Three-dimensional analysis of the human pharyngoesophageal sphincter

Safety of a Novel Upper Esophageal Sphincter Balloon Dilator

OBJECTIVE

The shape of esophageal dilators has not changed in over 350 years. Clinical and animal research suggests that the upper esophageal sphincter (UES) is not round but approximates a kidney shape and that cylindrical dilators may be suboptimal. The Infinity UES Dilation System has been developed specifically for the anatomic configuration of the UES. This study evaluates the safety of the UES-specific Infinity Dilation System.

METHODS

All patients undergoing dilation of the UES between January 1, 2022 and September 1, 2023 were included. Demographics, procedure indication, dilator type, minor adverse events, and major complications were abstracted. Minor adverse events, complications, and maximum dilation dimension (mm) were compared between groups.

RESULTS

A total of 477 patients were included. Eight hundred and seventy-three total UES dilations were performed. The primary indications for UES dilation were cricopharyngeus muscle dysfunction (43%) and stenosis from radiation toxicity (40%). Twenty-three percent (202/873) of dilations were performed with an Infinity balloon, 31% (270/873) were performed using two conventional balloons placed side by side, and 46% (401/873) were performed with one singleton conventional balloon. The average maximum dilation dimension was 33 (±4.7) mm for Infinity balloons, 32 (±3.8) mm for two side-by-side balloons, and 18 (±3.4) mm for singleton balloons. There were three major complications with conventional balloons and none with Infinity balloons. There were no significant differences in minor adverse events between groups.

CONCLUSIONS

A UES-specific esophageal dilator provides a greater maximum dilation dimension and appears to be at least as safe as dilation with a single cylindrical balloon designed to dilate the esophagus.

LEVEL OF EVIDENCE

3 Laryngoscope, 135:66-72, 2025.

The Manometric Representation of the Upper Esophageal Sphincter During the Resting State: A Descriptive Study

The upper esophageal sphincter (UES) is the high-pressure zone marking the transition between the hypopharynx and esophagus. There is limited research surrounding the resting UES using pharyngeal high-resolution manometry (HRM) and existing normative data varies widely. This study describes the manometric representation of the resting UES using a clinically accessible method of measurement. Data were obtained from 87 subjects in a normative database of pharyngeal HRM with simultaneous videofluoroscopy. The resting UES manometric region was identified and ten measurement segments of this region were taken throughout the duration of the study using the Smart Mouse function within the manometry software. Intraclass correlation coefficients (ICC) were used to analyze within-subject reliability across measurements. Linear mixed-effects regression models were used to analyze how subject characteristics and manometric conditions influence resting UES pressure. There was excellent within-subject reliability between resting UES mean pressures (ICC = 0.96). In bivariate analysis, there were significant effects of age, number of sensors contained within the resting UES, and preceding swallow volume on mean resting UES pressure. For every 1 unit increase in age, there was a 0.19 unit decrease in resting UES pressure (p = 0.008). For every 1 unit increase in number of sensors contained within the resting UES, there was a 3.71 unit increase in resting UES pressure (p < 0.001). This study presents normative data for the resting UES, using a comprehensive and clinically accessible protocol that can provide standard comparison for the study of populations with swallowing disorders, particularly UES dysfunction, and provides support for UES-directed interventions.

Correlating Dysphagia Severity with Fluoroscopic Parameters in Patients with Zenker's Diverticulum

Zenker's diverticulum (ZD) is an uncommon condition characterized by formation of a pseudodiverticulum in the hypopharynx that presents with considerable variability in swallowing symptomatology. Identifying radiographic features of ZD most associated with clinical impact could prove useful in counseling patients and predicting treatment response. This study was a retrospective case series of patients undergoing videofluoroscopic swallowing studies (VFSS) for Zenker's diverticulum at a tertiary dysphagia center. Anatomic parameters identified on VFSS of patients with ZD were correlated with subjective perception of swallowing using Eating Assessment Tool (EAT-10) scores. Upper esophageal sphincter (UES) opening at the point of maximal distention, area of diverticulum on the lateral view, height of the diverticulum, and entrance angle of the esophagus were measured. We identified 40 patients with ZD (52.5% male, mean age = 71.2 years). Narrow UES opening was significantly correlated with dysphagia severity (r = - 0.3445, p = 0.035). Largest area of diverticulum (r = 0.0188, p = 0.87), diverticulum height (r = 0.1435, p = 0.45), and esophageal entrance angle (r = 0.1677, p = 0.42) were not correlated with EAT-10 scores. Maximum UES opening size was predictive of severity of swallowing dysfunction in patients with ZD. Size of ZD and the angle of bolus entry in patients with ZD are not predictive of swallowing dysfunction. Understanding the predictors of swallowing dysfunction will assist in counseling patients on postoperative expectations.

An anatomical study of the anterior wall of the hypopharyngeal and the cervical esophageal junction

OBJECTIVE

The upper esophageal sphincter plays a significant role by forming a physical barrier at the junction of the hypopharynx and the cervical esophagus. As few studies have focused on the ventral aspect of this junction, the contribution of the anterior wall of the cervical esophagus to upper esophageal sphincter function remains unknown. The purpose of this study was to examine the muscle fibers' arrangement at the junction, especially of those forming its anterior wall.

METHODS

Thirteen specimens from 13 Japanese cadavers were analyzed. Six specimens were dissected macroscopically, while the remaining seven were examined histologically.

RESULTS

The outer longitudinal layer of the proximal esophagus was well-developed anterolaterally. The uppermost fibers of the inner circular layer of the esophagus ascended longitudinally. The anterolateral part of the outer longitudinal layer and the uppermost region of the inner circular layer were continuous with the median tendinous band, in turn reaching superior to the cricoid cartilage. Histological analysis showed that the tendinous band was also continuous with the superior part of the perichondrium of the cricoid cartilage and with the aponeurosis of the transverse and oblique arytenoids.

CONCLUSION

The well-developed anterolateral region of the outer longitudinal layer and the uppermost fibers of the inner circular layer were continuous with the median tendinous band, which reached superior to the cricoid cartilage. The contraction of the proximal esophagus may result in protrusion of the anteromedian esophageal wall into the lumen, thereby supporting the closure of the upper esophageal sphincter.