[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.


OBJECTIVE
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.


METHODS
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.
Costa
Milton Melciades Barbosa
MM
Laboratório de Motilidade Digestiva do Departamento de Anatomia, Universidade Federal do Rio de Janeiro, RJ, Brasil. mcosta@anato.ufrj.br
D000328:Adult; D001905:Botulinum Toxins / Q000008:administration & dosage*; D002102:Cadaver; D002404:Catheterization; D003413:Cricoid Cartilage / Q000033:anatomy & histology / Q000601:surgery; D005260:Female; D006801:Humans; D007013:Hypopharynx / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology; D008297:Male; D008365:Manometry; D010609:Pharyngeal Muscles / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology / Q000601:surgery
D001905:Botulinum Toxins