Three‐dimensional manometry of the upper esophageal sphincter in swallowing and nonswallowing tasks

OBJECTIVES/HYPOTHESIS High-resolution manometry (HRM) is useful in identifying disordered swallowing patterns and quantifying pharyngeal and upper esophageal sphincter (UES) physiology. HRM is limited by unidirectional sensors and circumferential averaging of pressures, resulting in an imperfect understanding of pressure from asymmetrical pharyngeal anatomy. This study aims to evaluate UES pressures simultaneously from different axial directions. STUDY DESIGN Case series. METHODS Three-dimensional HRM was performed on eight healthy subjects to evaluate circumferential UES pressure patterns at rest, during the Valsalva maneuver, and during water swallowing. RESULTS Multivariate analysis of the variance revealed a significant main effect of circumferential direction on pressure while at rest (P < .001); pressure was greater in the anterior and posterior portions of the UES versus lateral portions. A significant main effect of direction on pressure was not found during the Valsalva maneuver. During swallowing of a 5-mL water bolus, circumferential direction had a significant main effect on pressure immediately before UES pressure dropped (P = .001), while the UES was open (P = .01) and at UES closure (P < .001). There was also a significant main effect of sensor level along the vertical axis on pressure immediately before UES pressure dropped (P = .032) and at UES closure (P < .001). Anterior and posterior pressures were again greater than lateral pressures at all swallowing events. CONCLUSIONS These results confirm that UES pressures vary significantly based on their circumferential origin, with the majority of the total pressure generated in anterior and posterior regions. Improved understanding of UES pressure in a three-dimensional space can lead to more sophisticated treatments for pharyngeal and UES dysfunction. LEVEL OF EVIDENCE 4. Laryngoscope, 126:2539-2545, 2016.