Esophageal Impedance Monitoring: Clinical Pearls and Pitfalls

Abstract

The development of intraluminal esophageal impedance monitoring has improved our ability to detect and measure gastroesophageal reflux without dependence on acid content. This ability to detect previously unrecognized weak or nonacid reflux episodes has had important clinical implications in the diagnosis and management of gastroesophageal reflux disease (GERD). In addition, with the ability to assess bolus transit within the esophageal lumen, impedance monitoring has enhanced the recognition and characterization of esophageal motility disorders in patients with nonobstructive dysphagia. The assessment of the intraluminal movement of gas and liquid has also been proven to be of diagnostic value in conditions such as rumination syndrome and excessive belching. Further, alternative applications of impedance monitoring, such as the measurement of mucosal impedance, have provided novel insights into assessing esophageal mucosal integrity changes as a consequence of inflammatory change. Future applications for esophageal impedance monitoring also hold promise in esophageal conditions other than GERD. However, despite all of the clinical benefits afforded by esophageal impedance monitoring, important clinical and technical shortcomings limit its diagnostic value and must be considered when interpreting study results. Overinterpretation of studies or application of impedance monitoring in patients can have deleterious clinical implications. This review will highlight the clinical benefits and limitations of esophageal impedance monitoring and provide clinical pearls and pitfalls associated with this technology.

Esophageal and Small Intestinal Mucosal Integrity in Eosinophilic Esophagitis and Response to an Elemental Diet

“…In brief, impedance is the measure of the degree to which an electric circuit resists to an alternating electric current when impressed through tissue (21). Mucosal impedance reflects how electricity travels through intestinal tissue (22).…”

Advances in the Diagnosis of GERD Using the Esophageal pH Monitoring, Gastro-Esophageal Impedance-pH Monitoring, And Pitfalls

“…2) A catheter-based MII-pH monitoring will cause the patient’s poor tolerance for monitoring pH-impedance [ 45 ].…”

“…3) Dietary changes during the MI-pH evaluation may lead to a poor predictor of gastroesophageal reflux [ 45 ].…”

Diagnosis of gastro‐oesophageal reflux disease is enhanced by adding oesophageal histology and excluding epigastric pain

“…It is still available in only a small number of centres and is not part of the mainstream toolkit used by most gastroenterologists. A recent systematic review of pH impedance concluded that important clinical and technical shortcomings limit its diagnostic value and must be considered when interpreting study results . In contrast to earlier versions, the Rome IV criteria include patients with physiological acid exposure in the distal oesophagus and an abnormal SAP in the definition of functional heartburn .…”

“…A recent systematic review of pH impedance concluded that important clinical and technical shortcomings limit its diagnostic value and must be considered when interpreting study results. 29 In contrast to earlier versions, the Rome IV criteria include patients with physiological acid exposure in the distal oesophagus and an abnormal SAP in the definition of functional heartburn. 30 This modification to the Rome criteria needs validation, but it should be noted that the number of patients with physiological acid exposure and a positive symptom association probability in our study was too small to influence the results.…”