Main aspects of infantile larynx comparing to adults?
The infantile larynx is proportionally smaller and higher than that of the adult compared to body size and is more funnel shaped. Its narrowest part isat the junction of the subglottic larynx with the trachea.
Final AP diameter of larynx in adults?
Subdivisions of larynx?
The larynx is divided anatomically into the supraglottis,glottis and subglottis by the false and true cords. The supraglottis consists of superiorly the epiglottis and aryepiglottic folds as they sweep down to the arytenoids. Its lower border is the ventricular bands(false cords) which form the upper border of the glottis.The glottis includes the vocal cords and anterior commissure and posterior commissure. The definitionof the junction between the glottis and the subglottis has been debated in the literature at some length and is either defined as at the level of the vocal folds or 5-10 mm below. The subglottis becomes the trachea at the lowerborder of the cricoid.
Layers of Vocal fold?
- 1) superficial layer of nonkeratinizing, stratifiedsquamous epithelium, beneath which is:
- 2) the laminapropria. This has three distinct layers. The superficial layer (Reinke's space) contains a fibrous substance with similar characteristics to gelatin. The intermediate layer contains elastic fibres and the deep layer collagen fibres.The intermediate and deep layers make up the vocalligament.
- 3) The vocalis muscle, which forms the main body of the vocal fold, lies lateral and deep.
What is Macula flava of vocal folds?
At the anterior end of the vocal fold there is a mass of collagen fibres which are connected to the inner perichondrium of the thyroid cartilage and to the deep layer of the lamina propria posteriorly. Adjacent to this mass of collagen fibres just posteriorly, there is another mass of elastic fibres continuous with the intermediate layer of the lamina propria called the anterior macula £lava. A similar structure is seen at the posterior end of the membranous part of the vocal fold.
What is the name of the anterior three fifth part of the vocal cords and posterior two-fifth of them?
What is the histology of mucous membrane of larynx?
- Most of the larynx is lined by pseudostratified ciliated columnar 'respiratory' -type epithelium.
- The upper half of the posterior surface of the epiglottis, the upper part of the aryepiglottic fold, the posterior glottis and the vocal folds are covered with nonkeratinizingstratified squamous epithelium.
How are the vocal folds get lubricated?
The vocal folds do not possess any glands and are lubricated by mucusfrom the glands within the saccules
Nerve supply of the larynx?
- External: motor to Cricothyroid muscle
- Internal(upper, lower branches): sensation and secretomotor of the supraglot
- Motor to all other muscles
- sensation of glot/subglot
What is Galen's anastomosis?
The superior laryngeal nerve ends by piercing the inferior constrictor of the pharynx and unites with an ascending branch of the recurrent laryngeal nerve.This branch is called Galen's anastomosis and is purelysensory.
What are preepiglottic space boundaries?
The preepiglottic space is a wedge-shaped space with the point of the wedge inferiorly. It is bounded anteriorly by the thyrohyoid ligament and hyoid bone and posteriorly by the epiglottis. Superiorly, the hyoepiglottic ligament connects the epiglottis to the hyoid bone.
What is paraglottic space?
The paraglottic space is bounded laterally by the thyroid cartilage, medially by the conus elasticus and quadrangular membrane and posteriorly by the piriform fossa mucosa. It encompasses the laryngeal ventricles and saccules.
How is the lymphatic drainage of the larynx?
- The lymphatic drainage of the larynx is separated into upper and lower drainage groups by the vocal folds. The larynx above the vocal folds is drained into the upper deep cervical lymph nodes.
- The larynx below the vocal folds drains to the lower deep cervical chain often through prelaryngeal and pretracheal nodes. The vocal folds themselves are firmly bound down to the underlying vocal ligament and there are no lymphatics present in this plane.
What is pharyngeal plexus?
The pharyngeal nerve of Vagus descends between the internal and external carotid arteries to supply the middle pharyngeal constrictor muscle. Its fibres subsequently join with the glossopharyngeal and external laryngeal nerves, together with branches from the sympathetic trunk, to form the pharyngeal plexus. The pharynx and all the muscles of the soft palate, except the tensor palati, are supplied by fibres from the pharyngeal plexus.
What nerves provide the motor supply for extrinsic laryngeal muscles?
Cranial nerves V (trigeminal), VII (facial), XII (hypoglossal)and cervical spinal nerves Cl-C3
What is vibratory cycle?
- adduction of vocal cords
- aerodynamic separation
this cycle travles from inferior to superior surface of vocal cords
Main disorders of voice?
- Dysphonia: Any impairment of the voice or difficulty speaking.
- Dysarthria: Difficulty in articulating words, caused by impairment of the muscles used in speech.
- Dysarthrophonia: Dysphonia in conjunction with dysarthria, for example after a cerebrovascular accident, head injury or part of a degenerative neurological condition, such as motor neurone disease.
- Dysphasia: Impairment of the comprehension of spoken or written language (sensory dysphasia) or impairment of the expression by speech or writing(expressive dysphasia), especially when associated with brain injury.
- Hoarseness: A perceived rough, harsh or breathy qualityto the voice.
The main causes of voice disorders?
- structural or neoplastic
- muscle tension imbalance
Specific voice disorders?
- muscle tension dysphonia;• laryngitis/muscle tension dysphonia secondary to poor vocal hygiene, dietary and lifestyle issues;• extraoesophageal reflux (laryngopharyngeal reflux);• vocal fold nodules;• vocal fold polyps;• vocal fold cysts;• vocal fold palsy and paresis;• arylenoid granulomas.
- Less frequent:
- sulci and mucosal bridges;• spasmodic dysphonia;• papillomatosis;• microvascular lesions;• laryngeal trauma, including post-surgical causes;• other neuromuscular causes;• hyperkeratosis, dysplasia and carcinoma;• endocrine causes;• amyloid;• other laryngeal tumours.
What is vocal cord polyp?
benign swelling of greater than 3 mm that arises from the free edge of the vocal fold. It is usually solitary, but can occasionally affect both vocal cords. polyps are the most common structural abnormality that cause hoarseness and they affect men more than women. Theyare most frequently seen in smokers and between the ages of 30 and 50 years.
What areVocal fold nodules?
- Vocal nodules are bilateral, small swellings (less than 3mm in diameter) that develop on the free edge of the vocal fold at approximately the mid membranous portion.
- In children, they are more common in boys than in girls, while in adults they are very much more commonly found in women particularly under the age of 30.
Definition and grading of Reinke's oedema?
chronically and irreversibly swollen vocal cords
- 1) Marginal edge oedema
- 2) Obvious sessile swelling, thrown over vocalis muscle during phonation
- 3) Large bag-like swelling, filled with fluid
- 4) Partially obstructing lesion, medial borders in contact along most of length
Indications of surgical treatment of Reinke's oedema?
- 1) Leukoplakia is present and a histological diagnosis isrequired
- 2) Gross Reinke's oedema is present causing choking episodes or airway compromise
- 3) Pitch elevation of the voice is the main requirementof treatment.
Types of vocal fold cysts?
- mucus retention (DD polyp)
- epidermoid cyst: lined by squamous epithelium and filled with keratin and cholestrol debris.
what is sulcus vocalis?
localiazed invagination of the mucosa of varying depth
Types of spasmodic dysphonia?
Definition of muscle function dysphonia?
Muscle tension dysphonia is a group of conditions characterized by an imbalance of the synergist and antagonist muscles affecting the vocal fold position and tensioning relative to one another and also the position of the larynx relative to the rest of the vocal tract.
What is sulcus vergeture?
unilateral or more commonly bilateral linear adherence of the epithelium to the underlying ligament or muscle along the membranous portion of the vocal fold. Reinke's space exists superolaterally and inferomedially to the vergeture. They are thought to result from a congenital failure of development of Reinke's space as they are commonly apparent at puberty and can be familial.
Hypotheses of muscle tension dysphonia?
- chronic imbalance of muscle pull, for example, of the cricothyroid muscle can lead to irreversible joint damage and ligament stretching giving a flaccid bowed appearance to the vocal folds.
- a viral neuropathic paresis has developed causing hypotrophy of the thyroarytenoid muscle and consequent poor glottal contact and secondary compensatory hyperfunction.
Daignosis? clinical features?
An external/combined laryngocoele presents as an intermittent neck swelling that can be inflated by the patient with Valsalva manoeuvre. Compression may empty air and fluid into the larynx (Bryce's sign). Distension of an internal laryngocoele due to infection may cause airway obstruction.
What is contact pachydermia?
- Contact ulcer in larynx, epithelial thickening with a central depression near mucosa of vocal process.
What are the main areas of laryngeal injury after intubation?
- posterior glottis
- cricoid cartilage (in infants)
What is diagnosis? the potential cause?
- Vocal cord nodule
- voice abuse, LPR
- Reinke’s edema
- Is associated with female gender, tobacco use, reflux disease, and voice use
- VC hemorrhage
- More in men, working in noisy area, being on aspirin
- Glottic sulcus
- vocal overuse, self ruptured cyst
Describe the picture
narrowing of supraglottic larynx with antero-posterior approximation of lower laryngeal surface of epiglottis and its petiole region.
Intubation (contact) granuloma
Causes of intubation trauma?
- Physical trauma: difficult intubation
- Duration of intubation >7 days
- State of larynx: croup, traumatic
- Movement of tube (coughing, ventilator pulses, transportin patient)
- Mucociliary mechanism
- Gastroesophageal reflux
- Poor general health
- Nasogastric tube
- Bacterial superinfection
- Tube characteristics: rubber tubes
The clinical features of laryngeal intubation trauma occur at various times after removal of the tube:
- Immediately: severe obstruction caused by flaplike "tongues" of granulation tissue.
- In the first hours: subglottic reactive edema.
- In the first days: persistent edema and granulation tissue.
- Weeks later: intubation granuloma.
- Months later: posterior glottic or subglottic stenosis matures.
Classification of laryngeal trauma due to prolonged intubation seen after extubation?
- -- Tongues of granulation tissue at the VCs
- -- Ulcerated troughs
- -- Healed furrows
- -- Healed fibrous nodule
Which patients are more prone to develop laryngeal traumas due to intubation?
- in unconscious patients with a head injury who remain intubated for a long time.
- in children cared for in an adult hospital when a large,a cuffed, or even a rubber tube is used.
- when prolonged intubation is followed by a tracheotomy in a patient who remains unconscious.
- in patients with multiple systemic problems.
Main lesions noted in late phase post extubation?
Interarytenoid adhesion, Posterior glottic stenosis, Subglottic stenosis, Complete stenosis, Ductal retention cysts, Vocal cord paralysis, Dislocation of arytenoid, Fixation of crico-arytenoid joint.
Definition of congenital subglottic stenosis?
Subglottis diameter smaller than 4 mm in term and 3 mm in preterm neonates, not related to trauma, intubation.
Prof Sani says: if you can not intubate the child with a 2 size smaller then related size of ETT
The 3 major sites of possible damage due to ETT?
- 1. The arytenoid: The medial surface of the cartilage, medial aspect of thecricoarytenoid joint, and at the vocal process.
- 2. The posterior glottis: The posterior commissure in the inerarytenoid region.
- 3. The cricoid cartilage: The subglottic region, especially the anterior surface of theposterior lamina
Duration of intubation before possible complications in adults, children and neonates?
- adults: 7 days
- Children: 1-2 weeks
- neonates: almost unlimited (a few weeks)
What is Ductal retention cyst?
Submucosal ductal retention cysts may be large or small and develop in the subglottic region, usually posteriorly, in infants who have been intubated.
What do you know about vocal cord palsy post intubation?
Unilateral and rarely bilateral vocal cord paralysis may be a complication both of short term or of prolonged intubation. The nerve damage is thought to be a compression injury of the anterior ramus of the recurrent laryngeal nerve as it passes between the arytenoid and the laryngeal cartilages. Spontaneous recovery can usually be expected within 6 months. Laryngeal EMG may behelpful in predicting recovery of function.
In which side the dislocation fo arythenoid is more common in intubation?
It more commonly affects the left arytenoid region since intubation is through the right side of the mouth with the tube tending to go toward the left side of the larynx.
Why in burned patients that are suspected to have laryngeal thermal injury as well, intubation must be done before fluid resuscitation?
airway must be secured early in these injuries before fluid resuscitation of the associated burn injury begins, since this will lead to marked edema of the injured mucosa with loss of airway and inability to endotracheally intubate the patient.
What is the early sign of external laryngeal trauma
It is often associated with a change in voice.
What is the safe way of performing tracheostomy in paediatric laryngeal trauma?
In this instance rigid bronchoscopy is performed to secure the airway under direct visualization. A tracheotomy may then be performed over the bronchoscope.
What is the reason for RLN neurorrhaphy in laryngeal traumas?
The delicate function of abduction/adduction will not return, but the reinnervation may help maintain muscle tone and therefore voice quality.