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Updated: Jul 31, 2026

Coordinate Mapping of Hyolaryngeal Mechanics in Swallowing
Published on: May 6, 2014
Relationship between bolus transit and LES-relaxation studied with concurrent impedance and manometry
H N Nguyen1, G R Domingues, R Winograd
1Department of Medicine, Division of Gastroenterology and Helmholtz Institute of Biomedical Engineering University of Technology RWTH-Aachen, Germany. huan.nguyen@SK-MG.de
Lower esophageal sphincter (LES) relaxation during swallowing is primarily triggered by the arrival of the food bolus in the distal esophagus, influencing esophageal transit.
Area of Science:
- Gastroenterology
- Physiology
- Swallowing Mechanics
Background:
- Neuromuscular mechanisms of esophageal bolus transport are established.
- Limited data exist on the interplay between lower esophageal sphincter (LES) relaxation and bolus transit during standard motility tests.
Purpose of the Study:
- To investigate the temporal relationship between esophageal bolus transit and lower esophageal sphincter (LES) relaxation.
- To analyze how bolus presence influences LES relaxation patterns.
Main Methods:
- Simultaneous recording of esophageal bolus transit and LES pressure using integrated impedancometry and manometry.
- Studies conducted on 25 healthy subjects swallowing saline or yogurt.
Main Results:
- Lower esophageal sphincter (LES) relaxation often occurred after upper esophageal sphincter (UES) relaxation.
- LES relaxation predominantly occurred during bolus transit (76% of swallows).
- In most cases where LES relaxation occurred during transit, the bolus was near the LES.
Conclusions:
- Lower esophageal sphincter (LES) relaxation appears to be modulated by the presence of an esophageal bolus.
- LES relaxation is primarily initiated upon the bolus reaching the distal esophagus.
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