Relationship between dysphagia, lower esophageal sphincter relaxation, and esophagogastric junction distensibility

Background It is debated whether high-resolution manometric (HRM) integrated relaxation pressure (IRP) or functional lumen imaging probe (FLIP) distensibility index (DI) is the superior measure of esophagogastric junction (EGJ) opening. We examined the relationship between the DI and IRP and assessed correlations with dysphagia symptoms in patients with achalasia and EGJ outflow obstruction (EGJOO). Methods Patients with achalasia and those with barium tablet retention at the EGJ were grouped as follows: Group 1:Achalasia (IRP >= 15 mmHg + complete absence of normal peristalsis); Group 2: Manometric +FLIP EGJOO (IRP >= 15 mmHg with some intact peristalsis + DI <= 2.8 mm(2)/mmHg); Group 3: Abnormal DI only (DI <= 2.8 mm(2)/mmHg + IRP <15 mmHg); and Group 4: Normal IRP and DI (IRP >= 15 mmHg + DI > 2.8 mm(2)/mmHg). Correlation between the DI, baseline lower esophageal sphincter pressure (BLESP), IRP, and dysphagia (Eckardt score) was assessed. Multivariable analysis was used to assess variables associated with dysphagia score >= 2. Key Results A total of 79 patients were included: Group 1 (n = 31), Group 2 (n = 33), Group 3 (n = 14), and Group 4 (n = 1). DI did not correlate with BLESP or IRP in the whole sample or subgroups. DI was the only variable associated with dysphagia score >= 2 (p = 0.006). DI < 1.25 mm(2)/mmHg had sensitivity of 87% and specificity of 52% (p = 0.0003) for dysphagia score >= 2. Conclusions & Inferences DI does not correlate with HRM EGJ measurements and is the metric with the strongest effect on dysphagia severity. The various biological elements that may cause restrictive EGJ function should be the subject of future studies.