Upper oesophageal sphincter yield pressure in normal subjects and in patients with gastro-oesophageal reflux

Management of cricopharyngeus muscle dysfunction

The cricopharyngeus muscle (CPM) is a key component of the upper esophageal sphincter (UES). In dysphagia, cricopharyngeus muscle dysfunction (CPD) refers to the muscle's failure to appropriately and completely relax or expand during deglutition. A variety of disease processes may cause CPD, and the resultant clinical manifestation is solid food or solid and liquid dysphagia. Several diagnostic tools are available for dysphagia clinicians to distinguish CPD from other causes of UES dysfunction. For CPD, accurate diagnosis is paramount for the recommendation of appropriate treatment. In appropriately selected patients, intervention at the CPM may yield significant improvement in dysphagia.

Flexible endoscopic and surgical management of Zenker's diverticulum

Zenker's diverticulum is an outpouching of the mucosa through the Killian's triangle. The etiology of Zenker's diverticulum is not well understood. It is thought to be due to the incoordination or incomplete relaxation of the cricopharyngeal muscle. Most patients are men who present with symptoms of dysphagia between the seventh and eighth decades of life. The diagnosis is made with a dynamic contrast swallowing study. Treatment options include open surgical diverticulectomy and diverticulopexy with myotomy or myotomy alone using flexible or rigid endoscopes. Rigid endoscopic treatment is currently the preferred initial choice for Zenker's diverticulum of any size. The flexible endoscopic technique is used when there is a high risk of general anesthesia, or neck extension is contraindicated. Some centers use flexible endoscopy as the initial treatment option. Due to a lack of prospective studies, the treatment choice should be tailored to the individual patient and local expertise.

Current concepts in the anatomy and origin of pharyngeal diverticula

The role of this paper is to present the current concepts in anatomy and etiopathogenesis of pharyngeal diverticula. Precise anatomical considerations highly emphasizing the weak anatomic areas which predispose the pouch formation are discussed. Focus exposed in details will also be given upon the structural and functional characteristics of the upper esophageal sphincter as well as to its physiological states, architecture and dynamic functions. A brief review of hystorical and current perspectives regarding the origin of pharyngeal diverticula has also been given. Special attention is given to the abnormal cricopharyngeal function in patients with pharyngeal pouches in the terms of altered UES compliance, importance of gastroesophageal reflux and histopathologic changes of cricopharyngeal muscle.

Cricopharyngeal spasm and Zenker's diverticulum

Cricopharyngeal spasm and Zenker's diverticulum represent disorders of the pharyngoesophageal junction for which a unifying theory of etiology has yet to be established. There is, however, a large body of evidence that supports an association with gastroesophageal reflux. Cricopharyngeal myotomy is the key to successful management of both disorders. Newer transoral endoscopic techniques of management have a lower overall morbidity than traditional open approaches in appropriately selected patients and are therefore gaining popularity as the preferred method of treatment.

[Electromanometry of the upper esophageal sphincter before and after esophageal perfusion with hydrochloric acid 0,1N. Experimental study in dog]

BACKGROUND

The responses of the upper esophageal sphincter to gastroesophageal reflux is controversial.

OBJECTIVE

Study the effect of upper esophageal sphincter to the esophageal acid perfusion.

METHODS

Thirty adult dogs of both sexes were studied, being submitted to esophageal electromanometry. The pull through technique and continuous infusion of the catheters with distilled water were employed. These exams allowed us to measure the pressure width (mm Hg) and the length (cm) of the upper esophageal sphincter in basal conditions (moment 1). After this first phase the animals were submitted to esophagic infusion, being then divided in three groups, according to the solution used in the infusion and the moment of the study, as follows: Group 1: esophagic infusion with distilled water and electromanometric studies accomplished 15 minutes (moment 2) and 30 minutes (moment 3) of the end of the infusion. Group 2: esophagic infusion with HCl 0.1 N and electromanometric studies accomplished 15 minutes after the end of the infusion (moment 2). Group 3: esophagic infusion with HCl 0.1 N and electromanometric studies accomplished 30 minutes after the end of the infusion (moment 3).

RESULTS/CONCLUSIONS

This research was performed to evaluate the esophagic acidification influence on the upper esophageal sphincter. The observed results allowed us to conclude that the acidification of the esophagus did not cause any alteration on the pressure width and on the length of the upper esophageal sphincter.

The treatment of Zenker's diverticula: a review

A historical review reveals that the treatment of Zenker's diverticula has paralleled its presumed pathophysiology. With the development of technical facilities to better evaluate the pharyngoesophageal region, incomplete relaxation of the upper esophageal sphincter (UES) seems to represent the key element in the development of high pharyngeal pressures with a subsequent outpouching responsible for the diverticulum formation. Many studies have justified myotomy as an essential component in the treatment of pharyngoesophageal diverticula because it represents an efficient therapy with little morbidity. A diverticulopexy should be added for pouches between 1 and 4 cm and a diverticulectomy should be performed for sacs greater than 5 cm to expect the best relief of symptoms. Other treatment modalities have recently been used such as the endoscopic division of the common wall between the cervical esophagus and the diverticulum with either electrocautery (Dohlman's procedure), a laser, or a stapling device. This method is gaining popularity because it achieves a good clinical outcome, especially in high-risk patients. However, more studies are needed to confirm its long-term effectiveness.

Upper oesophageal sphincter function during general anaesthesia

The effect of anaesthesia on the upper oesophageal sphincter response to acid in the distal oesophagus and hypopharynx, and the effect of atracurium besylate on acid migration into the hypopharynx, was studied in 102 patients undergoing elective varicose vein surgery. Group 1 (n = 48) received a general anaesthetic and the muscle relaxant atracurium besylate whereas group 2 (n = 54) received a general anaesthetic without relaxation. Upper oesophageal sphincter tone was significantly lower in patients receiving muscle relaxants ('sphinctometer output', eight versus 14, P < 0.05). Sixteen patients (16 per cent) had reflux into the distal oesophagus during anaesthesia (nine in group 1 and seven in group 2, P not significant), of whom seven had reflux to the hypopharynx. There was no difference in incidence of hypopharyngeal acid exposure between groups. Upper oesophageal sphincter tone did not alter in response to reflux into the distal oesophagus or hypopharynx in either group. The upper oesophageal sphincter fails to protect the hypopharynx under general anaesthesia even if patients do not receive a muscle relaxant.

Upper esophageal sphincter and pharyngeal function and oropharyngeal (transfer) dysphagia

Through the application of videoradiography and solid-state manometry, much insight has been gained into the pathophysiology of oropharyngeal dysphagia, and considerable guidance has been provided toward appropriate therapies for the multitude of conditions causing this symptom. As noted earlier, a multidisciplinary approach to these patients often provides the most effective diagnosis and treatment regimen. In the diagnostic evaluation, barium videoradiography and solid-state intraluminal manometry should be considered as complementary procedures, with each providing important aspects of the overall assessment of the swallowing mechanism. It is important to note that controlled evaluations of the various treatment modalities are lacking and that therapy, although directed by information provided by the radiographic and manometric assessment, is primarily empiric. Despite this limitation, great strides have been made in the overall management of these patients during the past decade.

Primary disorders of oesophageal motility

Primary motor disorders of the oesophagus have distinct manometric patterns but require full oesophageal investigation to exclude a secondary cause. Myotomy and forceful dilatation give good results in achalasia, though myotomy is superior in the long term. Indications for surgery are rare in diffuse spasm and nutcracker oesophagus. Non-cardiac chest pain may be related to reflux, diffuse spasm or nutcracker oesophagus, but correlation between motor abnormalities and symptoms is poor and psychological disturbances are frequent.

Studies of the oesophageal clearance responses to intraluminal acid

Contraction of the upper oesophageal sphincter combined with secondary peristalsis clears the oesophagus of refluxed gastric contents and protects the trachea, but the nature of these reflex stimuli remains controversial. Secondary peristaltic and sphincteric responses were measured during intraluminal infusion of 0.1 N hydrochloric acid and equiosmolar saline solutions in seven normal volunteers. Responses to a single volume infused at varying sites in the oesophagus and to progressively increasing volumes of test solution were measured. In addition oesophageal responses to similar degrees of distension induced by inflation of an intraluminal balloon were also recorded. The sphincteric responses to both stimuli were similar, decreasing in value with distance from the sphincter from values of 70 (68-85) mmHg (median (range] for HCl; and 70 (55-85) mmHg for NaCl at 5 cm below the sphincter to 40 (30-60) mmHg for both HCl and NaCl at 20 cm. As the volume of the solution infused into the proximal oesophagus was increased, the sphincter pressure also rose from a median basal value of 30 (25-50) mmHg to 40 (30-50) mmHg for HCl and NaCl after 1 ml, while after 7 ml infusion, the responses were greater, 65 (45-85) mmHg for HCl, and 60 (45-80) mmHg for NaCl. In the more distal oesophagus, responses were qualitatively similar but quantitatively smaller than proximally, being 30 (25-40) mmHg for HCl and 30 (25-50) mmHg for NaCl following 1 ml and 45 (40-55) mmHg for HCl and NaCl after 7 ml. Secondary peristalsis was also induced equally by both solutions and varied with volumes infused and site of infusion in a manner similar to the sphincter responses. After a 7 ml/min acid infusion 14 (1- 40) secondary contractions/three min were recorded at 5 cm and eight (2 - 18)/three min were recorded at 20 cm. Values for saline were similar, 13 (1- 38)/three min at 5 cm and eight (4 - 25)/three min at 20 cm. Oesophageal distension by a balloon positioned 10 cm below the sphincter induced identical clearance responses to those seen after similar volumes of either acid or saline infused at the same site. These results suggest that the principal stimulus for upper oesophageal clearance is intraluminal distension and do not support the idea that the oesophagus is pH sensitive.

Esophageal motility disorders

Esophageal motility disorders consist of a complex array of disturbances in normal esophageal function associated with dysphagia, gastroesophageal reflux, and noncardiac chest pain. A thorough knowledge of normal esophageal anatomy and physiology is important to a full understanding of these motility derangements. Through a complicated interaction of neuromuscular and hormonal influences, the voluntary act of swallowing transforms into an automated sequence of peristaltic waves propelling food and liquids into the stomach in concert with coordinated relaxation of the sphincters. Anatomic and physiologic barriers exist within the esophagus protecting against gastroesophageal reflux and aspiration. With improvements in diagnostic tools such as barium contrast radiography, scintigraphy, pH measurements, and esophageal manometrics with provocative testing, motility disorders have become better defined and understood. Primary motility disorders consist of achalasia, diffuse esophageal spasm (DES), "nutcracker esophagus," hypertensive lower esophageal sphincter, and nonspecific esophageal motility dysfunction (NEMD). A host of secondary and miscellaneous motility disorders also affect the esophagus, including scleroderma and other connective tissue diseases, diabetes mellitus, Chagas' disease, chronic idiopathic intestinal pseudo-obstruction, and neuromuscular disorders of striated muscle. Gastroesophageal reflux disease (GERD) may also be promoted by associated motility disturbances. Treatment modalities include surgical myotomy; dilatation; and pharmacologic manipulations, including use of nitrates, calcium-channel blockers, H2-blockers, and psychotropic drugs where appropriate.

Clinical aspects of pseudodysphagia

Pseudodysphagia is the description of the sensation of a feeling of a lump in the throat--commonly known as the globus symptom. A prospective analysis of 145 consecutive patients with this symptom seen by an Otolaryngologist has provided confirmation that a high proportion of these patients have a treatable basis for their complaints and that most can be successfully managed without time-consuming and expensive investigations--provided clinical evaluation includes thorough visualisation of the oropharynx and supraglottis. The explanation for the symptomatology in patients who suffer from reflux oesophagitis is probably referred pain from the region of the lower oesophageal sphincter rather than spasm of the upper sphincter. The expression globus hystericus is outdated and should be discarded, and we recommended describing the symptoms as primary globus pharyngeus when there is no evident cause and secondary globus pharyngeus when the aetiology is detectable.

Gastroesophageal reflux and pharyngeal function

Pharyngeal function and gastroesophageal reflux were compared in 84 dysphagic patients examined clinically and radiologically. Cricopharyngeal muscle incoordination, assessed cineradiographically, was revealed in 5 of 41 patients (12%) without and 17 of 43 patients (40%) with gastroesophageal reflux assessed clinically (p less than 0.05). Thus, there was a positive correlation between dysfunction of the cricopharyngeal muscle and gastroesophageal reflux. There was no correlation with other types of pharyngeal dysfunction. Our results support the assumption of a positive relationship between gastroesophageal reflux and pharyngeal function in terms of cricopharyngeal dysfunction. The pathogenesis of this relation was, however, not revealed.

Pharyngoesophageal interrelationships: observations and working concepts

Simultaneous disorders of the pharynx and esophagus are so frequent that the complete swallowing chain should be examined in all patients with dysphagia. Data are presented to support the concept that such simultaneous disorders represent related phenomena; the mechanism involves changes in cricopharyngeal function seen radiographically as cricopharyngeal prominence. If neurologic disease has been excluded, cricopharyngeal prominence may be the clue to esophageal disease. When cricopharyngeal prominence is found during dynamic imaging of the pharynx, intensive examination of the esophagus and a search for signs of compensation or decompensation in the pharynx should be undertaken.

The defense mechanisms of the esophagus

Gastroesophageal reflux is a normal event, and the gastrointestinal tract possesses mechanisms to deal with the refluxed content so that symptoms are not produced. When the amount of refluxed material increases, or the quality changes, or one or more of the defense mechanisms breaks down, then the consequences occur in the esophagus. The variability of symptoms, of mucosal changes, and of motility patterns in response to pathologic gastroesophageal reflux imposes difficulties when one is trying to assess this disorder objectively.

Cervical esophageal dysphagia: indications for and results of cricopharyngeal myotomy

Twenty patients with cervical esophageal dysphagia were treated by cricopharyngeal myotomy. Of these 20 patients, ten had pharyngoesophageal diverticula, four had a hypertensive upper esophageal sphincter (UES), four had bulbar palsy, and two has miscellaneous forms of cricopharyngeal dysfunction. Preoperative esophageal manometric examination revealed mean UES pressures of 37.2 mmHg +/- 4.8 SEM in patients with diverticula-markedly lower (p = 0.01) than in normal patients (55.9 mmHg +/- 5.0 SEM). In patients with hypertensive UES the mean pressure was 166.2 mmHg +/- 13.4, significantly higher (p less than 0.001) than normal. Incoordination of the deglutitive response of the UES characterised by premature relaxation and contraction was present in all patients with diverticula and in one other patient. Another patient exhibited incomplete sphincteric relaxation (achalasia). A 4-5 cm myotomy of the cricopharyngeus muscle and adjacent esophageal muscle was performed in all patients. On the patients with diverticula two also had diverticulectomy. No patient with bulbar palsy was benefited. All other patients were relieved of dysphagia by the operation, with the exception of one patient with a diverticulum. A subsequent diverticulectomy was required in this patient. Postoperative manometric examination revealed an average decrease in UES pressure of 63% and an average decreased in length of the high pressure zone of 1.4 cm.

The effect of HCl infusion in the lower part of the oesophagus on the pharyngo-oesophageal sphincter pressure in normal subjects

A measuring unit combined with a perfused catheter has been developed for measurement of the pharyngo-oesophageal sphincter pressure. The system is able to register pressure measurements using either intermittent or continuous withdrawal of the catheter, at the same flow rate (0.5 ml/min). Repeated measurements of pharyngo-oesophageal sphincter pressure have been made on eight healthy volunteers. No differences were found in the sphincter pressures measured by the continuous and the intermittent withdrawal techniques (p greater than 0.10); the coefficient of variation was 0.18 for both techniques. The pharyngo-oesophageal sphincter pressure was measured during infusion of 0.1 N HCl (5 ml/min) 5 cm proximally to the gastro-oesophageal sphincter. There was an increase in the pharyngo-oesophageal sphincter pressure after 1 min of infusion (p less than 0.05). Measurements after 5 min and 10 min were no different from the initial value; thus a fall was observed between the first and the fifth minute (p less than 0.05). The observed rise in sphincter pressure may be explained as a response acting to prevent gastro-oesophageal reflux from entering the pharynx.

Lower-esophageal sphincter function does not determine resting upper-esophageal sphincter pressure

Records of 269 esophageal motility studies were reviewed to determine the relationship between lower-esophageal sphincter (LES) function and upper-esophageal sphincter (UES) pressure. Average and greatest UES pressures were similar in patients with LES pressures less than 10 mm Hg or greater than 20 mm Hg, and in patients with and without gastroesophageal reflux as determined by an intraesophageal pH electrode test. Although teliologically appealing, the belief that patients with weak lower-esophageal sphincters and gastroesophageal reflux have stronger upper-esophageal sphincters to guard against pharyngeal reflux and aspiration cannot be confirmed by current manometric techniques.