Intraoperative ultrasonography of the biliary tract using saline as a contrast agent: a fast and accurate technique to identify complex biliary anatomy

Background: Intraoperative assessment of biliary tract anatomy is relevant for a number of benign and malignant hepatobiliary diseases. During biliary reconstruction, drainage of all relevant bile ducts is imperative to prevent atrophy of undrained segment, cholangitis and secondary biliary cirrhosis. Intraoperative cholangiography, though widely used for intraoperative imaging of the biliary tract, involves heavy equipment use, radiation risk and has a limited role in the evaluation of isolated segmental bile ducts. Methods: We evaluated the use of a novel technique of intraoperative ultrasonography of the biliary tract using normal saline as a contrast agent. It involves injecting saline in any part of the biliary system while performing real-time intraoperative 2-dimensional ultrasonography. Results: This procedure was carried out in intraoperative situations to delineate complex biliary anatomy involving segmental bile ducts. Excellent image quality was obtained in the form of opacification and demarcation of the liver segment to which the duct belongs. The flow of saline microbubbles was clearly visible on real-time ultrasound images, leading to accurate identification of the duct. Conclusion: Intraoperative ultrasonography with saline as a contrast agent can accurately identify small isolated segmental bile ducts and help in surgery of the biliary tract. It is a simple and inexpensive technique that can be performed with minimal resources.