Four-dimensional impedance manometry volume metrics for predicting abnormal bolus retention

Area of Science:

• Gastroenterology
• Esophageal Physiology
• Diagnostic Imaging

Background:

• High-resolution manometry (HRM) requires objective metrics for esophageal bolus volume and clearance.
• Current Chicago classification may be enhanced by novel objective measurements.
• Four-dimensional impedance manometry (4D HRM) offers potential for improved esophageal motility assessment.

Purpose of the Study:

• To compare novel 4D HRM volume metrics with timed barium esophagram (TBE).
• To evaluate the utility of 4D HRM in objectively measuring esophageal bolus transport.
• To determine if 4D HRM metrics can classify esophageal motility abnormalities.

Main Methods:

• Adult patients with esophageal symptoms undergoing HRM and TBE were enrolled.
• A custom program analyzed 4D HRM impedance data to derive esophageal bolus volume and clearance.
• Key 4D HRM metrics included residual volume, maximal volume, retention volume, and clearance ratio.

Main Results:

• The clearance ratio demonstrated the highest accuracy (AUROC 0.89) in predicting abnormal TBE at 5 minutes.
• A strong negative correlation (r = -0.65) was observed between the clearance ratio and TBE retention at 5 minutes.
• 95 patients were analyzed, with varying esophageal motility diagnoses and TBE outcomes.

Conclusions:

• Novel 4D HRM volume metrics provide objective esophageal bolus volume and clearance data.
• The clearance ratio strongly correlates with TBE, suggesting it as a potential TBE substitute.
• 4D HRM offers a promising non-invasive method for assessing esophageal bolus retention.