This ASG video tip is sponsored by Braintree, maker of the newly approved Soufflave and Soutab. Hi, I'm Jessica Widmer, the Chief of Endoscopy and Advanced Endoscopy Fellowship Program Director at NYU Long Island. I'll be discussing a series of video tips on EOS-guided intrahepatic drainage. For this video tip, we'll be discussing anterograde stenting and transgastric stenting. 3 to 5% of biliary obstruction cases cannot be managed by conventional ERCP. This most commonly occurs due to ampullary pathology, periampullary diverticuli, surgically altered anatomy, and gastric outlet obstruction. EOS-guided biliary drainage is a well-described alternative technique when conventional ERCP fails. EOS-guided biliary drainage can be obtained in a transgastric approach if there are dilated intrahepatic ducts on cross-sectional imaging. If the guide wire is able to be advanced across the biliary system and across the papilla, a stent can be deployed in an anterograde fashion. If the guide wire cannot be manipulated across the papilla, a transmural stent can be placed, facilitating a hepaticogastrostomy. Once you have access into the biliary system with a guide wire, various dilating catheters can be used to facilitate stent placement. Ideally, a 6-French cystostome can be used, but this device is not currently available in the US. Other common dilating catheters include dilating balloons, graduated dilating catheters, a needle knife, or other cautery-enhanced catheters. I'll now focus on the procedural steps for the second series of the video tip. Once you've gained access to the biliary system with a guide wire, you can create a fistulas tract and deploy a decompressing stent. Which stent should be used? There are a variety of options, including plastic and metal stents. Plastic stents alone typically aren't used anymore. More frequently, biliary self-expanding metal stents are used. More often, either fully covered or partially covered metal stents are used. Some stents have anti-migratory characteristics to avoid stent migration. Some endoscopists will also opt to place a double pigtail plastic stent coaxially through the metal stent. Factors to consider when choosing a stent include stent diameter, often 8 or 10 mm diameter metal stents, and duct to lumen distance, often 6, 8, or 10 cm in length. Here, a dilated biliary radical is identified using EUS from the proximal stomach. A 19-gauge access needle is advanced into the targeted biliary radical and contrast is injected. The cholangiogram demonstrates severely dilated intrahepatic ducts with a distal biliary stricture. A guide wire is then advanced into the biliary system. The FNA needle is removed and exchanged for a balloon dilator. Using the balloon dilator to bolster this wire, the guide wire can be directed across the distal stenosis and into the duodenum. Be sure to maintain a stable scope position with taut wire tension to facilitate advancement of all catheters into the liver. Then both the distal stricture and the transgastric fistula tract are dilated to facilitate stent placement. A fully covered metal stent is then placed in an anterograde fashion. For stent deployment, the guide wire can be left in place in order to maintain the location of the fistula. When a clip is ready to be deployed, the guide wire is removed and the fistula closure can be obtained with an endoclip. If a guide wire cannot be advanced across the stenosis, a dilating balloon can be used to create a transgastric fistula in anticipation of stent placement. At this point, consider replacing the biopsy cap so that insufflation is possible when you need it. After dilation of the fistula with a dilating balloon catheter, a fully covered metal stent with anti-migratory fins was selected for hepaticogastrostomy. The stent is initially positioned in the liver and deployed proximally. After the distal end of the stent is deployed within the liver, CO2 is used to insufflate the stomach and the distal end of the stent is deployed with about 2 to 3 centimeters within the stomach to reduce the risk of migration. Let's review some take-home points. Minimize attempts to redirect the guide wire using the FNA needle, which causes shearing of the guide wire coating. Maintain stable scope position and taut wire tension to facilitate advancing catheters into the liver. After creating a transgastric fistula with a dilating catheter, the guide wire can be redirected if needed. If the guide wire can be advanced across the ampulla and into the duodenum, an anterograde stent can be placed followed by closure of the access point with an endoclip. If not, a transgastric stent can be placed to create a hepaticogastrostomy. When choosing the stent diameter, consider the diameter of the duct. When determining the length, be sure not to jail off any other biliary radicals and have at least 2 to 3 centimeters of the distal aspect of the stent in the gastric lumen.

EOS-guided biliary drainage

challenging cases

conventional ERCP

anterograde stenting

metal stents