Role of the Rapid Drink Challenge Test in Esophageal Motility Disorder Diagnosis

[Diagnosis of Dysphagia: High Resolution Manometry & EndoFLIP]

Esophageal motility disorders were re-defined when high-resolution manometry was employed to better understand their pathogenesis. Newly developed parameters including integrated relaxation pressure (IRP), distal contractile integral, and distal latency showed better diagnostic yield compared with previously used conventional parameters. Therefore, Chicago classification was formulated, and its diagnostic cascade begins by assessing the IRP value. However, IRP showed limitation due to its inconsistency, and other studies have tried to overcome this. Recent studies showed that provocative tests, supplementing the conventional esophageal manometry protocol, have improved the diagnostic yield of the esophageal motility disorders. Therefore, position change from supine to upright, solid or semi-solid swallowing, multiple rapid swallows, and the rapid drink challenge were newly added to the manometry protocol in the revised Chicago classification version 4.0. Impedance planimetry enables measurement of bag cross-sectional area at various locations. The functional lumen imaging probe (FLIP) has been applied to assess luminal distensibility. This probe can also measure pressure, serial cross-sectional areas, and tension-strain relationship. The esophagogastric junction's distensibility is decreased in achalasia. Therefore, EndoFLIP can be used to assess contractility and distensibility of the esophagus in the patients with achalasia, including repetitive antegrade or retrograde contractions. EndoFLIP can detect achalasia patients with relatively low IRP, which was difficult to diagnose using the current high-resolution manometry. EndoFLIP also provides information on the contractile activity and distensibility of the esophageal body in patients with achalasia. The use of provocative tests, newly added in Chicago classification 4.0 version, and EndoFLIP can expand understanding of esophageal motility disorders.

The Challenges of Esaphagogastric Junction Outflow Obstruction, Is It Really a Diagnosis? Creating a Systematic Clinical Approach for EGJOO

Esophagogastric junction outflow obstruction (EGJOO) is currently diagnosed according to the Chicago Classification V3 by an elevated median integrated relaxation pressure on high resolution manometry. However, EGJOO may not be an accurate diagnosis, as it may be based on abnormal IRP from an artifact, affected by narcotics, an achalasia variant, or a mechanical cause of obstruction. This heterogenous diagnosis can often lead to unnecessary testing and treatment. The purpose of this study is to develop a stepwise clinical management protocol on how to evaluate EGJOO. Motility studies were reviewed for the last 2 years and 39 patients were diagnosed with EGJOO. Clinical information was reviewed, and patients were classified into six stepwise categories to explain an elevated IRP resulting in EGJOO diagnosis: (1) underlying catheter artifact (2) opioid use (3) achalasia variant (4) jackhammer esophagus with obstruction (5) missed esophageal lesion (ex. Schatzki ring, EOE) and (6) extrinsic compression. 40% (n = 14) of patients with elevated IRP were due to an underlying catheter artifact. 8.6% (n = 3) were due to opioid use. 8.6% (n = 3) were due to achalasia variant. 31.4% (n = 11) were due to jackhammer esophagus with obstruction. 5.7% (n = 2) were due to missed esophageal lesion. 5.7% (n = 2) were due to external compression by cardiomegaly and aortic aneurism. EGJOO is not a diagnostic end point, but a heterogenous category with multiple underlying etiologies. We believe the use of a stepwise approach to these patients can help avoid further unnecessary testing.