Efficacy of digital single-operator cholangioscopy in the visual interpretation of indeterminate biliary strictures: a systematic review and meta-analysis. Surg Endosc. 2020;34:3321-3329. [PMID: 32342216 DOI: 10.1007/s00464-020-07583-8]

Advancements in biliopancreatic endoscopy: a comprehensive review of artificial intelligence in EUS and ERCP

The development and implementation of artificial intelligence (AI), particularly deep learning (DL) models, has generated significant interest across various fields of gastroenterology. While research in luminal endoscopy has seen rapid translation to clinical practice with approved AI devices, its potential extends far beyond, offering promising benefits for biliopancreatic endoscopy like optical characterization of strictures during cholangioscopy or detection and classification of pancreatic lesions during diagnostic endoscopic ultrasound (EUS). This narrative review provides an up-to-date of the latest literature and available studies in this field. Serving as a comprehensive guide to the current landscape of AI in biliopancreatic endoscopy, emphasizing technological advancements, main applications, ethical considerations, and future directions for research and clinical implementation.

Diagnostic accuracy and interobserver agreement of cholangioscopy for indeterminate biliary strictures: A single-center experience

BACKGROUND AND STUDY AIMS

Characterization of indeterminate biliary strictures (IDBS) still represents a major challenge. Digital single-operator cholangioscopy (DSOC) could potentially overcome limits of conventional biopsy and brush sampling. The aim of this study was to compare diagnostic accuracy of visual evaluation and DSOC-guided biopsies to conventional trans-papillary sampling techniques and to evaluate the inter-observer agreement (IOA) on visual diagnosis.

PATIENTS AND METHODS

All consecutive patients undergoing DSOC-guided biopsy after conventional sampling techniques for IDBS during a six-year period were retrospectively evaluated. Final diagnosis was based on histological evaluation of the surgical specimen if available or a clinical follow-up of at least 6 months. For IOA, 20-second DSOC clips were retrospectively reviewed by 6 experts and 6 trainees and classified according to the Monaco Classification.

RESULTS

Thirty-five patients underwent DSOC for IDBS in the study period; 14 patients (F = 9) with a median age of 64 years (range 53-76) met the study aim. After DSOC, strictures location was changed in three patients (additional yield of 21.4 %). Intraductal DSOC-guided biopsy were technically successful in all cases, with an adequacy of 92.8 %. No adverse events were recorded. Final diagnosis was benign disease in five cases and cholangiocarcinoma in the others. For IOA, 29 videos were evaluated with almost perfect agreement for final diagnosis (kappa 0.871; agreement 93.1, p <0.001), although overall accuracy of DSOC visual finding was 73.6 % and 64.4 % for experts and trainees, respectively.

CONCLUSIONS

DSOC could improve diagnostic accuracy for IDBS, since it showed high sensitivity for visual finding and high specificity for DSOC guided-biopsy. Visual diagnosis seems reliable for diagnosis using the Monaco Classification.

Accurate and safe diagnosis and treatment of neoplastic biliary lesions using a novel 9F and 11F digital single-operator cholangioscope

Background and study aims Digital single-operator cholangioscopy (DSOC) allows the diagnosis of biliary duct disorders and treatment for complicated stones. However, these technologies have limitations such as the size of the probe and working channel, excessive cost, and low image resolution. Recently, a novel DSOC system (eyeMAX, Micro-Tech, Nanjing, China) was developed to address these limitations. We aimed to evaluate the usefulness and safety of a novel 9F and 11F DSOC system in terms of neoplastic diagnostic accuracy based on visual examination, ability to evaluate tumor extension and to achieve complete biliary stone clearance, and procedure-related adverse events (AEs). Patients and methods Data from ≥ 18-year-old patients who underwent DSOC from July 2021 to April 2022 were retrospectively recovered and divided into a diagnostic and a therapeutic cohort. Results A total of 80 patients were included. In the diagnostic cohort (n = 49/80), neovascularity was identified in 26 of 49 patients (46.9%). Biopsy was performed in 65.3% patients with adequate tissue sample obtained in 96.8% of cases. Biopsy confirmed neoplasia in 23 of 32 cases. DSOC visual impression achieved 91.6% sensitivity and 87.5% specificity in diagnosing neoplasms. In the therapeutic cohort (n = 43/80), 26 of 43 patients required lithotripsy alone. Total stone removal was achieved in 71% patients in the first session. Neither early nor late AEs were documented in either the diagnostic or therapeutic cohort. Conclusions The novel DSOC device has excellent diagnostic accuracy in distinguishing neoplastic biliary lesions as well as therapeutic benefits in the context of total stone removal, with no documented AEs.

Case report: The diagnostic dilemma of indeterminate biliary strictures: report on two cases with a literature review

Background

It is still a challenging problem for clinicians to explore the nature of the indeterminate biliary strictures (IBSs). Approximately 20% of biliary strictures remain undetermined after a thorough preoperative assessment.

Case presentation

Here, we present two cases of indeterminate biliary strictures patients, whose cross- sectional imaging and endoscopic examination were nondiagnostic. The patients underwent exploratory laparotomy finally and were confirmed as malignancy. We also reviewed the recent reports in literatures regarding the evaluation of IBSs.

Conclusions

Given the majority of the biliary strictures are malignancy, preoperative differentiation between benign and malignant is critical for choosing the best therapeutic regimen. Thus, close follow-up, multiple multidisciplinary discussion, and prompt surgical exploration are necessary for some difficult diagnostic cases.

Surgical management, including the role of transplantation, for intrahepatic and peri-hilar cholangiocarcinoma

Intrahepatic and peri-hilar cholangiocarcinoma are life threatening disease with poor outcomes despite optimal treatment currently available (5-year overall survival following resection 20-35%, and <10% cured at 10-years post resection). The insidious onset makes diagnosis difficult, the majority do not have a resection option and the high recurrence rate post-resection suggests that occult metastatic disease is frequently present. Advances in perioperative management, such as ipsilateral portal vein (and hepatic vein) embolisation methods to increase the future liver remnant volume, genomic profiling, and (neo)adjuvant therapies demonstrate great potential in improving outcomes. However multiple areas of controversy exist. Surgical resection rate and outcomes vary between centres with no global consensus on how 'resectable' disease is defined - molecular profiling and genomic analysis could potentially identify patients unlikely to benefit from resection or likely to benefit from targeted therapies. FDG-PET scanning has also improved the ability to detect metastatic disease preoperatively and avoid futile resection. However tumours frequently invade major vasculo-biliary structures, with resection and reconstruction associated with significant morbidity and mortality even in specialist centres. Liver transplantation has been investigated for very selected patients for the last decade and yet the selection algorithm, surgical approach and both value of both neoadjuvant and adjuvant therapies remain to be clarified. In this review, we discuss the contemporary management of intrahepatic and peri-hilar cholangiocarcinoma.

Clinical practice guideline on the use of single-operator cholangioscopy in the diagnosis of indeterminate biliary stricture and the treatment of difficult biliary stones

BACKGROUND AND AIMS

Single-operator cholangioscopy (SOC) offer a diagnostic and therapeutic alternative with an improved optical resolution over conventional techniques; however, there are no standardized clinical practice guidelines for this technology. This evidence-based guideline from the Colombian Association of Digestive Endoscopy (ACED) intends to support patients, clinicians, and others in decisions about using in adults the SOC compared to endoscopic retrograde cholangiopancreatography (ERCP), to diagnose indeterminate biliary stricture and to manage difficult biliary stones.

METHODS

ACED created a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. Universidad de los Andes and the Colombia Grading of Recommendations Assessment, Development and Evaluation (GRADE) Network supported the guideline-development process, updating and performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The GRADE approach was used, including GRADE Evidence-to-Decision frameworks.

RESULTS

The panel agreed on one recommendation for adult patients with indeterminate biliary strictures and one for adult patients with difficult biliary stones when comparing SOC versus ERCP.

CONCLUSION

For adult patients with indeterminate biliary strictures, the panel made a conditional recommendation for SOC with stricture pattern characterization over ERCP with brushing and/or biopsy for sensitivity, specificity, and procedure success rate outcomes. For the adult patients with difficult biliary stones the panel made conditional recommendation for SOC over ERCP with large-balloon dilation of papilla. Additional research is required on economic estimations of SOC and knowledge translation evaluations to implement SOC intervention in local contexts.

The Role of Cholangioscopy in Biliary Diseases

Endoscopy plays a central role in diagnostic and therapeutic approaches to biliary disease in both benign and malignant conditions. A cholangioscope is an endoscopic instrument that allows for the direct exploration of the biliary tree. Over the years, technology has improved endoscopic image quality and allowed for the development of an operative procedure that can be performed during cholangioscopy. Different types of instruments are available in this context, and they can be used in different anatomical access points according to the most appropriate clinical indication. The direct visualization of biliary mucosa is essential in the presence of biliary strictures of unknown significance, allowing for the appropriate allocation of patients to surgery or conservative treatments. Cholangioscopy has demonstrated excellent performance in discriminating malignant conditions (such as colangiocarcinoma) from benign inflammatory strictures, and more recent advances (e.g., artificial intelligence and confocal laser endomicroscopy) could further increase its diagnostic accuracy. Cholangioscopy also plays a primary role in the treatment of benign conditions such as difficult bile stones (DBSs). In this case, it may not be possible to achieve complete biliary drainage using standard ERCP. Therapeutic cholangioscopy-guided lithotripsy allows for stone fragmentation and complete biliary drainage. Indeed, other complex clinical situations, such as patients with intra-hepatic lithiasis and patients with an altered anatomy, could benefit from the therapeutic role of cholangioscopy. The aim of the present review is to explore the most recent diagnostic and therapeutic advances in the roles of cholangioscopy in the management of biliary diseases.

Artificial intelligence for diagnosing neoplasia on digital cholangioscopy: development and multicenter validation of a convolutional neural network model

BACKGROUND

We aimed to develop a convolutional neural network (CNN) model for detecting neoplastic lesions during real-time digital single-operator cholangioscopy (DSOC) and to clinically validate the model through comparisons with DSOC expert and nonexpert endoscopists.

METHODS

In this two-stage study, we first developed and validated CNN1. Then, we performed a multicenter diagnostic trial to compare four DSOC experts and nonexperts against an improved model (CNN2). Lesions were classified into neoplastic and non-neoplastic in accordance with Carlos Robles-Medranda (CRM) and Mendoza disaggregated criteria. The final diagnosis of neoplasia was based on histopathology and 12-month follow-up outcomes.

RESULTS

In stage I, CNN2 achieved a mean average precision of 0.88, an intersection over the union value of 83.24 %, and a total loss of 0.0975. For clinical validation, a total of 170 videos from newly included patients were analyzed with the CNN2. Half of cases (50 %) had neoplastic lesions. This model achieved significant accuracy values for neoplastic diagnosis, with a 90.5 % sensitivity, 68.2 % specificity, and 74.0 % and 87.8 % positive and negative predictive values, respectively. The CNN2 model outperformed nonexpert #2 (area under the receiver operating characteristic curve [AUC]-CRM 0.657 vs. AUC-CNN2 0.794, P < 0.05; AUC-Mendoza 0.582 vs. AUC-CNN2 0.794, P < 0.05), nonexpert #4 (AUC-CRM 0.683 vs. AUC-CNN2 0.791, P < 0.05), and expert #4 (AUC-CRM 0.755 vs. AUC-CNN2 0.848, P < 0.05; AUC-Mendoza 0.753 vs. AUC-CNN2 0.848, P < 0.05).

CONCLUSIONS

The proposed CNN model distinguished neoplastic bile duct lesions with good accuracy and outperformed two nonexpert and one expert endoscopist.

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.

Case report: Single-operator peroral cholangioscopy system (SpyGlass) diagnosis of an extrahepatic biliary cystadenoma (video)

Biliary cystadenoma is a type of rare liver cystic tumor. Intrahepatic biliary cystadenomas are the most common, while extrahepatic biliary cystadenomas are rarely seen. Biliary cystadenoma tends to occur in middle-aged to older women and there is a lack of specific preoperative diagnostic markers. Recent advancements in technology and the development of the SpyGlass system have led to an increased use of cholangioscopy. Herein, we report a patient in whom a space-occupying lesion was found in the bile duct by SpyGlass, and who later underwent radical surgery. The pathology report indicated that the final diagnosis was biliary cystadenoma. SpyGlass cholangioscopy may be a novel and effective diagnostic method for biliary cystadenoma.

Utility of Digital Single-operator Video Cholangioscopy for the Endoscopic Management of Biliary Complications After Liver Transplantation-A Single-center Experience

BACKGROUND

Liver transplant recipients (LTRs) frequently develop biliary complications, and endoscopy is crucial for their subsequent management. Recently, single-operator video cholangioscopy (SOVC) with digital imaging quality was introduced. This study evaluated the utility of digital SOVC for the management of biliary complications in LTRs.

METHODS

This observational study retrospectively analyzed all LTRs undergoing digital SOVC between 2015 and 2019 at a tertiary referral center. Endpoints included the assessment of biliary strictures, performance of selective guidewire passage across biliary strictures, and diagnosis and treatment of biliary stone disease.

RESULTS

In total, 79 digital SOVCs performed in 50 LTRs were identified. Fifty-eight percent of the procedures were performed for biliary stricture assessment, and using visual signs or guided biopsies, SOVC excluded malignancy in all cases (100%). Of all the examinations, 29.1% (23/79) were performed solely because of a previous failure of conventional endoscopic methods to pass a guidewire across a biliary stricture. Using SOVC, guidewire passage was successfully performed in 73.9% of these examinations, enabling subsequent endoscopic therapy. Furthermore, biliary stones were found in 16.5% (13/79) of the examinations. In 38.5% of these cases, standard fluoroscopy failed to detect stones, which were only visualized using digital SOVC. Biliary stone treatment was successful in 92% (12/13) of the examinations. Complications occurred in 11.4% of all SOVCs. No procedure-associated mortalities were observed.

CONCLUSIONS

Digital SOVC is effective and safe for the endoscopic management of biliary complications in LTRs and offers unique diagnostic and therapeutic opportunities that strongly impact the clinical course in selected cases.

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).

Digital single-operator video cholangioscopy improves endoscopic management in patients with primary sclerosing cholangitis-a retrospective observational study

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) are at a high risk of developing cholestatic liver disease and biliary cancer, and endoscopy is crucial for the complex management of these patients.

AIM

To clarify the utility of recently introduced digital single-operator video cholangioscopy (SOVC) for the endoscopic management of PSC patients.

METHODS

In this observational study, all patients with a history of PSC and in whom digital SOVC (using the SpyGlass DS System) was performed between 2015 and 2019 were included and retrospectively analysed. Examinations were performed at a tertiary referral centre in Germany. In total, 46 SOVCs performed in 38 patients with a history of PSC were identified. The primary endpoint was the evaluation of dominant biliary strictures using digital SOVC, and the secondary endpoints were the performance of selective guidewire passage across biliary strictures and the diagnosis and treatment of biliary stone disease in PSC patients.

RESULTS

The 22 of 38 patients had a dominant biliary stricture (57.9%). In 4 of these 22 patients, a cholangiocellular carcinoma was diagnosed within the stricture (18.2%). Diagnostic evaluation of dominant biliary strictures using optical signs showed a sensitivity of 75% and a specificity of 94.4% to detect malignant strictures, whereas SOVC-guided biopsies to gain tissue for histopathological analysis showed a sensitivity of 50% and a specificity of 100%. In 13% of examinations, SOVC was helpful for guidewire passage across biliary strictures that could not be passed by conventional methods (technical success rate 100%). Biliary stone disease was observed in 17.4% of examinations; of these, in 37.5% of examinations, biliary stones could only be visualized by SOVC and not by standard fluoroscopy. Biliary stone treatment was successful in all cases (100%); 25% required SOVC-assisted electrohydraulic lithotripsy. Complications, such as postinterventional cholangitis and pancreatitis, occurred in 13% of examinations; however, no procedure-associated mortality occurred.

CONCLUSION

Digital SOVC is effective and safe for the endoscopic management of PSC patients and may be regularly considered an additive tool for the complex endoscopic management of these patients.

More Endoscopy-Based Brushing Passes Improve the Detection of Malignant Biliary Strictures: A Multicenter Randomized Controlled Trial

INTRODUCTION

Endoscopic biliary brushing is the most common method used for sampling in patients with malignant biliary strictures (MBSs); however, its sensitivity is relatively low. There is still no consensus on endoscopy-based biliary brushing, although brushing 10 times in 1 specimen is routinely performed. This study was designed to compare the sensitivity of brush cytology for 10, 20, or 30 brushing times of a pass in 1 specimen in patients with MBSs.

METHODS

In this multicenter, prospective, randomized controlled study, patients who underwent endoscopic retrograde cholangiopancreatography for suspected MBSs were enrolled. Patients were randomly assigned to receive 10, 20, and 30 brushing times of a pass. The primary outcome was to compare the sensitivity of brush cytology among the 3 groups. Patients were prospectively followed up for 6 months after endoscopic brushing for malignancy diagnosis.

RESULTS

A total of 443 patients were enrolled for intention-to-treat analysis (147, 148, and 148 patients in the 10-times, 20-times, and 30-time groups, respectively). The 3 groups were similar in baseline characteristics. The sensitivity of brush cytology was 38%, 47%, and 57% in the 10-times, 20-times, and 30-times groups, respectively, and the 30-times group showed significantly higher sensitivity than the 10-times group (P = 0.001). The multivariate analysis revealed that stricture length and the number of brushing passes were significant factors for the detection of biliary malignancy. No significant differences were observed in procedure-related complications among the 3 groups.

DISCUSSION

Brushing 30 times could increase the diagnostic sensitivity without increasing complications and seems to be preferred for the endoscopic sampling and diagnosis of MBSs (chictr.org.cn, identifier: ChiCTR1800015978).

Artificial intelligence in the endoscopic approach of biliary tract diseases: A current review

In recent years there have been major developments in the field of artificial intelligence. The different areas of medicine have taken advantage of this tool to make various diagnostic and therapeutic methods more effective, safe, and user-friendly. In this way, artificial intelligence has been an increasingly present reality in medicine. In the field of Gastroenterology, the main application has been in the detection and characterization of colonic polyps, but an increasing number of studies have been published on the application of deep learning systems in other pathologies of the gastrointestinal tract. Evidence of the application of artificial intelligence in the assessment of biliary tract is still scarce. Some studies support the usefulness of these systems in the investigation and treatment of choledocholithiasis, demonstrating that they have the potential to be integrated into clinical practice and endoscopic procedures, such as endoscopic retrograde cholangiopancreatography. Its application in cholangioscopy for the investigation of undetermined biliary strictures also seems to be promising. Assessing the bile duct through endoscopic ultrasound can be challenging, especially for less experienced operators, thus becoming an area of potential interest for artificial intelligence. In this review, we summarize the state of the art of artificial intelligence in the endoscopic diagnosis and treatment of biliary diseases.

Cholangioscopy: Has It Changed Management?

The single operator per oral cholangioscope is a catheter-based system that allows for direct visualization of the bile duct and pancreatic duct. The instrument with its improved imaging technique and larger accessory channel allows for high-quality image acquisition and performance of therapeutic and diagnostic procedures within the bile duct and pancreatic duct. There has been an increase in the range of indications for the use of the cholangioscope. The current indications include management of difficult biliary stones, pancreatic calculi, assessment of indeterminate biliary stricture, pancreatic stricture, intra-ductal papillary mucinous neoplasms, and extractions of proximally migrated stents. The use of laser lithotripsy and electro-hydraulic lithotripsy has improved the management of difficult bile duct stones. Direct visualization of biliary and pancreatic duct strictures is helpful in the diagnosis of indeterminate strictures. In this review, we explore how cholangioscopy has changed management.

Improving Diagnostic Yield in Indeterminate Biliary Strictures

Indeterminate biliary strictures are defined as a narrowing of the bile duct that cannot be differentiated as malignant or benign after performing cross-sectional imaging and an ERCP. Identifying the etiology of a bile duct stricture is the single most important step in determining whether a complex and potentially morbid surgical resection is warranted. Due to this diagnostic and therapeutic dilemma, new technologies, laboratory tests, and procedures are emerging to solve this problem.

Artificial intelligence for automatic diagnosis of biliary stricture malignancy status in single-operator cholangioscopy: a pilot study

BACKGROUND AND AIMS

The diagnosis and characterization of biliary strictures (BSs) is challenging. The introduction of digital single-operator cholangioscopy (DSOC) that allows direct visual inspection of the lesion and targeted biopsy sampling significantly improved the diagnostic yield in patients with indeterminate BSs. However, the diagnostic efficiency of DSOC remains suboptimal. Convolutional neural networks (CNNs) have shown great potential for the interpretation of medical images. We aimed to develop a CNN-based system for automatic detection of malignant BSs in DSOC images.

METHODS

We developed, trained, and validated a CNN-based on DSOC images. Each frame was labeled as a normal/benign finding or as a malignant lesion if histopathologic evidence of biliary malignancy was available. The entire dataset was split for 5-fold cross-validation. In addition, the image dataset was split for constitution of training and validation datasets. The performance of the CNN was measured by calculating the area under the receiving operating characteristic curve (AUC), sensitivity, specificity, and positive and negative predictive values.

RESULTS

A total of 11,855 images from 85 patients were included (9695 malignant strictures and 2160 benign findings). The model had an overall accuracy of 94.9%, sensitivity of 94.7%, specificity of 92.1%, and AUC of .988 in cross-validation analysis. The image processing speed of the CNN was 7 ms per frame.

CONCLUSIONS

The developed deep learning algorithm accurately detected and differentiated malignant strictures from benign biliary conditions. The introduction of artificial intelligence algorithms to DSOC systems may significantly increase its diagnostic yield for malignant strictures.

Consensus guidelines on the role of cholangioscopy to diagnose indeterminate biliary stricture

BACKGROUND

Indeterminate strictures pose a therapeutic dilemma. In recent years, cholangioscopy has evolved and the availability of cholangioscopy has increased. However, the position of cholangioscopy in the diagnostic algorithm to diagnose malignancy have not been well established. We aim to develop a consensus statement regarding the clinical role of cholangioscopy in the diagnosis of indeterminate biliary strictures.

METHODS

The international experts reviewed the evidence and modified the statements using a three-step modified Delphi method. Each statement achieves consensus when it has at least 80% agreement.

RESULTS

Nine final statements were formulated. An indeterminate biliary stricture is defined as that of uncertain etiology under imaging or tissue diagnosis. When available, cholangioscopic assessment and guided biopsy during the first round of ERCP may reduce the need to perform multiple procedures. Cholangioscopy are helpful in diagnosing malignant biliary strictures by both direct visualization and targeted biopsy. The absence of disease progression for at least 6 months is supportive of non-malignant etiology. Direct per-oral cholangioscopy provides the largest accessory channel, better image definition, with image enhancement but is technically demanding. Image enhancement during cholangioscopy may increase the diagnostic sensitivity of visual impression of malignant biliary strictures. Cholangioscopic imaging characteristics including tumor vessels, papillary projection, nodular or polypoid mass, and infiltrative lesions are highly suggestive for neoplastic/malignant biliary disease. The risk of cholangioscopy related cholangitis is higher than in standard ERCP, necessitating prophylactic antibiotics and ensuring adequate biliary drainage. Per-oral cholangioscopy may not be the modality of choice in the evaluation of distal biliary strictures due to inherent technical difficulties.

CONCLUSION

Evidence supports that cholangioscopy has an adjunct role to abdominal imaging and ERCP tissue acquisition in order to evaluate and diagnose indeterminate biliary strictures.

Clinical practice patterns in indirect peroral cholangiopancreatoscopy: outcome of a European survey

Background and aims  Indirect peroral cholangiopancreatoscopy (IPOC) is a relatively new diagnostic and therapeutic tool for biliopancreatic diseases. This international survey aimed to evaluate clinical practice patterns in IPOC among endoscopists in Europe. Methods  An online survey was developed comprising 66 questions on the use of IPOC. Questions were grouped into four domains. The survey was sent to 369 endoscopists who perform IPOC. Results  86 respondents (23.3 %) from 21 different countries across Europe completed the survey. The main indications for cholangioscopy were determination of biliary strictures (85 [98.8 %]) and removal of common bile duct or intrahepatic duct stones (79 [91.9 %]), accounting for an estimated use of 40 % (interquartile range [IQR] 25-50) and 40 % (IQR 30-60), respectively, of all cases undergoing cholangioscopy. Pancreatoscopy was mainly used for removal of pancreatic duct stones (68/76 [89.5 %]), accounting for an estimated use of 76.5 % (IQR 50-95) of all cases undergoing pancreatoscopy. Only 13/85 respondents (15.3 %) had an institutional standardized protocol for targeted cholangioscopy-guided biopsy sampling. IPOC with lithotripsy was used as first-line treatment in selected patients with bile duct stones or pancreatic stones by 24/79 (30.4 %) and 53/68 (77.9 %) respondents, respectively. Conclusions  This first European survey on the clinical practice of IPOC demonstrated wide variation in experience, indications, and techniques. These results emphasize the need for prospective studies and development of an international consensus guideline to standardize the practice and quality of IPOC.

Endoscopic tissue sampling - Part 1: Upper gastrointestinal and hepatopancreatobiliary tracts. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that, where there is a suspicion of eosinophilic esophagitis, at least six biopsies should be taken, two to four biopsies from the distal esophagus and two to four biopsies from the proximal esophagus, targeting areas with endoscopic mucosal abnormalities. Distal and proximal biopsies should be placed in separate containers.Strong recommendation, low quality of evidence. 2: ESGE recommends obtaining six biopsies, including from the base and edge of the esophageal ulcers, for histologic analysis in patients with suspected viral esophagitis.Strong recommendation, low quality of evidence. 3: ESGE recommends at least six biopsies are taken in cases of suspected advanced esophageal cancer and suspected advanced gastric cancer.Strong recommendation, moderate quality of evidence. 4: ESGE recommends taking only one to two targeted biopsies for lesions in the esophagus or stomach that are potentially amenable to endoscopic resection (Paris classification 0-I, 0-II) in order to confirm the diagnosis and not compromise subsequent endoscopic resection.Strong recommendation, low quality of evidence. 5: ESGE recommends obtaining two biopsies from the antrum and two from the corpus in patients with suspected Helicobacter pylori infection and for gastritis staging.Strong recommendation, low quality of evidence. 6: ESGE recommends biopsies from or, if endoscopically resectable, resection of gastric adenomas.Strong recommendation, moderate quality of evidence. 7: ESGE recommends fine-needle aspiration (FNA) and fine-needle biopsy (FNB) needles equally for sampling of solid pancreatic masses.Strong recommendation, high quality evidence. 8: ESGE suggests performing peroral cholangioscopy (POC) and/or endoscopic ultrasound (EUS)-guided tissue acquisition in indeterminate biliary strictures. For proximal and intrinsic strictures, POC is preferred. For distal and extrinsic strictures, EUS-guided sampling is preferred, with POC where this is not diagnostic.Weak recommendation, low quality evidence. 9: ESGE suggests obtaining possible non-neoplastic biopsies before sampling suspected malignant lesions to prevent intraluminal spread of malignant disease.Weak recommendation, low quality of evidence. 10: ESGE suggests dividing EUS-FNA material into smears (two per pass) and liquid-based cytology (LBC), or the whole of the EUS-FNA material can be processed as LBC, depending on local experience.Weak recommendation, low quality evidence.

Tips and tricks for the diagnosis and management of biliary stenosis-state of the art review

Biliary stenosis may represent a diagnostic and therapeutic challenge resulting in a delay in diagnosis and initiation of therapy due to the frequent difficulty in distinguishing a benign from a malignant stricture. In such cases, the diagnostic flowchart includes the sequential execution of imaging techniques, such as magnetic resonance, magnetic resonance cholangiopancreatography, and endoscopic ultrasound, while endoscopic retrograde cholangiopancreatography is performed to collect tissue for histopathological/cytological diagnosis or to treat the stenosis by insertion of stent. The execution of percutaneous transhepatic drainage with subsequent biopsy has been shown to increase the possibility of tissue diagnosis after failure of the above techniques. Although the diagnostic yield of histopathology and imaging has increased with improvements in endoscopic ultrasound and peroral cholangioscopy, differential diagnosis between malignant and benign stenosis may not be easy in some patients, and strictures are classified as indeterminate. In these cases, a multidisciplinary workup including biochemical marker assays and advanced technologies available may speed up a diagnosis of malignancy or avoid unnecessary surgery in the event of a benign stricture. Here, we review recent advancements in the diagnosis and management of biliary strictures and describe tips and tricks to increase diagnostic yields in clinical routine.

Stent versus Balloon Dilation for the Treatment of Dominant Strictures in Primary Sclerosing Cholangitis: A Systematic Review and Meta-Analysis

Background/Aims

The endoscopic management of primary sclerosing cholangitis (PSC)-associated dominant strictures remains challenging. This systematic review and meta-analysis aimed to compare balloon dilation and stent placement in the treatment of dominant strictures among PSC patients.

Methods

Literature searches on MEDLINE, EMBASE, Cochrane CENTRAL and Lilacs/Bireme were performed for studies published until December 2020. Measured outcomes included clinical efficacy, stricture recurrence, cumulative recurrencefree rate, transplant rate, 5-year survival rate, and adverse events (i.e., pancreatitis, cholangitis, bleeding, perforation and death).

Results

A total of 5 studies (n=467) were included. Based on pooled analyses, there were no differences in clinical efficacy (risk difference [RD], -0.13; 95% confidence interval [CI], -0.58 to 0.33; I²=93%) or transplant rates (RD, -0.09; 95% CI, -0.19 to 0.01; I²=0%); however, the risk of occurrence of adverse events was lower with balloon dilatation than with stent placement (RD,-0.34; 95% CI, -0.45 to -0.23; I²=61%). Among the types of adverse events reported, only the rates of cholangitis/bacteremia were significantly lower in balloon dilation patients (RD, -0.19; 95% CI, -0.25 to -0.13; I²=51%).

Conclusions

Compared to balloon dilation, stent placement for dominant strictures in PSC appeared to have higher complication rates without significant differences in efficacy.

Personalized Endoscopy in Complex Malignant Hilar Biliary Strictures

Malignant hilar biliary obstruction (HBO) represents a complex clinical condition in terms of diagnosis, surgical and medical treatment, endoscopic approach, and palliation. The main etiology of malignant HBO is hilar cholangiocarcinoma that is considered an aggressive biliary tract's cancer and has still today a poor prognosis. Endoscopy plays a crucial role in malignant HBO from the diagnosis to the palliation. This technique allows the collection of cytological or histological samples, direct visualization of the suspect malignant tissue, and an echoendoscopic evaluation of the primary tumor and its locoregional staging. Because obstructive jaundice is the most common clinical presentation of malignant HBO, endoscopic biliary drainage, when indicated, is the preferred treatment over the percutaneous approach. Several endoscopic techniques are today available for both the diagnosis and the treatment of biliary obstruction. The choice among them can differ for each clinical scenario. In fact, a personalized endoscopic approach is mandatory in order to perform the proper procedure in the singular patient.

Role of pancreatography in the endoscopic management of encapsulated pancreatic collections – review and new proposed classification

Pancreatic fluids collections are local complications related to acute or chronic pancreatitis and may require intervention when symptomatic and/or complicated. Within the last decade, endoscopic management of these collections via endoscopic ultrasound-guided transmural drainage has become the gold standard treatment for encapsulated pancreatic collections with high clinical success and lower morbidity compared to traditional surgery and percutaneous drainage. Proper understanding of anatomic landmarks, including assessment of the main pancreatic duct and any associated lesions – such as disruptions and strictures – are key to achieving clinical success, reducing the need for reintervention or recurrence, especially in cases with suspected disconnected pancreatic duct syndrome. Additionally, proper review of imaging and anatomic landmarks, including collection location, are pivotal to determine type and size of pancreatic stenting as well as approach using long-term transmural indwelling plastic stents. Pancreatography to adequately assess the main pancreatic duct may be performed by two methods: Either non-invasively using magnetic resonance cholangiopancreatography or endoscopically via retrograde cholangiopan-creatography. Despite the critical need to understand anatomy via pancrea-tography and assess the main pancreatic duct, a standardized approach or uniform assessment strategy has not been described in the literature. Therefore, the aim of this review was to clarify the role of pancreatography in the endoscopic management of encapsulated pancreatic collections and to propose a new classification system to aid in proper assessment and endoscopic treatment.

Determining the Indeterminate Biliary Stricture: Cholangioscopy and Beyond

PURPOSE OF REVIEW

Indeterminate biliary strictures (IDBS) continue to be an area of frustration for clinicians. Standard endoscopic retrograde cholangiopancreatography (ERCP) with conventional brush cytology and/or forceps biopsy has a low sensitivity for distinguishing benign from malignant biliary strictures. A delay in diagnosis of malignancy has consequences for subsequent therapy or surgery. In this article, we review current and emerging technologies that may aid in this diagnostic dilemma.

RECENT FINDINGS

Several technologies have been utilized in IDBS to establish a diagnosis which include peroral cholangioscopy, confocal laser endomicroscopy, endoscopic ultrasound with fine needle aspiration, intraductal ultrasound, optical coherence tomography, fluorescence in situ hybridization, next generation sequencing, integrated molecular pathology, and DNA-image cytometry. While cholangioscopy and confocal laser endomicroscopy have become standards of care in expert centers for the evaluation of patients with IDBS, there are several endoscopic and molecular modalities that may also aid in establishing a diagnosis. Further head-to-head prospective diagnostic studies as well as cost-efficacy studies are needed.

Efficacy and Safety of Digital Single-Operator Cholangioscopy in the Diagnosis of Indeterminate Biliary Strictures by Targeted Biopsies: A Systematic Review and Meta-Analysis

BACKGROUND

Biliary strictures are frequently encountered in clinical practice. The determination of their nature is often difficult. This study aims to systematically evaluate the efficacy and safety of the second generation of digital single-operator cholangioscopy (SpyGlass DS, DSOC) in indeterminate biliary strictures (IBDS) through biopsies.

METHODS

All relative studies published in Medline, the Cochrane Library, Web of Science, and EMBASE were included. The diagnostic tests for IBDS were compared to the surgical histology, autopsy, or long-term clinical follow-up. The methodological quality of the included studies was evaluated by the Quality Assessment of Studies of Diagnostic Accuracy Included in Systematic Reviews (QUADAS-2).

RESULTS

A total of 11 studies, which involved 356 patients diagnosed through biopsies, were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were 0.74 (95% CI: 0.67-0.80), 0.98 (95% CI: 0.95-1.00), 10.52 (95% CI: 5.45-20.32), 0.31 (95% CI: 0.23-0.41), and 65.18 (95% CI: 26.79-158.61), respectively. The area under the curve (AUC) was 0.9479, and the pooled adverse event rate was 7%. The sensitivity and specificity in the heterogeneity analysis were I2 = 48.1% and I2 = 25.4%, respectively.

CONCLUSION

SpyGlass DS is a safe and effective technique for IBDS. However, future randomized trials are needed to determine optimal number of biopsies.