Surgical management of bilateral abductor paralysis of vocal cords

Introduction:
     Bilateral abductor paralysis of vocal cords is a surgical emergency.  If it is noticed on the table extubation can be deferred.  Usually it is identified only during the first few days following surgery.  In these patient management of airway takes precedence over voice management.  Air way should be secured immediately by performing a tracheostomy.  In this article I attempt to discuss the role of various surgical modalities available in managing this problem.

Causes of bilateral abductor paralysis:

1. Surgical trauma (Total thyroidectomy)

2. Malignancies

3. Endotracheal intubation

4. Neurologic disorders

5. Idopathic (mostly viral infections)

6. Metabolic causes: Hypokalemia, Hypocalcemia and diabetes mellitus

Bilateral abductor paralysis of vocal cords following endotracheal intubation is caused by:

1. Dislocation of arytenoid cartilages
2. Anterior displacement of thryoid cartilage in relation to cricoid cartilage causing stretching and damage to the recurrent laryngeal nerve
3. Hyperextension of neck during difficult intubation procedures may cause stretching damage to the vagus nerve
4. Excessive cuff pressure may cause damage to the recurrent laryngeal nerve
5. Introduction of laryngeal mask may also damage the recurrent laryngeal nerve
6. Prolonged intubation may cause damage to the recurrent laryngeal nerves

Surgical causes of bilateral abductor paralysis:

1. Thyroid surgery

2. Parathyroid surgery

3. Esophageal surgery

4. Tracheal surgery

5. Brain stem surgery

Neurological causes of bilateral abductor paralysis:

1. Arnold chiari malformation

2. Meningomyelocele

3. Amyotrophic lateral sclerosis

4. Shy Drager syndrome

5. Hydrocephalus

Presenting features:

Stridor: Need to addressed first (tracheostomy)
Voice changes: Usually are minimal
Swallowing difficulties

Videolaryngoscopic examination: Shows both vocal cords to be in paramedian position.  Cords are not mobile.

Surgical procedures:

1. Posterior cordotomy (unilateral / bilateral).  Aspiration will be a problem if bilateral cordotomy is performed
2. Arytenoidectomy (partial / complete): Endoscopic / external
3. Cordopexy / lateralization of vocal cord

1. In all patients of bilateral abductor paralysis of vocal cords air way management takes precedence over voice. Air way should be secured immediately by performing tracheostomy.
2. Efforts should be made to decannulate the patient as early as possible
3. In patients who have failed the efforts of decannulation, surgical management becomes a necessity.
Posterior cordotomy can be performed in patients with mild / moderate compromise of the airway. This procedure is more conservative, and has very little risk of aspiration.
Posterior cordotomy was first performed by Kashima and Dennis in 1989.
Suspension laryngoscope is used to visualize the larynx.
If laser is available it is better to perform laser cordotomy, because bleeding is minimal when laser is used.
Incision is made over the posterior portion of the true cord, just in front of the vocal process of the arytenoid cartilage.
About 1/3 of the posterior portion of the vocal cord is removed. Care should be taken not to damage the ventricle as it would cause
irreversible damage to the patient's voice.