Randomized Trial for Extraction of Difficult Bile Duct Stones
Condition: Common Bile Duct Stones
MeSH terms: Calculi
Study type: Interventional

Summary: 
      Removal of bile duct stones can be challenging at ERCP, particularly, when the size of the
      stone is at least 1.2cm, and may require more than one ERCP session. Various techniques for
      removal of difficult bile duct stones include using a balloon to enlarge the opening of the
      bile duct (large balloon sphincteroplasty), mechanical lithotripsy or single-operator
      cholangioscopy guided laser lithotripsy techniques. There are currently no randomized trials
      comparing laser lithotripsy and sphincteroplasty techniques for the removal of difficult bile
      duct stones and the aim of this randomized trial is to determine which technique is superior
      in the removal of difficult bile duct stones.
    

Detailed description: 
      Stones in the common bile duct (CBD) can result in various complications including acute
      cholangitis, acute pancreatitis and secondary biliary cirrhosis. Bile duct stones should
      therefore be removed and this can be successfully achieved in 85-90% of patients with small
      bile duct stones using standard endoscopic techniques. This comprises endoscopic
      sphincterotomy whereby the duodenal sphincter at the entrance of the bile duct is cut during
      endoscopic retrograde cholangiopancreatography (ERCP) and subsequent removal of the stone is
      achieved using standard accessories such as a basket and/or extraction balloon. However,
      large/difficult bile duct stones (at least 12mm in size), multiple stones and those located
      in non-dilated bile ducts can be difficult to remove by endoscopic sphincterotomy and using
      only standard accessories. In such cases, the three most commonly practiced advanced
      maneuvers for extraction of difficult CBD stones are mechanical lithotripsy, large balloon
      sphincteroplasty (LBS) of the major duodenal papilla and single operator
      cholangioscopy-guided laser lithotripsy (SOC-LL).

      Endoscopic large balloon sphincteroplasty (using CRE Wireguided Balloon Dilatation Catheter;
      Boston Scientific Corp., Natick, MA, USA) is a technique in which a balloon is used to dilate
      the papilla located at the bile duct opening by up to 20mm (depending on size of the distal
      CBD) after performing an endoscopic sphincterotomy. Following dilation, the stone is removed
      using a basket and/or extraction balloon. This technique was shown to be effective in
      clearing the bile duct in 50-60% of patients with difficult bile stones in whom initial
      endoscopic sphincterotomy was unsuccessful.

      The SpyGlass Direct Visualization System (Boston Scientific Corp., Natick, MA, USA) is a
      single-operator cholangioscopy system, which allows direct visualization of the bile duct
      stone. The main advantage of this technique is that the cholangioscope can be inserted into
      the endoscope and then guided through the bile duct to reach the stone. A probe can then be
      inserted into the cholangioscope to allow the energy from laser (laser lithotripsy) to be
      accurately focused onto the stone to cause stone fragmentation under direct visualization.
      The use of SpyGlass system with laser lithotripsy has been shown to be successful in the
      clearance of difficult bile duct stones in 73-100% patients.

      Although various methods for removal of bile duct stones exist, there have been thus far no
      studies directly comparing endoscopic large balloon sphincteroplasty with
      cholangioscopy-guided laser lithotripsy for clearance of difficult bile duct stones. The aim
      of this study is therefore to compare the efficiency of the single-operator
      cholangioscopy-directed laser lithotripsy using the SpyGlass Direct Visualization system
      versus endoscopic large balloon sphincteroplasty for clearance of difficult bile duct stones.
    

Intervention name(s): Single-operator cholangioscopy-guided laser lithotripsy; Balloon Sphincteroplasty
Intervention type(s): Procedure; Procedure
Intervention description(s): Ability to clear the bile duct of all stones in one ERCP session using laser lithotripsy-based technique, including use of mechanical lithotripsy; Ability to clear the bile duct of all stones in one ERCP session using large balloon sphincteroplasty-based technique, including use of mechanical lithotripsy
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: common bile duct stones; mechanical lithotripsy; balloon sphincteroplasty; single-operator cholangioscopy-guided laser lithotripy