stricture level, stricture length, and cancer type.

Prospective evaluation of the short access cholangioscopy for stone clearance and evaluation of indeterminate strictures

BACKGROUND

Peroral cholangioscopy facilitates diagnosis and therapy of biliary disorders. This study prospectively evaluated a new short access cholangioscopy.

METHODS

Consecutive patients were included as follows: difficult stones (group 1) underwent cholangioscopy with electrohydraulic lithotripsy and indeterminate biliary strictures (group 2) were evaluated with macroscopic assessment and cholangioscopy guided biopsy sampling. We evaluated the complete stone clearance rate (group 1) and diagnostic accuracy (group 2). Follow-up was performed over a median of 13 and 16 months, respectively.

RESULTS

Group 1 (n=21): complete stone clearance defined as lack of stones in cholangiography and stone removal during cholangioscopy was achieved in 15 (71.4%) patients. Clinical stone clearance defined as lack of symptoms, laboratory abnormalities and hospital visits during follow-up, irrespective of stone clearance was evident in 17 (81.0%) patients. One serious adverse event occurred (bile duct perforation). Group 2 (n=28): malignancy was confirmed in 15 patients. Sensitivity, specificity and diagnostic accuracy of cholangioscopy were 85.7%, 75.0% and 80.7%, respectively. Sensitivity, specificity and diagnostic accuracy of biopsies were 54.5%, 100.0% and 72.2%, respectively. No serious adverse events occurred, and one patient was lost to follow-up.

CONCLUSIONS

The novel system enabled complex stone treatment and biliary stricture diagnosis. Cholangioscopy outperformed direct biopsy regarding characterization of indeterminate strictures.

Dilation of Strictures in Patients with Inflammatory Bowel Disease: Who, When and How

Stricture formation occurs in up to 40% of patients with inflammatory bowel disease (IBD). Patients are often symptomatic, resulting in significant morbidity, hospitalizations, and loss of productivity. Strictures can be managed endoscopically in addition to traditional surgical management (sphincteroplasty or resection of the affected bowel segments). About 3% to 5% patients with IBD develop primary sclerosing cholangitis (PSC), which results in stricture formation in the biliary tree, managed for the most part by endoscopic therapies. In this article, we discuss endoscopic management of strictures both in the alimentary tract and biliary tree in patients with IBD and/or PSC.

Transpapillary biliary biopsy for malignant biliary strictures: comparison between cholangiocarcinoma and pancreatic cancer

BACKGROUND

Tissue sampling for biliary stricture is important for differential diagnosis and further treatment. This study aims to assess the differences of transpapillary biliary biopsy for malignant biliary strictures between cholangiocarcinoma and pancreatic cancer.

METHODS

From January 2010 to December 2013, we retrospectively studied 79 patients who suffered from biliary strictures and received transpapillary forceps biopsy after sphincterotomy for tissue sampling. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of forceps biopsy were calculated in all cases for both cholangiocarcinoma and pancreatic cancer patients. Possible factors that distinguish malignant strictures from benign strictures and which could affect the accuracy of tissue sampling were analyzed.

RESULTS

There are 65 malignant and 14 benign biliary stricture patients enrolled. The malignant group has a significantly higher serum bilirubin level than the benign group, but age, clinical presentation, level of serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, and alkaline phosphatase are not. The sensitivity, specificity, PPV, and NPV of forceps biopsy for biliary stricture are 53.85, 100, 100, and 31.82%, respectively. The cholangiocarcinoma group has a higher sensitivity (73.53 versus 29.17%, p < 0.001), older age, lower CA 19-9 level, and more common hepatic duct strictures than the pancreatic group. The age, serum CEA, CA 19-9 and the alkaline phosphatase level, serum bilirubin level >10 mg/dL, tissue sampling ≧3 are not significant factors affecting diagnostic accuracy in forceps biopsy for pancreatobiliary strictures. There is neither major bleeding nor perforation in our study.

CONCLUSIONS

Transpapillary forceps biopsy of biliary strictures after sphincterotomy for tissue sampling is safe and a significantly higher sensitive method in cholangiocarcinoma but not in pancreatic cancer.

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.

The Role of Endoscopy in the Diagnosis and Management of Cholangiocarcinoma

Cholangiocarcinomas (CCAs) are associated with poor overall survival, and majority of the tumors are unresectable at the time of diagnosis. Early diagnosis at a resectable stage is essential for improved outcomes. Noninvasive imaging plays an important role in evaluating patients with biliary obstruction, but is limited due to the lack of tissue sampling and in many cases due to the absence of a mass, especially for extrahepatic CCAs. Endoscopic diagnosis is needed in majority of patients with CCA and the diagnostic yield depends on the tumor location as well as the expertise and experience of the endoscopist. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound remain the most common endoscopic diagnostic tools although newer technologies including fluorescence in situ hybridization, single-operator cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound are being increasing used. Traditionally, the role of endoscopy has been mainly palliative and limited to biliary drainage in patients with obstructive jaundice, however, newer treatment options like photodynamic therapy and radiofrequency ablation have shown promise toward improved patient survival. Multidisciplinary approach that involves medical oncology, gastroenterology, radiology, and surgical oncology teams is imperative for improved outcomes. In this review, we will first review the diagnostic approach to CCAs including imaging and endoscopic methods followed by a discussion of different endoscopic techniques in management of patients after a diagnosis of CCA.

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.