Vocal Fold Augmentation
What is Vocal Fold Augmentation?
Augmentation of the vocal folds (or vocal cords) refers to procedures that are carried out to augment (or bulk up) the vocal folds to improve their function. For the treatment of some conditions only one vocal fold is augmented (a unilateral procedure), while for the treatment of others both vocal folds are augmented (a bilateral procedure).
Why is Vocal Fold Augmentation Performed?
Augmentation of the vocal folds is used to treat glottic insufficiency. Glottic insufficiency means that the vocal folds do not close fully or do not close strongly, causing symptoms such as a weak or quiet voice, a breathy voice, or vocal fatigue. Several disorders may cause glottis insufficiency, such as:
Vocal fold paralysis: one of the vocal folds does not move, usually resulting in a weak and breathy voice.
Vocal fold paresis: weakness of one or both of the vocal folds.
Vocal fold atrophy (or vocal fold bowing): the vocal folds lose their bulk and become thin, either due to ageing, or in some cases due to medications (such as steroid inhalers for asthma).
Vocal fold scar: scar tissue on the vocal fold is often associated with glottic insufficiency that may respond to augmentation.
Vocal fold sulcus: a sulcus is a depression in the lining of the vocal fold that is often associated with glottic insufficiency that may respond to augmentation.
How is Vocal Fold Augmentation Performed?
There are two types of augmentation procedures: injection laryngoplasty, which is injection of the vocal folds with a filler, and medialisation thyroplasty, which is the surgical placement of implants into the vocal folds.
Injection laryngoplasty is usually a temporary treatment, and medialisation thyroplasty is a permanent treatment. Often a temporary treatment is used first either to confirm the diagnosis (for example, in cases of suspected weakness), or to determine how much augmentation improves the voice, before a permanent procedure is carried put. Sometimes a temporary treatment may be all that is required if recovery is expected (for example, in some cases of paralysis of the vocal fold).
What is Injection Laryngoplasty?
Injection laryngoplasty (IL) is a procedure in which the vocal fold is injected with a viscous material that bulks up the vocal fold. This material is known as a “filler”, and so injection laryngoplasty is injection of the vocal fold with a filler.
Injection laryngoplasty may be performed in the office using local anaesthetic (LA), in which case the person receiving the injection is awake, or in the operating room where the person receiving the injection is asleep under general anaesthetic (GA).
What substances are injected into the vocal folds to augment them?
The laryngeal injectables I prefer to use are temporary injectables, and are discussed below. I prefer not to use permanent injectable fillers such a Teflon or Silicone because of the risk of adverse reactions to these fillers.
Hyaluronic acid (eg. Restylane or Restylane Perlane)
Hyaluronic acid is a synthetic material made from bacterial fermentation. This is a clear gel that is very safe to inject into the vocal folds. It is used for temporary augmentation. Restylane is a short term injectable that lasts for 3-6 months before it is resorbed by the body, and then loses its effect. Restylane Perlane is a longer lasting (medium term) injectable that lasts for 6-12 month before it is resorbed by the body.
Calcium hydroxylapatite (eg. Radiesse)
Calcium hydroxylapatite is a synthetic material composed of tiny calcium based microspheres suspended in a water based gel. This is a white paste that is also safe to inject into the vocal folds. It is important to be very accurate about which part of the vocal fold it is injected into, as Radiesse is firmer than Restylane and needs to be injected deeply into the vocal fold.
What is Medialisation Thyroplasty?
Medialisation Thyroplasty (MT) is a procedure in which one of both of the vocal folds is/are augmented by placing an implant into the vocal fold. If both vocal folds are augmented this is called a bilateral medialisation thyroplasty. I prefer to use a strip of GoreTex which is packed into the larynx through an opening in the main cartilage of the larynx - the thyroid cartilage. This is a permanent treatment for augmentation of the vocal folds, although the implant can be removed or changed in the future if required.
MT is carried out in the operating room in hospital. I usually perform the procedure with local anaesthetic (LA) and intravenous (IV) sedation, although sometimes a general anesthetic is used.