This ASGE Video Tip is sponsored by Braintree, maker of the newly approved Suflav and SuTab. Hello, I'm Sumit Tiwani with Rockford Gastroenterology Associates in Rockford, Illinois. This is the ASGE Video Tip on Cholangioscopy-Directed Electrohydraulic Lithotripsy, or EHL. I have no relevant disclosures. Large and difficult baldock stones may not be amenable to effective management using standard ERCP techniques. Up to 10% of stones can be considered difficult, including stones above strictures, those causing Maritzzi syndrome, intrahepatic stones, and stones larger than 10-15mm in size. Incomplete management carries increased risks of complications, including cholangitis. Cholangioscopy-Directed Electrohydraulic Lithotripsy, or EHL, is a safe and effective option for the management of difficult baldock stones. The principle of EHL is the creation of an electric high-voltage spark between two isolated electrodes at the tip of a fiber. The electric sparks are delivered in short pulses that create an immediate expansion of the surrounding fluid, inducing a spherical shock wave. The shock wave oscillates and generates pressure to fragment the stone. Visualization of EHL is best achieved under direct visualization since the shock waves can also injure normal tissue. This is afforded by the use of a cholangioscope to allow direct visualization of the entire baldock and to assess the extent of the stone burden. The probe will not function if it and the stone are not in a fluid medium, so continuous saline irrigation into the baldock is used to maintain that surrounding fluid. This also serves to magnify the EHL power, it aids in flushing out debris, and it facilitates the visualization. In order to illustrate the use of EHL for difficult baldock stones, we have a case of a 37-year-old woman who is 4 months postpartum and presents with symptoms of epigastric pain and jaundice. Ultrasound shows cholelithiasis and common baldock dilation to 8 mm. MRCP showed cholelithiasis and choledocholithiasis with a stone at the junction of the cystic duct and common duct, as seen here. The initial ERCP confirmed choledocholithiasis with a fixed stone at the junction of the proximal common baldock and the cystic duct, with cystic duct obstruction. Sphincterotomy and balloon sweeps yielded only a small amount of stone debris, and the fixed filling defect remained unchanged. A biliary stent was placed and she was referred for cholangioscopy with EHL. In the interim, she actually developed acute cholecystitis and was hospitalized at another hospital where she was managed medically with antibiotic therapy with resolution of her symptoms. Repeat ERCP confirmed choledocholithiasis with at least three fixed filling defects in the common hepatic duct and proximal common baldock, as well as cystic duct obstruction. These filling defects remained unchanged with balloon sweeps. Cholangioscopy identified three impacted stones in the common baldock and common hepatic duct treated with EHL with successful fragmentation followed by balloon extraction. Here you can see the technique of targeting the EHL fiber directly across, directly against the center of the stone under direct endoscopic visualization and the resulting stone fragmentation. The tip of the fiber should be as close to the stone as possible without actually touching the stone. The stone can be touched if necessary, but this can damage the probe itself and reduce its function. EHL is delivered using a preset power wattage and number of consecutive pulsations. Both the power and the number of consecutive pulsations can be adjusted as needed to achieve the desired effect. Once fragmentation is complete, the resulting stone fragments are removed using standard ERCP techniques. After successful clearance of the common baldock stones, an impacted stone was also identified at the cystic duct confluence with the common duct, which was also successfully treated with EHL. In this instance, the fiber can be directed tangentially to cause chipping of the stone, but taken care to avoid contact with the baldock wall, which can cause epithelial injury and risk perforation or bleeding. Finally, one additional impacted stone was identified deeply within the cystic duct with obstruction, also treated with EHL. After successful EHL, there was drainage of purulent material noted from within the gallbladder and the cystic duct, compatible with cholecystitis. Cholangioscopy confirmed complete clearance of the stone debris from within the common baldock, and final cholangiogram showed filling of the cystic duct and gallbladder. The stones were successfully fragmented during this single session with clearance of the common baldock and cystic duct obstructions. The fragments were removed with flushing and balloon sweeps. A new biliary stent was placed, antibiotics were resumed, and she was referred back to surgery for a cholecystectomy. She has done well since the procedure without any further issues with biliary obstruction. Direct visualization and stone clearance using EHL has been shown to be clinically effective with demonstrated procedural success in 90% of patients and single-session stone clearance in rates of 76%. Achieving single-session stone clearance and reducing the need for repeat procedures delivers greater patient satisfaction and decreases unnecessary procedure costs. Adverse events associated with cholangioscopy and EHL are similar to the risks of ERCP itself. The most serious adverse event associated with EHL is perforation of the bile duct, which can occur if the EHL probe touches the bile duct wall. Perforation can also occur due to extreme elevation of the surface temperature of the stone and the surrounding ductal tissue, which is usually caused by prolonged application of EHL. However, perforation of the bile duct is rare and carries an overall risk of less than 1%. Bleeding can also occur from touching the wall of the bile duct with the probe. The overall risk of that is also probably less than 1%. In summary, cholangioscopy-directed EHL is a safe and effective option for the management of large and difficult bile duct stones. An electric high-voltage spark between two isolated electrodes at the tip of a fiber is delivered in short pulses to create a spherical shock wave, which oscillates and generates pressure to fragment the stone. Risks of the procedure include cholangitis, bleeding, and most seriously, perforation. Thank you. www.microsoft.com

Cholangioscopy-Directed Electrohydraulic Lithotripsy

bile duct stones

EHL technique

stone fragmentation

choledocholithiasis