Biliary strictures are a known association with many neoplastic and inflammatory diseases of the bile duct, pancreas and ampulla.Differentiating the benign from malignant strictures is essential for a proper treatment and follow- up of the patient.Though radiological techniques like ultrasonography, Computer Tomography, Endoscopic Ultrasound and Magnetic Resonance Cholangio Pancreatography (MRCP) can diagnose the strictures, they are not sufficient in differentiating the benign from malignant strictures.Brush cytology has a high specificity , but its drawback is the lower sensitivity rates. New biliary brush models were proposed in order to increase the sensitivity. Some models provided a better diagnostic yield while others did not.There are no published randomized prospective studies comparing the older brush with newer ones (with respect to the newer brushes in market as of 2011). Also, no studies have been proposed in India based on the newer biliary brushes available in the market. The present randomized controlled study will address these issues and will compare the older biliary brush with a newer one.

This will be a randomized, participant and outcome assessor blinded, active controlled, prospective study. 

Patients with high risk for malignant biliary strictures will be studied. They include patients presenting to the gastroenterology department with features of cholestatic jaundice and clinical diagnosis of cholangiocarcinoma or stricture in common bile duct and those with elevated serum alkaline phosphatase and elevated serum total bilirubin. Biliary brushing in the intervention group will be performed with  a newer variety of biliary brush (9 Fr wire-guided cytology brush (Infinity sampling device, US Endoscopy). It has a combination of soft and stiff bristles and hypothesized for better tissue acquisition).

Biliary brushing in the comparator group will be performed with wire guided "RX Cytology Brush by Boston Scientific". It measures 2.1 mm X 2.7mm (8 Fr)

The study will recruit 52 participants  with 26 each in the intervention group and in the comparator group.

After obtaining consent from the patient, he/ she will be subjected to Endoscopic Retrograde Cholangio Pancreatography (ERCP). The common bile duct will be visualized under flouroscopy. The presence of stricture in common bile duct will be confirmed. The biliary brush will be supplied to the endoscopist by an assistant. The assistant will pick the relevant type of biliary brush based on the randomized code. The assistant will not be a part of the study. Biliary brushungs will be obtained from the common bile duct. The biliary brush will be retracted and will be placed in a sterile plastic continer filled with Cytolyt solution (methanol). The tip of the brush with bristles will be cut and will also be placed in the solution. Cell block will be prepared and will be analyzed by the pathologist. The pathologist will be blinded regarding the type of biliary brush used for that patient.

The sensitivity, specificity, positive predictive value and negative predictive value will be calculated for both the randomized groups. Analysis will be done based on percentages, chi square test and other relevant tests of significance.