Is single-operator peroral cholangioscopy a useful tool for the diagnosis of indeterminate biliary lesion? A systematic review and meta-analysis

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.

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma

A consensus meeting of national experts from all major national hepatobiliary centres in the country was held on May 26, 2023, at the Pakistan Kidney and Liver Institute & Research Centre (PKLI & RC) after initial consultations with the experts. The Pakistan Society for the Study of Liver Diseases (PSSLD) and PKLI & RC jointly organised this meeting. This effort was based on a comprehensive literature review to establish national practice guidelines for hilar cholangiocarcinoma (hCCA). The consensus was that hCCA is a complex disease and requires a multidisciplinary team approach to best manage these patients. This coordinated effort can minimise delays and give patients a chance for curative treatment and effective palliation. The diagnostic and staging workup includes high-quality computed tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography. Brush cytology or biopsy utilizing endoscopic retrograde cholangiopancreatography is a mainstay for diagnosis. However, histopathologic confirmation is not always required before resection. Endoscopic ultrasound with fine needle aspiration of regional lymph nodes and positron emission tomography scan are valuable adjuncts for staging. The only curative treatment is the surgical resection of the biliary tree based on the Bismuth-Corlette classification. Selected patients with unresectable hCCA can be considered for liver transplantation. Adjuvant chemotherapy should be offered to patients with a high risk of recurrence. The use of preoperative biliary drainage and the need for portal vein embolisation should be based on local multidisciplinary discussions. Patients with acute cholangitis can be drained with endoscopic or percutaneous biliary drainage. Palliative chemotherapy with cisplatin and gemcitabine has shown improved survival in patients with irresectable and recurrent hCCA.

Evaluation of the effectiveness and safety of single-operator cholangiopancreatoscopy with the SpyGlass™ system

BACKGROUND AND STUDY AIMS

The single-operator cholangiopancreatoscopy (SOCP) with the SpyGlass™ system is a endoscopy technique whose use has grown exponentially in recent years. The aims of this study were to evaluate the efficacy and safety of SOCP with SpyGlass™ and determine the factors related to the onset of adverse events (AEs).

PATIENTS AND METHODS

Retrospective study at a single tertiary institution with inclusion of all consecutive patients undergoing SOCP with SpyGlass™ from February-2009 to December-2021. No exclusion criteria were considered. A descriptive statistical analysis was performed. The factors associated with the existence of AE were analyzed using Chi-square and Student's t-test.

RESULTS

A total of 95 cases were included. The most common indications were biliary strictures (BS) evaluation (66.3%) or treatment of difficult common bile duct stones (27.4%). Technical and clinical success was attained in 98.9%. Single-session stone clearance was obtained in 84%. The AE rate was 7.4%. To detect malignancy in BS, optical diagnosis presents a sensitivity and specificity of 100% and 91.2%, respectively; while histology results were 36.4% and 100% respectively. A previous endoscopic sphincterotomy was associated with a lower rate of AEs (2.4% vs 41.7%; p<0.001).

CONCLUSIONS

SOCP with SpyGlass™ is a safe and effective technique to diagnose and treat pancreatobiliary pathology. The presence of sphincterotomy performed prior to the procedure could improve the technique's safety.

Diagnostic value of new biliary biopsy cannulae for malignant bile duct strictures via endoscopic retrograde cholangiopancreatography pathway

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) plays a major role in the diagnosis of malignant biliary strictures. ERCP fluoroscopy-guided biliary biopsy is more sensitive than brushing, but it is more difficult to perform and less successful. Therefore, a new technique of biliary biopsy using a new biliary biopsy cannula via the ERCP route was developed in our center with the aim of improving the diagnosis rate of malignant biliary strictures.

METHODS

This is a retrospective study that included 42 patients who underwent ERCP-guided biliary brushing and biliary biopsy for biliary strictures using a new biliary biopsy cannula in our department from January 2019 to May 2022. The final diagnosis was determined after brushing, biliary biopsy under the new biliary biopsy cannula or adequate follow-up. Diagnostic rates were calculated and analyzed for relevant factors.

RESULTS

The satisfactory rates of pathological specimens of 42 patients who underwent bile duct biopsy with bile duct brush and new bile duct biopsy cannula were 57.14% and 95.24% respectively. Cholangiocarcinoma was diagnosed in 45.23% and 83.30% of the samples by biliary brush examination and biliary biopsy using the new biliary biopsy cannula, respectively (p < 0.001).

CONCLUSIONS

The ERCP route using a new biliary biopsy cannula for biliary biopsy technique can improve pathology positivity and benefit ratio. It provides a new approach in the diagnosis of malignant stenosis in the bile duct.

British Society of Gastroenterology guidelines for the diagnosis and management of cholangiocarcinoma

These guidelines for the diagnosis and management of cholangiocarcinoma (CCA) were commissioned by the British Society of Gastroenterology liver section. The guideline writing committee included a multidisciplinary team of experts from various specialties involved in the management of CCA, as well as patient/public representatives from AMMF (the Cholangiocarcinoma Charity) and PSC Support. Quality of evidence is presented using the Appraisal of Guidelines for Research and Evaluation (AGREE II) format. The recommendations arising are to be used as guidance rather than as a strict protocol-based reference, as the management of patients with CCA is often complex and always requires individual patient-centred considerations.

Percutaneous transhepatic cholangioscopy for benign and malignant biliary disease using a novel short single-operator cholangioscope

BACKGROUND

The length of conventional single-use cholangioscopes poses a challenge for percutaneous or laparoscopic approaches for direct visualization of the biliary tract. The aim of this retrospective observational clinical study was to assess the use of a dedicated percutaneous short single-operator cholangioscope (PSSOC) for diagnosis and treatment of benign or malignant biliary diseases.

METHODS

Retrospective analysis of a prospectively maintained database including all consecutive patients undergoing percutaneous transhepatic cholangioscopy with the PSSOC between 06/2021 and 01/2023.

RESULTS

Forty patients were included (22F/18 M, age 58.7 ± 16.7 years). The diagnostic and therapeutic management plan was based on procedural findings. Indications were bile duct obstruction associated with complex anatomy (n = 13), choledocholithiasis (n = 11), suspected malignant stenosis of the biliary tract (n = 11), biliary stent placement (n = 2) and removal (n = 1), and failed endoscopic retrograde cholangiopancreatography (n = 2). The cholangioscopies were diagnostic (n = 5), therapeutic (n = 20) or both simultaneously (n = 15). The most frequent procedures were electrohydraulic lithotripsy (n = 25) and biopsy sampling (n = 12). Complications occurred in 7 cases (17.5%), including cholangitis (n = 4, B2), pleural perforation (n = 1, B2), portal bleeding (n = 1, B3), and Tako-Tsubo syndrome (n = 1, B3), classified according to the Society of Interventional Radiology classification. Intraprocedural visual diagnosis was confirmed by the histopathologic result in 11/12 patients in which biopsies were performed (91.7%). PSSOC was relevant to avoid surgery in 2 patients (5%) with indeterminate strictures, allowing to rule out malignancy and treat the lithiasis.

CONCLUSIONS

Direct visualization of the biliary tract enabled targeted biopsies for histopathological diagnosis. The visual and histopathological diagnoses were concordant in all but one case. Percutaneous cholangioscopy with a dedicated PSSOC allows to optimize identification and treatment of complex biliary disease including biliary lithiasis while assessing bile duct patency. The clinical use of the novel PSSOC system was safe and effective and could prevent surgical exploration in select patients.

Deep Learning for Automatic Diagnosis and Morphologic Characterization of Malignant Biliary Strictures Using Digital Cholangioscopy: A Multicentric Study

Digital single-operator cholangioscopy (D-SOC) has enhanced the ability to diagnose indeterminate biliary strictures (BSs). Pilot studies using artificial intelligence (AI) models in D-SOC demonstrated promising results. Our group aimed to develop a convolutional neural network (CNN) for the identification and morphological characterization of malignant BSs in D-SOC. A total of 84,994 images from 129 D-SOC exams in two centers (Portugal and Spain) were used for developing the CNN. Each image was categorized as either a normal/benign finding or as malignant lesion (the latter dependent on histopathological results). Additionally, the CNN was evaluated for the detection of morphologic features, including tumor vessels and papillary projections. The complete dataset was divided into training and validation datasets. The model was evaluated through its sensitivity, specificity, positive and negative predictive values, accuracy and area under the receiver-operating characteristic and precision-recall curves (AUROC and AUPRC, respectively). The model achieved a 82.9% overall accuracy, 83.5% sensitivity and 82.4% specificity, with an AUROC and AUPRC of 0.92 and 0.93, respectively. The developed CNN successfully distinguished benign findings from malignant BSs. The development and application of AI tools to D-SOC has the potential to significantly augment the diagnostic yield of this exam for identifying malignant strictures.

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

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

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fluorescence In Situ Hybridization in Primary Diagnosis of Biliary Strictures: A Single-Center Prospective Interventional Study

Background and aims: Diagnosis of the biliary stricture remains a challenge. In view of the low sensitivity of brush cytology (BC), fluorescence in situ hybridization (FISH) has been reported as a useful adjunctive test in patients with biliary strictures. We aimed to determine performance characteristics of BC and FISH individually and in combination (BC + FISH) in the primary diagnosis of biliary strictures. Methods: This single-center prospective study was conducted between April 2019 and January 2021. Consecutive patients with unsampled biliary strictures undergoing first endoscopic retrograde cholangiopancreatography in our institution were included. Tissue specimens from two standardized transpapillary brushings from the strictures were examined by routine cytology and FISH. Histopathological confirmation after surgery or 12-month follow-up was regarded as the reference standard for final diagnosis. Results: Of 109 enrolled patients, six were excluded and one lost from the final analysis. In the remaining 102 patients (60.8% males, mean age 67.4, range 25–92 years), the proportions of benign and malignant strictures were 28 (27.5%) and 74 (72.5%), respectively. The proportions of proximal and distal strictures were 26 (25.5%) and 76 (74.5%), respectively. In comparison to BC alone, FISH increased the sensitivity from 36.1% to 50.7% (p = 0.076) while maintaining similar specificity (p = 0.311). Conclusions: Dual-modality tissue evaluation using BC + FISH showed an improving trend in sensitivity for the primary diagnosis of biliary strictures when compared with BC alone.

Identification of patients with malignant biliary strictures using a cholangioscopy-based deep learning artificial intelligence (with video)

BACKGROUND AND AIMS

Accurately diagnosing malignant biliary strictures (MBSs) as benign or malignant remains challenging. It has been suggested that direct visualization and interpretation of cholangioscopy images provide greater accuracy for stricture classification than current sampling techniques (ie, brush cytology and forceps biopsy sampling) using ERCP. We aimed to develop a convolutional neural network (CNN) model capable of accurate stricture classification and real-time evaluation based solely on cholangioscopy image analysis.

METHODS

Consecutive patients with cholangioscopy examinations from 2012 to 2021 were reviewed. A CNN was developed and tested using cholangioscopy images with direct expert annotations. The CNN was then applied to a multicenter, reserved test set of cholangioscopy videos. CNN performance was then directly compared with that of ERCP sampling techniques. Occlusion block heatmap analyses were used to evaluate and rank cholangioscopy features associated with MBSs.

RESULTS

One hundred fifty-four patients with available cholangioscopy examinations were included in the study. The final image database comprised 2,388,439 still images. The CNN demonstrated good performance when tasked with mimicking expert annotations of high-quality malignant images (area under the receiver-operating characteristic curve, .941). Overall accuracy of CNN-based video analysis (.906) was significantly greater than that of brush cytology (.625, P = .04) or forceps biopsy sampling (.609, P = .03). Occlusion block heatmap analysis demonstrated that the most frequent image feature for an MBS was the presence of frond-like mucosa/papillary projections.

CONCLUSIONS

This study demonstrates that a CNN developed using cholangioscopy data alone has greater accuracy for biliary stricture classification than traditional ERCP-based sampling techniques.

Efficacy and safety of direct peroral cholangioscopy using a new multibending ultra-slim endoscope for the management of biliary diseases

BACKGROUND/PURPOSE

Compared with currently available duodenoscopy-assisted systems, direct peroral cholangioscopy (DPOC) using an ultra-slim endoscope is limited by technical difficulties. The multibending (MB) ultra-slim endoscope was introduced as a dedicated cholangioscope for DPOC to challenge the technical problem. We retrospectively analyzed the clinical utility of DPOC using an MB endoscope with free-hand insertion into the bile duct in patients with biliary diseases.

METHODS

A total of 145 patients who underwent DPOC using an MB endoscope were analyzed. The primary outcome was the technical success rate of DPOC using the free-hand insertion of the MB endoscope. The secondary outcomes were the technical success rates of DPOC-guided diagnostic and therapeutic interventions, the diagnostic accuracy of DPOC-guided target biopsy, and adverse events related to DPOC.

RESULTS

Free-hand biliary insertion of a MB endoscope for DPOC was technically successful in 133 patients (91.7%). DPOC-guided target biopsy was successful in 36 of 38 patients (94.7%) and had a diagnostic accuracy of 91.7% (95% confidence interval, 82.6-100). Sixty-nine therapeutic interventions were performed; technical success was achieved in 65 (94.2%). No severe adverse events were observed.

CONCLUSIONS

The MB ultra-slim endoscope was technically effective to perform a DPOC including various diagnosis and therapeutic interventions without device assistance. MB endoscope is considered to contribute to expanding a role of DPOC in diagnosis and treatment of diverse biliary tract diseases.

A tissue attached to self-expandable metal stents for biliary stricture could be useful to find malignancy

Biliary strictures can have several benign or malignant causes. We attempted to determine the usefulness of establishing a diagnosis using self-expandable metal stents (SEMS) in a prospective series of patients with suspected malignant biliary obstruction. Data of patients who underwent SEMS removal from August 2016 to December 2019 were collected. During this period, 55 patients underwent endobiliary biopsy and SEMS insertion and removal. Fifty-five consecutive patients (mean age, 69 years; range 53-90 years) were enrolled, and of these, 37 were male and 18 were female. A final diagnosis was established using biopsy specimens in 37 cases (67.3%) and surgical specimens in 6 cases (10.9%), with 12 cases (21.8%) diagnosed on radiological follow-up. The final diagnoses included malignancy in 34 cases (61.8%) and benign stricture in 21 cases (38.2%). Endobiliary biopsy had a sensitivity and specificity of 44.1% and 95.2%, whereas SEMS cytology had a sensitivity and specificity of 52.9% and 100%, respectively. Combining endobiliary biopsy and/or SEMS cytology yielded a sensitivity and specificity of 73.5% and 95.2%, respectively. (1) The use of biopsy results alone as a diagnostic tool yielded an area under the receiver operating characteristic curve (AUC) of 0.70 (0.60-0.79). (2) The addition of SEMS to the biopsy results yielded an AUC of 0.86 (0.78-0.94). (3) The addition of CA 19-9 levels to the biopsy results yielded an AUC of 0.81 (0.71-0.94). (4) Combining the endobiliary biopsy results, SEMS tissues, and CA 19-9 levels yielded the best diagnostic accuracy, with an AUC of 0.90 (0.83-0.98). Detection of biliary obstruction using the combination strategy was better than the diagnostic results based on biopsy alone according to recent 3-year data. Our study suggested that SEMS removal could help establish a diagnosis of suspected malignant biliary obstruction.

Endoscopic Evaluation and Management of Cholangiocarcinoma

Cholangiocarcinoma is a rare malignancy of the biliary tract with a relatively poor prognosis. As a gastroenterologist, our main role is to differentiate between benign and malignant biliary disease, help achieve a diagnosis, and palliate jaundice related to biliary obstruction. This article focuses on summarizing the various tools currently available for endoscopic evaluation and management of cholangiocarcinoma.

Identification of endoscopic predictors of biliary malignancy during digital cholangioscopy

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic accuracy of probe-based confocal laser endomicroscopy and tissue sampling by endoscopic retrograde cholangiopancreatography in indeterminate biliary strictures: a meta‑analysis

Probe-based confocal laser endomicroscopy (pCLE), also known as optical biopsy, is a new endoscopic technique that provides real-time magnification of 1000 × microscopic tissue information to diagnose indeterminate biliary strictures. Tissue sampling by endoscopic retrograde cholangiopancreatography (ERCP) is routinely performed to evaluate indeterminate biliary strictures. To evaluate the accuracy of pCLE and tissue sampling by ERCP in the diagnosis of indeterminate biliary strictures, 18 articles were included from 2008 to 2021 through Embase, PubMed, Web of Science, and Cochrane library databases. The summary estimates for the pCLE diagnosis of indeterminate biliary strictures were: sensitivity 0.88 (95% confidence interval (CI), 0.84-0.91); specificity 0.79 (95% CI 0.74-0.83); and Diagnostic Odds Ratio (DOR) 24.63 (95% CI 15.76-38.48). The summary estimates for tissue sampling by ERCP diagnosis for indeterminate biliary strictures were: sensitivity 0.54 (95% CI 0.49-0.59); specificity 0.96 (95% CI 0.94-0.98); and DOR 11.31 (95% CI 3.90-32.82). The area under the sROC curve of pCLE diagnosis of indeterminate biliary strictures is 0.90 higher than 0.65 of tissue sampling by ERCP. The pCLE is a better approach than tissue sampling by ERCP for the diagnosis of indeterminate biliary strictures by providing real-time microscopic images of the bile ducts.

Advanced Imaging of the Biliary System and Pancreas

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

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.

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.

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.

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.

Endoscopic Evaluation of Biliary Strictures: Current and Emerging Techniques

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

Premalignant lesions of the extrahepatic biliary tract. A territory to be explored hand in hand with cholangioscopy

The biliary mucosa, both intrahepatic and extrahepatic, is lined by a single layer of columnar cells with oval nuclei near the base and a slightly eosinophilic cytoplasm. Although normal biliary ducts have no goblet cells, there are periductal mucous glands lined by mucus-producing cuboidal cells, with mucin from these glands draining to the lumen of bile ducts.

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.

Digital single-operator peroral cholangioscopy-guided biopsy sampling versus ERCP-guided brushing for indeterminate biliary strictures: a prospective, randomized, multicenter trial (with video)

BACKGROUND AND AIMS

Accurately diagnosing indeterminate biliary strictures is challenging but important for patient prognostication and further management. Biopsy sampling under direct cholangioscopic vision might be superior to standard ERCP techniques such as brushing or biopsy sampling. Our aim was to investigate whether digital single-operator cholangioscopy (DSOC) compared with standard ERCP workup improves the diagnostic yield in patients with indeterminate biliary strictures.

METHODS

Patients with an indeterminate biliary stricture on the basis of MRCP were randomized to standard ERCP visualization with tissue brushing (control arm [CA]) or DSOC visualization and DSOC-guided biopsy sampling (study arm [SA]). This was a prospective, international, multicenter trial with a procedure-blinded pathologist.

RESULTS

The first sample sensitivity of DSOC-guided biopsy samples was significantly higher than ERCP-guided brushing (SA 68.2% vs CA 21.4%, P < .01). The sensitivity of visualization (SA 95.5% vs CA 66.7%, P = .02) and overall accuracy (SA 87.1% vs CA 65.5%, P = .05) were significantly higher in the SA compared with the CA, whereas specificity, positive predictive value, and negative predictive value showed no significant difference. Adverse events were equally low in both arms.

CONCLUSIONS

DSOC-guided biopsy sampling was shown to be safe and effective with a higher sensitivity compared with standard ERCP techniques in the visual and histopathologic diagnosis of indeterminate biliary strictures. (Clinical trial registration number: NCT03140007.).

Cholangioscopy Biopsies Improve Detection of Cholangiocarcinoma When Combined with Cytology and FISH, but Not in Patients with PSC

BACKGROUND AND AIMS

Single-operator cholangioscopy (SOC) has been suggested to be a cost-effective strategy for the detection of cholangiocarcinoma (CCA). The aim of this study is to compare the performance characteristics of SOC-guided biopsies and transpapillary biopsies with standard sampling techniques for the detection of CCA.

METHODS

A retrospective cohort study of patients undergoing SOC between 1/2007 and 10/2018 at a single academic center was performed. Demographic, procedural, and outcomes data were recorded and analyzed using STATA 14.0. Sensitivity comparison between diagnostic tests was performed using exact McNemar test exclusively among patients with CCA. Two-sided p value < 0.05 was considered statistically significant.

RESULTS

Ninety-two patients were included; 36 (39.1%) with primary sclerosing cholangitis (PSC), 41 (44.6%) with CCA, and median follow-up was 15.1 months. In the overall cohort, brush cytology demonstrated a sensitivity of 44.7% and increased with the addition of FISH (56.8%; p = 0.12), FISH with SOC-guided biopsy (71.4%; p = 0.03), and FISH with transpapillary biopsy (64.5%; p = 0.01). However, in patients with PSC, there was no significant improvement in sensitivity with the addition of SOC-guided biopsy or transpapillary biopsy in addition to FISH when compared to brush cytology. There was no difference in the rates of overall adverse events (14% vs. 23.2%; p = 0.27) or infection (3% vs. 4%; p = 0.83) in patients with and without PSC.

CONCLUSIONS

SOC-guided and transpapillary biopsies improve sensitivity for the detection of cholangiocarcinoma in combination with other ERCP-based techniques compared to brush cytology alone. However, while safe, these modalities do not significantly improve the sensitivity for the detection of malignancy in PSC patients.

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.

Prospective randomized trial of a new multibending versus conventional ultra-slim endoscope for peroral cholangioscopy without device or endoscope assistance (with video)

BACKGROUND AND AIMS

Currently available peroral cholangioscopy (POC) is a duodenoscopy-assisted procedure that does not involve directly inserting an endoscope into the biliary tree. A prototype multibending (MB) ultra-slim endoscope has been developed as a dedicated cholangioscope to overcome the technical difficulties of direct POC. In this study, we evaluated the efficacy of the new MB ultra-slim endoscope compared with a conventional ultra-slim endoscope for free-hand insertion of an endoscope into the bile duct for direct POC without the assistance of accessories.

METHODS

Ninety-two patients with biliary disease requiring diagnostic and/or therapeutic direct POC were assigned randomly to groups examined using an MB ultra-slim endoscope (MB group, n=46) versus a conventional ultra-slim endoscope (conventional group, n=46). The primary outcome was the technical success of free-hand insertion of the endoscope during direct POC, defined as successful insertion of the endoscope through the ampulla of Vater and advancement of the endoscope up to the bifurcation or to the obstructed segment of the biliary tree without any accessories within 15 minutes.

RESULTS

Free-hand biliary insertion of the endoscope for direct POC was technically successful in 41 patients (89.1%) in the MB group, which was significantly higher than the rate (14 patients, 30.4%) in the conventional group (P < .001). The procedure time (mean ± standard deviation) of direct POC using free-hand biliary insertion of the endoscope was significantly shorter in the MB group than in the conventional group (3.2 ± 1.8 vs 6.0 ± 3.0 minutes, P = .004). Adverse events were observed in 3 patients (6.5%) in the MB group and 2 patients (4.3%) in the conventional group (P = .500), all of whom were treated conservatively. The technical success rates of the diagnostic or therapeutic intervention were not significantly different between the 2 groups in patients undergoing successful direct POC.

CONCLUSIONS

Free-hand biliary insertion of the MB ultra-slim endoscope showed a high technical success rate without severe adverse events and effectively decreased procedure time compared with a conventional ultra-slim endoscope. Direct POC using the MB ultra-slim endoscope can be used for novel diagnostic and therapeutic procedures of the biliary tree without the assistance of another endoscope or accessory. (Clinical trial registration number: NCT02189421.).

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

BACKGROUND AND AIMS

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

PATIENTS AND METHODS

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

DESIGN

Prospective open-label multicentre trial.

RESULTS

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

CONCLUSION

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

The clinical value of ERCP-guided cholangiopancreatoscopy using a single-operator system

BACKGROUND

Single-operator, per-oral cholangiopancreatoscopy (SOPCP) enables direct biliopancreatic ductal visualization, targeted tissue sampling, and therapeutic intervention. At Karolinska University Hospital, SOPCP was introduced early and has since been extensively utilized according to a standardized protocol. We analysed the clinical value of SOPCP in the diagnosis and treatment of biliopancreatic diseases in a single high volume center.

METHODS

All SOPCP procedures performed between March 2007 and December 2014 were retrospectively reviewed. Each procedure's diagnostic yield and therapeutic value was evaluated using a predefined 4 grade scale; 1 - no diagnostic or therapeutic value, 2 - information gained did not impact clinical decision-making and in case of a therapeutic intervention, did not alter the clinical course of the patient, 3 - information gained had an impact on clinical decision-making and in the case of a therapeutic intervention, assisted subsequent disease management, and finally, 4 - information gained was essential and critical for clinical decision-making and in case of a therapeutic intervention, solved the clinical problem requiring no further therapeutic actions. Descriptive statistics were used to analyse results, with uni- and multivariate analyses completed to assess risk of adverse events.

RESULTS

During the study period, 365 SOPCP procedures were performed. We found SOPCP of pivotal importance (grade 4) in 19% of cases, and of great clinical significance (grade 3) in 44% of cases. SOPCP did not affect clinical decision-making or alter clinical course (grade 1 and 2) in 37% of cases.

CONCLUSION

SOPCP offers direct access to the biliopancreatic ducts for both diagnostic and therapeutic purposes, adding significant clinical value in 64% of cases.

TRIAL REGISTRATION

As this is a purely observational and retrospectively registered study in which the assignment of the medical intervention was not at the discretion of the investigator, it has not been registered in a registry.

Role of digital single-operator cholangioscopy in the diagnosis and treatment of biliary disorders

Due to the need for improvement in the diagnosis and minimally invasive therapy of the bile duct disorders new technologies for cholangioscopy have been recently developed. Per-oral cholangioscopy has become an important diagnostic and therapeutic tool leading to avoidance of aggressive and unnecessary surgery in many clinical scenarios. This paper focuses on the newly developed SpyGlass DS technology, its advantages, and the technique of single-operator cholangioscopy (SOC), biliary indications and possible adverse events. We also review the available literature; discuss the limitations and future expectations. Digital SOC (D-SOC) is a useful technique, which provides endoscopic imaging of the biliary tree, optical diagnosis, biopsy under direct vision and therapeutic interventions. The implementations are diagnostic and therapeutic. Diagnostic indications are indeterminate biliary strictures, unclear filling defects, staging of cholangiocarcinoma, staging of ampullary tumors (extension into the common bile duct), unclear bile duct dilation, exploring cystic lesions of the biliary tree, unexplained hemobilia, posttransplant biliary complications. Therapeutic indications are lithotripsy of difficult stones, retrieval of migrated stents, foreign body removal, guide wire placement, transpapillary gallbladder drainage and endoscopic tumor ablative therapy. Most studied and established indications are the diagnosis of indeterminate biliary stricture and intraductal lithotripsy of difficult stones. The adverse events are not different and more common compared to those of Endoscopic retrograde cholangiopancreatography (ERCP) alone. D-SOC is a safe and effective procedure, adjunct to the standard ERCP and the newly available digital technology overcomes many of the limitations of the previous generations of cholangioscopes.

Role of Image-Enhanced Endoscopy in Pancreatobiliary Diseases

Recent advances in cholangiopancreatoscopy technology permit image-enhanced endoscopy (IEE) for pancreatobiliary diseases. There are limitations in endoscopy performance and in the study of the clinical role of IEE in bile duct or pancreatic duct diseases. However, currently available IEEs during cholangiopancreatoscopy including traditional dye-aided chromoendoscopy, autofluorescence imaging, narrow-band imaging, and i-Scan have been evaluated and reported previously. Although the clinical role of IEE in pancreatobiliary diseases should be verified in future studies, IEE is a useful promising tool in the evaluation of bile duct or pancreatic duct mucosal lesions.

Prospective Comparison of Intraductal Ultrasonography-Guided Transpapillary Biopsy and Conventional Biopsy on Fluoroscopy in Suspected Malignant Biliary Strictures

Background/Aims

In suspected malignant biliary strictures (MBSs), the diagnostic yield of endoscopic retrograde cholangiopancreatography (ERCP)-based tissue sampling is limited. Transpapillary forceps biopsy (TPB) under intraductal ultrasonography (IDUS) guidance is expected to improve the diagnostic accuracy in patients with indeterminate biliary strictures. We evaluated the usefulness of IDUS-guided TPB in patients with suspected MBS.

Methods

Consecutive patients with suspected MBS were prospectively enrolled in the study. ERCP with IDUS was performed in all patients. Both conventional TPB and IDUS-guided TPB on fluoroscopy were performed in each patient. The primary outcome was the diagnostic accuracy of conventional TPB and IDUS-guided TPB.

Results

The technical success rate of IDUS-guided TPB was 97.0% (65/67 patients). Of these 65 patients, the final diagnosis was malignancy in 61 patients (93.8%). On IDUS, the most common finding of IDUS was an intraductal infiltrating lesion in 29 patients (47.5%). The overall diagnostic accuracy was significantly higher using IDUS-guided TPB than that using conventional TPB (90.8% vs 76.9%, p=0.027). According to the subgroup analysis based on the tumor morphology, IDUS-guided TPB had a significantly higher cancer detection rate than conventional TPB for intraductal infiltrating lesions (89.6% vs 65.5%, p=0.028).

Conclusions

IDUS-guided TPB appears to improve the accuracy of histological diagnosis in patients with MBS.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cholangioscopy Is Safe and Feasible in Elderly Patients

BACKGROUND & AIMS

Although cholangioscopy is widely used during endoscopic retrograde cholangiopancreatiography (ERCP), its safety and feasibility for elderly patients are not well established. We aimed to evaluate the safety and feasibility of cholangioscopy in elderly patients.

METHODS

We performed a retrospective study of all ERCPs with single-operator cholangioscopy (SOC) performed at 3 tertiary referral hospitals from March 2012 through October 2015. We collected data on patient demographics, procedure indications, findings, complications, and success rates (complete success was achieved if all intended diagnostic and therapeutic procedures were performed, such as tissue sample collection or complete removal of stones). The cohort was divided into 3 groups: patients younger than 65 years (group 1, n = 178), patients 65-75 years old (group 2, n = 86), and patients older than 75 years (group 3, n = 77). We used 1-way ANOVA, the χ² test, and the Wilcoxon sum rank test to compare study variables. The primary aim was to assess rates of complications from ERCP with SOC in elderly patients compared with younger patients.

RESULTS

Baseline clinical features were similar among groups, except for a higher prevalence of co-morbidities in group 3. The indication for and findings from ERCP with SOC differed among the groups; stricture or tumor was the most common indication in groups 1 and 3-the most common findings were strictures and masses, respectively. In group 2, choledocholithiasis was the most common indication and finding. The success rate, analyzed in a subset of 209 patients, was 88.5% overall and did not differ significantly among groups. The overall rate of complication was 7.33% with no significant difference among groups (7.30% for group 1, 6.98% for group 2, and 7.79% for group 3) (P < .17).

CONCLUSIONS

In a retrospective analysis of ERCPs with SOCs, we found this procedure to be safe for elderly patients (older than 75 years), who had rates of complications and hospital admission similar to those of younger patients.

Diagnostic and therapeutic single-operator cholangiopancreatoscopy with SpyGlassDS™: results of a multicenter retrospective cohort study

BACKGROUND AND AIMS

The aim of the study was to evaluate the usefulness and diagnostic and therapeutic outcome of the single-operator cholangiopancreatoscopy (SOC) with SpyGlassDS™.

METHODS

In a retrospective multicenter study between November 2015 and January 2017, SpyGlassDS™ procedures were analyzed in participating centers. Indications, accuracy of SOC-guided biopsies, management of large bile duct stones, and complications were analyzed. Follow-up was 4 months.

RESULTS

Two hundred and six patients out of 250 examinations were evaluated. Indications were biliary stones (n = 132), bile duct stenosis (n = 93), stones and stenosis combined (n = 24), and bile duct leakage (n = 1). Of the 117 cases which were suspicious of malignancy, in 99 cases the lesion could be stratified into benign (n = 55) or malignant (n = 44) indicating a sensitivity of 95.5% and a specificity of 94.5% for the indication tumor. SOC-guided biopsies revealed a sensitivity of 57.7% with a specificity of 100%. In 107 examinations, biliary stones were visualized and could be completely removed in 91.1% with a need of three procedures (range 1-6) to achieve final stone clearance. In 75 cases, lithotripsy was performed and was successful in 71 cases (95%). Four out of 45 patients (8.9%) underwent cholecystectomy with surgical bile duct revision as a final therapy. Adverse Event (AE) occurred in 33/250 patients (13.2%) and Serious Adverse Event (SAE) occurred in 1/250 patients (0.4%). Cholangitis was 1% (n = 102) after peri-interventional administration of antibiotics and 12.8% (n = 148) without antibiotic prophylaxis (p < 0.001).

CONCLUSIONS

SOC with SpyGlassDS™ became a new standard for the diagnosis of indefinite biliary lesions and therapy of large bile duct stones. The diagnostic yield of SOC-guided biopsies facilitated a definite diagnosis in most cases and should be improved by standardized biopsy protocols. SOC-guided interventions allowed removal of large biliary stones by SOC-guided lithotripsy. The complication rate of 13.2% can be considerably reduced by use of a single-shot antibiotic treatment.

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

BACKGROUND AND STUDY AIMS

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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