Mechanisms of Esophago-Pharyngeal Acid Regurgitation in Human Subjects

• Published in: PloS one Vol. 6; no. 7; p. e22630
• Main Authors: Szczesniak, Michal Marcin, Williams, Rohan Benjamin, Cook, Ian James
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.07.2011; Public Library of Science (PLoS)
• Subjects: Acids; Adult; Aged; Asthma; Biology; Dysphagia; Esophageal Sphincter, Upper - physiopathology; Esophagus; Esophagus - physiopathology; Female; Gastroenterology; Gastroesophageal reflux; Humans; Hydrogen ions; Hydrogen-Ion Concentration; Laryngopharyngeal Reflux - etiology; Laryngopharyngeal Reflux - physiopathology; Male; Measurement techniques; Medical instruments; Medical research; Medicine; Middle Aged; Monitoring; Morphology; Motility; Muscle Relaxation; Otology; Parkinson's disease; Patients; pH effects; Pharynx; Posture; Pressure; Regurgitation; Sensors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0022630

Esophago-pharyngeal regurgitation is implicated in various otolaryngologic and respiratory disorders. The pathophysiological mechanisms causing regurgitation are still largely unknown. To determine the principal mechanisms behind esophago-pharyngeal regurgitation. We studied 11 patients with extra-esophageal GORD symptoms in whom esophago-pharyngeal acid regurgitation had previously been demonstrated using ambulatory, dual (pharyngo-esophageal) pH metry (>2 episodes/day using previously validated pH-metric criteria). Patients underwent continuous, 24 hr, stationary monitoring of pharyngo-esophageal manometry and dual (pharyngeal and esophageal) pH recordings. They were intubated with a 14-channel manometric assembly incorporating 2 sleeve sensors monitoring the upper and lower esophageal sphincters simultaneously. A dual pH catheter recorded pH signals 2 cm above the UES midpoint and 7 cm above the LES midpoint. A total of 32 episodes of spontaneous esophago-pharyngeal acid regurgitation were recorded. All episodes occurred in the upright posture and 91% occurred within 3 hrs post-prandium. All regurgitation events were associated with a relaxation of the UES, which were classified as transient non-swallow related relaxations in 29 (91%) and swallow-related in the remaining 3 (9%). Straining was an additional associated factor in 41% of regurgitation events, but strain alone was not sufficient to cause esophago-pharyngeal regurgitation. Some form of active UES relaxation is necessary for regurgitation to occur. The dominant mechanism underlying esophago-pharyngeal acid regurgitation is the non-swallow related, transient UES relaxation. N/A.