The role of direct peroral cholangioscopy using an ultraslim endoscope for biliary lesions: indications, limitations, and complications

Direct peroral cholangioscopy with conventional upper gastrointestinal endoscope

An 83-year-old male with a history of Whipple procedure (pancreatoduodenectomy) due to pancreatic cancer, underwent endoscopic retrograde colangiopancreatography (ERCP) for acute cholangitis. Because of the altered anatomy, an upper gastrointestinal endoscope was used. Severe stricture of the hepaticojejunal anastomosis was found. The anastomotic stricture was dilated with a 12mm through-the-scope (TTS) balloon under fluoroscopy and direct visualization. Right and left ducts were explored with Dormia basket and balloon, with extraction of bile duct stones and pus. Cholangioscopy with upper gastrointestinal endoscope was performed and residual cholesterol stones were identified in branches of the left hepatic duct and these were removed with the stone extraction balloon under endoscopic visualization. Ciprofloxacin was administered for 5 days and post interventional course was uneventful. Direct peroral colangioscopy using a conventional endoscope provides high quality endoscopic imaging, enabling access to virtual chromoendoscopy and the 2.8 mm diameter working channel allows for interventional procedures. This strategy is useful and economical, helping confirm clearance of common bile duct stones, while allowing extraction of any residual stones. New, cost effective scopes for peroral cholangioscopy are needed to improve the safety and success rate.

Advanced endoscopy meets molecular diagnosis of cholangiocarcinoma

Cholangiocarcinoma remains an aggressive and deadly malignancy that is often diagnosed late. Intrinsic tumour characteristics and the growth pattern of cancer cells contribute to the challenges of diagnosis and chemoresistance. However, establishing an early and accurate diagnosis, and in some instances identifying targetable changes, has the potential to impact survival. Primary sclerosing cholangitis, a chronic cholangiopathy prodromal to the development of a minority of cholangiocarcinomas, poses a particular diagnostic challenge. We present our diagnostic and theranostic approach to the initial evaluation of cholangiocarcinomas, focusing on extrahepatic cholangiocarcinoma. This involves a multipronged strategy incorporating advanced imaging, endoscopic methods, multiple approaches to tissue sampling, and molecular markers. We also provide an algorithm for the sequential use of these tools.

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.

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.

Utility of Direct Peroral Cholangioscopy Using a Multibending Ultraslim Endoscope for Difficult Common Bile Duct Stones

Background/Aims

Treatment options for difficult bile duct stones are limited. Direct peroral cholangioscopy (POC)-guided lithotripsy may be an option. A newly developed multibending (MB) ultraslim endoscope has several structural features optimized for direct POC. We evaluated the utility of direct POC using an MB ultraslim endoscope for lithotripsy in patients with difficult bile duct stones.

Methods

Twenty patients with difficult bile duct stones, in whom stone removal using conventional endoscopic methods, including mechanical lithotripsy, had failed were enrolled from March 2018 to August 2019. Direct POC-guided lithotripsy was performed by electrohydraulic lithotripsy or laser lithotripsy. The primary outcome was complete ductal clearance, defined as the retrieval of all bile duct stones after lithotripsy confirmed by balloon-occluded cholangiography and/or direct POC.

Results

The technical success rate of direct POC was 100% (20/20), and the free-hand insertion rate was 95% (19/20). Direct POC-guided lithotripsy, attempted by electrohydraulic lithotripsy in nine patients (45%) and laser lithotripsy in 11 patients (55%), was successful in 95% (19/20) of the patients. Complete ductal clearance after direct POC-guided lithotripsy was achieved in 95% (19/20) of patients. Patients required a median of 2 (range, 1-3) endoscopic retrograde cholangiopancreatography sessions for complete stone removal. Adverse event was observed in one patient (5%) with hemobilia and was treated conservatively.

Conclusions

Direct POC using an MB ultraslim endoscope was safe and effective for lithotripsy in patients with difficult bile duct stones.

Optimal tissue sampling during ERCP and emerging molecular techniques for the differentiation of benign and malignant biliary strictures

Patients with cholangiocarcinoma have poor survival since the majority of patients are diagnosed at a stage precluding surgical resection, due to locally irresectable tumors and/or metastases. Optimization of diagnostic strategies, with a principal role for tissue diagnosis, is essential to detect cancers at an earlier stage amenable to curative treatment. Current barriers for a tissue diagnosis include both insufficient tissue sampling and a difficult cyto- or histopathological assessment. During endoscopic retrograde cholangiopancreatography, optimal brush sampling includes obtaining more than one brush within an individual patient to increase its diagnostic value. Currently, no significant increase of the diagnostic accuracy for the new cytology brush devices aiming to enhance the cellularity of brushings versus standard biliary brush devices has been demonstrated. Peroral cholangioscopy with bile duct biopsies appears to be a valuable tool in the diagnostic work-up of indeterminate biliary strictures, and may overcome current technical difficulties of fluoroscopic-guided biopsies. Over the past years, molecular techniques to detect chromosomal instability, mutations and methylation profiling of tumors have revolutionized, and implementation of these techniques on biliary tissue during diagnostic work-up of biliary strictures may be awaited in the near future. Fluorescence in situ hybridization has already been implemented in routine diagnostic evaluation of biliary strictures in several centers. Next-generation sequencing is promising for standard diagnostic care in biliary strictures, and recent studies have shown adequate detection of prevalent genomic alterations in KRAS, TP53, CDKN2A, SMAD4, PIK3CA, and GNAS on biliary brush material. Detection of DNA methylation of tumor suppressor genes and microRNAs may evolve over the coming years to a valuable diagnostic tool for cholangiocarcinoma. This review summarizes optimal strategies for biliary tissue sampling during endoscopic retrograde cholangiopancreatography and focuses on the evolving molecular techniques on biliary tissue to improve the differentiation of benign and malignant biliary strictures.

Peroral Cholangioscopy: How Technology and Imaging Have Changed ERCP

Endoscopic retrograde cholangiopancreatography (ERCP) is the minimally invasive standard of care for the treatment of several biliary and pancreatic pathologies. One of the limitations of this technique is the lack of endoluminal vision within the biliary tree or Wirsung's duct. This limits the diagnostic accuracy of the procedure and reduces the effectiveness of many treatments. Technological progress and the use of increasingly ergonomic and high-definition imaging equipment have led to the dissemination of peroral cholangioscopy (POC). Thanks to the high quality of video image resolution, POC could well be a powerful tool used to characterize malignant biliary strictures. It could also allow targeted biopsies or local treatments, hence reducing the risk of complications and increasing outcomes. The technological improvement of the last generation of POC is opening new horizons in the treatment of biliopancreatic pathologies, thereby contributing to refine and enhance the ERCP management of several diseases in the near future.

Efficacy of digital single-operator cholangioscopy and factors affecting its accuracy in the evaluation of indeterminate biliary stricture

BACKGROUND AND AIMS

Indeterminate biliary stricture remains a significant diagnostic challenge. The current method of ERCP with bile duct brush cytology has substantial room for improvement. We aimed to determine the efficacy of a digital single-operator cholangioscopy (DSOC) in evaluation of indeterminate biliary stricture.

METHODS

An observational cohort study was conducted among the patients who underwent DSOC for the indication of indeterminate biliary stricture at a tertiary academic medical center. The outcomes of interests were the accuracy of DSOC in visual interpretation and bile duct sample and identification of any factor(s) that could influence its effectiveness.

RESULTS

One hundred five patients were included. The overall accuracy of DSOC in visual interpretation was 89.5%, whereas the accuracy of bile duct sample was 83.2%. The sensitivities of visual impression and bile duct sample were 89.1% and 69.8% and their specificities were 90% and 97.9%, respectively. The degree of endoscopists' experience with fewer than 25 cases and the severity of hyperbilirubinemia negatively impacted the accuracy of DSOC. Among 55 patients with definitive diagnosis of malignant stricture, the sensitivity of combined intraductal forceps biopsy sampling and brush cytology was 80.6%, whereas the sensitivity of brush cytology alone was 47.1%.

CONCLUSIONS

DSOC augments ERCP in evaluating indeterminate biliary stricture. The acquisition of intraductal forceps biopsy samples should be a requisite in evaluation of indeterminate biliary stricture with DSOC. Discovery of modifiable factors such as the degree of endoscopists' expertise and the severity of hyperbilirubinemia, which can influence the accuracy of DSOC, warrants further studies on patient preprocedure optimization and an endoscopic training program that will cultivate procedural competency.

Review article: Asia-Pacific consensus recommendations on endoscopic tissue acquisition for biliary strictures

BACKGROUND

Pre-operative tissue diagnosis for suspected malignant biliary strictures remains challenging.

AIM

To develop evidence-based consensus statements on endoscopic tissue acquisition for biliary strictures.

METHODS

The initial draft of statements was prepared following a systematic literature review. A committee of 20 experts from Asia-Pacific region then reviewed, discussed, and modified the statements. Two rounds of independent voting were conducted to reach a final version. Consensus was considered to be achieved when 80% or more of voting members voted "agree completely" or "agree with some reservation."

RESULTS

Eleven statements achieved consensus. The choice of tissue sampling modalities for biliary strictures depends on the clinical setting, the location of lesion, and availability of expertise. Detailed radiological and endoscopic evaluation is useful to guide the selection of appropriate tissue acquisition technique. Standard intraductal biliary brushing and/or forceps biopsy is the first option when endoscopic biliary drainage is required with an overall (range) sensitivity and specificity of 45% (26%-72%) and 99% (98%-100%), and 48% (15%-100%) and 99% (97%-100%), respectively, in diagnosing malignant biliary strictures. Probe-based confocal laser endomicroscopy and fluorescence in situ hybridisation using 4 fluorescent-labelled probes targeting chromosomes 3, 7, 17 and 9p21 locus may be added to improve the diagnostic yield. Cholangioscopy-guided biopsy and EUS-guided tissue acquisition can be considered after prior negative conventional tissue sampling with an overall (range) sensitivity and specificity of 60% (38%-88%) and 98% (83%-100%), and 80% (46%-100%) and 97% (92%-100%), respectively, in diagnosing malignant biliary strictures.

CONCLUSION

These consensus statements provide evidence-based recommendations for endoscopic tissue acquisition of biliary strictures.

Step-by-step strategy in the management of residual hepatolithiasis using post-operative cholangioscopy

Hepatolithiasis is the presence of calculi within the intrahepatic bile duct specifically located proximal to the confluence of the left and right hepatic ducts. The ultimate goal of hepatolithiasis treatment is the complete removal of the stone, the correction of the associated strictures and the prevention of recurrent cholangitis. Although hepatectomy could effectively achieve the above goals, it can be restricted by the risk of insufficient residual liver volume, and has a 15.6% rate of residual hepatolithiasis. With improvements in minimally invasive surgery, post-operative cholangioscopy (POC), provides an additional option for hepatolithiasis treatment with higher clearance rate and fewer severe complications. POC is very safe, and can be performed repeatedly until full patient benefit is achieved. During POC three main steps are accomplished: first, the analysis of the residual hepatolithiasis distribution indirectly by imaging methods or directly endoscopic observation; second, the establishment of the surgical pathway to relieve the strictures; and third, the removal of the stone by a combination of different techniques such as simple basket extraction, mechanical fragmentation, electrohydraulic lithotripsy or laser lithotripsy, among others. In summary, a step-by-step strategy of POC should be put forward to standardize the procedures, especially when dealing with complicated residual hepatolithiasis. This review briefly summarizes the classification, management and complications of hepatolithiasis during the POC process.

A snare-assisted peroral direct choledochoscopy and pancreatoscopy using an ultra-slim upper endoscope: A case series study

OBJECTIVE

To evaluate the feasibility, effectiveness and safety of a new snare-assisted peroral direct choledochoscopy/pancreatoscopy (PDCPS) technique.

METHODS

From November 2014 through December 2016, 20 consecutive patients with indications for PDCPS were enrolled in this observational study. Endoscopic retrograde cholangiography was initially performed using a conventional duodenoscope, and endoscopic papillary balloon dilation was performed. Next, an ultra-slim endoscope was inserted to perform the PDCPS; a snare tightened around the end of the scope's bending section facilitated its entry into the common bile duct (CBD). The primary endpoint was the overall success rate of the PDCPS procedure (successful biliary intubation and visualization of the area of interest) and the time for biliary intubation with the ultra-slim upper endoscope.

RESULTS

Participants (11 men and 9 women; mean age, 72.2 years [range, 41-93 years]) had CBD adenoma (n=1), large CBD stones after failed extraction/lithotripsy treatment (n=13), CBD strictures (n=4), pancreatic duct tumor (n=1) or pancreatic duct dilation (n=1). The success rate was 95%. The mean intubation time was 18min (range, 4-57min). No adverse events were reported.

CONCLUSIONS

A snare-assisted PDCPS technique appears to be technically feasible, effective and safe for both diagnostic and therapeutic applications.

Effects of carbon dioxide insufflation during direct cholangioscopy on biliary pressures and vital parameters: a pilot study in porcine models

BACKGROUND AND AIMS

Direct per-oral cholangioscopy allows endoscopic visualization of the biliary tract. Insufflation with carbon dioxide (CO₂) is an alternative to saline solution irrigation during direct cholangioscopy. There are no data on maximal CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism. We aimed to evaluate the safety of increasing CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism.

METHODS

This was an in vivo animal study. Four domestic pigs, under general endotracheal anesthesia, were used. The first animal was used to validate the feasibility of direct cholangioscopy and biliary pressure measurements, after which all animals underwent laparotomy, insertion of a pressure transducer in the cystic duct, and direct transpapillary placement of the cholangioscope. The common bile duct (CBD) and cystic duct were ligated to contain the instilled gas and exclusively expose the biliary tree. Insufflation of CO₂ started at 200 mL/min and was continuously increased until there was evidence of bile duct rupture (as measured by a drop in intraductal pressures) or instability of vital signs (hypotension, bradycardia, bradypnea, O₂ desaturation). Necropsy was performed on all animals to assess the liver and biliary system for evidence of barotrauma.

RESULTS

CO₂ was insufflated up to 8 L/min without causing bile duct rupture or instability in vital signs despite increasing CBD pressure with insufflation. There was significant correlation between CO₂ flow with partial pressure of CO₂ in arterial blood (PaCO₂) (coefficient, 0.96-1.00; P < .01) and end tidal expired CO₂ (EtCO₂) (coefficient, 0.94-1.00; P < .01). However, the pulse rate, respiratory rate, arterial blood pressure, and O₂ did not correlate with the amount of CO₂ flow. There was no evidence of hepatic or biliary barotrauma on necropsy.

CONCLUSIONS

This pilot experience in porcine models suggests that CO₂ insufflation is safe for direct cholangioscopy and does not result in biliary barotrauma or vital signs instability.

Advances in direct peroral cholangioscopy using an ultrathin endoscope

Some endoscopists have reported the usefulness of direct peroral cholangioscopy for the diagnosis and therapy of bile duct lesions. Advantages of direct peroral cholangioscopy (POC) using an ultra-slim endoscope include use of conventional endoscopy equipment, operation by a single endoscopist, and superior image quality of the biliary tree with easy application of enhanced endoscopy and a large working channel. Although ultra-slim endoscopes are usually used for direct peroral cholangioscopy, direct scope insertion is considerably difficult. Moreover, this technique still has some severe complications and limitations. Continuous development of specialized endoscopes and accessories is expected to facilitate the diagnostic and therapeutic roles of direct POC.

Types of Peroral Cholangioscopy: How to Choose the Most Suitable Type of Cholangioscopy

OPINION STATEMENT

A number of case studies have described the usefulness of peroral cholangioscopy for diagnosis and therapy, performed by visualizing the inner cavity of the bile duct. Currently available types of peroral cholangioscopy include peroral videocholangioscopy (POCS) using a mother-baby scope system (MBSS), direct peroral videocholangioscopy (D-POCS), and SpyGlass™ Direct Visualization System (SGDVS). POCS started with cholangioscopy using MBSS, requiring two skilled endoscopists using two endoscopic systems. On the other hand, D-POCS and SGDVS were developed as single-operator techniques. In MBSS, the videocholangioscope is inserted into the bile duct through the accessory channel of a conventional therapeutic duodenoscope. MBSS enables comparatively easy scope insertion into the bile duct and stable scope positioning. POCS using MBSS provides excellent images and can be coupled with an image-enhanced function system. However, it has a smaller accessory channel, limiting the devices that can be used. Additionally, scope fragility is serious problem. D-POCS using an ultraslim upper endoscope has been introduced to overcome the drawback of POCS using MBSS. D-POCS has a larger working channel and requires only one endoscopist. D-POCS allows a greater variety of procedures under excellent imaging even with an image-enhanced function system; however, scope insertion is still challenging. SGDVS is designed for single-operator use and is dedicated to procedural purposes. It comprises a reusable optical probe and disposable delivery catheter, which has four-way deflected steering and dedicated irrigation channels. These features lead to good maneuverability, although image quality is poor due to its optical probe system. All systems' features should be recognized and the appropriate system used depending on the need. Cholangioscopy has shown dramatic progress from diagnosis to therapy with high future growth potential.

A newly modified access balloon catheter for direct peroral cholangioscopy by using an ultraslim upper endoscope (with videos)

BACKGROUND AND AIMS

Direct peroral cholangioscopy (POC) by using an ultraslim upper endoscope has been increasingly applied for diagnosis and treatment of diverse biliary diseases. Recently, an intraductal balloon catheter has been used commonly to guide the flexible ultraslim endoscope. However, accessibility into the bile duct remains a limitation of the procedure. The aim of this study was to evaluate the feasibility and success rate of an intraductal balloon-guided direct POC by using an ultraslim endoscope with a newly modified 5F balloon catheter.

METHODS

In total, 36 patients with biliary obstruction were included prospectively for a direct POC by using an ultraslim endoscope with a newly modified intraductal 5F balloon catheter. The main outcome measure was technical success, defined as successful advancement of the ultraslim endoscope into the obstructed segment of the biliary tree or the bifurcation. Secondary outcomes were mean time for the total procedure, intubation into the common bile duct and advancement up to the target site after intubation of the ultraslim endoscope, technical success rates of diagnostic and therapeutic interventions, and adverse events.

RESULTS

The intraductal balloon-guided direct POC using a newly modified 5F balloon catheter was completed successfully in 35 of 36 patients (97.2%). The mean times for total procedure, intubation into the distal common bile duct, and advancement up to the obstructed bile duct segment were 27.3 ± 7.2, 2.2 ± 0.5, and 0.8 ± 0.4 minutes, respectively. In total, 49 interventions were performed in 35 patients, excluding 1 patient in whom we failed to perform direct POC. Technical success of the interventions was achieved with 44 of 49 procedures (89.8%). No adverse events, including cholangitis, were observed.

CONCLUSIONS

A newly modified 5F balloon catheter seemed to facilitate performing intraductal balloon-guided direct POC for direct visual examination of the bile duct in patients with biliary obstruction. Continued development of endoscopes and accessories are expected to further improve the performance of direct POC.

Advanced endoscopic imaging of indeterminate biliary strictures

Endoscopic evaluation of indeterminate biliary strictures (IDBSs) has evolved considerably since the development of flexible fiberoptic endoscopes over 50 years ago. Endoscopic retrograde cholangiography pancreatography (ERCP) was introduced nearly a decade later and has since become the mainstay of therapy for relieving obstruction of the biliary tract. However, longstanding methods of ERCP-guided tissue acquisition (i.e., biliary brushings for cytology and intraductal forceps biopsy for histology) have demonstrated disappointing performance characteristics in distinguishing malignant from benign etiologies of IDBSs. The limitations of these methods have thus helped drive the search for novel techniques to enhance the evaluation of IDBSs and thereby improve diagnosis and clinical care. These modalities include, but are not limited to, endoscopic ultrasound, intraductal ultrasound, cholangioscopy, confocal endomicroscopy, and optical coherence tomography. In this review, we discuss established and emerging options in the evaluation of IDBSs.

Can image-enhanced cholangioscopy distinguish benign from malignant lesions in the biliary duct?

A new video peroral cholangioscopy (POCS) has been developed with high-quality digital imaging, and its clinical use has been reported. Additionally, direct peroral cholangioscopy (D-POCS) using an ultraslim endoscope has been proposed recently. To improve the diagnostic yield of POCS or D-POCS, image-enhanced endoscopy has been used in combination. Chromoendoscopy with methylene blue staining (ME), autofluorescence imaging (AFI), and narrow-band imaging (NBI) has been evaluated in biliary tract diseases. Observation of the mucosal structure and vessels is reportedly important for distinguishing non-neoplasms from neoplasms. Therefore, NBI is the most promising tool among image-enhanced endoscopies as it can enhance visualization of the mucosal structure and vessels simultaneously. There are currently few reports that have evaluated the utility of POCS or D-POCS based on pathological findings. Thus, endoscopic findings of the bile duct mucosa have not yet been fully established. At present, POCS-guided biopsy should be carried out.