Comparison of the diagnostic accuracy of peroral video-cholangioscopic visual findings and cholangioscopy-guided forceps biopsy findings for indeterminate biliary lesions: a prospective study

Direct Single-Operator Cholangioscopy and Intraductal Ultrasonography in Patients with Indeterminate Biliary Strictures: A Single Center Experience

The evaluation of biliary strictures poses a challenge due to the low sensitivity of standard diagnostic approaches, but the advent of direct single-operator cholangioscopy (DSOC) has revolutionized this paradigm. Our study aimed to assess the diagnostic performance of DSOC and DSOC-targeted biopsies, intraductal ultrasound (IDUS), and standard brush cytology in patients with indeterminate biliary strictures (IBS). We reviewed patients who underwent advanced diagnostic evaluation for IBS at our endoscopy unit from January 2018 to December 2022, all of whom had previously undergone at least one endoscopic attempt to characterize the biliary stricture. Final diagnoses were established based on surgical pathology and/or clinical and radiological follow-up spanning at least 12 months. A total of 57 patients, with a mean age of 67.2 ± 10.0 years, were included, with a mean follow-up of 18.2 ± 18.1 months. The majority of IBS were located in the distal common bile duct (45.6%), with malignancy confirmed in 35 patients (61.4%). DSOC and IDUS demonstrated significantly higher accuracies (89.5% and 82.7%, respectively) compared to standard cytology (61.5%, p < 0.05). Both DSOC visualization and IDUS exhibited optimal diagnostic yields in differentiating IBS with an acceptable safety profile.

The contribution of new methods in cytology for increasing sensitivity in the diagnosis of extrahepatic bile duct lesions

The aim of this review is to provide a comprehensive analysis of the existing literature pertaining to cytology of extrahepatic bile ducts. A search using the keywords "biliary brush cytology" was conducted in the PubMed database, with a focus on recent articles. The inclusion criteria primarily encompassed publications addressing problematic biliary stenosis. Emphasis was placed on identifying articles that explored innovative or less-utilized examination techniques aimed at enhancing the sensitivity of cytological examination. This review presents a comprehensive overview of the various types of materials used in sampling and the corresponding sampling methods. Additionally, it explores cytological and cytogenetic techniques, such as fluorescence in situ hybridization (FISH) and genetic methods (miRNA, NGS, cfDNA). These techniques possess the potential to improve the accuracy of diagnosing bile duct tumors, although their sensitivity varies. Furthermore, their utilization can facilitate early therapy, which plays a crucial role in patient prognosis. Each examination is always dependent on the quality and quantity of material delivered. A higher sensitivity of these examinations can be achieved by combining biliary cytology and other complementary methods.

Clinical approach to indeterminate biliary strictures: Clinical presentation, diagnosis, and workup

Despite advances in cross-sectional imaging and endoscopic technology, bile duct strictures remain a challenging clinical entity. It is crucial to make an early determination of benign or malignant nature of biliary strictures. Early diagnosis not only helps with further management but also minimizes mortality and morbidity associated with delayed diagnosis. Conventional imaging and endoscopic techniques, particularly endoscopic retrograde cholangiopancreatography (ERCP) and tissue sampling techniques play a key in establishing a diagnosis. Indeterminate biliary strictures (IDBSs) have no definite mass on imaging or absolute histopathological diagnosis and often warrant utilization of multiple diagnostics to ascertain an etiology. In this review, we discuss possible etiologies, clinical presentation, diagnosis, and management of IDBSs. Based on available data and expert opinion, we depict an evidence based diagnostic algorithm for management of IDBSs. Areas of focus include use of traditional tissue sampling techniques such as ERCP with brush cytology, intraductal biopsies, fluorescence in situ hybridization and flow cytometry. We also describe the role of endoscopic ultrasound (EUS)-guided fine needle aspiration and biopsies, cholangioscopy, confocal laser endomicroscopy, and intraductal EUS in management of IDBSs.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A comparative study on the application of different endoscopic diagnostic methods in the differential diagnosis of benign and malignant bile duct strictures

Objective

To compare the diagnostic value of cytobrush, ERCP-guided biopsy, SpyGlass direct visual impression and SpyGlass-guided biospy (SpyBite) in the differential diagnosis of benign and malignant bile duct strictures.

Methods

The data of 1,008 patients who were clinically diagnosed with indeterminate biliary strictures and underwent ERCP-guided biopsy, cytobrush, SpyGlass direct visual impression or SpyBite at the First Affiliated Hospital of Nanchang University between January 2010 and December 2019 were collected and analyzed retrospectively. The final diagnose was determined by surgical pathological specimen or follow-up (Malignant stricture can be identified if the stricture showed malignant progression during one year of follow-up). The differential diagnostic value of the above endoscopic diagnostic methods was evaluated by means of sensitivity, specificity, accuracy, positive predictive value, negative predictive value, etc. and safety was evaluated by the incidence rate of adverse events.

Results

In terms of sensitivity, standard biopsy group (48.6%) and SpyBite group (61.5%) were significantly higher than cytobrush group (32.0%), and visual impression group (100%) was significantly higher than any other group. As far as specificity was concerned, cytobrush group (99.0%), standard biopsy group (99.3%) and the SpyBite group (100%) were significantly higher than visual impression (55.6%), but there was no statistical difference among the three groups above. As far as accuracy was concerned, standard biopsy group (65.3%), and SpyBite group (80.0%) were significantly higher than cytobrush group (44.4%), and SpyBite group (80.0%) was significantly higher than visual impression group (54.8%). In terms of safety, visual impression group and SpyBite group were significantly higher than cytobrush group and standard biopsy group in post-ERCP cholangitis.

Conclusion

SpyBite combined with SpyGlass-guided visual impression was better for differential diagnosis of benign and malignant bile duct strictures in terms of sensitivity and accuracy compared with conventional endoscopic diagnostic methods such as cytobrush and standard biopsy. Furthmore, the incidence rates of adverse events after SpyGlass examination was similar to those after conventional endoscopic diagnostic methods except for higher cholangitis, which could be controlled by antibiotics and might be avoided by adequate biliary drainage.

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Screening for hilar biliary invasion in ampullary cancer patients

BACKGROUND

The treatment for ampullary cancer is pancreatoduodenectomy or local ampullectomy. However, effective methods for the preoperative investigation of hilar biliary invasion in ampullary cancer patients have not yet been identified.

AIM

To determine the necessity of and an appropriate method for investigating hilar biliary invasion of ampullary cancer.

METHODS

Among 43 ampullary cancer patients, 34 underwent endoscopic treatment (n = 9) or surgery (n = 25). The use of imaging findings (thickening and enhancement of the bile duct wall on contrast-enhanced computed tomography, irregularity on endoscopic retrograde cholangiography, thickening of the entire bile duct wall on intraductal ultrasonography (IDUS), and partial thickening of the bile duct wall on IDUS) and biliary biopsy results for diagnosing hilar biliary invasion of ampullary cancer was compared.

RESULTS

Hilar invasion was not observed in every patient. Among the patients who did not undergo biliary stent insertion, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results showed the highest accuracy (100%) for diagnosing hilar biliary invasion. However, each imaging method and biliary biopsy yielded some false-positive results.

CONCLUSION

Although some false-positive results were obtained with each method, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results was useful for diagnosing hilar biliary invasion of ampullary cancer. However, hilar invasion of ampullary cancer is rare; therefore, the investigation of hilar biliary invasion of ampullary cancer might be unnecessary.

Identification of endoscopic predictors of biliary malignancy during digital cholangioscopy

OBJECTIVES

Biliary brushings and biopsies obtained during endoscopic retrograde cholangiopancreatography (ERCP) have a low sensitivity for the diagnosis of malignant biliary strictures. While cholangioscopic analysis is useful, visual criteria have not yet been defined. The aim of this study was to identify visual criteria for the diagnosis of indeterminate biliary strictures (IDBS).

METHODS

A multicenter study was conducted based on the analysis of cholangioscopic recordings of IBDS. Diagnostic criteria were identified in a study group and verified in a validation group.

RESULTS

Four criteria were identified to be associated with malignancy, one negatively ("endobiliary material," odds ratio [OR]  0.62, 95% confidence interval [CI] 0.41-0.92) and three positively ("vascularized villous projections," OR  1.52, 95% CI 1.03-2.24; "twisted or dilated vessels," OR  2.18, 95% CI 1.47-3.24; and "dark color of the mucosa," OR  1.82, 95% CI 1.23-2.70). Between two playbacks, the mean (95% CI) sensitivity of the observer's visual diagnosis increased from 66.1% (60-72) to 73.8% (69-78) (P = 0.004); in the second playback, the kappa value for interobserver agreement ranged between 0.36 (color) and 0.56 (endobiliary material), with a significant improvement (P = 0.0031-0.0001) between the first and second playbacks. Blind assessment by endoscopists not involved in this study had a diagnostic accuracy of 73% (71.4-74.5).

CONCLUSION

The four identified cholangioscopic features are easy to implement in clinical practice and have the potential to increase the level of diagnostic confidence during the workup of IDBS.

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.

Advanced Imaging of the Biliary System and Pancreas

Despite advances in noninvasive techniques for imaging the pancreaticobiliary system, several disease processes including indeterminate biliary strictures as well as neuroendocrine tumors, inflammatory pseudotumors, and complex cysts of the pancreas remain difficult to characterize. New endoscopic imaging technologies have emerged to address these challenges. Cholangioscopy and intraductal ultrasound (IDUS) are powerful tools to characterize subtle biliary concretions and strictures. Confocal Laser Endomicroscopy (CLE) and Optical Coherence Tomography (OCT) are emerging approaches for the most difficult biliary lesions. Contrast harmonic endoscopic ultrasound (CH-EUS), elastography, and 3D-EUS are improving the approach to subtle pancreatic lesions, particularly in the context of indeterminate tissue sampling. Pancreatoscopy, pancreatic IDUS, and intracystic CLE hold promise to further improve the assessment of pancreatic cysts. We aim to comprehensively review the emerging clinical evidence for these innovative endoscopic imaging techniques.

Digital single-operator cholangioscopy interobserver study using a new classification: the Mendoza Classification (with video)

BACKGROUND AND AIMS

Digital single-operator cholangioscopy (DSOC) allows direct visualization of the biliary tree for evaluation of biliary strictures. Our objective was to assess the interobserver agreement (IOA) of DSOC interpretation for indeterminate biliary strictures using newly refined criteria.

METHODS

Fourteen endoscopists were asked to review an atlas of reference clips and images of 5 criteria derived from expert consensus. They then proceeded to score 50 deidentified DSOC video clips based on the visualization of tortuous and dilated vessels, irregular nodulations, raised intraductal lesions, irregular surface with or without ulcerations, and friability. The endoscopists then diagnosed the clips as neoplastic or non-neoplastic. Intraclass correlation (ICC) analysis was done to evaluate inter-rater agreement for both criteria sets and final diagnosis.

RESULTS

Clips of 41 malignant lesions and 9 benign lesions were scored. Three of 5 revised criteria had almost perfect agreement. ICC was almost perfect for presence of tortuous and dilated vessels (.86), raised intraductal lesions (.90), and presence of friability (.83); substantial agreement for presence of irregular nodulations (.71); and moderate agreement for presence of irregular surface with or without ulcerations (.44). The diagnostic ICC was almost perfect for neoplastic (.90) and non-neoplastic (.90) diagnoses. The overall diagnostic accuracy using the revised criteria was 77%, ranging from 64% to 88%.

CONCLUSIONS

The IOA and accuracy rate of DSOC using the new Mendoza criteria shows a significant increase of 16% and 20% compared with previous criteria. The reference atlas helps with formal training and may improve diagnostic accuracy. (Clinical trial registration number: NCT02166099.).

Tissue Sampling through Endoscopic Ultrasound-Guided Fine Needle Aspiration versus Endoscopic Retrograde Cholangiopancreatographic Brushing Cytology Technique in Suspicious Malignant Biliary Stricture

BACKGROUND Differentiation of benign and malignant biliary strictures plays a pivotal role in managing biliary strictures. Brush cytology via endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are two diagnostic methods. In the present study, we aimed to compare the accuracy of the results of EUS-FNA and ERCP-based sampling of biliary strictures. METHODS In a prospective study, between January 2019 and March 2020, patients with indeterminate biliary strictures who had no history of hepatobiliary surgery, opium usage, cancer of pancratobiliary system, and acute liver disease were selected. They underwent EUS and ERCP in the same session. They were followed up for 6 months, and the sensitivity, specificity, positive and negative predictive values, and accuracy of these imaging modalities were compared. RESULTS A total of 60 patients were enrolled. 28 lesions were located in the distal and 32 lesions in the proximal parts of the biliary tree. 55 malignant and 5 benign lesions were diagnosed. The sensitivity and accuracy of EUS-FNA and ERCP tissue sampling were 78.2% and 80.0% versus 50.9% and 55.0%, respectively (p = 0.024). The combination of both methods improved the sensitivity and accuracy to 85.5% and 86.7%, respectively. Regarding the location, EUS-FNA is superior to ERCP-brush cytology in diagnosing proximal lesions with sensitivity and specificity of 73.3% and 75.0% vs. 50.0% and 53.1%, respectively (p = 0.04). CONCLUSION EUS-FNA is superior to ERCP brushing in the diagnosis of indeterminate biliary strictures, particularly in distal lesions. Combining ERCP brushing and EUS-FNA improves the diagnosis accuracy.

Diagnostic value of peroral cholangioscopy in addition to computed tomography for indeterminate biliary strictures

BACKGROUND

Peroral cholangioscopy (POCS) has been used to overcome the difficulty in diagnosing indeterminate biliary stricture or tumor spread. However, the value of adding POCS to computed tomography (CT) remains unclear. Our aim was to evaluate the diagnostic value of adding POCS to CT for indeterminate biliary stricture and tumor spread by interpretation of images focusing on the high diagnostic accuracy of visual findings in POCS.

METHODS

We retrospectively identified 52 patients with biliary stricture who underwent endoscopic retrograde cholangiography (ERC) at our institution between January 2013 and December 2018. Two teams, each composed of an expert endoscopist and surgeon, performed the interpretation independently, referring to the CT findings of the radiologist. The CT + ERC + POCS images (POCS group) were evaluated 4 weeks after the evaluation of CT + ERC images (CT group). A 5-point scale (1: definitely benign to 5: definitely malignant) was used to determine the confident diagnosis rate, which was defined as an evaluation value of 1 or 5. Tumor spread was also evaluated.

RESULTS

In the evaluation of 45 malignant diagnoses, the score was significantly closer to 5 in the POCS group than in the CT group in both teams (P < 0.001). The confident diagnosis rate was significantly higher for the POCS group (92% and 73%) than for the CT group (25% and 12%) in teams 1 and 2, respectively (P < 0.001). We found no significant difference in diagnostic accuracy for tumor spread between the groups.

CONCLUSION

Visual POCS findings confirmed the diagnosis of biliary strictures. POCS was useful in cases of indefinite diagnosis of biliary strictures by CT.

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.

Peroral Cholangioscopy-Guided Forceps Mapping Biopsy for Evaluation of the Lateral Extension of Biliary Tract Cancer

Background: Peroral cholangioscopy (POCS)-guided forceps mapping biopsy (FMB) is a method for the accurate preoperative identification of the extent of the disease of biliary tract cancer (BTC). However, the diagnostic value of POCS-FMB is still uncertain. Objectives: We evaluated the diagnostic utility of POCS-FMB for the identification of lateral extension—superficial intraductal spread longitudinally and continuously from the main lesion—of BTC. Methods: In the retrospective study, patients who received POCS-FMB and surgery for curative resection of BTC between September 2016 and August 2019 at our medical institution were enrolled. The diagnostic accuracy of POCS-FMB for the identification of lateral extension of BTC was evaluated. Furthermore, we also evaluated the factors affecting the diagnostic accuracy of POCS-FMB. Results: A total of 23 patients with BTC were enrolled, and 24 procedures of POCS-FMB from 96 sites of biliary tracts were performed. The sensitivity, specificity, and accuracy of POCS-FMB were 53.8%, 63.9%, and 63.1%, respectively. In the multivariate logistic regression analyses, the biopsy from the bifurcation of biliary tracts was a significant factor affecting the diagnostic accuracy of POCS-FMB (odds ratio 3.538, 95%; confidence interval 1.151–10.875, p = 0.027). Conclusions: The diagnostic accuracy of POCS-FMB for the identification of lateral extension of BTC was insufficient. The biopsy from the bifurcation of biliary tracts was a positive factor affecting the diagnostic accuracy of POCS-FMB.

Endoscopic retrograde cholangiopancreatography guided interventions in the management of pancreatic cancer

Pancreatic cancer is the leading cause of cancer-related morbidity and mortality with an overall five-year survival of less than 9% in the United States. At presentation, the majority of patients have painless jaundice, pruritis, and malaise, a triad that develops secondary to obstruction, which often occurs late in the course of the disease process. The technical advancements in radiological imaging and endoscopic interventions have played a crucial role in the diagnosis, staging, and management of patients with pancreatic cancer. Endoscopic retrograde cholangiopancreatography (ERCP)-guided diagnosis (with brush cytology, serial pancreatic juice aspiration cytologic examination technique, or biliary biopsy) and therapeutic interventions such as pancreatobiliary decompression, intraductal and relief of gastric outlet obstruction play a pivotal role in the management of advanced pancreatic cancer and are increasingly used due to improved morbidity and complication rates compared to surgical management. In this review, we highlight various ERCP-guided diagnostic and therapeutic interventions for the management of pancreatic cancer.

Adequate tissue acquisition rate of peroral cholangioscopy-guided forceps biopsy

Background

Peroral cholangioscopy (POCS)-guided forceps biopsy is a method for diagnosing indeterminate biliary strictures and for the preoperative identification of the exact perihilar and distal margins of biliary tract cancer (BTC). However, POCS-guided forceps biopsy may result in an insufficient amount of specimen at times. Therefore, we evaluated the adequate tissue acquisition rate and the factors affecting the adequate tissue acquisition of POCS-guided forceps biopsy for the biliary tract.

Methods

Patients who underwent POCS-guided forceps biopsy for biliary disease between September 2016 and October 2018 at our hospital were enrolled retrospectively. We evaluated the adequate tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion and that for non-stenotic bile duct. In addition, the factors affecting the adequate tissue acquisition rate of POCS-guided forceps biopsy were evaluated.

Results

We enrolled 47 patients with biliary disease and performed POCS-guided forceps biopsy for biliary lesion and POCS-guided forceps mapping biopsy for non-stenotic bile duct in 40 and 36 patients, respectively. The adequate tissue acquisition rates of POCS-guided forceps biopsy for biliary lesions and that for non-stenotic bile duct were 86.4%, and 68.9%, respectively. In the multivariate logistic regression analyses, age, and previous biliary stenting before POCS were factors affecting the adequate tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion. For non-stenotic bile duct, the location of the biliary lesion, endoscopic sphincterotomy (EST), and procedure time of POCS were factors affecting the adequate tissue acquisition rate of POCS-guided forceps mapping biopsy.

Conclusions

Previous biliary stenting was a factor affecting a low tissue acquisition rate of POCS-guided forceps biopsy for the biliary lesion. In the POCS-guided forceps mapping biopsy, the location of the biliary lesion, EST, and procedure time were factors affecting tissue acquisition rates.

Endoscopic Perspective in Cholangiocarcinoma Diagnostic Process

Cholangiocarcinoma is a malignancy arising from the epithelial lining of the intrahepatic or extrahepatic biliary tract. Timely diagnosis is challenging due to its silent clinical course. As reliable laboratory markers are lacking, diagnostic imaging plays a pivotal role. While cross-sectional imaging studies are usually conclusive for intrahepatic lesions, endoscopy plays an essential role in cases of extrahepatic tumors. Rational utilization of different diagnostic methods based on available evidence is needed. This article focuses on the diagnostic role of advanced biliary endoscopy, including endoscopic retrograde cholangiopancreatography, cholangioscopy, endoscopic ultrasonography, and intraductal sonography.

The value of DNA image cytometry combined with brush routine cytology in diagnosing indeterminate biliary strictures: A large sample size retrospective study

BACKGROUND AND AIM

Brush cytology is widely applied to diagnosis indeterminate biliary stricture but suffer from low sensitivity. Changes in DNA content are a character of malignant cell and can be detected by DNA image cytometry (DNA-ICM). The study aimed to estimate the value of routine cytology (RC), DNA-ICM, and their combination in diagnosing indeterminate biliary strictures.

METHODS

A total of 362 patients who underwent both RC and DNA-ICM tests were analysed. Their results were retrospectively applied to final diagnoses. Diagnostic values were compared among RC, DNA-ICM, and their combination based on the location of strictures.

RESULTS

The DNA-ICM and combination of two methods had higher diagnostic accuracy than RC in all strictures (63.3% vs 42.3%, P < 0.001, 64.36% vs 42.3%, P < 0.001) and in distal strictures (65.36% vs 42.81%, P < 0.001, 66.01% vs 42.81%, P < 0.001). But in proximal strictures, DNA-ICM showed no superior (51.8% vs 42.81%, P = 0.184). Combination of two methods was not fully significant superior to RC in proximal strictures (55.36% vs 39.29%, P = 0.089). After classification of "suspicious for malignancy" as positive for malignancy, the diagnostic accuracy of DNA-ICM was still higher than that of RC in all strictures (63.3% vs 51.9%, P = 0.002) and in distal strictures (65.36% vs 52.29%, P = 0.001). Combination of two methods was no superior to DNA-ICM alone (64.36% vs 63.3%, P = 0.757). The utilization of DNA-ICM was more accurate in distal strictures than in proximal strictures (65.36% vs 51.8%, P = 0.017).

CONCLUSION

DNA-ICM is an objective and effective addition tool with RC, especially in distal strictures. The combination of DNA-ICM and RC showed no superior to DNA-ICM alone but could improve diagnostic accuracy to RC in proximal strictures although not fully significant.

Biliary interventions using single-operator cholangioscopy

Cholangioscopy provides an opportunity to directly visualize the bile duct for diagnosing biliary lesions and for therapeutic interventions. Although there are different cholangioscopy techniques available, single-operator cholangioscopy has gained widespread acceptance as the standard technique for interventions in the biliary system because of its ease of use and widespread availability. Single-operator cholangioscopy can be used for both diagnostic and therapeutic indications in the biliary tract. Diagnostic cholangioscopy is used for direct evaluation of indeterminate bile duct strictures with biopsies, diagnosing filling defects in the bile ducts observed during endoscopic retrograde cholangiography (ERC) imaging, preoperative mapping of the precise location and extension of tumors of the biliary tract, and diagnosis of intraductal neoplasms. Therapeutic cholangioscopy is used for visually guided treatment of biliary stones that have failed extraction with conventional ERC techniques, residual or impacted stones by using intraductal lithotripsy, ablation of biliary tumors and for facilitation of guidewire advancement into selective intrahepatic ducts for adequate biliary drainage. In this review, we will focus on advances in the single-operator cholangioscopy techniques in the diagnosis and management of biliary disorders.

Peroral cholangioscopy with cholangioscopy-directed biopsies in the diagnosis of biliary malignancies: a systemic review and meta-analysis

BACKGROUND AND AIM

Accurate diagnosis is essential in the appropriate management of biliary strictures. Our aim is to evaluate the efficacy of cholangioscopy-directed biopsies in differentiating biliary intraductal malignancies from benign lesions.

MATERIALS AND METHODS

Articles were searched in Medline, PubMed, and Ovid journals. Pooling was performed by both fixed-effects and random-effects models. Only studies from which a 2×2 table could be constructed for true-positive, false-negative, false-positive, and true-negative values were included.

RESULTS

Initial search identified 2110 reference articles for peroral cholangioscopy; of these, 160 relevant articles were selected and reviewed. Data were extracted from 15 studies (N=539) that fulfilled the inclusion criteria. Pooled sensitivity of cholangioscopy-directed biopsies in diagnosing malignancy was 71.9% [95% confidence interval (CI): 66.1-77.1] and pooled specificity was 99.1% (95% CI: 96.9-99.9). The positive likelihood ratio of cholangioscopy-directed biopsies was 18.1 (95% CI: 9.1-35.8), whereas the negative likelihood ratio was 0.3 (95% CI: 0.2-0.4). The pooled diagnostic odds ratio was 71.6 (95% CI: 32.8-156.4). All the pooled estimates calculated by fixed-effects and random-effect models were similar. Summary receiver operating characteristic curves showed an area under the curve of 0.98. The χ heterogeneity for all the pooled accuracy estimates was 5.62 (P=0.96).

CONCLUSION

Peroral cholangioscopy with cholangioscopy-directed biopsies has a high specificity in differentiating intraductal malignancies from benign lesions. Cholangioscopy-directed biopsies should be strongly considered for biliary stricture evaluation.

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

BACKGROUND AND AIMS

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

PATIENTS AND METHODS

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

DESIGN

Prospective open-label multicentre trial.

RESULTS

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

CONCLUSION

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

Peroral Cholangioscopy-Guided Forceps Biopsy and Endoscopic Scraper for the Diagnosis of Indeterminate Extrahepatic Biliary Stricture

Background: Peroral cholangioscopy (POCS) has become a widely-used technique in diagnosing indeterminate biliary strictures, enabling optical viewing of the biliary system and targeted biopsies under direct vision. The diagnostic utility of the new endoscopic scraper, Trefle^®, for extrahepatic cholangiocarcinoma (ECC) has also been reported. However, the diagnostic utility of POCS-guided and Trefle^®-assisted tissue acquisition for ECC has never been compared empirically. We evaluated the efficacy and safety of Trefle^®-assisted tissue acquisition for diagnosing ECC compared with POCS-guided tissue sampling. Methods: Patients who underwent Trefle^®-assisted tissue acquisition or POCS-guided forceps biopsy to differentiate ECC from benign biliary disease between April 2014 and March 2018 were enrolled retrospectively. We evaluated the diagnostic performance of Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy based on pathological evaluation. We also compared adverse events associated with Trefle^®-assisted tissue acquisition with those of POCS-guided forceps biopsy. Results: We enrolled 34 patients with biliary disease and performed Trefle^®-assisted tissue acquisition and POCS-guided forceps biopsy in 14 and 20 patients, respectively. Sensitivity, specificity, and accuracy of Trefle^®-assisted tissue acquisition were 87.5%, 83.3%, and 85.7%, respectively, and for POCS-guided forceps biopsy, these were 90.0% each. Statistical values of Trefle^®-assisted tissue acquisition and POCS-guided tissue acquisition were not significantly different. There were no significant differences in the occurrence of adverse events between the Trefle^®-assisted tissue acquisition and the POCS-guided forceps biopsy (35.7% vs. 25.0%, p = 0.770). Compared with patients who underwent POCS procedure, endoscopic sphincterotomy was performed for fewer patients who underwent Trefle^®-assisted tissue acquisition (p < 0.001). Conclusions: The diagnostic ability of Trefle^®-assisted tissue acquisition for ECC is similar to that of POCS-guided tissue acquisition. Trefle^®-assisted tissue acquisition might also help to preserve the sphincter of Oddi and its digestive function.

Digital cholangioscopy: the diagnostic yield and impact on management of patients with biliary stricture

OBJECTIVES

Biliary strictures frequently present a diagnostic challenge. The aim of this study was to evaluate the impact of digital single-operator cholangioscopy (DSOC) on subsequent treatment of patients with biliary stricture.

METHODS

Consecutive patients undergoing DSOC for biliary stricture were enrolled. Gold standard for final diagnosis included histology from surgical resection. In patients without surgery, clinical evaluation methods and repeated imaging studies were used for comparison of DSOC findings and final diagnosis. Patients were followed-up prospectively focusing on subsequent treatment.

RESULTS

Among 30 enrolled patients, final diagnosis was malignant in 13 (43%) and benign in 17 (57%). The sensitivity and specificity of visual impression in diagnosing malignant stricture were 100% (95% CI: 75 - 100) and 76% (95% CI: 50 - 93), respectively. The sensitivity and specificity for biopsy were 92% (95% CI: 62 - 100) and 100% (95% CI: 78 - 100), respectively. One (3%) case of complicating cholangitis with fatal outcome occurred. Final treatment included surgery in 7 (23%), endoscopy in 18 (60%) and chemotherapy in 3 (10%) of patients.

CONCLUSIONS

In this study, favorable operating characteristics of DSOC were confirmed. Absolute negative predictive value of visual impression provided reassurance to patients with benign strictures who avoided unnecessary surgery in 53%. One (3%) case of cholangitis with fatal outcome occurred.

Appropriate number of biliary biopsies and endoscopic retrograde cholangiopancreatography sessions for diagnosing biliary tract cancer

BACKGROUND

Biliary ductal cancer (BDC) is a lethal disease; however, diagnosing BDC is challenging. Biliary biopsies are performed to pathologically diagnose BDC, but the appropriate parameters for biliary biopsy [number of biliary biopsies, number of endoscopic retrograde cholangiopancreatography (ERCP) sessions, etc.] are unknown.

AIM

To clarify what constitutes an adequate method for biliary biopsy.

METHODS

In total, 95 patients who underwent endoscopic biliary biopsy without choledochoscopy and who were pathologically diagnosed with BDC were enrolled in this study. The patients were divided into two groups. Seventy-six patients who were diagnosed by biliary biopsy were defined as the positive group (P group), and nineteen patients who were not diagnosed by biliary biopsy were defined as the negative group (N group). The patient characteristics and ERCP-related procedures were compared between the P and N groups.

RESULTS

The numbers of ERCP sessions and biliary biopsies were significantly different between the two groups [ERCP sessions (one/two), P group 72/4 vs N group 15/4, P value = 0.048; number of biliary biopsies, P group 2 (1-6) vs N group 2 (1-7), P value = 0.039]. In a multivariate analysis, fewer than 2 ERCP sessions was an independent factor influencing the positivity of the biliary biopsies.

CONCLUSION

This study clarified that ERCP and biliary ductal biopsy should only be performed once. If biliary cancer is not pathologically diagnosed after the first ERCP session, other methods (Endoscopic ultrasonography-guided fine needle aspiration or choledochoscopy-guided biliary ductal biopsy) should be employed.

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

BACKGROUND AND AIM

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

METHODS

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

VALIDATION

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

RESULTS

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

CONCLUSIONS

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

Role of endoscopy in the management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare but prominent fibroinflammatory cholangiopathy which can affect individuals of essentially any age. It carries a median survival of 15-20 years, regardless of age at diagnosis, and is a foremost risk factor for cholangiocarcinoma. Given the chronic and progressive nature of PSC, its inherent risk for biliary tract and other complications, and the paucity of effective pharmacotherapies, endoscopy plays a major role in the care of many patients with this disorder. In this review, we discuss the endoscopic management of PSC, including established and evolving approaches to the diagnosis and treatment of its benign as well as malignant sequelae. Owing to the rarity of PSC and dearth of high-quality evidence, we propose pragmatic approaches based on both currently available data and expert opinion.

Reliability and accuracy of a novel classification system using peroral cholangioscopy for the diagnosis of bile duct lesions

BACKGROUND

The aim of this study was to propose a novel, comprehensive, macroscopic classification for bile duct lesions.

METHODS

A two-stage protocol was designed. In Stage I, a retrospective study (September 2013 to September 2015) of patients with bile duct lesions detected by peroral cholangioscopy (POCS) was performed. A total of 315 images with at least 6 months of follow-up were recorded, analyzed, and correlated to histology, and were classified as non-neoplastic (one of three types, 1 - 3) or neoplastic (one of four types, 1 - 4) based on morphological and vascular patterns. In Stage II, a prospective, nonrandomized, double-blind study was performed from December 2015 to December 2016 to validate the proposed classification. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and positive and negative likelihood ratios (LR + and LR - , respectively) were calculated (gold standard: 6-month follow-up). Inter- and intraobserver agreement (kappa value, κ) among experts and non-experts were calculated.

RESULTS

171 patients were included (65 retrospective; 106 prospective). In Stage I, 28/65 cases were neoplastic and 37 /65 were non-neoplastic, according to the final diagnosis. In Stage II, 56/106 were neoplastic with a sensitivity, specificity, PPV, NPV, LR + , and LR - for neoplastic diagnosis of 96.3 %, 92.3 %, 92.9 %, 96 %, 12.52, and 0.04, respectively. The proposed classification presented high reproducibility among observers, for both neoplastic and subtypes categories. However, it was better for experts (κ > 80 %) than non-experts (κ 64.7 % - 81.9 %).

CONCLUSION

The novel classification system could help physicians to distinguish non-neoplastic from neoplastic bile duct lesions.

Novel triple lumen catheter for ERCP tissue diagnosis

INTRODUCTION

 The ideal endoscopic retrograde cholangiopancreatography (ERCP) tissue sampling technique should be simple, inexpensive, and yield sufficient tissue for histology while permitting contrast-guided targeting under fluorescence and multiple passes into the bile duct. Current techniques do not fulfill these requirements comprehensively. We designed a catheter for optimized targeting of large intrabiliary biopsies.

METHODS

 A 3.5-mm sterile, single-use prototype catheter was developed, with three independent lumina extending continuously to the distal tip for three distinct functions to be available simultaneously: passage of large volume biopsy forceps (1.8 mm), wire guidance (0.035″), and contrast injection.

RESULTS

 First clinical use in five patients (four transpapillary, one percutaneous access) allowed good intrabiliary manipulation in 4/5 patients. Contrast-guided sampling provided adequate specimens. No adverse events were noted.

DISCUSSION

 Technical aspects and preliminary clinical data for the novel triple lumen biopsy catheter are encouraging. The catheter allowed wire guidance and contrast application to guide sampling of larger pieces of tissue. In perspective, the working channel could host any accessory for targeted intrabiliary diagnosis and therapy, and catheter use is not limited to bile ducts.

Endoscopic management of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare but clinically important cholestatic liver disease. Histopathologically and cholangiographically, PSC is characterized by intra- and/or extra-hepatic bile duct inflammation and fibro-obliteration, which ultimately leads to biliary cirrhosis and related sequelae, including development of hepatobiliary and colorectal carcinomata. PSC can be diagnosed at essentially any age and carries a median survival of 15-20 years, regardless of age at diagnosis, and is a foremost risk factor for cholangiocarcinoma. Given the chronic and progressive nature of PSC, its inherent association with both neoplastic and non-neoplastic biliary tract complications, and the lack of effective pharmacotherapies, alimentary and biliary tract endoscopy plays a major role in the care of patients with PSC. Areas covered: Here, we provide a narrative review on endoscopic management of PSC, including established and evolving applications to the diagnosis and treatment of both its benign and malignant complications. Expert commentary: Due to the rarity of PSC and the considerable patient-years required to rigorously study major endpoints, there remains a paucity of high-quality evidence regarding its management. As the advanced endoscopic repertoire expands, so has the interest in developing best practices in PSC, which we discuss herein.

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.

A Cholangioscopy-Based Novel Classification System for the Phenotypic Stratification of Dominant Bile Duct Strictures in Primary Sclerosing Cholangitis-the Edmonton Classification

Background

Primary sclerosing cholangitis (PSC) is a chronic inflammatory condition causing bile duct strictures. Differentiating inflammatory strictures from malignant transformation is challenging. Cholangioscopy allows direct visualization with the option to biopsy. We describe our experience of cholangioscopy in PSC and propose a novel stricture classification system based on cholangioscopic findings.

Methods

All patients with PSC and a dominant stricture referred for cholangioscopy were reviewed. Based on visual characteristics with direct cholangioscopy, we propose a novel classification system for the extrahepatic form of PSC.

Results

The proposed Edmonton Classification system for extrahepatic PSC strictures consists of the following phenotypes: 1) ‘inflammatory type’, with mucosal erythema and active inflammatory exudate, 2) ‘fibro-stenotic type’, with concentric fibrotic scars, and 3) ‘nodular or mass-forming type’, with a mass in the involved segment of extrahepatic bile duct. From 2011–2017, 30 patients with PSC and a dominant stricture (21 M, mean age 46 years) underwent 32 cholangioscopy procedures. Cholangioscopy was technically successful in 29 of 32 procedures (91%). In these 29 stricture cases, inflammatory type was seen in 16 (55%), fibro-stenotic type in seven (24%) and nodular or mass-forming type in five (17%). In one (4%) procedure, there was no stricture or abnormality identified.

Conclusion

Cholangioscopy is effective and safe for the evaluation of dominant biliary strictures in PSC. Based on our experience with cholangioscopy, we propose a novel classification system of extrahepatic PSC phenotypes: the Edmonton Classification.

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.

Indeterminate biliary strictures: a simplified approach

Pre-operative evaluation of biliary strictures remains challenging. The dilemma that exists is how to balance the risk of failing to detect malignancy and the potential morbidity caused by unnecessary surgery in patients with benign etiologies. With emerging novel diagnostic modalities, this study aims to assess the efficacy of diagnostic techniques and facilitate a clinical approach to indeterminate biliary strictures. Areas covered: Conventional imaging modalities are crucial in identifying the location of a stricture and are helpful for choosing further diagnostic modalities. Utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS), is key in establishing a diagnosis. The emergence of novel diagnostic modalities, such as fluorescence in-situ hybridization (FISH), peroral cholangioscopy (POC), intraductal endoscopic ultrasound (IDUS) and confocal laser endomicroscopy (CLE), enhance the diagnostic yield in the evaluation of indeterminate biliary strictures. Expert commentary: More reliable and validated visual criteria for differentiating malignancy from benign biliary conditions, utilizing advanced imaging modalities such as POC and CLE, need to be established. It is of significance to further evaluate these novel diagnostic modalities through ongoing trials and to develop a diagnostic algorithm that reconciles cost-effectiveness with diagnostic accuracy.

Endoscopic Management of Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) remains a rare but potentially devastating chronic, cholestatic liver disease. PSC causes obstruction of intra- and/or extra-hepatic bile ducts by inflammation and fibrosis, leading to biliary obstruction, cirrhosis and portal hypertension with all associated sequelae. The most dreaded consequence of PSC is cholangiocarcinoma, occurring in 10-20% of patients with PSC, and with population-based estimates of a 398-fold increased risk of cholangiocarcinoma in patients with PSC compared to the general population. We use the 4-D approach to endoscopic evaluation and management of PSC based on currently available evidence. After laboratory testing with liver chemistries and high-quality cross-sectional imaging with MRCP, the first D is Dominant stricture diagnosis and evaluation. Second, Dilation of strictures found during ERCP is performed using balloon dilation to as many segments as possible. Third, Dysplasia and cholangiocarcinoma diagnosis is performed by separated brushings for conventional cytology and fluorescence in situ hybridization (FISH), and consideration for direct cholangioscopy with SpyGlass™. Fourt and finally, Dosing of antibiotics is critical to prevent peri-procedural cholangitis. The aim of this review article is to explore endoscopic tools and techniques for the diagnosis and management of PSC and provide a practical approach for clinicians.

Role of endoscopy in primary sclerosing cholangitis: European Society of Gastrointestinal Endoscopy (ESGE) and European Association for the Study of the Liver (EASL) Clinical Guideline

This guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE) and of the European Association for the Study of the Liver (EASL) on the role of endoscopy in primary sclerosing cholangitis. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations.

Per-oral video cholangiopancreatoscopy with narrow-band imaging for the evaluation of indeterminate pancreaticobiliary disease

BACKGROUND AND AIMS

Cholangiopancreatoscopy for evaluating pancreaticobiliary pathology is currently limited by suboptimal optics. The aim of this study was to characterize the operating characteristics of per-oral video cholangiopancreatoscopy with narrow-band imaging (POVCP) findings in indeterminate pancreaticobiliary disease and to describe their association with neoplasia.

METHODS

Data from consecutive patients undergoing POVCP for the evaluation of indeterminate pancreaticobiliary disease at a single tertiary care center were analyzed. Two experienced investigators had previously agreed on POVCP findings and terminology that were documented in endoscopy reports. Endoscopic procedural data from POVCPs performed between January 2006 and April 2015 and clinical data were abstracted from the endoscopic database and electronic medical records. Study endpoints included tissue-proven neoplasia or benign disease with ≥1 year of follow-up.

RESULTS

A total of 109 patients were identified; 13 were excluded because of the presence of stone disease, known pancreaticobiliary malignancy, or presumed benign disease with ≤1 year of follow-up. Most patients (85%) underwent POVCP for biliary disease and 15% underwent POVCP for a pancreatic cause. Tortuous and dilated vessels (P < .001), infiltrative stricture (P < .001), polypoid mass (P = .003), and the presence of fish-egg lesions (P = .04) were found to be significantly associated with neoplasia. The overall POVCP impression had a high sensitivity (85%) and negative predictive value (89%) in assessing for the presence of neoplasia.

CONCLUSIONS

Per-oral video cholangiopancreatoscopy is effective in the evaluation of indeterminate pancreaticobiliary disease. Tortuous and dilated vessels, infiltrative stricture, polypoid mass, and the presence of fish-egg lesions are significantly associated with neoplasia.

Intraductal biopsies in indeterminate biliary stricture: Evaluation of histopathological criteria in fluoroscopy- vs. cholangioscopy guided technique

BACKGROUND

Differentiating malignancy from benign disease in indeterminate biliary stricture by imaging modalities is limited. Definite diagnosis relies on histopathological diagnosis.

AIMS

To assess accuracy of histopathological diagnosis of fluoroscopy-guided vs. cholangioscopy-directed intraductal biopsies in indeterminate biliary stricture.

METHODS

All patients with indeterminate biliary stricture and fluoroscopically (n=68) or cholangioscopy-directed (working channel 2mm, n=38) biopsies were included. Histopathological results of biopsies were classified into inflammatory lesion (class 1), dysplasia/intraepithelial neoplasia (class 2) and malignancy (class 3) and results as well as macroscopic diagnosis were compared with final diagnosis.

RESULTS

Sensitivity and specificity of fluoroscopy-guided vs. cholangioscopy-directed biopsies were 22.9% and 100% vs. 25.0% and 100% for class 1+2 vs. class 3 lesions, respectively. Sensitivity for class 1 vs. class 2+3 lesions was 45.7% (p=0.044) vs. 58.3% (p=0.214) for fluoroscopy-guided vs. cholangioscopy-directed biopsies, respectively, while specificity was 100% in both. There was no difference in size of the obtained sample (p=0.992). True positive diagnosis rate increased with the number of biopsies taken (p=0.028).

CONCLUSION

Fluoroscopy-guided and cholangioscopy-directed intraductal biopsies are equally limited in establishing the diagnosis of malignancy in indeterminate biliary stricture. Categorizing dysplasia or intraepithelial neoplasia as malignancy increases sensitivity without decrease in specificity. By taking more biopsies, diagnostic yield is increased.

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

BACKGROUND AND STUDY AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.