Duodenal EUS to identify thickening of the extrahepatic biliary tree wall in primary sclerosing cholangitis

Abstract

Background: Diagnosing primary sclerosing cholangitis (PSC) is problematic and requires meeting a burden of proof through clinical, biochemical, radiologic, and histological features. Endoscopic ultrasound yields detailed images of the extrahepatic biliary tree, but its value in contributing to the diagnosis of this condition is unknown.

Objectives: To determine the potential for transduodenal EUS to detect common bile duct wall thickening in PSC.

Design: A prospective, controlled study with retrospective, blinded data analysis.

Setting: Single tertiary referral center for inflammatory bowel disease and EUS.

Patients: Four groups of patients were assessed with radial endosonography: PSC (n = 9); inflammatory bowel disease (IBD) with abnormal liver blood tests (n = 21); choledocholithiasis (n = 15); and normal controls (n = 50). Measurements were made of the common bile duct diameter and wall thickness.

Interventions: Transduodenal radial EUS of the biliary tree.

Main outcome measurements: Common bile duct diameter and wall thickness.

Results: The mean diameter (SD) of the common bile duct for the PSC, IBD, choledocholithiasis, and normal control groups measured 8.9 mm (2.8), 5.4 mm (1.7), 7.2 mm (2.2), and 5.0 mm (1.9), respectively (PSC and choledocholithiasis groups compared to the IBD group, P < .05 for a single test of hypothesis, but correction for the multiple testing of data removed this significance; normal control group P < .005). Mean ductal wall thickness (SD) was 2.5 mm (0.8) for the PSC group, 0.7 mm (0.4) for the IBD group, 0.8 mm (0.4) for the choledocholithiasis group, and 0.8 mm (0.4) for the normal control group, respectively (PSC group compared to the other 3 groups, P < .005).

Limitations: Assessment of intrahepatic PSC is problematic.

Conclusion: Thickening (>1.5 mm) of the common bile duct wall is seen in patients with PSC but not in those with apparently uncomplicated IBD or choledocholithiasis. The results of this study suggest that standard endosonography contributes to the imaging and potentially to the diagnosis of PSC.