Table 1: Patient's characteristics.

AOE ( ) control ( )

Age (years)
 Mean74.868.5
 Range57–9249–91
Sex
 Male5114
  Female146
Diagnosis
 Choledocholithiasis388
 Obstructive jaundice196
  Pancreatic cancer51
  Gallbladder cancer5
  Bile duct cancer41
  Hepatocellular carcinoma2
  Carcinoma of papilla of Vater13
  Metastatic lymphadenopathy2
  Malignant lymphoma 1
 Bile leakage2
 Pancreatic pseudocyst1
 Chronic pancreatitis22
 Peribiliary cyst1
 Others24