Upper esophageal sphincter function during gastroesophageal reflux events revisited

Abstract

Upper esophageal sphincter (UES) function during gastroesophageal reflux events is not completely elucidated because previous studies addressing this issue yielded conflicting results. We reexamined the UES pressure response to intraluminal esophageal pressure and pH changes induced by reflux events. We studied 14 healthy, asymptomatic volunteers (age 49 +/- 6 yr) and 7 gastroesophageal reflux disease patients (age 48 +/- 5 yr). UES pressure, intraesophageal pressure, and pH were monitored at the distal, middle, and proximal esophagus concurrently in the supine position 1 h before and 2 h after a 1,000-calorie meal. A total of 321 reflux events were identified by the development of abrupt reflux-induced intraesophageal pressure increase (IPI); 285 events occurred in patients and 36 in control subjects. In control subjects 33 of 36 and in patients 252 of 285 IPI events were associated with a pH drop. Among patients and control subjects, 99% and 100%, respectively, of all IPI events irrespective of pH drop were associated with abrupt increase in UES pressure (34 +/- 2 and 27 +/- 6 mmHg, respectively). The average percentage of maximum UES pressure increase over prereflux values ranged between 66% and 96% (control subjects) and 34% and 122% (patients). IPIs induced by both acidic and nonacidic reflux events evoke strong UES contractile responses.

Effect of maturation of the magnitude of mechanosensitive and chemosensitive reflexes in the premature human esophagus

“…This finding may be because of increase in muscle mass and therefore stronger contraction or enhanced nerve-muscle interaction. An increase in UES tone has been noted in children and adults during GER events 8,15,27 ; and from our study, an increased level of aerodigestive tract protection is evident with volume increments. Mechanisms such as EUCR may provide airway protection against retrograde aspiration.…”

“…Clearance mechanisms including primary peristalsis (PP), secondary peristalsis (SP) and esophago-upper esophageal sphincter (UES)-contractile reflexes (EUCR) that may prevent the entry of refluxate into the pharynx or larynx are well recognized in healthy adults and those with GER disease. [8][9][10][11] Immaturity, rapid development, and changing feeding behavior distinctly separate evolving pathophysiology in neonates from that of older subjects.Aerodigestive symptoms may result from delayed clearance, airway aspiration, or chemoreceptor stimulation. 12-15 We described methods to evaluate the esophageal body and UES motor responses resulting from esophageal provocation.…”

Differential relaxation and contractile responses of the human upper esophageal sphincter mediated by interplay of mucosal and deep mechanoreceptor activation

“…In fact, we found that experimental acidification enhanced the UES contractile response. This response may protect the esophagus against acid exposure because similar chemostimulatory augmentation of UES pressure has been observed previously during esophageal acid infusion (6) and during spontaneous gastroesophageal acid reflux (25). The upregulation of the UES contractile response by acute esophageal acid infusion observed in healthy controls may not be indicative of UES responses in patients with chronic acid exposure in whom the possibility exists that afferent nerves are desensitized or damaged by prolonged acid exposure.…”

Oropharyngeal dysphagia in patients with chronic obstructive pulmonary disease: a systematic review

“…Although this systematic review did not concentrate on the data pertaining to the prevalence of COPD and GERD, it is important not to ignore the high prevalence of GERD in this population as a concomitant contributor to oropharyngeal swallowing complaints 54,55 , and as an exacerbating factor in respiratory decompensation 14,30,[32][33][34]41,47 .…”