Endoscopic needle aspiration biopsy at ERCP in the diagnosis of biliary strictures

We have developed a ball-tipped catheter with a retractable 22-gauge, 7-mm long needle to perform endoscopic needle aspiration (ENA) for cytology and compared this technique to brush cytology of malignant-appearing biliary strictures during ERCP. Of 31 patients, 26 had proven malignant strictures involving the common bile duct and 5 had benign lesions. All 31 patients had ENA and 29 were brushed. Positive ENAs were obtained in 16 of 26 patients (61.5%) and positive brushings in 2 of 24 (8.3%). With the addition of two suspicious ENAs for pancreatic adenocarcinoma, 73% of patients had positive or suspicious cytology for malignancy by combined ENA and brush with a specificity of 100%. Although ENA appeared to be more sensitive in diagnosing cholangiocarcinoma, it proved to be most effective in the diagnosis of pancreatic adenocarcinoma when compared with brush cytology. One patient with cholangiocarcinoma in our series was diagnosed by brush cytology only, with a negative ENA, supporting our recommendation of using both endoscopic brushings and ENA for cytology when evaluating biliary strictures.