A human model of restricted upper esophageal sphincter opening and its pharyngeal and UES deglutitive pressure phenomena

Abstract

Oropharyngeal dysphagia due to upper esophageal sphincter (UES) dysfunction is commonly encountered in the clinical setting. Selective experimental perturbation of various components of the deglutitive apparatus can provide an opportunity to improve our understanding of the swallowing physiology and pathophysiology. The aim is to characterize the pharyngeal and UES deglutitive pressure phenomena in an experimentally induced restriction of UES opening in humans. We studied 14 volunteers without any dysphagic symptoms (7 men, 66 ± 11 yr) but with various supraesophageal reflux symptoms. To induce UES restriction, we used a handmade device that with adjustment could selectively apply 0, 20, 30, or 40 mmHg pressure perpendicularly to the cricoid cartilage. Deglutitive pharyngeal and UES pressure phenomena were determined during dry and 5- and 10-ml water swallows × 3 for each of the UES perturbations. External cricoid pressure against the UES resulted in a significant increase in hypopharyngeal intrabolus pressure and UES nadir deglutitive relaxation pressure for all tested swallowed volumes (P < 0.05). Application of external cricoid pressure increased the length of the UES high pressure zone from 2.5 ± 0.2 to 3.1 ± 0.2, 3.5 ± 0.1, and 3.7 ± 0.1 cm for 20, 30, and 40 mmHg cricoid pressure, respectively (P < 0.05). External cricoid pressure had no significant effect on pharyngeal peristalsis. On the other hand, irrespective of external cricoid pressure deglutitive velopharyngeal contractile integral progressively increased with increased swallowed volumes (P < 0.05). In conclusion, acute experimental restriction of UES opening by external cricoid pressure manifests the pressure characteristics of increased resistance to UES transsphincteric flow observed clinically without affecting the pharyngeal peristaltic contractile function.

Characterization of swallow modulation in response to bolus volume in healthy subjects accounting for catheter diameter

“…[5][6][7]26 Larger volumes elicit stronger lingual propulsive forces, which initiate a swallow adapted to accommodate that bolus size. 8,26 The effect of bolus volume on the occlusive pressure between velopharynx and tongue base previously reported by others 27 were clearly observed in this study ( Fig. 2A).…”

“…Thus, our potential to measure volume‐related contractile pressure differences in this region may be compromised. Studies investigating the symmetry of deglutitive pharyngeal and UES pressures using state‐of‐the‐art three‐dimensional high‐resolution impedance manometry catheters have recently been published . Although it could be argued that circumferential sensors are optimal for pharyngeal manometry the provision of circumferentially averaged results for each sensor is not necessarily akin to obtaining multiple separate, radially orientated readings .…”

Characterization of pharyngeal peristaltic pressure variability during volitional swallowing in healthy individuals

“…All these are complimented by the contraction of pharyngeal longitudinal muscles contributing to pharyngeal shortening along with contraction of extrapharyngeal suprahyoid muscles. 13,16 Each of these muscle groups may be uniquely amenable to and demonstrate a unique response to a given intervention as has been shown in the case of velopharyngeal muscle group exhibiting increased pressure with swallowing of larger water volumes, 8 a response not reported for the rest of the pharynx.…”

Upper esophageal sphincter augmentation reduces pharyngeal reflux in nasogastric tube–fed patients

“…It is conceivable that increasing the assist pressure level will further reduce the trans‐sphincteric reflux. Earlier studies have shown that assist pressures as high as 40 mm Hg are well tolerated. Therefore, the effect of assist device pressures exceeding 20 to 30 mm Hg merits further investigation.…”

“…In this study, we determined the effect of experimental enhancement of the UES pressure barrier on trans‐sphincteric retrograde flow of gastric refluxate. To enhance the UES pressure, we used an externally applied handmade device that compressed the UES between the cricoid cartilage and the spine in a controlled fashion delivering a constant pressure of 20 to 30 mm Hg . To monitor the intraesophageal and trans‐UES refluxate flow, we used a multisite impedance monitoring technique.…”