Efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones: a systematic review and meta-analysis

Endoscopic Management of Difficult Biliary Stones: An Evergreen Issue

Choledocholithiasis is one of the most common indications for endoscopic retrograde cholangiopancreatography (ERCP) in daily practice. Although the majority of stones are small and can be easily removed in a single endoscopy session, approximately 10-15% of patients have complex biliary stones, requiring additional procedures for an optimum clinical outcome. A plethora of endoscopic methods is available for the removal of difficult biliary stones, including papillary large balloon dilation, mechanical lithotripsy, and electrohydraulic and laser lithotripsy. In-depth knowledge of these techniques and the emerging literature on them is required to yield the most optimal therapeutic effects. This narrative review aims to describe the definition of difficult bile duct stones based on certain characteristics and streamline their endoscopic retrieval using various modalities to achieve higher clearance rates.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Predictors of success of conventional ERCP for bile duct stones and need for single-operator cholangioscopy

Background and study aims The characteristics of difficult stones requiring cholangioscopy-assisted lithotripsy are poorly defined. We sought to determine clinician perception of these characteristics and decision-making in biliary endoscopy. Methods One hundred twenty-four delegates attending an online course were invited to assess 20 clinical stone cases. Each image was graded on a 4-point Likert for: grading of stone difficulty, confidence of clearance with conventional endoscopic retrograde cholangiopancreatography (ERCP) methods, likelihood of needing cholangioscopy-assisted lithotripsy, and confidence of clearance with one session of lithotripsy. An independent reviewer rated each case on largest stone size, stone number, presence of stricture distal to stone, size of stone relative to distal duct size, and acute common bile duct (CBD) angulation < 135°. Multilevel (mixed) statistical methods with a two-level model were utilized with multilevel ordinal logistic regression. Results Stone size and location, stricture and stone diameter:duct ratio impacted perceived procedural difficulty P < 0.01). Stone:duct ratio (< 50% odds ratio [OR] 0.22, P < 0.001), stricture (OR 7.26, P < 0.001) and stone location impacted confidence of clearance with conventional ERCP. Intrahepatic and cystic duct stones were least likely to engender confidence ( P < 0.01). The same factors plus CBD angulation < 135° predicted cholangioscopy requirement ( P < 0.01). Stone number did not influence procedure difficulty or cholangioscopy requirement. Strictures (OR 0.29, P < 0.001) and location, especially intrahepatic (OR 0.42, P < 0.001) impaired confidence in clearance with one cholangioscopy session. Conclusions Ductal anatomy, the presence of a stricture distal to a stone, cystic and intrahepatic stones and stones larger than the distal duct are considered by endoscopists to be significant predictors of requiring cholangioscopy-assisted lithotripsy.

The Role of Cholangioscopy in Biliary Diseases

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

Cholangioscopy-guided electrohydraulic lithotripsy versus laser lithotripsy for the treatment of choledocholithiasis: a systematic review

BACKGROUND

Endoscopic management of large bile duct stones may be challenging and refractory to standard endoscopic retrograde cholangiopancreatography (ERCP) techniques. To this end, per-oral cholangioscopy (POC)-guided electrohydraulic lithotripsy (EHL) or laser lithotripsy (LL) has been increasingly utilized during ERCP. There are limited data, however, comparing EHL and LL in the management of choledocholithiasis. Therefore, the aim was to analyze and compare the efficacy of POC-guided EHL and LL for the treatment of choledocholithiasis.

METHODS

A database search on PubMed was performed selecting prospective English-language articles published by September 20th, 2022, in accordance with PRISMA guidelines. Studies selected included bile duct clearance as an outcome.

RESULTS

A total of 21 prospective studies (15 using LL, 4 using EHL, and 2 both) including 726 patients were included for analysis. Complete ductal clearance was achieved in 639 (88%) patients with 87 (12%) patients having incomplete ductal clearance. Patients treated with LL had an overall median stone clearance success rate of 91.0% (IQR, 82.7-95.5), whereas EHL achieved a median stone clearance success rate of 75.8% (IQR, 74.0-82.4), [p = .03].

CONCLUSIONS

LL is a highly effective form of POC-guided lithotripsy for the treatment of large bile duct stones, particularly when compared to EHL. However, direct, head-to-head randomized trials are needed to identify the most effective form of lithotripsy for treating refractory choledocholithiasis.

Cholangioscopy for biliary diseases

PURPOSE OF REVIEW

Cholangioscopy is a mini-invasive endoscopic procedure, which consists in a direct intraductal visualization of the biliary tract. The purpose of this review is to summarize the technique, the clinical applications, as well as future perspectives of cholangioscopy.

RECENT FINDINGS

Numerous technologic advances during the last decades have allowed for an improved utility and functionality, leading to a broader use of this procedure, for diagnostic or therapeutic purposes, in the setting of biliary diseases. Novel tools and emerging indications have been developed and more are yet to come.

SUMMARY

Cholangioscopy can be performed by peroral, percutaneous transhepatic or intra-operative transcystic or transcholedochal access. Clinical applications of cholangioscopy are multiple, ranging from visual impression and optical guided biopsies of indeterminate biliary strictures to the management of difficult stones , guidance before biliary stenting and retrieval of migrated ductal stents. Multiple devices such as lithotripsy probes, biopsy forceps, snares and baskets have been developed to help achieve these procedures successfully.Cholangioscopy has improved the way biliary diseases can be visualized and treated. New technology, accessories, and applications are expected in the future.

Endoscopic holmium laser lithotripsy for therapy of Bouveret syndrome

Video 1Video of holmium laser lithotripsy procedure.

Factors Influencing Performance of Cholangioscopy-Guided Lithotripsy Including Available Different Technologies: A Prospective Multicenter Study with 94 Patients

BACKGROUND

Peroral cholangioscopy (POC)-guided lithotripsy is an effective treatment for difficult biliary stones. A clear definition of factors associated with the efficacy of POC-guided lithotripsy in one session and the performance of electrohydraulic lithotripsy (EHL) and laser lithotripsy (LL) have not clearly emerged.

METHODS

This was a non-randomized prospective multicenter study of all consecutive patients who underwent POC lithotripsy (using EHL and/or LL) for difficult biliary stones. The primary endpoint of the study was the number of sessions needed to achieve complete ductal clearance and the factors associated with this outcome. Secondary endpoints included the evaluated efficacies of LL and EHL.

RESULTS

Ninety-four patients underwent 113 procedures of EHL or LL. Complete ductal clearance was obtained in 93/94 patients (98.94%). In total, 80/94 patients (85.11%) achieved stone clearance in a single session. In the multivariate analysis, stone size was independently associated with the need for multiple sessions to achieve complete ductal clearance (odds ratio = 1.146, 95% confidence interval: 1.055-1.244; p = 0.001). Using ROC curves and the Youden index, 22 mm was found to be the optimal cutoff for stone size (95% confidence interval: 15.71-28.28; p < 0.001). The majority of the patients (62.8%) underwent LL in the first session. Six patients failed the first session with EHL after using two probes and therefore were crossed over to LL, obtaining ductal clearance in a single additional session with a single LL fiber. EHL was significantly associated with a larger number of probes (2.0 vs. 1.02) to achieve ductal clearance (p < 0.01). The mean procedural time was significantly longer for EHL than for LL [72.1 (SD 16.3 min) versus 51.1 (SD 10.5 min)] (p < 0.01).

CONCLUSIONS

POC is highly effective for difficult biliary stones. Most patients achieved complete ductal clearance in one session, which was significantly more likely for stones < 22 mm. EHL was significantly associated with the need for more probes and a longer procedural time to achieve ductal clearance.

Future of Cholangioscopy

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

Difficult Biliary Stones: A Comprehensive Review of New and Old Lithotripsy Techniques

Biliary stones represent the most common indication for therapeutic endoscopic retrograde cholangiopancreatography. Many cases are successfully managed with biliary sphincterotomy and stone extraction with balloon or basket catheters. However, more complex conditions secondary to the specific features of stones, the biliary tract, or patient’s needs could make the stone extraction with the standard techniques difficult. Traditionally, mechanical lithotripsy with baskets has been reported as a safe and effective technique to achieve stone clearance. More recently, the increasing use of endoscopic papillary large balloon dilation and the diffusion of single-operator cholangioscopy with laser or electrohydraulic lithotripsy have brought new, safe, and effective therapeutic possibilities to the management of such challenging cases. We here summarize the available evidence about the endoscopic management of difficult common bile duct stones and discuss current indications of different lithotripsy techniques.

Cracking Difficult Biliary Stones

Apart from difficult biliary cannulation, biliary stone removal is considered one of the hurdles in endoscopic retrograde cholangiopancreatography. Generally, simple common bile duct (CBD) stones can be removed either with an extraction balloon or a basket. However, there are difficult stones that cannot be removed using these standard methods. The most difficult stones are large CBD stones and impacted stones in a tapering CBD. A few decades ago, mechanical lithotripsy was usually required to manage these stones. At present, endoscopic papillary large balloon dilation (EPLBD) of the biliary orifice has become the gold standard for large CBD stones up to 1.5 cm. EPLBD can reduce the procedural time by shortening the stone removal process. It can also save the cost of the devices, especially multiple baskets, used in mechanical lithotripsy. Unfortunately, very large CBD stones, stones impacted in a tapering CBD, and some intrahepatic duct stones still require lithotripsy. Peroral cholangioscopy provides direct visualization of the stone, which helps the endoscopist perform a probe-based lithotripsy either with an electrohydraulic probe or a laser probe. This technique can facilitate the management of difficult CBD stones with a high success rate and save procedural time without significant technical complications.