Electrohydraulic lithotripsy for difficult-to-treat bile duct stones

Evidence-based recommendations on electrohydraulic lithotripsy for difficult-to-treat bile duct stones in adults. This involves breaking up the stone with soundwaves.

# Recommendations
Evidence on the efficacy of electrohydraulic lithotripsy for difficult-to-treat bile duct stones is adequate. However, evidence on its safety is limited in quantity. Therefore, it should only be used with special arrangements for clinical governance, consent, and audit or research. Find out what special arrangements mean on the NICE interventional procedures guidance page.
Clinicians wishing to do electrohydraulic lithotripsy for difficult-to-treat bile duct stones should:
Inform the clinical governance leads in their healthcare organisation.
Give patients (and their families and carers as appropriate) clear written information to support shared decision making, including NICE's information for the public.
Ensure that patients (and their families and carers as appropriate) understand the procedure's safety and efficacy, and any uncertainties about these.
Audit and review clinical outcomes of all patients having the procedure. The main efficacy and safety outcomes identified in this guidance can be entered into NICE's interventional procedure outcomes audit tool (for use at local discretion).
Discuss the outcomes of the procedure during their annual appraisal to reflect, learn and improve.
Healthcare organisations should:
Ensure systems are in place that support clinicians to collect and report data on outcomes and safety for every patient having this procedure.
Regularly review data on outcomes and safety for this procedure.
The procedure should only be done in specialised centres with experience of managing difficult-to-treat bile duct stones.
Patient selection should be done by a multidisciplinary team including a hepatobiliary surgeon and clinicians with expertise in endoscopic retrograde cholangiopancreatography.# The condition, current treatments and procedure

# The condition
Bile duct stones that form from cholesterol or bile pigments can block the bile ducts. Difficult-to-treat bile duct stones are defined by their diameter (above 15 mm), number, unusual shape (such as barrel-shaped), location (intrahepatic or cystic duct), stone impaction, narrowing of the bile duct distal to the stone, or the anatomy of the common bile duct (sigmoid-shaped, short distal length or acute distal angulation of less than 135 degrees).

# Current treatments
Diagnosis and management of bile duct stones is described in NICE's guideline on gallstone disease. Treatments for bile duct stones include bile duct clearance and laparoscopic cholecystectomy. Conventional stone extraction involves endoscopic retrograde cholangiopancreatography (ERCP) and a sphincterotomy, then extracting the stones from the ducts using balloon and basket catheters. For difficult-to-treat bile duct stones, treatment options include temporary stenting to allow biliary drainage if the stones cannot be removed or stone fragmentation (lithotripsy).

# The procedure
Electrohydraulic lithotripsy (EHL) aims to fragment bile duct stones that cannot be treated using conventional stone removal techniques.
This procedure is usually done using general anaesthesia and direct visualisation of the stones using an endoscope inserted into the biliary tract. An EHL probe is inserted through the endoscope and the tip of the probe is positioned near the stone. Liquid is then injected around the stone and high-voltage energy from the probe generates shock waves that break the stone into smaller pieces. The procedure is usually done with the endoscope passed orally and through the stomach into the duodenum. However, a percutaneous approach is also possible.
When the stone fragmentation is complete, the fragments are flushed out or removed by standard techniques (such as a basket or balloon catheter). The endoscope is then removed. This procedure takes longer to complete than a standard ERCP, usually about 60 minutes.