Optimizing Outcomes of Single-Operator Cholangioscopy-Guided Biopsies Based on a Randomized Trial

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 the biliary 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.

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.

Still elusive: Developments in the accurate diagnosis of indeterminate biliary strictures

Indeterminate biliary strictures pose a significant diagnostic dilemma for gastroenterologists. Despite advances in endoscopic techniques and instruments, it is difficult to differentiate between benign and malignant pathology. A positive histological diagnosis is always preferred prior to high risk hepatobiliary surgery, or to inform other types of therapy. Endoscopic retrograde cholangiopancreatography with brushings has low sensitivity and despite significant improvements in instruments there is still an unacceptably high false negative rate. Other methods such as endoscopic ultrasound and cholangioscopy have improved diagnostic quality. In this review we explore the techniques available to aid accurate diagnosis of indeterminate biliary strictures and obtain accurate histology to facilitate clinical management.

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

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

Methods

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

Results

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

Conclusions

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

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.

Innovative method for the diagnosis of bile duct lesions using a novel tapered-tip sheath system to facilitate biliary biopsies

BACKGROUND AND AIMS

Pathologic evaluation of bile duct lesions is crucial for a definitive diagnosis and determination of an appropriate therapeutic strategy; however, current methods are limited by several challenges. This study evaluated the impact of a novel tapered-tip sheath system on biliary stricture diagnosis.

METHODS

This observational study evaluated 47 consecutive patients who underwent transpapillary biliary stricture biopsy using the novel tapered-tip sheath system from July 2020 to March 2022 compared with 51 historical control subjects undergoing conventional biopsies. Technical success rate, total biopsy time, number of biopsy specimens, adequate tissue sampling rate, adverse events, and diagnostic performance for biliary strictures were assessed.

RESULTS

The technical success rate was favorable in both groups, showing no significant difference (97.9% [46 of 47] vs 88.2% [45 of 51], P = .114). However, the total biopsy time was significantly shorter in the novel system group (3.7 vs 7.7 minutes, P < .001). The number of biopsy specimens did not differ between the groups; however, the novel system group had significantly more cases in which ≥3 tissue samples could be obtained (71.7% [33 of 46] vs 51.1% [23 of 45], P = .043), a higher adequate tissue sampling rate (88.2% vs 66.4%, P < .001), and fewer adverse events (6.4% vs 21.6%, P = .043). Although the diagnostic specificity of both groups was 100%, the novel system group had significantly higher diagnostic sensitivity and accuracy (82.1% vs 50% [P = .004] and 84.8% vs 55.5% [P = .005], respectively).

CONCLUSIONS

The novel tapered-tip sheath system is a promising tool for biliary stricture diagnosis.

A novel peroral digital cholangioscope with a large accessory channel: An experimental study

BACKGROUND/PURPOSE

A peroral cholangioscope (POCS) can allow direct visualization of the biliary mucosa and its use is becoming more widespread due to improvements in functionality, image quality, and operability, as well as the development of related devices. Recently, a novel mother-baby peroral cholangioscope (nMB-POCS) with a large (2-mm) accessory channel has been developed. In this study, we evaluated the feasibility of this novel POCS in a dry simulation and animal model.

METHODS

We evaluated the ease of insertion and maneuverability of the nMB-POCS, the image quality, and the passage of the devices into the accessory channel and into the common bile duct in a dry and live porcine model.

RESULTS

In both models, the nMB-POCS could be easily inserted into the duodenoscope and into the distal bile duct and hilum. The image quality was good, and it was possible to observe the surface structure and the vascular network of the bile duct mucosa in detail.

CONCLUSIONS

The nMB-POCS with its larger accessory channel is expected to improve the efficiency of diagnosis and  treatment, and reduce the procedure time. Clinical studies in patients are warranted.

A Preoperative Diagnosis of Advanced Cystic Duct Carcinoma Using SpyGlass DS Cholangioscopy: A Report of Two Cases

Primary cystic duct carcinoma is a rare tumor. The curative treatment of cystic duct carcinoma is complete surgical resection, for which the evaluation of local extension is important. We herein report two cases of cystic duct carcinoma in which a preoperative examination was performed using per-oral cholangioscopy (POCS). Both patients underwent POCS due to suspicion of cystic duct carcinoma based on imaging findings. A visual analysis and biopsy were performed to evaluate local extension, which led to surgery. These cases suggest that POCS is useful for the preoperative assessment of local extension in advanced cystic duct carcinoma.

Digital single-operator cholangioscopy in diagnostic and therapeutic bilio-pancreatic diseases: A prospective, multicenter study

BACKGROUND AND AIM

Digital single-operator cholangioscopy (D-SOC) is an endoscopic procedure that is increasingly used for the management of bilio-pancreatic diseases. We aimed to investigate the efficacy and safety of D-SOC for diagnostic and therapeutic indications.

METHODS

This is a multicenter, prospective study(January 2016-June 2019) across eighteen tertiary centers. The primary outcome was procedural success of D-SOC. Secondary outcomes were: D-SOC visual assessment and diagnostic yield of SpyBite biopsy in cases of biliary strictures, stone clearance rate in cases of difficult biliary stones, rate of adverse events(AEs) for all indications.

RESULTS

D-SOC was performed in 369 patients (201(54,5%) diagnostic and 168(45,5%)therapeutic). Overall, procedural success rate was achieved in 360(97,6%) patients. The sensitivity, specificity, PPV, NPV and accuracy in biliary strictures were: 88,5%, 77,3%, 83,3%, 84,1% and 83,6% for D-SOC visual impression; 80,2%, 92,6%, 95,1%, 72,5% and 84,7% for the SpyBite biopsy, respectively. For difficult biliary stones, complete duct clearance was obtained in 92,1% patients (82,1% in a single session). Overall, AEs occurred in 37(10%) cases.The grade of AEs was mild or moderate for all cases, except one which was fatal.

CONCLUSION

D-SOC is effective for diagnostic and therapeutic indications.Most of the AEs were minor and managed conservatively, even though a fatal event has happened that is not negligible and should be considered before using D-SOC.

Future of Cholangioscopy

This article highlights the current status of cholangioscopy. In addition, the authors present their view on the future directions of cholangioscopy, including novel clinical applications, the need for technologic developments, and the expansion on the use of cholangioscopy in clinical practice. The authors envision that cholangioscopy will eventually become a conventional tool in the shelf of any biliary endoscopist. Future technologic improvements including optics, maneuverability, and full device accessories, plus the introduction of real-time artificial intelligence algorithms, will optimize the outcomes of cholangioscopy, but baseline proficiency in therapeutic endoscopic retrograde cholangiopancreatography will remain necessary for its successful utilization.

Multidisciplinary Approach to Indeterminate Biliary Strictures

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

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).

Next-generation sequencing of bile cell-free DNA for the early detection of patients with malignant biliary strictures

OBJECTIVE

Despite significant progresses in imaging and pathological evaluation, early differentiation between benign and malignant biliary strictures remains challenging. Endoscopic retrograde cholangiopancreatography (ERCP) is used to investigate biliary strictures, enabling the collection of bile. We tested the diagnostic potential of next-generation sequencing (NGS) mutational analysis of bile cell-free DNA (cfDNA).

DESIGN

A prospective cohort of patients with suspicious biliary strictures (n=68) was studied. The performance of initial pathological diagnosis was compared with that of the mutational analysis of bile cfDNA collected at the time of first ERCP using an NGS panel open to clinical laboratory implementation, the Oncomine Pan-Cancer Cell-Free assay.

RESULTS

An initial pathological diagnosis classified these strictures as of benign (n=26), indeterminate (n=9) or malignant (n=33) origin. Sensitivity and specificity of this diagnosis were 60% and 100%, respectively, as on follow-up 14 of the 26 and eight of the nine initially benign or indeterminate strictures resulted malignant. Sensitivity and specificity for malignancy of our NGS assay, herein named Bilemut, were 96.4% and 69.2%, respectively. Importantly, one of the four Bilemut false positives developed pancreatic cancer after extended follow-up. Remarkably, the sensitivity for malignancy of Bilemut was 100% in patients with an initial diagnosis of benign or indeterminate strictures. Analysis of 30 paired bile and tissue samples also demonstrated the superior performance of Bilemut.

CONCLUSION

Implementation of Bilemut at the initial diagnostic stage for biliary strictures can significantly improve detection of malignancy, reduce delays in the clinical management of patients and assist in selecting patients for targeted therapies.

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.

The Role Of Cytology In The Investigation And Management Of Pancreatobiliary Lesions With A Transition Towards A Standardised Reporting System: An Institutional Perspective

Pancreatobiliary pathology encompasses all benign and malignant disease within the pancreas and biliary tract; pancreatic cancer is currently the seventh leading cause of death worldwide accounting for approximately 466,000 deaths per annum. Cytology has been increasingly used in the physician's toolbox to provide an accurate, non-invasive and cost-effective modality for the diagnosis of pancreatobiliary lesions. The cytological appearance alone may be insufficient to establish the diagnosis and it is crucial for effective clinicopathological correlation in a multidisciplinary setting highlighting, the vital role of the pathologist to ensure effective and quality care. The advent of modern diagnostic techniques has allowed for a less invasive approach to tissue sampling which when combined with routine staining and specialised immunohistochemistry can help guide the diagnosis. The Papanicolaou Classification is comparable to the current C1-C5 system which will enable standardised reporting to help to improve communication with clinical colleagues and subsequent patient management and our article will discuss the criteria used by cytopathologists to determine the grade of both pancreatic and biliary lesions.

Peroral cholangioscopy: Update on the state-of-the-art

Peroral cholangioscopy (POC) is an endoscopic procedure that allows direct intraductal visualization of the biliary tract. POC has emerged as a vital tool for indeterminate biliary stricture evaluation and treatment of difficult biliary stones. Over several generations of devices, POC has fulfilled additional clinical needs where other diagnostic or therapeutic modalities have been inadequate. With adverse event rates comparable to standard endoscopic retrograde cholangioscopy and unique technical attributes, the role of POC is likely to continue expand. In this frontiers article, we highlight the existing and growing clinical applications of POC as well as areas of ongoing research.

Peroral Cholangioscopy-Guided Targeted Biopsy versus Conventional Endoscopic Transpapillary Forceps Biopsy for Biliary Stricture with Suspected Bile Duct Cancer

Background: The recent improvement of peroral cholangioscopy (POCS) maneuverability has enabled the precise, targeted biopsy of bile duct lesions under direct cholangioscopic vision. However, as only small-cup biopsy forceps can pass through the scope channel, the resulting small sample size may limit the pathological diagnosis of biopsy specimens. This study compared the diagnostic abilities of POCS-guided biopsy and conventional fluoroscopy-guided biopsy for bile duct cancer. Method: This multicenter, retrospective cohort study included patients exhibiting bile duct stricture with suspected cholangiocarcinoma in whom POCS-guided and fluoroscopy-guided biopsies were performed in the same session. The primary endpoint was the diagnostic sensitivity for malignancy. The size and quality of the biopsy specimens were also compared. Result: A total of 59 patients were enrolled. The sensitivity of POCS-guided biopsy was similar to that of fluoroscopy-guided biopsy (54.0% and 64.0%, respectively). However, when the modalities were combined, the sensitivity increased to 80.0%. The mean specimen size from POCS-guided biopsy was significantly smaller than that from fluoroscopy-guided biopsy. The specimen quality using fluoroscopy-guided biopsy was also better than that using POCS-guided biopsy. Conclusions: The diagnostic sensitivity of POCS-guided biopsy is still insufficient, mainly because of the limited specimen quantity and quality. Therefore, conventional fluoroscopy-guided biopsy would be helpful to improve diagnostic sensitivity.

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.

Choledochoscopy: An update

Choledochoscopy, or cholangioscopy, is an endoscopic procedure for direct visualization within the biliary tract for diagnostic or therapeutic purposes. Since its conception in 1879, many variations and improvements are made to ensure relevance in diagnosing and managing a range of intrahepatic and extrahepatic biliary pathologies. This ranges from improved visual impression and optical guided biopsies of indeterminate biliary strictures and clinically indistinguishable pathologies to therapeutic uses in stone fragmentation and other ablative therapies. Furthermore, with the evolving understanding of biliary disorders, there are significant innovative ideas and techniques to fill this void, such as nuanced instances of biliary stenting and retrieving migrated ductal stents. With this in mind, we present a review of the current advancements in choledo-choscopy with new supporting evidence that further delineates the role of choledochoscopy in various diagnostic and therapeutic interventions, complications, limitations and put forth areas for further study.

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.

Diagnostic performance of digital and video cholangioscopes in patients with suspected malignant biliary strictures: a systematic review and meta-analysis

BACKGROUND

Per-oral cholangioscopy (POC) has evolved over the past decade from fiberoptic to digital and video imaging systems. Nowadays, only direct per-oral cholangioscopy (DPOC) and digital single-operator cholangioscopy (DS) are performed in daily practice. With better image resolution, POC is increasingly used as diagnostic tools in patients with suspected malignant biliary stricture (MBS). We aimed to evaluate the diagnostic yield of digital/video cholangioscopes for the diagnosis of MBS.

METHODS

A systematic search was performed in MEDLINE, Embase, and ISI Web of Knowledge databases until April 2020, to identify randomized controlled trials and prospective studies using digital or video POC. The meta-analysis of diagnostic accuracy study was performed to calculate summary estimates of the primary outcomes, including pooled sensitivity, and specificity of POC to diagnose MBS using bivariate random-effects models. Tissue histopathology was used as the reference standard for MBS diagnosis. For benign stricture, negative tissue histopathology and at least 6 months clinical follow-up were required.

RESULTS

Thirteen original articles with 876 patients were identified. The overall pooled sensitivity and specificity were 88 (95% CI 83-91) and 95 (95% CI 89-98), respectively. The area under the curve (AUROC) was 0.94 (95% CI 0.92-0.96). Subgroup analysis showed that cholangioscopic image impression provided significantly higher sensitivity (93% (95% CI 88-96) vs 82% (95% CI 76-87); p = 0.007), but lower specificity 86% (95% CI 75-92) vs 98 (95% CI 95-99); p < 0.001) than the tissue diagnosis from cholangioscopic-guided biopsy. In addition, biopsy obtained from DPOC had significantly higher sensitivity than that of DS (92% (95% CI 81-97) vs 79% (95% CI 72-84); p = 0.004). Diagnostic performance under image-enhanced endoscopy was not significantly better from white light endoscopy.

CONCLUSIONS

Digital/video POC has very high diagnostic performance to diagnose MBS. While image diagnosis provides higher sensitivity than biopsy, its specificity drops as a trade-off.

Cholangioscopy- versus fluoroscopy-guided transpapillary mapping biopsy for preoperative evaluation of extrahepatic cholangiocarcinoma: a prospective randomized crossover study

BACKGROUND

To evaluate the lateral extent of extrahepatic cholangiocarcinoma, the value of cholangioscopy-guided mapping biopsy (CMB) compared with that of fluoroscopy-guided mapping biopsy (FMB) remains unknown. The aim of this study was to compare these two techniques.

METHODS

In this prospective, randomized, crossover study, both CMB and FMB techniques were performed for all patients in a randomized order. Target sites for the mapping biopsy were determined based on resection lines of possible surgical procedures. At least two biopsy strokes were attempted at each target site. The primary outcome was the rate of site-based successful biopsies, which was defined as acquisition of epithelium-containing material appropriate for diagnosing benignancy/malignancy from each site, regardless of amount of materials obtained from the same site.

RESULTS

Between September 2016 and October 2018, 28 patients (16 distal bile duct cancer and 12 perihilar bile duct cancer) were enrolled and divided into two groups of 14 patients: CMB first and FMB first. Although all 118 target sites could be approached using CMB, FMB forceps reached only 71% of them with significantly poor accessibility to the B2/3 confluence. Since several materials were too small and did not contain epithelium, the overall rates of site-based successful biopsies were 78% (92/118) using CMB and 64% (76/118) using FMB (P = 0.031).

CONCLUSIONS

The rate of site-based successful biopsies using CMB was significantly higher than that using FMB when evaluated using specimens obtained from several biopsy strokes.

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.

Efficacy of digital single-operator cholangioscopy in the visual interpretation of indeterminate biliary strictures: a systematic review and meta-analysis

OBJECTIVE

Indeterminate biliary strictures remain a significant diagnostic challenge. Digital single-operator cholangioscopy (D-SOC) incorporates digital imaging which enables higher resolution for better visualization and diagnosis of biliary pathology. We aimed to conduct a systematic review and meta-analysis of available literature in an attempt to determine the efficacy of D-SOC in the visual interpretation of indeterminate biliary strictures.

MATERIAL AND METHODS

Electronic searches were performed using Medline (PubMed), EMBASE, and Cochrane Library. All D-SOC studies that reported the diagnostic performance in visual interpretation of indeterminate biliary strictures and biliary malignancies were included. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 was used to evaluate the quality of the included studies. All data were extracted and pooled to construct a 2 × 2 table. The visual interpretation of D-SOC was compared to resected surgical specimens or clinical follow-up in the included patients. Pooled sensitivity, specificity, positive predictive value, negative predictive value, prevalence, positive likelihood ratio (+LR), negative likelihood ratio (-LR), and diagnostic odds ratio (OR) were calculated. The summarized receiver operating characteristic (SROC) curve corresponding with the area under the curve (AUC) was also analyzed.

RESULTS

The search yielded 465 citations. Of these, only six studies with a total of 283 procedures met inclusion criteria and were included in the meta-analysis. The overall pooled sensitivity and specificity of D-SOC in the visual interpretation of biliary malignancies was 94% (95% CI 89-97) and 95% (95%CI 90-98), respectively, while +LR, -LR, diagnostic OR, and AUC were 15.20 (95%CI 5.21-44.33), 0.08 (95%CI 0.04-0.14), 308.83 (95%CI 106.46-872.82), and 0.983, respectively. The heterogeneity among 6 included studies was moderate for specificity (I² = 0.51) and low for sensitivity (I² = 0.17) and diagnostic OR (I² = 0.00).

CONCLUSION

D-SOC is associated with high sensitivity and specificity in the visual interpretation of indeterminate biliary strictures and malignancies. D-SOC should be considered routinely in the diagnostic workup of indeterminate biliary lesions.

The Expansion of Cholangioscopy: Established and Investigational Uses of SpyGlass in Biliary and Pancreatic Disorders

Direct visualization of bile and pancreatic duct pathology is proving to be beneficial in patients where previous techniques have failed. Recent advancements in technology and the development of the SpyGlass system have led to an increased use of cholangioscopy. It is already known that SpyGlass is beneficial in patients with difficult bile duct stones and indeterminate biliary lesions through the use of targeted lithotripsy and visually guided biopsy. Cholangioscopy allows the visualization of hidden stone and guide wire placement across difficult strictures and selective cannulation of the intrahepatic and cystic ducts. It is also demonstrating its utility in investigational applications such as post-liver transplant and primary sclerosing cholangitis stricture treatment, evaluation of hemobilia, and guided radiofrequency ablation of ductal tumors. In addition to having clinical utility, cholangioscopy may also be cost-effective by limiting the number of repeat procedures. Cholangioscopy overall has similar complication rates compared to other standard endoscopic retrograde cholangioscopy (ERCP) techniques, but there may be higher rates of cholangitis. This could be mitigated with prophylactic antibiotic use, and overall, cholangioscopy has similar complication rates compared to other techniques.