Modern evaluation of esophageal function in the gastrointestinal motility laboratory: a narrative review

Abstract

Objective: To review the current state of functional esophageal evaluation in the gastrointestinal (GI) motility laboratory, highlighting updates in established modalities along with new technologies. Background: The GI motility laboratory has been transformed the decade, modernizing its approaches for the evaluation of esophageal motility disorders and gastroesophageal reflux disease (GERD). Conclusions: The esophageal motility evaluation often starts with high-resolution esophageal manometry, now with enhanced protocols using provocative maneuvers to increase detection and understanding of esophageal motility disorders. Esophageal manometry now involves recording esophageal motility both in the supine and upright positions as well as in response to multiple rapid swallows and rapid drinking challenge. Endoscopic functional luminal imaging probe (EndoFLIP) using impedance planimetry technology can assess the compliance of the lower esophageal sphincter (LES), as well as can be utilized for assessment of esophageal motility during endoscopy. Ambulatory esophageal pH monitoring studies remain the standard for the diagnosis of GERD. Multichannel intraluminal impedance-pH (MII-pH) has the advantage of measuring impedance to identify non-acidic reflux episodes—a particularly important feature in patients not responding to proton pump inhibitors (PPIs), those with atypical GERD symptoms, and in patients who cannot stop their PPIs for their evaluation. Novel metrics include mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index which help differentiate GERD, non-erosive reflux disease (NERD), and reflux hypersensitivity from functional heartburn and normal subjects. They also can help predict outcome and response to medical and procedural therapies. Wireless pH capsule monitoring involves endoscopic attachment of a radiotelemetry capsule in the distal esophagus providing multi-day recording of esophageal pH. It is more tolerable than MII-pH allowing patients to resume their daily activities that might precipitate reflux. The GI motility laboratory has modernized approaches for the evaluation of esophageal function. for impedance For normal subjects PPI the upper of AET is 2.5% and normal subjects taking PPI BID, the upper limit of esophageal acid exposure to 1.3%.