Performance of bile aspiration plus brushing to diagnose malignant biliary strictures during endoscopic retrograde cholangiopancreatography

BACKGROUND AND STUDY AIMS Endobiliary brushing during endoscopic retrograde cholangiopancreatography (ERCP) is the main technique used to diagnose a malignant stricture, but has a poor sensitivity. This study evaluated the diagnostic performance of bile aspiration associated with biliary brushing during ERCP to diagnose a malignant stricture, compared to brushing alone. PATIENTS AND METHODS Between January 2007 and December 2012, all consecutive patients undergoing ERCP to treat a biliary stricture were included. After a biliary sphincterotomy, 3 mL to 10 mL of bile was aspirated into the brush catheter and collected in a dry sterile tube before and after brushing (to yield three samples). Brushing was performed as commonly recommended. RESULTS One hundred eleven patients (68 males, 43 females) were included; mean age 67 ± 15.4 years. A final diagnosis of malignant stricture was established in 51 patients, including 43 cholangiocarcinomas; 60 patients had benign strictures. Specificity (Sp) and positive predictive values were 100% for all samples. The diagnostic performance of the three-sample combination of bile aspiration + brushing + bile aspiration was significantly greater than brushing alone (P = 0.004): sensitivity (Se) = 84.3 % vs. Se = 66.7 %. The three-sample combination gave a negative predictive value of 88.2 %, and a diagnostic accuracy of 92.8 %. When suspicious results were added to malignant results as positive results, the three-sample combination gave Sp = 91.7 % and Se = 94.1 %. CONCLUSIONS In cases of biliary stricture, conducting bile aspiration before and after brushing significantly increased the ability to diagnose a malignant stricture with a sensitivity of 84.3 % (P = 0.004).