The long road to stone management in the bile duct – what else to wish?

Despite significant advances in endoscopic retrograde cholangiopancreatography (ERCP) within the past several decades, difficult bile duct stones have remained a persistent clinical challenge for therapeutic endoscopists. In this issue of Endoscopy, Maydeo et al. describe the use of peroral cholangioscopy (POCS)-guided lithotripsy in a single session of ERCP for the clearance of difficult bile duct stones [1]. Their prospective multinational registry evaluated 156 patients and demonstrated a high clinical success rate (80 %) for stone clearance in a single POCS procedure with a low serious adverse event rate (1.9 %).

The present study provides the largest prospective series to date evaluating POCS-guided lithotripsy using the SpyGlass Direct Visualization System (Boston Scientific Corporation, Marlborough, Massachusetts USA) and offers important data to help guide interventional endoscopic clinical practice. Specifically, Maydeo et al. demonstrate that in a multinational setting, the rate of stone clearance in the first POCS-guided ERCP using electrohydraulic lithotripsy (EHL) was 82 % (96/117) vs. using laser lithotripsy, which was 74 % (29/39; P = 0.35); therefore, there appears to be no statistically significant advantage to using EHL over laser lithotripsy. However, this study does clearly demonstrate that size matters when it comes to POCS, given that stone clearance was significantly more likely in a single POCS-guided EHL or laser lithotripsy procedure when the largest stone was less than 30 mm in size (92 %) vs. cases in which the largest stone was larger than 30 mm (65 %).

“...endoscopic papillary large balloon dilation may also be an effective first-line therapy for patients with difficult stones that are defined by large stone size, as opposed to the situation in patients with intrahepatic duct stones or stones located above a stricture, in which case POCS may have advantages.”

Several notable limitations of the study by Maydeo et al. exist with regard to the generalizability of their data. Less than half of the patients in their cohort had previously undergone endoscopic papillary large balloon dilation (EPLBD), which for patients with large stones is becoming standard practice. The recent ESGE 2019 guidelines now endorse limited sphincterotomy combined with EPLBD as the first-line approach to the removal of difficult common bile duct stones [2]. While 21 % of the 156 patients did not undergo a prior attempt at ERCP-based stone clearance and instead proceeded directly to POCS based on imaging, 13 % of patients had stones of 10 mm or smaller, and for both of these situations, the direct indication for POCS is unclear. This study notably excluded patients with suppurative cholangitis, given the risks of cholangitis with POCS, and was conducted exclusively at tertiary referral centers with extensive experience in POCS, thereby limiting the generalizability of these data.

One of the most important clinical questions that remains unanswered from the single-arm study of Maydeo et al. is how POCS compares with conventional therapies, including EPLBD. Previous studies have evaluated the effectiveness of POCS-guided lithotripsy for difficult stone clearance, including the recent randomized controlled trial (RCT) by Buxbaum et al. [3], which demonstrated higher endoscopic stone clearance rates and decreased need for surgery in patients who had undergone POCS-guided laser lithotripsy compared with conventional therapy alone. Buxbaum et al. evaluated 60 patients with stones larger than 1 cm and found that endoscopic clearance was achieved in 93 % of patients treated with cholangioscopy-guided laser lithotripsy compared with 67 % of patients treated with conventional therapy only (P = 0.009). However, the conventional therapies in that study, including mechanical lithotripsy or EPLBD, were also allowed in the laser lithotripsy group, thereby diluting the ability of the study to compare head-to-head papillary balloon dilation with POCS for difficult stones.

In another recent RCT, Franzini et al. [4] compared POCS-guided EHL with EPLBD for removing complex biliary stones and the two methods were found to be insignificantly different in terms of effectiveness and safety. Specifically, there were no clear differences regarding the technical success rate, radiologic exposure, or adverse events, although the procedure time was approximately 25 minutes shorted in the EPLBD group. This suggests that EPLBD may also be an effective first-line therapy for patients with difficult stones that are defined by large stone size, as opposed to the situation in patients with intrahepatic duct stones or stones located above a stricture, in which case POCS may have advantages. Future work is needed to address these remaining questions, as well as to define the cost-effectiveness, given the rising healthcare costs throughout the world.

In summary, the results of this study provide additional important data that POCS-guided lithotripsy in a single session of ERCP for the clearance of difficult bile duct stones is effective and safe. While modern therapeutic endoscopists stand on the shoulders of giants that have provided us with a robust armamentarium of techniques to manage choledocholithiasis, the dictum of personalized medicine asks that we customize our endoscopic approach for each patient’s unique circumstances.

• References

• 1 Maydeo AP, Rerknimitr R, Lau JY. et al. Cholangioscopy-guided lithotripsy for difficult bile duct stone clearance in a single session of ERCP: results from a large multinational registry demonstrate high success rates. Endoscopy 2019; 51: 922-929
• 2 Manes G, Paspatis G, Aabakken L. et al. Endoscopic management of common bile duct stones: European Society of Gastrointestinal Endoscopy (ESGE) guideline. Endoscopy 2019; 51: 472-491
• 3 Buxbaum J, Sahakian A, Ko C. et al. Randomized trial of cholangioscopy-guided laser lithotripsy versus conventional therapy for large bile duct stones (with videos). Gastrointest Endosc 2018; 87: 1050-1060
• 4 Franzini T, Moura RN, Bonifacio P. et al. Complex biliary stones management: cholangioscopy versus papillary large balloon dilation - a randomized controlled trial. Endosc Int Open 2018; 6: E131-E138