Treatment of True Vocal Cord Paralysis:   The most common causes of true vocal cord  paralysis are lung carcinoma, surgical injury, and idiopathic (unknown) causes.   If the paralysis is from idiopathic causes, it will often resolve in the course of six to nine months.   If the left true vocal cord is paralyzed, the presence of a lung carcinoma or other chest disease is likely.  The left recurrent laryngeal nerve extends deep into the neck and loops around the aortic arch.  It is in the chest that the lung cancer injures the nerve.   The two most common surgical causes of true vocal cord paralysis are thyroid surgery, with injury to the recurrent laryngeal nerve; and carotid endarterectomy, with injury to the vagus nerve.

  
There are two basic methods of treating  true vocal cord paralysis:                

• The first is is external larynogplasty with the placement of a lateral laryngeal implant.   This method was pioneered by James Netterville from Vanderbilt University in Nashville, TN.  It can be performed under local anesthesia, has a high success rate and is reversible.  An external neck incision is required to do the procedure.
    

• The second is injection laryngoplasty, which consists of of injecting the true vocal cord with gel-foam or with a variety of permanent substances.   Teflon was used in the past but fell into disfavor because of tissue compatibility problems.  All permanent injectable substances can be very difficult to remove if injected in the wrong place.  Permanent substances include hydroxy-appetite, silicone, hyluronic acid derivatives, autologist fascia and others.  One needs to be careful to match the implant with the patient.  Tissue compatibility and safety are of primary concerns.  Patients with a long longevity need to be injected with a well tested highly tissue compatible substance.    View Abstract on using Radiesse (hydroxylapatite) for Vocal Fold Augmentation. 
  
  Carroll and Rosen reported that injectable calcium hydroxylapatite remains a safe and effective therapy, however the long term benefit was found to be 18.6 months 64% of subjects showing loss of benefit of the hydroxylapatite material.   View Abstract
  
  Gel-foam is absorbed and can be used to temporize.  This method can be performed under local anesthesia, has about a 80% success rate.  However it is temporary with relief lasting only for 2 to 3 months.  An external incision is not required and if injected in the wrong place, it will absorb and the procedure can be repeated.   The surgery is preformed with a long needle through and laryngoscope.

Current Status of Injection Laryngoplasty 
 

Excellent article on the treatment of true   vocal cord paralysis by injecting the paralyzed true vocal cord with Teflon or Gel-Foam. 

• Search PubMed for Vocal Cord Paralysis
    

• Search PubMed for Vocal Cord Injection

This is a patient with lung carcinoma and a paralysis of the left true vocal cord.  The left true vocal cord (left side of screen) is markedly bowed during phonation, and the patient has a breathy  voice:

The far lateral mid-portion of the membranous true vocal cord is injected with Gel-Foam   The needle is placed 4.5 mm into the larynx but the depth will vary between 3 to 5 mm depending upon the size of the larynx.

After first gel-foam injection at the far lateral mid-membranous portion of the true vocal cord.  At this point, the patient's voice was good.  This is the point that injection should stop when Teflon is used.

However this patient was being injected with gel-foam.  Much of the gel-foam past is water which will be quickly absorbed.   The gel-foam is also slowly absorbed over 4 to 6 months.  Thus, when using gel-foam you want to over inject the true vocal cord.

A second injection was performed at the far lateral mid-membranous true vocal cord .  This injection bowed the cord medial in an attempt to compensate for the water and gel-foam absorption.

In addition a third injection was placed lateral to the arytenoid to move the posterior cord towards midline.

Often an additional injection is needed, lateral to the anterior part of the vocal process of the arytenoid, to close the posterior glottis.  This patient had very thin vocal cords and, thus, the injection was placed posterior lateral to the vocal process.

The patient had an excellent voice result

Play to Hear Pre-Operative Voice:

Play to Hear Post-Operative Voice:

View Video Of Pre-Operative Laryngoscopy