DIGITAL CHOLANGIOSCOPY FOR DETECTION OF MISSED STONES IN THE BILE DUCTS AFTER ENDOSCOPIC THERAPY- A SINGLE CENTER STUDY

Aims To evaluate the efficacy and safety of digital cholangioscopy for detection of missed or retained bile ducts stones after conventional endoscopic therapy.

Methods Data was collected retrospectively from a prospective data base from January to December 2018. A total of 149 patients with choledocholithiasis were treated by ERCP and stone removal. Among them 38 patients underwent digital cholangioscopy after stone extraction and negative occlusion cholangiogram to exclude residual stones. The indications for cholangioscopy were at least one of the following: when mechanical lithotripsy was performed, when multiple stones (over 3) were extracted or when the common bile duct was dilated (over 15 mm), leading to difficulties to obtain good quality cholangiography. We also explored factors like common bile duct diameter, presence of distal bile duct stricture, duodenal diverticula or surgically altered anatomy and their possible relation with the probability of missed stones.

Results Residual stones were found in 26,3% (10) of cases. In 18,4% (7) the stones were in the common bile duct, in 5,3% (2)- in the intrahepatic bile ducts and in 2,6% (1)- in the cystic ducts stump. No correlation between the common bile duct size and the presence of residual stones was found. The distal common bile duct stricture, duodenal diverticulum or surgically altered anatomy were not found to be risk factors for retained lithiasis after conventional endoscopic therapy. No adverse events were observed in the studied group of patients.

Conclusions Factors like common bile duct size, presence of ductal stricture, duodenal diverticulum or surgically altered anatomy cannot predict the risk of residual stones, missed by occlusion cholangiogram. Digital cholangioscopy is safe and highly effective in the detection of fluoroscopically missed bile duct lithiasis and should be considered to confirm ductal clearance in some clinical scenarios. Further studies are needed to evaluate the cost effectiveness.