Is ineffective esophageal motility associated with gastropharyngeal reflux disease?
IEM is associated with an increased acid clearance times in the distal esophagus. Gastropharyngeal reflux causes supraesophageal manifestations such as globus, chronic cough, hoarseness, asthma, chronic sinusitis, or other otorhinolaryngologic diseases. It might be hypothesized that patients with IEM would be unable to clear refluxed acid; this would lead to a prolonged esophageal dwell time of the refluxed acid and then the refluxed acid would reach to a higher level. As a result, it would be presumed that patients with IEM have more gastropharyngeal reflux than those patients with normal esophageal motility. A research article to be published on October 21, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Prof. Kim from Pusan National University Hospital evaluated the association between IEM and gastropharyngeal reflux in a large series of patients who underwent ambulatory 24-hour dual-probe pH monitoring for the evaluation of supraesophageal symptoms. They showed that the frequency of gastroesophageal reflux disease (GERD) and gastropahryngeal reflux disease, as defined by ambulatory pH monitoring was not different between the patients with normal esophageal motility and those with IEM.
Why is IEM not associated with GPRD as well as GERD? Conventional manometry may be unable to evaluate the "true effectiveness" of esophageal peristalsis. In addition, the refluxed acid is neutralized by both the esophageal submucosal secretions and the swallowed salivary secretions, so it becomes non-acid reflux material. Therefore, even though this non-acid refluxate in the upper level actually increased in the patients with IEM, the proximal pH probe cannot detect it. To solve this problem, a prospective study using a combined multichannel intraluminal impedance and pH measurement, which are able to detect both acid and non-acid reflux, as well as the proximal extent of the refluxate, will be needed.
