[Laryngopharyngeal structural analysis and its morphofunctional correlation with cricopharyngeal myotomy, botulinum toxin injection and balloon dilation]

BACKGROUND

The cricopharyngeal muscle is of the skeletal type and, in this way, unable to sustain continuous contraction for long periods. Despite of this it has been considered as the responsible by the high pressure area, registered by manometry into the pharyngoesophageal transition. For this reason, it has been the object of therapeutics that promote the rupture of its integrity.

AIMS

To give the anatomical bases to define the limits of participation of the cricopharyngeal muscle in the pharyngoesophageal transition function. To consider a morphological and functional alternative to explain the high pressure area on pharyngoesophageal transition and the implications of the myotomy, use of the botulinum toxin and balloon dilatation on pharyngoesophageal transition function.

MATERIAL AND METHOD

Study of the laryngopharyngeal region in their morphologic characteristics and relationships on 24 pieces obtained from adults' corpses of both sexes fixed in 10% formaldehyde solution.

RESULTS

The cricopharyngeal muscle presenting its anterior-lateral insertion, with a C-shaped outline, on the posterior-lateral edge of the cricoid cartilage. This kind of morphology blocks the possibility to generate a predominant anterior and posterior high pressure during its contraction like that we find at the pharyngoesophageal transition. The observation of this kind of pressure has its explanation in a tweezers-like relationship exerted on one side by the vertebral body and on the other side by the posterior contour of the cricoid cartilage.

CONCLUSIONS

The muscular organization of the laryngopharyngeal segment allowed us to sustain that a large myotomy of the pharyngoesophageal transition, that takes more than just the cricopharyngeal transversal fasciculus, hinders the ejection function in a region where the dimension do not need any parietal sectioning. Myotomy that encompasses only the transversal fasciculus can contribute to improve the pharyngoesophageal flux by a decrease of the local resistance. The efficiency of this myotomy depends mostly on some residual pharyngeal ejection force and also on a slight hyolaryngeal displacement. The transversal fasciculus of the cricopharyngeal muscle is a narrow strip of muscular mass to be injected by percutaneous way with solution of botulinum toxin; maybe endoscopically. For this reason, dose, dilution and injection sites have an important meaning in the cricopharyngeal therapeutics using botulinum toxin. The efficiency of this procedure, like myotomy, depends on some residual pharyngeal ejection force and on, at least, some hyolaryngeal displacement. The dilation of the pharyngoesophageal transition with pneumatic balloon does not seem to be an adequate procedure for a region that does not present a narrow lumen determined by fibrosis. For anatomical characteristics of the TFE region, mean pressure as registered by the manometric method does not evaluate either the effectiveness or inadequacy of surgical myotomy, denervation or dilation using pneumatic balloon.

Changes of Esophageal Motility after Total Laryngectomy

OBJECTIVE: Total laryngectomy completely interrupts the continuity of the proximal digestive tract and may lead to derangement in esophageal motility. The purpose of this investigation was to find out how total laryngectomy changes the resting and the maximum contracting pressures of the upper esophageal sphincter muscle and how it affects the coordination of the contraction and the relaxation between the pharynx and the upper esophageal sphincter muscles. If changes in the function of the upper esophageal sphincter muscle should occur, this study will also demonstrate how it affects the motility of the esophagus and the lower esophageal sphincter muscle.

METHODS: In an attempt to explain postoperative motility changes, the stationary pull through method of manometric evaluation was used to quantify the alteration in esophageal motility. For the manometric evaluation of the esophagus, a polyethylene catheter with 8 internal tubes was used. The study was performed on a group of 15 patients with total laryngectomy and 15 people without esophageal disease or symptoms as the control group.

RESULTS: There was a statistically significant difference between the laryngectomy group and the control group for both the resting and maximum contraction pressures as well as for coordination and relaxation of the upper esophageal sphincter. ( P < 0.05) In the laryngectomy group, 3 patients who complained of postoperative dysphasia showed more severe functional changes. The proximal esophageal body pressure and peristaltic waves were significantly decreased in the laryngectomy group. No significant difference between the laryngectomy group and the control group was noted in terms of the lower esophageal resting sphincter pressure and the postdeglution pressure. There also was no significant difference between the two groups in the degree of lower esophageal sphincter coordination and relaxation.

CONCLUSION: From these results, it may be concluded that interruption of the cricopharyngeal muscle and pharyngeal plexus after laryngectomy not only may produce local derangement of upper esophageal sphincter function but also may produce abnormalities in peristalsis of the proximal esophageal body. However, the function of lower esophageal sphincter did not show any significant difference between the laryngectomy group and the control group.

The innervation of the human upper esophageal sphincter

The neuroanatomy and physiology of the human upper esophageal sphincter (UES) has long been controversial. As a result, there has been little progress in diagnosing and treating dysphagias involving this area. In this study, three specimens of the UES obtained from human autopsies were examined by Sihler's stain. This stain clears soft tissue while counterstaining the nerves, thereby allowing nerve supply to each muscle of the UES to be demonstrated. It was found that the nerve supply to each component of the UES is substantially different. The inferior pharyngeal constrictor (IPC) is supplied by a dense linear plexus which is about 1.0-1.5 cm wide and 10 cm long and located about 1.5 cm lateral to the attachment of the IPC on the thyroid lamina. The cricopharyngeal (CP) muscle receives its innervation from below via the recurrent laryngeal nerve (RLN) and from above via the pharyngeal plexus. Neural connections between the RLN and the pharyngeal plexus were observed. Finally, the upper esophagus (UE) is innervated by the RLN. The innervation pattern of each component of the UES suggests functional differences between these muscles. These observations help clarify the innervation of the UES. Accurate knowledge of the neuroanatomy of the UES is necessary for advances in diagnosis and treatment of pharyngeal dysphagia.

Quantitative assessment of pharyngeal bolus driving forces

This study analyzes the differences between wet and dry swallows; a manofluorogram is used to determine forces that affect pharyngeal bolus flow. By defining bolus pressures, many of the limitations of pharyngeal manometry are surmounted. This makes manometry a more useful clinical tool. The study results indicate that only a small portion of pharyngeal-generated pressure is directly applied to the bolus. The manofluorogram demonstrates that bolus transit relies on the synergistic action of two pumps--the oropharyngeal propulsion pump and the hypopharyngeal suction pump. A technique is illustrated for quantifying the forces that affect bolus flow. Quantification of force can differentiate abnormal forces responsible for lingual, pharyngeal, and hypopharyngeal pathology in dysphagic patients. The degrees of impairment can be measured.

Cricopharyngeal myotomy: management of cervical dysphagia

Cricopharyngeal myotomy has gained widespread acceptance as surgical treatment for various forms of cervical dysphagia. The case records of 33 patients who underwent cricopharyngeal myotomy for dysphagia originating from varying underlying diseases are reviewed. The majority of these patients were able to resume oral feeding following myotomy. Analysis of preoperative pharyngoesophageal manometry and contrast radiography identified diagnostic criteria for appropriate case selection.

Effect of total laryngectomy on esophageal motility

Total laryngectomy for cancer can result in dysphagia and altered esophageal motility. Manometric changes in the upper esophageal sphincter (UES), and in proximal and distal esophageal function have been reported. However, most studies have failed to take into account radiation therapy and appropriate controls. We selected ten male patients (54.3 +/- 1.9 yr) for longitudinal manometric evaluation prior to laryngectomy then at two weeks and again six months later. No patient received preoperative radiation therapy, had a previous history of esophageal surgery, or developed a postoperative wound infection or fistula. Seven of ten patients had positive nodes and received 6,000-6,600 rads postoperative radiation therapy. Preoperatively 4 of 10 patients complained of dysphagia which did not significantly change following surgery and radiation. Two of three patients who did not complain of dysphagia preoperatively and received radiation postoperatively developed dysphagia. No patient without dysphagia preoperatively who received no radiation therapy developed symptoms. Our studies show that laryngectomy causes alterations in the UES resting and peak pressures but not in the proximal or distal esophagus, or the lower esophageal sphincter. These data also imply radiation therapy may be associated with progressive alterations in motility and symptomatology. Further study regarding the effects of radiation on esophageal motility and function are urged.

Cricopharyngeus myotomy as the only treatment for Zenker diverticulum

Cricopharyngeal dysfunction, one of the most common causes of pharyngeal dysphagia, exhibits a variety of manifestations, one of which is Zenker diverticulum. This paper examines the physiology of swallowing, pathophysiology of its aberrations, and various methods of treating Zenker diverticulum. It is our purpose to emphasize cricopharyngeus (CP) myotomy as the only needed treatment for this diverticulum. Even in its advanced stages, excision of the diverticulum is a needless surgical exercise. Seven cases of Zenker diverticulum are reported in elderly patients; one of them had an excision of the diverticulum prior to presentation. Some were either completely obstructed or aspirating on esophagram. Cricopharyngeus myotomy, the only treatment provided, proved to be safe and effective without morbidity or fatalities. Patients' ability to eat orally was restored on the night of or the morning after surgery. No Levin tube is necessary and there is no risk of suture line leakage after the conventional diverticulectomy and CP myotomy. Hospital stay is greatly reduced and there is no risk of structure formation. In contrast to endoscopic division of CP muscle, there is no risk of mediastinitis because there is no break through the mucosa.