Intrabolus pressure gradient identifies pathological constriction in the upper esophageal sphincter during flow

Area of Science:

• Gastroenterology
• Physiology
• Medical Imaging

Background:

• Bolus transport through the upper esophageal sphincter (UES) relies on pressure gradients overcoming frictional forces.
• Abnormal UES constriction can impede bolus passage, leading to dysphagia.
• Understanding the pressure dynamics within a bolus is crucial for diagnosing swallowing disorders.

Purpose of the Study:

• To quantify space-time patterns of intrabolus pressure (IBP) and intrabolus pressure gradient (IBPG).
• To correlate these pressure patterns with pathological disruptions in transsphincteric bolus transport.
• To identify how abnormal UES constriction affects bolus propulsion dynamics.

Main Methods:

• Employed high-resolution, high-fidelity perfused manometry alongside videofluoroscopy.
• Recruited 6 healthy controls and 10 patients with UES opening restrictions.
• Analyzed data across 4 different bolus volumes, interpolating pressures spatially to create space-time isocontours.

Main Results:

• Patients with UES restriction exhibited significantly higher average hypopharyngeal IBP and locally maximal IBPG compared to controls (P < 0.001).
• Maximum IBPG was not significantly affected by bolus volume.
• The location of maximal IBPG in patients strongly correlated with the site of maximal UES constriction (r = 0.84, P < 0.01).

Conclusions:

• IBPG serves as a sensitive indicator of localized frictional resistance caused by pathological UES constriction.
• The magnitude and location of IBPG effectively pinpoint abnormal constrictions during bolus transit.
• Space-time IBP and IBPG patterns provide insights into the decompensation of the pharyngeal swallow mechanism.