In patients with vocal fold insufficiencies, the vocal folds do not close completely, which allows air to escape, resulting in a more breathy, weaker voice with less projection, Dr. Garrett explained. Basically the materials are just filler that add bulk to the vocal fold so they can better close.
Explore This IssueOctober 2009
Advantages of Office-Based Injections
In addition to convenience and cost and time savings, advantages of office-based injections include real-time monitoring of voice quality, avoidance of general anesthesia, and a reduced risk of complications compared with open surgical procedures, the specialists say.
The newest injection material on the block is calcium hydroxylapatite (CaHA) particles in a gel carrier composed of water, glycerine, and sodium carbomethylcellulose (Radiesse, BioForm). Dr. Shaw said that advantages of the CaHA voice gel, which has been approved by the FDA for vocal fold augmentation, are that it lasts a long time and could even be permanent.
Additionally, it does not require extra time to harvest, prepare, or reconstitute, which is common with other injectable materials, said Dr. Shaw, who participated in a prospective study of the gel.
Preliminary results on more than 50 patients, presented by Clark A. Rosen, MD, of the Eye and Ear Institute in Pittsburgh, at the annual Combined Otolaryngology Spring Meetings in May 2006, showed that 73% reported their voice was greatly or significantly improved after 12 months of treatment. The patients suffered from either unilateral vocal fold paralysis or glottal insufficiency due to vocal fold atrophy and/or vocal fold paresis.
Autologous fat, which is typically harvested from the patient’s abdomen or hip and purified, has the advantages of coming from the own patient and being relatively inexpensive, Dr. Shaw said.
Dr. Garrett said that she finds it difficult to inject in the clinic, as you usually have to go through the mouth due to the size of the needle. But theoretically you could inject it percutaneously like the others.
Additionally, variability in resorption leads to unpredictable long-term outcomes and repeat injections may be necessary, she said.
Many people had hoped it would be a permanent fix, but I would rather do a procedure where I can better predict the outcomes, she said.
Human and Bovine Collagen
Dr. Garrett said that she prefers to use human collagen (Cymetra), a freeze-dried micronized dermis purified from cadaver dermis. In my experience, it has the longest and most predictable duration of effect in that it can be used to augment the paralyzed vocal fold for two to five months, Dr. Garrett said.