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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
Background/Aims:
Neuromuscular mechanisms regulating esophageal bolus transport are well studied. However, detailed data about the relationship between bolus transit and lower esophageal sphincter (LES)-relaxation during conventional motility testing are still lacking.
Methodology:
We performed systematic studies in 25 normal subjects, employing a catheter that integrates the two techniques impedancometry and manometry in a single instrument for simultaneous recording and analysis of the relationship between bolus transit and LES relaxation after swallowing saline or yogurt.
Results:
195 swallows were analyzed. LES relaxation occurred frequently later than UES relaxation. The mean latency between bolus entry into the esophagus and LES relaxation was 3.6 +0.2 sec. Two types of swallow-induced LES relaxation were observed: (a) LES relaxation preceding bolus transit (46 cases or 24%) and (b) LES relaxation occurring during bolus transit (149 cases or 76%). In the later case, during 114 (76%) cases of this deglutition, the position of the bolus was very close to the LES.
Conclusions:
During deglutition, LES relaxation seems to be modulated by bolus transit and occurs predominantly upon arrival of the bolus in the distal esophagus.
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