Prospective Evaluation of Residual Bile Duct Stone by Peroral Cholangioscopy After Conventional ERCP

Peroral cholangioscopy (POC) provides direct visualization of the bile duct during ERCP and its benefits are well documented in numerous published studies. POC has been described for therapy of difficult to remove biliary stones utilizing electrohydraulic lithotripsy or laser lithotripsy with success rates of \>90%. POC has also been used for evaluation of indeterminate filling defects and to assess for residual stones missed with cholangiogram. In a multicenter study evaluating POC for a variety of indications, 11% (7/66) of patients had bile duct stones identified only by POC that were missed on ERCP. In a study of patients with primary sclerosing cholangitis, 30% (7/23) of patients were found to have stones with POC that were missed with cholangiography. Takao et al. assessed residual bile duct stones found with POC in comparison to balloon-cholangiography; they found that 24% (26/108) of patients had residual stones seen with POC that were missed with balloon-cholangiography. Although POC has been available for over thirty years, it has not become a widespread technique due to the fact that traditional cholangioscopes are fragile, cumbersome to use, and usually require two endoscopists to perform the procedure. A recent single operator semi-disposable cholangioscope, SpyGlass (Boston Scientific, Natick, Massachusetts), has addressed those concerns and has been shown in a studies to be a useful tool in visualizing the bile ducts and performing therapeutic maneuvers for biliary stones. Both ERCP and Cholangioscopy are standard of care procedures to treat gall stones. The primary goal of the study is to assess if POC will enhance the diagnostic yield in the detection of residual biliary stones that are missed during conventional ERCP. Residual bile duct stones can especially be seen in the setting of bile duct dilation, history of recurrent abnormal liver function tests, and after lithotripsy (mechanical, electrohydraulic, or laser). Missed biliary stones can lead to recurrent biliary symptoms, pancreatitis, and cholangitis. POC after conventional ERCP can be a useful diagnostic tool to confirm complete extraction of bile duct stones, and thus lead to decreased morbidity and decreased cost by avoiding unnecessary tests and repeat procedures.