Nasal backflow and the difficulty of relaxation in the upper esophageal sphincter

Abstract

Objectives/Hypothesis: Nasal backflow is the regurgitation of material into nasopharynx during swallowing and it can be easily observed by videofluoroscopy. We aimed to evaluate the association between nasal backflow and the prevalence of aspiration, as well as the relationship between nasal backflow and the opening of the upper esophageal sphincter.Study Design: Retrospective case-control study.Methods: There were 182 cases of videofluoroscopic swallowing studies that were retrospectively reviewed. The presence of nasal backflow and laryngeal aspirations were checked, and the anteroposterior maximum width of the upper esophageal sphincter opening was measured on lateral images of videofluoroscopic swallowing studies. The difference in maximum upper esophageal sphincter width between the group with nasal backflow and the group without nasal backflow was statistically verified.Results: Twenty patients showed nasal backflow, which was closely related to laryngeal aspiration (odds ratio ¼ 10.97; 95% CI ¼ 2.46-48.85; P < 0.05). Their maximal upper esophageal sphincter width (mean 6 standard deviation) was 6.82 6 1.96 mm and significantly different from the group without nasal backflow (9.35 6 1.56 mm) (P < 0.05).Conclusion: Nasal backflow was closely associated with the presence of aspiration; the opening of upper esophageal sphincters significantly decreased in the cases of nasal backflow.

The Effects of Imidapril Hydrochloride on Aspiration and Velopharyngeal Regurgitation

“…Park JW, et al reported that velopharyngeal regurgitation is closely related to aspiration and that impaired upper esophageal sphincter relaxation is associated with velopharyngeal regurgitation combined with normal velopharyngeal function [7]. Thus, in our subjects the ACE inhibitor might have ameliorated the discoordination of the initiation of the esophageal phase, which should follow the pharyngeal phase of swallowing.…”

“…Angiotensin-Converting Enzyme (ACE) inhibitors are known to prevent aspiration [3,4], especially in Asian populations [5], and their suggested mechanism of action involves the promotion of the release of substance P from the glossopharyngeal and vagal nerves, resulting in an improvement in impaired swallowing processes and the cough reflex [2,5,6]. The patients with aspiration often suffer from velopharyngeal regurgitation; i.e., the reflux of oral contents into the nasopharyngeal space, during food intake [7]. We experienced cases in which velopharyngeal regurgitation and aspiration were both improved by the administration of imidapril hydrochloride (an ACE inhibitor).…”

Location of the upper oesophageal sphincter during swallowing: Analysis using swallowing CT

“…Several anatomical landmarks have been used as UES proxies, but not consistently between studies. Landmarks include the trachea (15-20 mm below the top of the tracheal air column 5 ), vocal folds (10-20 mm inferior to the vocal folds [6][7][8][9] ), and the cervical vertebrae (the narrowest region between C3 and C6 [10][11][12][13][14][15] or C4-C6 [16][17][18][19][20] ).…”