Which patients with dilated common bile and/or pancreatic ducts have positive findings on EUS?

Background: Patients with dilated common bile duct (CBD) (>7mm) and/or pancreatic duct (PD) on abdominal imaging are often referred for endoscopic ultrasound (EUS). In many cases, the EUS shows no obvious etiology for the dilated ducts.

Objective: Find clinical factors that may predict which patients are more likely to have positive findings on EUS to explain the etiologies for the dilated ducts.

Design: Retrospective database analysis.

Setting: Tertiary-care university hospital.

Patients: Patients referred for EUS for dilated CBD and/or PD from January 2004 to February 2010 were included in this study. Only patients without an obvious etiology for the dilated ducts on abdominal imaging were included.

Interventions: An EUS was performed by using either a radial echoendoscope or a linear endoscope to evaluate the common bile duct and/or the pancreatic duct. When appropriate fine needle aspiration of the mass or cyst was performed.

Main outcome measurements: The characteristics of patients who had positive findings on EUS to explain the etiology of their dilated PD and/or CBD.

Results: A total of 140 patients were included in the study with a mean age of 64 years, 51 (36%) male and 115 (82%) white. The majority of our patients had a presenting symptom of abdominal pain 105 (75%). 49 (36%) had elevated AST or ALT, 25 (8%) had an elevated bilirubin and 13 (23%) had an elevated lipase. EUS findings explained the dilated ducts in 54 (39%) of our patients, most common diagnoses included: CBD stone in 11 (8%), non-calcific chronic pancreatitis in 9 (6%), pancreatic mass in 8 (6%), IPMN in 7 (5%). On bivarate analysis patients who were older (p = 0.006), male (p = 0.001), had elevated LFTs (p = <0.001), had elevated lipase (p = 0.021) or had dilated CBD and PD (p = 0.007) were more likely to have an etiology for their dilated duct(s) discovered on EUS.

Limitations: A retrospective study with a small number of patients.

Conclusion: Older patients, males and those patients presenting with concurrent elevations in the AST/ALT and/or lipase were more likely to have an underlying etiology discovered on EUS. Furthermore, EUS may detect an undiagnosed pancreatic malignancy in patients presenting with unexplained duct dilation.