Devices for esophageal function testing

Abstract

Background and aims: Esophageal function testing is an integral component of the evaluation of refractory GERD and esophageal motility disorders. This review summarizes the current technologies available for esophageal function testing, including the functional luminal imaging probe (FLIP), high-resolution esophageal manometry (HRM), and multichannel intraluminal impedance (MII) and pH monitoring.

Methods: We performed a MEDLINE, PubMed, and MAUDE database literature search to identify pertinent clinical studies through March 2021 using the following key words: esophageal manometry, HRM, esophageal impedance, FLIP, MII, and esophageal pH testing. Technical data were gathered from traditional and web-based publications, proprietary publications, and informal communications with pertinent vendors. The report was drafted, reviewed, and edited by the American Society for Gastrointestinal Endoscopy Technology Committee and approved by the Governing Board of the American Society for Gastrointestinal Endoscopy.

Results: FLIP is a high-resolution impedance planimetry system used for pressure and dimension measurement in the esophagus, pylorus, and anal sphincter. FLIP provides complementary information to HRM for esophageal motility disorders, especially achalasia. The Chicago classification, based on HRM data, is a widely adopted algorithmic scheme used to diagnose esophageal motility disorders. MII detects intraluminal bolus movement and, combined with pH measurement or manometry, provides information on acid and non-acid gastroesophageal reflux and bolus transit in patients with refractory GERD and for preoperative evaluation for anti-reflux procedures.

Conclusions: Esophageal function testing techniques (FLIP, HRM, and MII-pH) have diagnostic and prognostic value in the evaluation of esophageal motility disorders and refractory GERD. Newer technologies and classification systems have enabled an increased understanding of these diseases.

Keywords: AET, acid exposure time; ASGE, American Society for Gastrointestinal Endoscopy; BMI, body mass index; CC, Chicago classification; CD, contractile deceleration; CSA, cross-sectional area; DI, distensibility index; DP, distensibility plateau; DRI, dysphagia risk index; EGJ, esophagogastric junction; EGJOO, esophagogastric junction outflow obstruction; EM, esophageal manometry; EPT, esophageal pressure topography plots; EoE, eosinophilic esophagitis; FLIP, functional luminal imaging probe; HRM, high-resolution esophageal manometry; IEM, ineffective esophageal motility; IRP, integrated relaxation pressure; LES, lower esophageal sphincter; LHM, laparoscopic Heller myotomy; MII, multichannel intraluminal impedance; MRS, multiple rapid swallows; MSA, magnetic sphincter augmentation; NOD, nonobstructive dysphagia; POEM, peroral endoscopic myotomy; PPI, proton pump inhibitors; SAP, symptom association probability; SI, Symptom index; UES, upper esophageal sphincter.

Figure 1

Image of an EndoFLIP system. ©2020 Medtronic. All rights reserved. Used with the permission of Medtronic.

Figure 2

Examples of functional luminal imaging probe planimetry. A, Normal contraction pattern with repetitive antegrade contractions and normal distensibility index. B, Absent esophageal body contractility with reduced distensibility index in achalasia (courtesy of Dr Diana Snyder, Mayo Clinic Arizona).

Figure 3

Hiatus hernia identified by high-resolution esophageal manometry. A, Normal esophagogastric junction without hiatus hernia; the lower esophageal sphincter and diaphragm are at the same position. B, Hiatus hernia, with displacement of the lower esophageal sphincter to a few centimeters above the diaphragm.

Figure 4

Example of an impedance-pH report detailing reflux-related data and symptom association (courtesy of Dr Michael Crowell, Mayo Clinic Arizona).