RISK OF CHOLEDOCHOLITHIASIS IN PATIENTS WITH HIGH PRE-PROCEDURE PROBABILITY FOR CBD STONES AND IMPROVING BILIRUBIN LEVELS

Aims American Society for Gastrointestinal Endoscopy guidelines are commonly used to identify patients with high risk for choledocholithiasis. Presence of bilirubin >4 mg/dl, bilirubin >1.8 and dilated common bile duct (CBD) and/or clinical cholangitis are considered high risk criteria that predict the need for interventional ERCP. However, no time frame is mentioned in guidelines, and high-risk patients often have improvement in bilirubin levels before the ERCP. Our aim was to evaluate the risk of choledocholithiasis in patients with suspected CBD stones and bilirubin >4 mg/dl, with decline in bilirubin levels below 4 mg/dl prior the ERCP.

Methods In a single center retrospective study we investigated the records of hospitalized patients that had ERCP or EUS for presumed choledocholithiasis between 6.2018- 6.2010 and had bilirubin >4 mg/dl prior the examination. All patients had abdominal imaging before the endoscopy. Patients with active malignancy, external biliary drainage or PSC were excluded. Choledocholithiasis risk was assessed in a cohort of patients with bilirubin that declined below 4 md/dl compared to those with bilirubin remaining above 4 mg/dl prior the endoscopic procedure.

Results Out of 717 patients screened, 291 met the inclusion criteria. Choledocholithiasis was found in 65/102 (63%) patients with decline in bilirubin below 4 mg/dl, compared to 144/189 (76%) patients with bilirubin that remained above 4 mg/dl (p=0.02). In patients with elevated bilirubin as an only high-risk criteria for CBD stones, choledocholithiasis was found in only 9/34 (26%) of those with bilirubin decrease below 4 mg/dl, compared to 33/52 (63%) of those with bilirubin >4 mg/dl before the ERCP (p=0.0008).

Conclusions Decrease in bilirubin below 4 mg/dl is associated with lower risk for choledocholithiasis in patients presenting with increased bilirubin levels, and is especially pronounced for those with bilirubin > 4md/dl as an only high-risk criterion. EUS or MRCP should be considered before ERCP in those patients.