Endoscopic Retrograde Cholangiopancreatography (ERCP) is the recommended procedure for the management of choledocholithiasis. Different modalities of cholangioscopy-assisted intraductal therapy, including laser lithotripsy and electrohydraulic lithotripsy (EHL), have been developed for managing difficult biliary stones¹. However, these have been associated with a higher risk of adverse events (6%-15%), mainly cholangitis². Difficult biliary stones are defined by their diameter (>1.5 cm), number, unusual shape, and anatomical factors that can prevent their removal³.  

 We aimed to evaluate the effectiveness of cholangioscopy-guided EHL using data collected prospectively at a single high-volume tertiary referral centre (450 - 500 ERCP procedures annually).

We included all patients who underwent acholangioscopy-assisted EHL for choledocholithiasis from October 2018 to September 2025. 

 All procedures were performed by two expert endoscopists (> 50 procedures/year) with a single-operator cholangioscopic system. Technical success was defined as complete stone clearance. The primary endpoint was the number of cholangioscopy-assisted EHL sessions needed to achieve full stone clearance. Patient-related factors (e.g. stone burden) and procedure-related variables were analysed. 

 The complications recorded were post-ERCP pancreatitis (PEP), cholangitis, upper gastrointestinal haemorrhage (UGIH), and perforation (which were graded as mild, moderate, or severe⁴) occurring during or within 30 days post-procedure.

 A total of 81 EHL procedures were performed in 75 patients (49 females, 65.3%). The median age was 73 years (range 29-95). Complete stone clearance was achieved in a single session in 68 patients (90.7%); one additional procedure was required in 6 patients (8%), and two procedures were required in a single patient. Overall, the technical success rate was 100%. EHL was used as the first-line therapy in 11 patients (14.7%). Conversely, 44 (58.8%) had undergone one prior ERCP, 14 (18.6%) had undergone two, and 6 (8.0%) had undergone three or more ERCP procedures before the EHL session. All procedures were done with anaesthetist-supported deep sedation or general anaesthesia.  

 Regarding the choledocholithiasis profile, the median size was 17mm (range 8-40mm). The number of stones varied, with one stone present in 45 interventions (55.6%), and ≥2 stones in 36 (44.4%). After EHL, the stone fragments were removed with a balloon catheter in all the procedures. In 42 procedures (51.9%), sphincteroplasty was necessary to achieve complete clearance. Case-by-case analysis showed that EHL use was influenced not only by stone size/number but the shape (e.g. faceted), the location (e.g. cystic duct), the presence of a stricture, or Mirizzi syndrome. 

 Prophylactic intravenous antibiotics were given peri-procedure, followed by a 3- to 5-day oral course (except cases with active treatment due to infection). Rectal Diclofenac (100mg) was administered to all patients unless contraindicated. 

 There were complications in 8 procedures (9.9%): One case of PEP (1.2%), two cases of UGIH (2.5%), four cholangitis (4.9%), and one perforation (1.2%). Five were mild, three were moderate. None of them had a native papilla. 

 Overall, our data showed that EHL is an effective and safe technique for managing complex choledocholithiasis when conventional ERCP has failed. Our complication rate was comparable to that reported in the literature. Cholangitis was more frequent, as expected with intraductal therapy, but remained within reported ranges. 

 Given high success rates in achieving complete stone clearance with EHL, we would recommend performing cholangioscopy/EHL following an incomplete stone clearance attempt at index ERCP, particularly if failure is due to difficult stones.