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.

Inclusion Criteria:

1. Patient receiving ERCP as standard of care for suspected or documented
choledocholithiasis as assessed by one or more of the following:

1. Abnormal imaging on ultrasound, endoscopic ultrasound (EUS), CT scan, or MRCP
suggestive of choledocholithiasis

2. Clinical signs and symptoms suggestive of choledocholithiasis such as jaundice,
abdominal pain, pruritis, pancreatitis, and/or cholangitis

3. Abnormal liver function tests suggestive of choledocholithiasis (eg: serum
bilirubin > 1.5 and/or elevated alkaline phosphatase levels)

2. In addition to one or more of the above inclusion criteria, patient must also satisfy
one or more of the following:

1. Mechanical lithotripsy, electrohydraulic lithotripsy, or laser lithotripsy
performed for therapy of bile duct stones.

2. Bile duct > 12mm on prior tests (any portion of duct)

3. History of recurrent abnormal LFTs with negative cholangiogram.

4. Positive EUS or MRCP for biliary stones with a negative cholangiogram

Exclusion Criteria:

1. Patients less than 18 years of age.

2. Patients not undergoing ERCP as their standard of care.

3. Patients who had the following surgeries - Billroth II surgery, Roux-en-Y Gastric
bypass surgery, and Whipple's surgery.