Biliary therapy: are we ready for EUS-guidance?

Endoscopic retrograde cholangiopancreaticography is the standard therapy for the therapy of biliary obstruction. However, the success rate is not 100%, depending on various patient and physician related factors. In these cases, where endoscopic drainage is not possible, either percutaneous drainage or surgery are established alternatives. Both modalities carry a higher complication rate and are more invasive than endoscopic drainage. With linear echo-endoscopes, left intrahepatic bile ducts as well as the distal common bile duct can be visualized from the stomach or the duodenal bulb respectively. This opens up the possibility of puncturing the bile ducts under real time ultrasound control from the intestinal lumen. There are two different techniques to achieve biliary drainage after gaining EUS guided access: The first is direct biliary drainage in the intestinal lumen by placing a stent through the wall of the stomach/duodenum after placement of a guidewire through an 19gauge needle into the biliary tract. This technique usually requires some form of bouginage once the guide wire has been placed and is very similar to EUS guided pseudocyst drainage. The second technique is the rendezvous technique, where the guidewire is manipulated through the stricture and the papilla. Thereafter the wire is captured with a standard duodenoscope and a biliary drainage is performed through the papilla in established fashion. With both techniques fluoroscopic control in addition to EUS is needed. So far both techniques have been described in case reports and small series only. Large prospective series as well as controlled trials that compare EUS guided techniques with ERCP or PTC are lacking. The most common complication is biliary leakage, especially if direct drainage is performed. Other common complications include cholangitis, stent migration and occlusion as well as pain. As long as large prospective series are lacking, EUS guided biliary drainage should be restricted to selected patients where ERCP has repeatedly failed or is impossible due to surgically altered anatomy. Furthermore this technically demanding procedure should be performed only in centres with extensive experience in linear EUS and therapeutic biliary ERCP. The possible advantages over percutaneous drainage like patient comfort and morbidity have to be proven in randomized trials.