Four-Dimensional Impedance Manometry in Esophageal Motility Disorders

Area of Science:

• Gastroenterology
• Esophageal Physiology
• Diagnostic Imaging

Background:

• Four-dimensional high-resolution impedance manometry (4D HRM) utilizes impedance to assess esophageal luminal cross-sectional area and intrabolus pressure (IBP).
• Existing methods for evaluating esophagogastric junction (EGJ) opening can be limited in complex motility disorders.

Purpose of the Study:

• To determine if 4D HRM metrics can define abnormal EGJ opening in patients with Chicago Classification v4.0 esophageal motility disorders.
• To compare the diagnostic capabilities of 4D HRM with functional lumen imaging probe (FLIP) metrics for EGJ assessment.

Main Methods:

• Symptomatic adult patients undergoing both 4D HRM and FLIP were compared with asymptomatic controls.
• 4D HRM analysis involved custom software to measure IBP, maximum EGJ diameter, and distensibility index during supine swallows.
• 4D HRM metrics were directly compared with FLIP-derived EGJ metrics.

Main Results:

• Ninety patients with various esophageal motility disorders (including achalasia and EGJ outflow obstruction) and controls were analyzed.
• Higher IBP was observed in type II and III achalasia compared to controls and normal motility groups (P < 0.03).
• Significantly lower maximum EGJ diameter and distensibility index were found in EGJ outflow obstruction and achalasia groups compared to controls (P < 0.03).
• 4D HRM correctly identified normal EGJ opening in 84% and reduced opening in 74% of subjects assessed by FLIP.

Conclusions:

• 4D HRM metrics align with clinical expectations across diverse esophageal motility disorders and effectively define EGJ obstruction.
• 4D HRM shows potential for characterizing EGJ obstruction, particularly in challenging cases involving EGJ outflow obstruction or absent peristalsis.