title: New observations on the gastroesophageal antireflux barrier.
abstract: The use of high-frequency ultrasound transducers combined with manometry in the gastrointestinal (GI) tract has yielded important findings concerning the anatomy, physiology, and pathophysiology of the high-pressure zone of the gastroesophageal junction and the sphincteric muscles within. These transducers have made previously invisible portions of the GI tract accessible to investigation. Three distinct high-pressure zones have been identified and correlated with anatomic structures: the extrinsic sphincter (crural diaphragm) and the two components of the intrinsic sphincter (an upper LES and a lower LES [the gastric sling fiber/clasp fiber complex]). This article discusses the possible underlying pathophysiology of gastroesophageal reflux disease; the biomechanics of the gastroesophageal junction high-pressure zone; and the mechanism of action of standard surgical and newer endoscopic therapies for gastroesophageal reflux disease.
authors.affiliation: Department of Gastroenterology, Temple University Hospital, Gastroenterology Section, 8th Floor, Parkinson Pavilion, Philadelphia, PA 19043, USA. vivi@temple.edu
authors.forename: Larry
authors.initials: L
authors.lastname: Miller
authors.forename: Anil
authors.initials: A
authors.lastname: Vegesna
authors.forename: Amit
authors.initials: A
authors.lastname: Kalra
authors.forename: Ramashesai
authors.initials: R
authors.lastname: Besetty
authors.forename: Qing
authors.initials: Q
authors.lastname: Dai
authors.forename: Annapurna
authors.initials: A
authors.lastname: Korimilli
authors.forename: James G
authors.initials: JG
authors.lastname: Brasseur
mesh_terms: D001696:Biomechanical Phenomena; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D019160:Endosonography / Q000379:methods*; D049630:Esophageal Sphincter, Lower / Q000000981:diagnostic imaging / Q000503:physiopathology; D018662:Fundoplication / Q000379:methods*; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005769:Gastrointestinal Motility / Q000502:physiology; D006801:Humans; D008365:Manometry; D011312:Pressure; D011379:Prognosis; D012720:Severity of Illness Index