Laser vs Electrohydraulic Lithotripsy for Difficult CBD Stones

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.

Inclusion criteria

• Aged >18 years
• Difficult CBD stone
• Large CBD stone (stone > 1.5 cm) or Stone impaction or CBD stones that were not completely removed using conventional techniques.

Exclusion criteria

• Pregnancy
• Unstable vital signs
• Severe comorbidities
• Uncorrected coagulopathy
• Surgically altered anatomy
• Unable to complete informed consent