Laser vs Electrohydraulic Lithotripsy for Difficult CBD Stones

Overview

Common bile duct (CBD) stones are a frequent condition that can lead to severe complications if not treated. The standard approach involves endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and stone extraction using balloons or baskets. However, approximately 10-15% of cases involve "difficult CBD stones" that cannot be removed using conventional methods. According to the European Society of Gastrointestinal Endoscopy (ESGE), difficult CBD stones are characterized by large size (≥15 mm), impaction, multiple stones, difficult locations (e.g., intrahepatic or cystic ducts), or altered anatomy due to previous surgeries. These cases require advanced techniques such as single-operator cholangioscopy (SOC) using the SpyGlass DS system, which allows direct stone visualization and lithotripsy-assisted fragmentation. Two primary lithotripsy methods are available: Electrohydraulic Lithotripsy (EHL): Uses shock waves from electrical energy to break stones. Laser Lithotripsy (LL): Uses laser energy to fragment stones through a water-mediated medium. While both techniques are effective, studies suggest LL has a higher first-attempt stone clearance rate (82-100%) compared to EHL (70.9-75%). However, EHL is more cost-effective and widely available, whereas LL offers greater precision but at a higher cost. Currently, no randomized controlled trial (RCT) directly compares their efficacy, procedural time, complication rates, or operator satisfaction. This study aims to fill that gap by conducting a randomized trial comparing EHL and LL in the treatment of difficult CBD stones. The primary outcome is the success rate of complete stone clearance in the first session, while secondary outcomes include procedural duration, post-procedural complications, and operator satisfaction. The findings will provide critical evidence for optimizing endoscopic stone management, improving patient outcomes, and guiding healthcare resource allocation.

Common bile duct (CBD) stones are a prevalent condition that can lead to severe complications if left untreated. The standard treatment method involves endoscopic retrograde cholangiopancreatography (ERCP) for stone removal. Conventional techniques include sphincterotomy combined with balloon or basket extraction. However, approximately 10-15% of patients present with "difficult CBD stones," which cannot be effectively removed using standard techniques. The European Society of Gastrointestinal Endoscopy (ESGE) defines difficult CBD stones as those meeting one or more of the following criteria: stone size ≥15 mm, impacted stones, multiple stones, stones in difficult-to-access locations (e.g., intrahepatic or cystic ducts), barrel-shaped stones, or stones in patients with altered anatomy due to prior surgical interventions (e.g., Roux-en-Y reconstruction). These cases often require specialized techniques to achieve successful stone clearance while minimizing complications. Intervention and Rationale: Single-operator cholangioscopy using the SpyGlass system has become a widely adopted approach for managing difficult CBD stones. This technique enables direct visualization of the stone and facilitates lithotripsy, which fragments stones into smaller pieces for easier removal. The two primary lithotripsy techniques available are: Electrohydraulic Lithotripsy (EHL): Uses shock waves generated by electrical energy transmitted through a probe to fragment stones. Laser Lithotripsy (LL): Uses laser energy delivered through a water-mediated medium to break stones into smaller pieces. Both techniques have demonstrated high success rates in stone fragmentation and removal, but debate persists regarding their relative efficacy. Some studies suggest that LL achieves higher first-attempt stone clearance rates (82-100%) compared to EHL (70.9-75%). However, EHL is generally more cost-effective and widely available, whereas LL offers greater precision at a higher procedural cost. Objective: This study aims to compare the effectiveness of EHL and LL in the management of difficult CBD stones through a randomized controlled trial (RCT). The primary outcome is the success rate of complete stone clearance in the first session. Secondary outcomes include procedural time, complication rates, and operator satisfaction. Study Design: Study Type: Randomized Controlled Trial Study Population: Patients diagnosed with difficult CBD stones requiring lithotripsy Intervention Groups: Group 1: EHL via SpyGlass DS Group 2: LL via SpyGlass DS Primary Endpoint: First-session complete stone clearance rate Secondary Endpoints: Procedural duration Post-procedural complications Operator satisfaction Significance: The findings from this study will provide valuable evidence for endoscopists regarding the optimal lithotripsy method for difficult CBD stones, ultimately improving patient outcomes and healthcare resource utilization. By identifying the most effective and efficient technique, this study aims to optimize treatment strategies and enhance clinical decision-making in endoscopic stone management.