Periampullary disorders: review of pathophysiology.

The ampulla of Vater is strategically located at the confluence of the terminal end of the bile duct and the pancreatic duct. It is entwined by smooth muscle fibers often referred to as the sphincter of Oddi. As a result, the ampulla demonstrates dynamic motor activity. A variety of structural and functional abnormalities can involve the ampulla and the periampullary region. Disorders involving the ampulla often produce remarkably similar clinical features, such as acute pancreatitis, biliary colic, or jaundice. Therefore, it is important that patients with periampullary disorders are systematically studied using endoscopic retrograde cholangiopancreatography, sphincter of Oddi manometry, and endoscopic ultrasonography. Common disorders involving the periampullary region and state-of-the-art techniques for diagnosis and treatment of these disorders are discussed.