Mobility of the upper esophageal sphincter in relation to the cervical spine: a morphologic study.

If the posterior part of the upper esophageal sphincter (UES) were to lag behind due to the presence of dense tissue strands between the sphincter and the prevertebral ligament, as suggested in the literature, it would be impossible to use the larynx as a radiographic indicator of the location of the UES at intraluminal pressure measurements. The goal of this investigation was to study UES behavior during induced movements in autopsy specimens and to search for dense fibrous strands between the UES and the prevertebral fascia. Histologic studies of frozen sections and paraffin sections showed a loose fatty tissue in the prevertebral space. There were no dense connective tissue strands. Autopsy specimens were used in experiments mimicking the laryngeal/UES elevation during swallowing. The results of this study indicate that the larynx and the UES move as one entity. When one is attempting to register the UES movement during swallowing, the laryngeal skeleton can therefore serve as a radiographic indicator of the UES movements.