Bilateral paralysis of recurrent laryngeal nerves. This condition is mainly due to physical compression due to hypertrophy of the left atrium (Ortner’s sign), dilated pulmonary artery, aortic aneurysm or a combination of these events, causing paralysis of the vocal cords .
[ hide ]
- 1 Etiology
- 2 Clinical manifestations
- 3 Diagnosis
- 4 Forecast
- 5 Treatment
- 6 Sources
Although the most common cause is trauma or acute neuritis , it is usually abrupt onset.
Initially, the vocal cords are in the intermediate or intermediate position, suffering from symptoms of severe dysphonia with adequate airway patency. Aspiration becomes a problem in elderly patients.
Over a certain period of time, the vocal cords gradually move towards the midline, with the consequent improvement in the voice and increased dyspnea , both the latter and the inspiratory stridor, worsening dramatically with exertion.
Acute laryngeal obstruction may develop in the later stages when an upper respiratory infection overlaps with laryngeal paralysis .
The examination reveals bilateral immobility of the vocal cords, the position of which will vary according to the time that has elapsed since the onset of paralysis. In cases of long-term paralysis, only an elliptical cleft is observed in the airway between the membranous vocal cords. that widen during inspiration.
Direct laryngoscopy is indicated to establish the degree of mobility of the cricothyroid joints with a prognostic purpose.
In many cases of non-traumatic origin, spontaneous functional recovery of one or both vocal cords is possible. Such recovery is less likely after surgical trauma or severe neck injury. Many patients with bilateral paralysis will progress to a symptomatic phase of glottic obstruction, except when one of the vocal cords recovers.
The time required for severe dyspnea to appear due to a bilateral medial position can range from a few days to twenty years. In general, paralysis after thyroidectomy occurs in those cases in which a longer period of time elapses before the laryngeal obstruction becomes more intense.
The treatment will vary according to the symptoms, but it must be directed, first of all, to the relief of dyspnea. Any procedure to improve the voice will cause a narrowing of the glottis, posing a danger due to possible further spontaneous narrowing; therefore, rehabilitation of dysphonia is of secondary importance.
In order to relieve dyspnea, a tracheostomy will generally be required as an initial procedure: the subsequent treatment will depend on three factors: a) The duration of the paralysis. b) The mobility of the cricoarytenoid joints. c) The possibilities of recovery.
Patients who have a chance of spontaneous recovery should be observed for at least six months before practicing any procedure other than a tracheostomy. In patients with persistent bilateral paralysis and an inadequate airway, several forms of treatment may be instituted.
- A permanent tracheostomy.
- A permanent tracheostomy using a valved cannula (for example, the Kistner cannula).
- Neurolysis of an external laryngeal nerve.
- Surgical widening of the glottis, generally due to some form of arytenoidectomy.
Treatment of a permanent tracheostomy without further therapy is indicated in patients with a fatal process or in elderly and debilitated patients who are unlikely to tolerate the necessarily insufficient glottis produced by surgical correction.
Valved tracheostomy is valuable in patients who require continued use of a good voice, in patients who refuse surgery, or, as a temporary measure, when recovery can still be expected.
Neurolysis of the external laryngeal nerve has been discussed by Tschiassny. By sectioning this nerve, the string in the middle position is intended to move laterally to the intermediate position, since the opening of the glottis to this position is a passive movement. The paralysis of a cricothyroid muscle will cause a widening of the glottis of up to 3 mm.
The advantage of the procedure lies in its simplicity compared to arytenoidopexy and in that it avoids the complications of this operation, among which the excessive widening of the glottis is included. Prognostic testing should be performed before proceeding with neurolysis.
- The mobility of the cricoarytenoid joint must be established.
- The cricothyroid muscle can be temporarily paralyzed, infiltrating it with local anesthesia. The position of the rope will indicate the degree of improvement that can be expected.
The success of this procedure is limited by the level of fibrosis of the denervated musculature and by the degree of movement limitation of the cricoarytenoid joint. Surgical widening of the glottis for dyspnea due to bilateral recurrent nerve palsy is indicated when:
- The paralysis has lasted for six to eight months now, and recovery is not evident.
- The cause of the paralysis leaves little chance of recovery.
- The cricoarytenoid joints are fixed.
- Temporary paralysis of a cricoarytenoid muscle does not achieve an adequate airway.