Evaluation Of Indeterminate Biliary Strictures Research Articles

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

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

S1953 An Unexpected Diagnosis in an Elderly Patient Presenting With Jaundice

Introduction: Cholangioscopy is an important tool in the evaluation of indeterminate biliary strictures allowing for direct visualization of strictures and targeted biopsies. We present an unusual case of painless jaundice where cholangioscopy played a crucial role in making the diagnosis. Case Description/Methods: A 76-year-old male with a past medical history of hypertension and diabetes mellitus, and a past surgical history of a laparoscopic cholecystectomy ten years prior to presentation was referred for one week of painless jaundice, darkening of urine, and pruritus. He denied any weight loss, abdominal pain, nausea, or vomiting. Laboratory evaluation was significant for a total bilirubin of 14.8, direct bilirubin of 7.6, AST 40, ALT 56, and alkaline phosphatase of 128. Magnetic resonance cholangiopancreatography was obtained, which revealed a poorly defined soft tissue lesion at the junction of the intrahepatic and extrahepatic common hepatic duct (CHD) with intrahepatic ductal dilation (IHD). Multiple small filling defects within the dilated ducts were also noted, suggestive of choleliths. The patient was referred for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP). EUS revealed IHD and a benign appearing porta hepatis lymph node with no endosonographic evidence of pancreatic mass or cysts. The lymph node at the porta hepatis was sampled using fine needle aspiration (FNA). ERCP was then performed, revealing a single stenosis at the level of the CHD with IHD. Cholagioscopy was performed, which revealed an inflammatory-appearing stenosis of the CHD with embedded suture material and a cholelith proximal to the stenosis (Figure). The stenosis was biopsied and dilated with a 4 mm balloon dilator. An 8.5 x 10 cm plastic biliary stent was placed with subsequent flow of bile. FNA cytology and pathology of the CHD stricture were both negative for malignancy. Discussion: Our patient likely sustained a bile duct injury during his prior cholecystectomy, which was repaired with suture, leading to an inflammatory stricture and obstructive jaundice. We had a high suspicion pre-procedure for malignancy given this patient’s presentation, and as such cholangioscopy was crucial in determining the etiology of this patient’s stricture. Our case highlights the importance of cholangioscopy in the evaluation of indeterminate biliary strictures, particularly in patients whom have undergone biliary surgery.Figure 1.: Left: Cholangiogram revealing hilar stricture. Right: Cholangioscopy revealing inflammatory stricture with embedded suture material.

First interobserver agreement of optical coherence tomography in the bile duct: A multicenter collaborative study.

Background and study aims Optical coherence tomography (OCT) is a new technology available for evaluation of indeterminate biliary strictures. It allows under-the-surface visualization and preliminary studies have confirmed standardized characteristics associated with malignancy. The aim of this study is to evaluate the first interobserver agreement in identifying previously agreed upon OCT criteria and diagnosing of malignant versus benign disease. Patients and methods Fourteen endoscopists were asked to review an atlas of reference clips and images of eight criteria derived from expert consensus A total of 35 de-identified video clips were then evaluated for presence of the eight criteria and for final diagnosis of malignant versus benign using the atlas as reference Intraclass correlation (ICC) analysis was done to evaluate interrater agreement. Results Clips of 23 malignant lesions and 12 benign lesions were scored. Excellent interobserver agreement was seen with dilated hypo-reflective structures (0.85) and layering effacement (0.89); hyper-glandular mucosa (0.76), intact layering (0.81), and onion-skin layering (0.77); fair agreement was seen with scalloping (0.58), and thickened epithelium (0.4); poor agreement was seen with hyper-reflective surface (0.36). The diagnostic ICC for both neoplastic (0.8) and non-neoplastic (0.8) was excellent interobserver agreement. The overall diagnostic accuracy was 51 %, ranging from 43 % to 60 %. Conclusions Biliary OCT is a promising new modality for evaluation of indeterminate biliary strictures. Interobserver agreement ranged from fair to almost perfect on eight previously identified criteria. Interobserver agreement for malignancy diagnosis was substantial (0.8). Further studies are needed to validate this data.

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

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

New technologies for indeterminate biliary strictures.

An early and accurate diagnosis of biliary strictures yields optimal patient outcomes; however, endoscopic retrograde cholangiopancreatography (ERCP) with cytobrush/biopsy forceps has low sensitivity with a high number of false negatives. Various attempts to improve the accuracy of diagnosing indeterminate biliary strictures though ERCP-guided specimen acquisition have been proposed, such as with the use of fluorescence in situ hybridization, an endoscopic scraper, and the wire-grasping method, with modest to large improvements in sensitivity. Direct visualization of the biliary tree during peroral cholangioscopy has shown high sensitivity and specificity for the differentiation of neoplastic and non-neoplastic biliary lesions; however, there is no consensus on the visual characteristics of neoplastic lesions and moderate agreement between observers. Peroral cholangioscopy system (POCS)-guided specimen acquisition using forceps has shown inferior sensitivity compared to the visual characteristics; however, the specificity remains high. Optimal specimen processing with onsite evaluations and touch imprint cytology have been shown to improve the sensitivity and accurately diagnose nearly 90% of patients. In vivo evaluations of biliary strictures with probe-based confocal laser endomicroscopy have demonstrated high sensitivity with modest specificity for malignant biliary strictures. Optical computed tomography described reproductible criteria for malignancy detection in biliary strictures, increasing the sensitivity during ERCP evaluations. Differentiating benign causes from malignant causes of biliary strictures is a challenging task in clinical practice, with various concerns that still need to be addressed. Efforts should be made to define each diagnostic method's role in the evaluation of indeterminate biliary strictures.

S1 Machine Learning for Classification of Indeterminate Biliary Strictures During Cholangioscopy

Introduction: Indeterminate biliary strictures remain a diagnostic challenge despite advancements in radiologic, endoscopic, and laboratory testing. More than 25% of patients presumed to have malignant strictures during cholangioscopy show benign pathology after major surgical intervention. Interpretation of the visual findings during cholangioscopy remains challenging even for experienced endoscopists. We therefore aimed to develop a software tool that classifies indeterminate biliary strictures as benign or malignant using both cholangioscopy images and clinical data. Methods: Our dataset included cholangioscopy images and clinical data from a retrospective cohort of patients undergoing cholangioscopy for evaluation of indeterminate biliary strictures. We annotated images for abnormal features suggestive of malignancy, including papillary mass, dilated and tortuous vessels and ulceration. We trained a convolutional neural network (CNN) based on ResNet-18 to detect presence of abnormal image features and tested it in patients of independent centers (external validation). We used multiple outputation to analyze the patient as the unit of analysis and estimated accuracy, sensitivity, specificity, positive and negative predictive values (PPV and NPV), and area under the receiver operating characteristic curve (AUC). Results: A total of 1,371,605 cholangioscopy images were obtained from 528 patients at 25 centers (13 North America, 7 Asia, 2 Europe, 2 Australia, 1 South America). Our training set included data from 254 patients at 14 centers, and the test set included data from 95 patients at 8 other independent centers. Table 1 shows the proportion of patients with abnormal cholangioscopy image features according to their final diagnosis. For detection of abnormal image features, the CNN showed a sensitivity of 0.81 (95% confidence interval: 0.72 to 0.91); specificity 0.91 (0.86 to 0.97); PPV 0.93 (0.88 to 0.98); NPV 0.77 (0.66 to 0.88); and AUC 0.86 (0.80 to 0.92). Conclusion: Using data from a large cohort of patients across the world, we trained and externally validated a CNN that can detect key cholangioscopy image features suggestive of malignancy and thus support intra-procedural decision-making. Our next step is to enhance the CNN with clinical data and evaluate it for diagnosing and predicting malignancy in indeterminate biliary strictures. This can improve clinical outcomes through accurate diagnosis of disease and prevention of unwarranted surgical intervention.Table 1.: Proportion of patients with cholangioscopy images showing abnormal features (suggestive of malignancy) according to their final diagnosis.

Diagnostic accuracy and interobserver agreement of digital single-operator cholangioscopy for indeterminate biliary strictures

Digital single-operator cholangioscopy (d-SOC) with cholangioscopic biopsy sampling has shown promise in the evaluation of indeterminate biliary strictures. Some studies have suggested higher sensitivity for visual impression compared with biopsy sampling, although assessors were not blinded to previous investigations. We aimed to investigate the diagnostic accuracy and interobserver agreement (IOA) of d-SOC in the visual appraisal of biliary strictures when blinded to additional information. A multicenter, international cohort study was performed. Cholangioscopic videos in patients with a known final diagnosis were systematically scored. Pseudonymized videos were reviewed by 19 experts in 2 steps: blinded for patient history and investigations and unblinded. Forty-four high-quality videos were reviewed of 19 benign and 25 malignant strictures. The sensitivity and specificity for the diagnosis of malignancy was 74.2% and 46.9% (blinded) and 72.7% and 62.5% (unblinded). Cholangioscopic certainty of a malignant diagnosis led to overdiagnosis (sensitivity, 90.6%; specificity, 33%), especially if no additional information was provided. The IOA for the presence of malignancy was fair for both assessments (Fleiss' κ= .245 [blinded] and κ= .321 [unblended]). For individual visual features, the IOA ranged from slight to moderate for both assessments (κ= .059-.400 vs κ= .031-.452). This study showed low sensitivity and specificity for blinded and unblinded d-SOC video appraisal of indeterminate biliary strictures, with considerable interobserver variation. Although reaching a consensus on the optical features of biliary strictures remains important, optimizing visually directed biopsy sampling may be the most important role of cholangioscopy in biliary stricture assessment.

Diagnostic Accuracy and Therapeutic Efficacy of Digital Single-Operator Cholangioscopy for Biliary Lesions and Stenosis

Background/Aims: Digital single-operator cholangioscopy (dSOC) has revolutionized bile duct visualization. Interventions like electrohydraulic or laser lithotripsy, inspection of suspicious areas, and targeted biopsies have become possible quick and easy. One main indication for dSOC remains the evaluation of indeterminate biliary strictures. Objective and Methods: We analyzed 180 consecutive dSOCs procedures performed in a high-volume tertiary center to evaluate sensitivity, specificity as well as positive and negative predictive values (PPV and NPV) for indeterminate strictures. Furthermore, technical success and complications were analyzed. Results: In 92–97%, the region of interest was reached and successfully visualized. In 83–100%, targeted biopsies were obtained from the suspicious area. Only the distal bile duct was less successful with only 84 and 62%, respectively. In general, dSOC procedures were safe. Cholangitis was the main complication. Regarding the diagnostic accuracy of dSOC of indeterminate biliary strictures, we found a sensitivity of 0.87 and specificity of 0.88, over all. Within the whole cohort, the investigators’ assessment directly after dSOC had a PPV of 0.63 and a NPV of 0.97. In patients with biliary lesions or stenosis suspicious for malignancy, the dSOC-based visual diagnosis revealed a very high diagnostic accuracy with sensitivity and specificity of 1.0 (95% CI 0.86–1.0) and 0.76 (95% CI 0.56–0.9) with a PPV of 0.77 (95% CI 0.59–0.9) and a high NPV of 1.0 (95% CI 0.85–1.0). Conclusions: Our study demonstrates that dSOC has a high diagnostic accuracy as well as a favorable safety profile. Therefore, dSOC should be discussed as standard of care during endoscopic retrograde cholangiography for indeterminate biliary lesions.

Percutaneous single-operator video cholangioscopy using a novel short disposable endoscope: first clinical case with treatment of a complex biliary stone and inaccessible papilla after Roux-en-Y reconstructive surgery.

Percutaneous single-operator video cholangioscopy using a novel short disposable endoscope: first clinical case with treatment of a complex biliary stone and inaccessible papilla after Roux-en-Y reconstructive surgery.

S3233 The Safety of Single Operator Per-Oral Cholangioscopy: A Single Center Experience

INTRODUCTION: Single operator per-oral cholangioscopy (SOC) has been increasingly used to provide direct visualization of the biliary tree in conjunction with endoscopic retrograde cholangiopancreatography (ERCP). There is a prevalent notion that SOC increases the risk of pancreatitis and cholangitis in addition to the well-recognized complications of ERCP that also includes pancreatitis, cholangitis, bleeding, and perforation. This study aims to determine the rate of complications when SOC is performed. METHODS: This is a retrospective study which included consecutive adult (> 18 years old) patients who underwent ERCP with SOC from October 2017 until June 2020. SOC was performed utilizing SpyGlass Direct Visualization System. All procedures were performed by endoscopists who annually performed more than 200 ERCPs. Data on patient demographics, procedural indication, type, and complications were obtained. RESULTS: Thirty-three patients (male/female = 18/15) underwent a total of 35 ERCP with SOC procedures with an average of 67 years old. Most were Caucasian (64%) and the average body mass index was 25.3 kg/m2. Majority of the indications included choledocholithiasis (40%), indeterminate biliary stricture (34%), and imaging findings suspicious of cholangiocarcinoma (14%). A greater percentage underwent stone removal (66%), biopsy (46%) and lithotripsy (17%). 29 out of the 33 patients (88%) had previous ERCP. Despite administering rectal indomethacin in 60% (21/35) of the procedures and placement of pancreatic duct stent in 11% (4/35) of the procedures, 1 patient developed post-ERCP pancreatitis the day after the procedure. Pre-procedure intravenous antibiotics were given in 74% (26/35) and no patients developed cholangitis or died within the 30 days of follow-up. CONCLUSION: Although a few studies published in literature demonstrate a higher rate of procedural complications with ERCP and SOC compared to ERCP alone, this study suggests that SOC in addition to ERCP does not confer an additional procedural risk of pancreatitis or cholangitis. Our patient developed post-ERCP pancreatitis despite indomethacin and antibiotic use since balloon dilation and sphincterotomy were also performed which are known post-ERCP pancreatitis risk factors. SOC is a relatively safe procedure and should be performed in addition to ERCP in the evaluation of indeterminate biliary strictures and imaging suspicious of malignancy, and in the treatment of difficult biliary and pancreatic stones.Table 1.: Baseline Characteristics of the Study Population

Author commentary on Majid A. Almadi et al.

Majid A. Almadi et al. Using single-operator cholangioscopy for endoscopic evaluation of indeterminate biliary strictures: results from a large multinational registry

Using single-operator cholangioscopy for endoscopic evaluation of indeterminate biliary strictures: results from a large multinational registry.

Peroral cholangioscopy (POCS) of indeterminate biliary strictures aims to achieve a diagnosis through visual examination and/or by obtaining targeted biopsies under direct visualization. In this large, prospective, multinational, real-life experience of POCS-guided evaluation of indeterminate biliary strictures, we evaluated the performance of POCS in this difficult-to-manage patient population. This prospective registry enrolled patients, with indeterminate biliary strictures across 20 centers in Asia, the Middle East, and Africa. The primary end points were the ability to visualize the lesion, obtain histological sampling when intended, and an assessment of the diagnostic accuracy of POCS for malignant strictures. Patients were followed for 6 months after POCS or until a definitive malignant diagnosis was made, whichever occurred first. 289 patients underwent 290 POCS procedures with intent to biopsy in 182 cases. The stricture/filling defect was successfully visualized in 286/290 (98.6 %), providing a visual diagnostic impression in 253/290 (87.2 %) and obtaining adequate biopsies in 169/182 (92.9 %). Procedure-related adverse events occurred in 5/289 patients (1.7 %). POCS influenced patient management principally by elucidating filling defects or the causes of bile duct stricture or dilation. The visual impression of malignancy showed 86.7 % sensitivity, 71.2 % specificity, 65.8 % positive and 89.4 % negative predictive value, and 77.2 % overall accuracy compared with final diagnosis. Histological POCS-guided samples showed 75.3 % sensitivity, 100 % specificity, 100 % positive and 77.1 % negative predictive value, and 86.5 % overall accuracy. In this large, real-life, prospective series, POCS was demonstrated to be an effective and safe intervention guiding the management of patients with indeterminate biliary strictures.

Digital Single-operator Cholangioscopy (DSOC) Improves Interobserver Agreement (IOA) and Accuracy for Evaluation of Indeterminate Biliary Strictures

Visual characteristics seen during digital single-operator cholangioscopy (DSOC) have not been validated. The aim of this 2-phase study was to define terminology by consensus for the visual diagnosis of biliary lesions to develop a model for optimization of the diagnostic performance of DSOC. In phase 1 (criteria identification), video-cholangioscopy clips were reviewed by 12 expert biliary endoscopists, who were blinded to the final diagnosis. Visual criteria were consolidated into the following categories: (1) stricture, (2) lesion, (3) mucosal features, (4) papillary projections, (5) ulceration, (6) abnormal vessels, (7) scarring, (8) pronounced pit pattern.During the second phase (validation), 14 expert endoscopists reviewed DSOC (SpyGlass DS, Boston Scientific) clips using the 8 criteria to assess interobserver agreement (IOA) rate. In phase 1, consensus for visual findings were categorized into 8 criteria titled the "Monaco Classification." The frequency of criteria were: (1) presence of stricture-75%, (2) presence of lesion type-55%, (3) mucosal features-55%, (4) papillary projections-45%, (5) ulceration-42.5%, (6) abnormal vessels-10%, (7) scarring-40%, and (8) pronounced pit pattern-10%. The accuracy on final diagnosis based on visual impression alone was 70%.In phase 2, the IOA rate using Monaco Classification criteria ranged from slight to fair. The presumptive diagnosis IOA was fair (κ=0.31, SE=0.02), and overall diagnostic accuracy was 70%. The Monaco classification identifies 8 visual criteria for biliary lesions on single-operator digital cholangioscopy. Using the criteria, the IOA and diagnostic accuracy rate of DSOC is improved compared with prior studies.

Ethanol-based fixation is superior to conventional brush cytology in the evaluation of indeterminate biliary strictures by endoscopic retrograde cholangiography

The aim of this study was to compare the diagnostic yield of conventional cytology (CC) with ethanol-based fixation, a cytological analysis using an ethanol based fixative system including a cell block procedure (EBF) to evaluate indeterminate biliary strictures (IBStr). We also compared additionally taken fluorescence-guided forceps biopsies (FB) with EBF concerning a potential additive diagnostic benefit.Early detection and accurate diagnosis are crucial for patients with suspected carcinoma within the biliary tree to preserve curative treatment options but diagnostics and patient care in the evaluation of IBStr are still challenging. ERC-guided brush cytology is the gold standard of nonsurgical evaluation of IBStr. However, accuracy is generally low. New specimen processing's are needed to higher the diagnostic yield in the evaluation of IBStr.We performed a retrospective evaluation in 404 patients referred for further diagnosis of IBStr. Gold standard was defined as surgically obtained histology or patient follow-up of at least 1 year to diagnose or exclude malignancy.Three hundred thirty-four patients were included into the final analysis. One hundred seventy-two strictures were malignant, 162 strictures benign. One hundred seventeen specimens were evaluated by CC, 217 processed by EBF. EBF performed significantly better in terms of sensitivity (24.6% vs 60%, P < .001) and accuracy (59.0% vs 75.1%, P = .006). Fifty-eight FB were additionally taken and showed a numerically improved sensitivity compared to EBF alone (80% vs 62.9%, P = .19).EBF is a simple and inexpensive technique that substantially improved sensitivity and accuracy in the evaluation of IBStr. FB specimen did not significantly improve diagnostic yield.

The Role of Peroral Cholangioscopy in Evaluating Indeterminate Biliary Strictures.

Biliary strictures are considered indeterminate when the initial radiologic evaluation and endoscopic retrograde cholangiopancreatography with brush cytology and/or forceps biopsy do not reveal diagnostic findings. Evaluation of these strictures is challenging and often requires a multidisciplinary approach and multiple procedures. Peroral cholangioscopy allows direct visualization of these lesions and targeted tissue acquisition using miniature biopsy forceps. In the past decade, there have been significant improvements in the field of cholangioscopy. These advances have allowed higher-quality image acquisition, easy setup, operation by a single operator, easy maneuverability, and excellent targeted tissue sampling performance. However, the interpretation of cholangioscopic visual findings remains challenging. In this review, we discuss the role of peroral cholangioscopy in the evaluation of indeterminate biliary strictures.

Sa1465 SINGLE OPERATOR CHOLANGIOSCOPY- DIRECTED BIOPSIES IMPROVES DIAGNOSTIC YIELD FOR CHOLANGIOCARCINOMA AND IS SAFE IN PATIENTS WITH PRIMARY SCLEROSING CHOLANGITIS

Single operator cholangioscopy (SOC) has demonstrated to be a useful tool in the evaluation of indeterminate biliary strictures. However much of the incremental benefit has been ascribed to the visual interpretation of cholangioscopy and not due to histologic yield from SOC-directed biopsies. Furthermore, SOC has been suggested to be a cost-effective strategy for evaluation of indeterminate biliary strictures in patients with primary sclerosing cholangitis (PSC), but data comparing the addition of fluorescent in situ hybridization (FISH) to SOC in this population is lacking. The purpose of this study is to assess the performance characteristics of histopathology from SOC-directed biopsies compared to traditional sampling techniques [Routine brush cytology (Bc), fluorescent in situ hybridization (FISH), and transpapillary fluoroscopic-guided cold biopsy (Bx)] for indeterminate biliary strictures and to compare diagnostic yield and safety of the procedure in patients with and without PSC.

Individual probe based confocal laser endomicroscopy criteria in the analysis of indeterminate biliary strictures

Objectives: Evaluation of indeterminate biliary strictures remains challenging due to limited sensitivity of endoscopic tissue sampling. Biliary probe-based confocal laser endomicroscopy (pCLE) has shown promise to detect and exclude neoplasia. However, knowledge of whether individual inflammatory criteria are more prevalent in neoplasia compared to benign strictures is limited. The objective of this work is to improve diagnosis of neoplastic and inflammatory conditions using pCLE.Materials and methods: The charts of all patients who underwent pCLE at a single referral center between 2009 and 2015 were reviewed. ERCP reports were reviewed for eleven Miami and Paris criteria. Primary outcome was the identification of neoplasia by histopathology (defined as high-grade dysplasia and/or adenocarcinoma). To model predictors of neoplasia, we fit a binary regression model incorporating data from pCLE operating criteria, pCLE impression, and PSC status.Results: 97 patients were identified. In the 27 patients with neoplasia, there was increasing number of Miami malignant criteria (Pearson r = 0.512, p < .001) while inflammatory criteria were less prevalent. 10% (5/51, p < .001) of patients with benign pCLE impression developed neoplasia, while 48% (22/46, p < .001) with suspicious pCLE impressions developed neoplasia. The binary regression model to predict neoplasia had a sensitivity of 83.3%, specificity of 92.5%, and overall accuracy 89.7%.Conclusions: Presence of malignant criteria and absence of certain inflammatory criteria are more prevalent in patients with neoplasia. Our model, which weights individual imaging components, shows impressive sensitivity and specificity over prior prognostic efforts. Prospective studies will be required to evaluate this model.

The risk of post-ERCP pancreatitis after single operator peroral spyglass cholangioscopy is highest in the beginning of practice

Evaluation of indeterminate biliary strictures by brush cytology and intraductal biopsies is limited by low sensitivity. The utility of SpyGlass peroral cholangioscopy for diagnosis of malignant biliary strictures and cholangiocarcinoma (CCA), in particular, remains unclear. Our aim was to study the utility of SpyGlass peroral cholangioscopy and targeted biopsy for diagnosis of malignant biliary strictures and CCA.In this systematic review, PubMed and Embase databases were reviewed for studies published to October 2014. The main outcomes of interest were sensitivity, specificity, and diagnostic odds ratio (DOR) of SpyGlass cholangioscopy in the diagnosis of malignant biliary strictures.The search yielded 10 studies involving 456 patients. The pooled sensitivity and specificity of cholangioscopy-guided biopsies in the diagnosis of malignant biliary strictures was 60.1% (95% confidence interval [CI], 54.9%-65.2%) and 98.0% (95% CI, 96.0%-99.0%), respectively. The pooled DOR to detect malignant biliary strictures was 66.4 (95% CI, 32.1-137.5). Four studies included patients who had previous negative imaging and brushings and/or intraductal biopsies. Among these 4 studies, the pooled sensitivity and specificity for diagnosis of malignant biliary strictures was 74.7% (95% CI, 63.3%-84.0%) and 93.3% (95% CI, 85.1%-97.8%), respectively. The pooled DOR was 46.0 (95% CI, 15.4-138.1). Only 1 study directly compared the yield of SpyBite biopsies with standard brushings and biopsies. SpyBite biopsies had a sensitivity of 76.5% compared with brushings (5.8%) and biopsies (29.4%). Six studies specifically reported the role of cholangioscopy with targeted biopsies in the diagnosis of CCA. The pooled sensitivity and specificity to detect CCA was 66.2% (95% CI, 59.7%-72.3%) and 97.0% (95% CI, 94.0%-99.0%), respectively. The pooled DOR to detect CCA was 79.7 (95% CI, 32.7-194.7).Our study suggests that SpyGlass cholangioscopy with SpyBite biopsies has moderate sensitivity for the diagnosis of malignant biliary strictures.

Peroral cholangiopancreatoscopy with the SpyGlass® system: what do we know 10 years later.

Smaller endoscopes and catheters have been developed that permit direct visualization of the bile and pancreatic ducts (cholangioscopy and pancreatoscopy, respectively). These endoscopes and catheters are passed through the working channel of a standard therapeutic duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). The SpyGlass Direct Visualization System (Boston Scientific Corp, Natick, MA, USA) is currently the most widely used and studied device. Cholangioscopy with intraductal lithotripsy has become an established modality in the treatment of difficult biliary lithiasis. When used in the evaluation of indeterminate biliary strictures by experienced endoscopists in recognizing intraductal pathology, it increases the diagnostic yield of tissue sampling. Pancreatoscopy is complementary to other imaging modalities in the evaluation of intraductal papillary mucinous neoplasms of the pancreas and is emerging as a sole or adjunctive therapy to extracorporeal shock wave lithotripsy for the treatment of main pancreatic duct stones. It remains investigational in the diagnosis of pancreatic adenocarcinoma. Complications specific to the performance of cholangiopancreatoscopy include cholangitis, which is related to intraductal fluid irrigation.

Tu1436 A Cost-Utility Analysis of Various Endoscopic Methods for Evaluation of Indeterminate Biliary Strictures

The evaluation of indeterminate biliary strictures (IS) remains a diagnostic challenge. Current investigative techniques include cytology brushing, intraductal biopsy, fluorescent in-situ hybridization (FISH), direct cholangioscopy visualization, and probe-based confocal endomicroscopy (pCLE). The aim of our study was to perform a cost-utility analysis comparing these various techniques during endoscopic retrograde cholangiopancreatography (ERCP).