Endoscopic UItrasound-Guided Biliary Drainage

摘要

The advances of fine-needle technologies, catheter cautery devices, dilators, and metal stents have gradually transformed endoscopic ultrasound (EUS) from merely a diagnostic modality to one that offers therapy over the past two decades. The ability to visualize extraluminal structures, such as the biliary tree, offers therapeutic options previously unavailable for biliary drainage (BD). Although endoscopic retrograde cholangiopancreatography (ERCP) remains the primary method for achieving BD, it is not universally successful. ERCP may fail for numerous reasons, such as failure to reach the papilla for attempted cannulation, or because of technical issues preventing successful navigation of a biliary stricture. Malignant obstruction of the gastric outlet or duodenum may prevent the endoscopist from reaching the papilla, or the biliary orifice may be obscured by a previously placed duodenal stent. A large pancreatic, duodenal, or ampullary tumor may make it impossible to recognize the ampullary structures to cannulate the bile duct. The papilla may be hidden within a duodenal diverticulum. The patient may have postsurgical anatomy, such as Billroth II or Roux-en-Y reconstruction, making the papilla difficult to reach and requiring specialized equipment, such as deep enteroscopes and modified cannulotomes. At other times, all the conditions may seem to be in favor of the endoscopist and yet cannulation fails despite all efforts, including specialized techniques, such as pancreatic duct stent placement, double-wire technique, or needle knife papillotomy.