Biomechanical assessment of the esophagogastric junction and application of predictive analytics to enhance evaluation of functional dysphagia

Dysphagia is a commonly encountered symptom that accounts for more than one million outpatient visits per year.1 If a mechanical esophageal obstruction is not identified on endoscopy, an evaluation of esophageal motility with manometry is recommended.6 However, in more than 75% of patients evaluated with high-resolution manometry (HRM), a major esophageal motility disorder (such as achalasia) is not detected and an etiology for patients’ symptoms is not identified.7, 8 This often leads to a diagnosis of functional dysphagia.8 Clinical management of functional dysphagia can be challenging as mechanisms for symptom generation are poorly understood and therapeutic strategies are varied with inconsistent effectiveness. However, we hypothesize that ‘functional dysphagia’ may actually include a cohort with abnormalities in function that are not detected by the standard evaluation. Thus, methods to improve clinical characterization, and subsequently direct targeted therapies, in functional dysphagia are needed.
A novel, FDA-approved and commercially-available device to evaluate esophageal motility is the functional luminal imaging probe (FLIP). The FLIP measures luminal diameters along the length of the esophagus in response to controlled distension. Distensive pressure is also measured which provides assessment of distensibility, i.e. the relationship of pressure and luminal dimensions. By shifting the focus from esophageal pressures as assessed with HRM to esophageal diameters and distensibility, FLIP provides a method to complement (or improve upon) the esophageal motility evaluation. Further, FLIP evaluates a novel property of esophageal function, the response to distension, which may have important consequences related to esophageal bolus clearance and symptom generation.
Our lab developed a novel analysis paradigm (FLIP panometry) that simultaneously assesses esophagogastric junction (EGJ) opening and distension-induced esophageal contractility akin to esophageal motility.2, 4, 5 We found that FLIP panometry could effectively identify patients with major esophageal motility disorders characterized by EGJ outflow obstruction, especially achalasia.2 Further, among patients with normal HRM, i.e. functional dysphagia, we identified abnormalities in EGJ distensibility in 41% (12/29) with FLIP panometry. These findings strongly suggest that FLIP panometry may improve diagnostic yield by detecting abnormalities not appreciated with standard testing procedures during the dysphagia evaluation.2
While promising, the functional consequences related to abnormalities in EGJ distensibility among patients with functional dysphagia require further investigation. Additionally, evaluation of EGJ distensibility may aid identification of distinct clinical phenotypes within the cohort defined as functional in the Rome Classification (IV) with potential management and outcome implications.