Extraintestinal Applications of Endoscopic Ultrasound

Since the joining of ultrasonographic and endoscopic technologies in 1980, there has been tremendous advancement in the use of endoscopic ultrasound (EUS). Initially EUS was used mainly to study the anatomic appearance of digestive organs. In the 1990s, with the development of the charge-coupled device, thinner, more flexible scopes were developed that simplified imaging for the endosonographer and improved patient safety. With the development of linear array EUS scopes, biopsies could be performed utilizing fine needle aspiration. Currently, several therapeutic techniques, which were formerly performed through radiologic or surgical procedures, are being safely done with EUS. These include celiac plexus neurolysis and endoscopic drainage of pancreatic cysts. With the advent of miniprobe technology, better delineation of the wall of the gastrointestinal tract can be obtained, facilitating endoscopic mucosal resection. Novel therapeutic uses for EUS are constantly emerging. This article describes the various extraintestinal applications of EUS that have been developed in the last 25 years. More gastroenterologists need training in order to utilize this challenging technology and improve patient access in the local community setting.