The upper esophageal sphincter in gastroesophageal reflux disease

: The relationship of the upper esophageal sphincter (UES) and gastroesophageal reflux is not well established. The phenomenon of refluxate violation of the UES has been well documented. Laryngopharyngeal reflux (LPR) which occurs when the refluxate has breached the UES has been linked to various atypical reflux symptoms, including laryngitis, hoarseness, chronic cough, asthma, aspiration pneumonia, and globus. This paper aims to review existing research on both physiologic and pathological UES functions related to reflux. The vagally mediated esophago-upper sphincter contraction reflex prevents oropharyngeal reflux while the esophago-upper sphincter relaxation reflex (EURR) allows gas venting. The UES responds to liquid refluxate with a contractile response in healthy, supine subjects. This mechanism serves to protect the respiratory tract and is distinct from the UES belch relaxation reflex. This response is innate and likely diminishes with age. Deficient esophago-upper sphincter contraction reflex and hyper-attenuated EURR have been linked with symptoms of supra-esophageal reflux disease (SERD). When this type of reflux leads to symptoms and other pharyngeal, laryngeal or airway pathology, it is considered SERD. Artificial augmentation of UES pressure has been proposed as a therapeutic option for the prevention of SERD. These findings have been reproduced in subsequent studies and correlate with a reduction in regurgitation and extraesophageal symptoms.