The Esophagiome: concept, status, and future perspectives

Impedance in the evaluation of the esophagus

The aim of this paper is to review esophageal electrical impedance technologies and to discuss the use of these technologies for physiological measurements, diagnostics, and therapy of esophageal disease. In order to develop a better understanding of the pathophysiology of and improve the diagnosis of esophageal disorders, such as gastroesophageal reflux disease (GERD) and achalasia, several new diagnostic tests, including intraluminal impedance, esophageal mucosal impedance, and the functional luminal imaging probe, have been developed. These technologies have proven valuable for assessment of the esophagus in recent years. They provide information on esophageal flow properties, mucosal integrity, lumen shape, and distensibility in esophageal disorders, in particular for GERD and achalasia. Despite their promise and novel clinical studies, the potential of these technologies has been far from realized. New multidisciplinary approaches will contribute to our understanding and interpretation of esophageal impedance data and disease mechanisms.

Theoretical tools to analyze anorectal mechanophysiological data generated by the Fecobionics device

A mechanical approach is needed for understanding anorectal function and defecation. Fecal continence is achieved by several interacting mechanisms including anatomical factors, anorectal sensation, rectal compliance, stool consistency, anal muscle strength, motility, and psychological factors. The balance is easily disturbed, resulting in symptoms such as fecal incontinence and constipation. Novel technologies have been developed in recent years for studying anorectal function. Especially the Fecobionics device, a simulated feces, has gained attention recently. This facilitates new analysis of anorectal mechanical function. In this study a theoretical model is developed to analyze anorectal mechanophysiological data generated by the Fecobionics device. Theoretical approaches can enhance future interdisciplinary research for unraveling defecatory function, sensory-motor disorders and symptoms. This is a step in the direction of personalized treatment for gastrointestinal disorders based on optimized subtyping of anorectal disorders.

What Is the Future of Impedance Planimetry in Gastroenterology?

The gastrointestinal (GI) tract is efficient in transporting ingested material to the site of delivery in healthy subjects. A fine balance exists between peristaltic forces, the mixing and delivery of the contents, and sensory signaling. This fine balance is easily disturbed by diseases. It is mandatory to understand the pathophysiology to enhance our understanding of GI disorders. The inaccessibility and complex nervous innervation, geometry and mechanical function of the GI tract make mechanosensory evaluation difficult. Impedance planimetry is a distension technology that assesses luminal geometry, mechanical properties including muscle dynamics, and processing of nociceptive signals from the GI tract. Since standardized models do not exist for GI muscle function in vivo, models, concepts, and terminology must be borrowed from other medical fields such as cardiac mechanophysiology. The review highlights the impedance planimetric technology, muscle dynamics assessment, and 3 applied technologies of impedance planimetry. These technologies are the multimodal probes that assesses sensory function, the functional luminal imaging probe that dynamically measures the geometry of the lumen it distends, and Fecobionics that is a simulated feces providing high-resolution measurements during defecation. The advanced muscle analysis and 3 applied technologies can enhance the quality of future interdisciplinary research for gaining more knowledge about mechanical function, sensory-motor disorders, and symptoms. This is a step in the direction of individualized treatment for GI disorders based on diagnostic subtyping. There seems to be no better alternatives to impedance planimetry, but only the functional luminal imaging probe is currently commercially available. Wider use depends on commercialization of the multimodal probe and Fecobionics.