[Physiology of the upper esophageal sphincter]

Influence of Acid Swallows on the Dynamics of the Upper Esophageal Sphincter

Mechanisms of the upper esophageal sphincter (UES) when exposed to acid are still incompletely understood. The presented work investigated the reaction of the UES to acid exposure during swallowing. Ten healthy individuals swallowed ten 2 ml neutral water boli of pH 7, followed by 10 swallows each of different levels of acidity (pH 1.8, pH 3 and pH 5). Effects were analyzed by high-resolution manometry (HRM) for the primary parameter Restitution Time, as well as Resting Pressures, maximal, minimal pressures and time intervals. Restitution Times measured mean values of 12.67 s (SD ± 7.03 s) for pH 1.8, pH 7 = 8.69 s (SD ± 2.72 s), pH 3 = 7.56 s (SD ± 2.23 s) and pH 5 = 7.29 s (SD ± 2.55 s), showing prolonged Restitution Times in the UES when exposed to strong bolus acidity. This difference was significant towards the neutral bolus, but also to less acidic boli (pH 5: p = 0.006, pH 3: p = 0.009, pH 7: p = 0.038). Considerable differences of mean values were found for Post-Swallow Maximum and Period of Sphincter Activity. Also, Pre-Swallow Maximum values were found to be highest with the strongest acid. Relaxation Times showed a slight trend of prolongation for the highest bolus acidity. Prolonged Restitution Times may represent a reflexive protective mechanism triggered by receptors in the pharyngeal mucosa or the UES preventing regurgitation of acid into the pharynx and larynx, besides representing ongoing attempts of acid clearance. Exposure to high levels of acidity by a swallowed bolus does influence UES functions during swallowing.

Potential for Volitional Control of Resting Pressure at the Upper Oesophageal Sphincter in Healthy Individuals

Resting pressure at the upper oesophageal sphincter (UOS) has been reported to be susceptible to factors such as emotional stress or respiration. This exploratory study investigated the potential for behavioural modulation of UOS resting pressure in healthy adults to increase our understanding of volitional control of UOS pressure, and the potential development of rehabilitation approaches. Six healthy adults were seen one hour daily for two weeks (10 days) and for one post-training session after a training break of two weeks. Manipulation of UOS resting pressure was practised during a protocol of alternating increased and decreased pressure. A high-resolution manometry contour plot was used as a biofeedback modality. Participants were asked to explore how to achieve warmer and cooler colours (pressure increase and decrease, respectively) at the UOS resting pressure band, without changing head position or manipulating activity of other muscles. Performance was analysed prior to training start and following daily training. Participants were able to increase resting pressure following one week of practice; however, there was no evidence for purposeful pressure decrease. The increased resting pressure achieved by participants indicates a capacity for purposeful pressure modulation given intensive biofeedback training. The lack of volitional reduction in pressure may be explained by sustained pressure generation due to the intrinsic muscular characteristics of the UOS and a flooring effect in healthy subjects, in whom physiology mandates a minimum degree of resting pressure to fulfil the barrier function. Distention caused by the presence of the intraluminal catheter cannot be ruled out.

[High-resolution manometry of pharyngeal swallowing dynamics]

BACKGROUND

To transport a bolus from the mouth into the stomach, regular contraction of the pharyngeal muscles and a coordinated function of the upper esophageal sphincter (UES) are necessary. The muscle contraction generates intraluminal pressure, which pushes the bolus continuously forward. In contrast to imaging studies, manometric methods enable assessment of intraluminal pressure buildup and the function of the muscles involved. These methods were initially established for the esophagus and have been used increasingly in the pharynx for 7-8 years. Pharyngeal high-resolution manometry (pHRM) allows pressure measurements in high spatial and temporal resolution, and assessment of pharyngeal swallowing dynamics.

OBJECTIVE

An overview is given of the implementation, evaluation, and interpretation of the pHRM data, as well as of the current state of research.

MATERIALS AND METHODS

PubMed and Scopus were searched for the keywords "high-resolution manometry" and "pharynx" or "upper esophageal sphincter". Original articles, reviews, and book chapters on the subject pHRM were included.

RESULTS

Swallowing pressure conditions in the pharynx and the UES can be assessed by pHRM. The spatiotemporal pressure plot gives an overview of changes in pharyngeal motor function. Determination of swallowing parameters enables a sophisticated evaluation of swallowing; a comparison with normal values permits delimitation of pathologies.

CONCLUSION

Although several swallowing parameters still need to be further evaluated for clinical routine, a pHRM study should nowadays always be carried out for a comprehensive evaluation of the swallowing process.

[High resolution manometry study of pharyngeal function in patients with myotonic dystrophy]

BACKGROUND

Patients with myotonic dystrophy (MD) are known to suffer from oropharyngeal dysphagia and esophageal motility disorders, which are often the cause of aspiration pneumonia. So far only little is known about the pharyngeal contractility and the function of the upper esophageal sphincter in these patients, in particular only few data are available for manometric investigations allowing assessment of the pharyngeal pressure build-up during swallowing. The aim of this study was to collect such data in patients with MD using high resolution manometry.

METHOD

In two patients with MD high resolution manometry studies were performed during swallowing and phonation to determine pressure-dependent parameters. The results were compared with normal values from healthy subjects.

RESULTS

In both patients a reduced pressure in the entire pharynx during swallowing was determined. The duration of the contraction in the velopharynx and tongue base region was shortened. The structural course of the swallowing process and the opening and closing functions of the upper esophageal sphincter were regular. During realization of closed vowels a reduced pressure build-up in the velopharyngeal region was observed.

CONCLUSION

The force of contraction and the associated pharyngeal pressure build-up during swallowing were reduced resulting in an incomplete clearing of the pharynx. Beside myopathic disorders, neuromuscular disorders also have to be considered. The functional course of the swallowing process and the swallowing pattern was retained. The reduced pressure build-up in the velopharyngeal region can be considered as the cause for rhinophonia. To evaluate the pharyngeal function in patients with MD, high resolution manometry is a useful tool for assessing the pharyngeal function besides the basic diagnostics.

Position paper of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery and the German Society of Phoniatrics and Pediatric Audiology - Current state of clinical and endoscopic diagnostics, evaluation, and therapy of swallowing disorders in children

Swallowing disorders are frequent. The main concern is mortality due to aspiration-induced pneumonia and malnutrition. In addition, quality of life is severely affected. The demographic trend indicates an increase of dysphagia in the future. Neurodegenerative diseases, tumors of the digestive tract, and sequelae of tumor treatment in the head and neck region are the main pathologic entities.

Predominantly ENT physicians and phoniatricians are asked for diagnostics and therapy, and will coordinate the interdisciplinary treatment according to the endoscopic findings.

A differentiated approach in history, diagnostics, and symptom-oriented treatment is necessary for these mostly complex disorders. Integration of non-medical staff such as speech therapists, physiotherapists, and occupational therapists in planning and executing an effective therapy expands and completes the patient-oriented care. Conservative treatment by these therapists is an important pillar in the treatment. Parts of the specific diagnostics can be taken over in close cooperation.

In particular, an interdisciplinary cooperation with the staff of intensive care medicine is essential.

The diagnostic procedures of specific endoscopy as described in this position paper are part of the primary and fundamental tasks of ENT specialists and phoniatrists.

Endoscopy is a medical service that is basically not delegable. Consequently, substitution of the physician is excluded.

[Importance of cellular tight junction complexes in the development of periprosthetic leakage after prosthetic voice rehabilitation]

BACKGROUND

The use of voice prostheses is currently the gold standard in voice rehabilitation after total laryngectomy. This method combines low complication rates and excellent rehabilitation results; however, approximately 30% of patients show periprosthetic leakage or severe fistula enlargement after laryngectomy and prosthetic voice restoration within the first 4 years. The development of this enlargement is controversially discussed in the literature but recently published studies have shown that high esophageal reflux plays a key role in this process, which leads to an inflammatory reaction and disturbs the intercellular tight junctions in the sense of an epithelial mesenchymal transition (EMT).

MATERIAL AND METHODS

A total of 44 patients underwent 24 h pH monitoring, a sample biopsy from the region of the fistula and a subsequent biomolecular examination for intracellular junction proteins as well as a correlation between the severity of reflux and tracheoesophageal fistula problems before and after antireflux therapy with proton pump inhibitors (PPI).

RESULTS

Immunohistochemical staining revealed decreases in membrane E-cadherin and β-catenin and a significant increase in the cytoplasmic fraction, depending on the severity of inflammation in the fistula tissue. In patients with an improvement of clinical fistula problems under oral PPI treatment an increase of membrane E-cadherin could be shown, whereas patients with persisting fistula enlargement demonstrated a further decrease of E-cadherin.

CONCLUSION

The data indicate a central role of EMT in the development of fistula enlargement after total laryngectomy. Patients with periprosthetic leakage showed a loss of membrane bound E-cadherin and β-catenin with an up-regulation of vimentin expression. In patients with mild or no leakage problems EMT could be resolved by aggressive antireflux treatment, whereas patients without any effect of PPI treatment on the fistula showed no reversal of EMT. These data contribute to the understanding of treatment resistant fistula enlargement after total laryngectomy.

[Position paper of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery and the German Society of Phoniatrics and Pediatric Audiology - current state of clinical and endoscopic diagnostics, evaluation, and therapy of swallowing disorders in children and adults]

Position Paper of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery and the German Society of Phoniatrics and Pediatric Audiology - Current State of Clinical and Endoscopic Diagnostics, Evaluation, and Therapy of Swallowing Disorders in Children and AdultsSwallowing disorders are frequent. The main concern is mortality due to aspiration induced pneumonia and malnutrition. On the other hand quality of life is severely affected. The demographic trend indicates an increase of dysphagia in the future. Neurodegenerative diseases, tumors of the digestive tract and sequelae of tumor treatment in the head and neck region are the main pathologic entities.Predominantly ENT physicians and phoniatrists, are asked for diagnostics and therapy who will coordinate the interdisciplinary treatment according to the endoscopic findings.A differentiated approach in history, diagnostics, and symptom oriented treatment is necessary for the mostly complex disorders. The integration of non-medical personnel such as logopeds (speech language pathologists), physiotherapists, and occupational therapists in planning and executing an effective therapy expands and completes the patient-oriented care. Conservative treatment by these therapists is an important pillar in the treatment. Parts of the specific diagnostics can be taken over by them in close cooperation.In particular an interdisciplinary cooperation with the staff from intensive care medicine is indispensable.The diagnostic procedures of specific endoscopy as described in this position paper are part of the primary and fundamental tasks of ENT specialists and phoniatrists.Endoscopy is a medical service that is basically not delegable. Consequently substitution of the physician is precluded.

[Anatomy of the upper esophageal sphincter]

The upper esophageal sphincter (UES) forms a barrier between the pharynx and the esophagus. When closed, the barrier function serves to prevent reflux and aerophagia; when open, swallowing, belching and vomiting are possible. The closing muscles include caudal parts of the inferior pharyngeal sphincter and cranial parts of the upper esophagus musculature. Sphincter opening is achieved by muscles that insert from the outside to connect to the larynx and pharynx in the sphincter region. The closing muscles are innervated by branches of the glossopharyngeal and vagal nerves, and central control is probably mediated by several reflexes. This article presents an overview of the current understanding of the complex UES anatomy.