RFA for Obstructive Sleep Apnea
The technique of RFA (Radiofrequency Ablation), as it relates to sleep apnea and reduction of the tongue base, was first researched by a group of doctors at Stanford University in in 1997(1).
After years of more research, the concept of RFA has since been applied to humans and is now recognized by the leading national authority on diagnoses and treatment of all ENT related disorders (the American Academy of Otolaryngology) as a safe treatment option for patients with mild to moderate sleep apnea (2).
In regards to treating Obstructive Sleep Apnea (OSA), RFA has two main benefits:
1. Unlike other forms of electric energy, RFA is unique in that it does not require high temperatures to bring about its effects. It accomplishes this by giving off low frequency radio waves (typically from 300kHz to 1MHz3), which in turn causes small amounts of heat (ionic agitation and friction). The agitation in turn starts to scar the tissue it is targeting, and causes the desired effect of changing the shape of the tongue (coagulation necrosis, inflammation, and fibrosis).
2. RFA is extremely effective at treating the desired tissue, without a lot of collateral tissue damage. Since there is a high density of very important nerves and blood vessels in close proximity, This is particularly important in the head and neck region. Studies of tissue that has been treated with RFA often demonstrate a very clear boundary between treated tissue and non-treated tissue.
The Golden Standard
When discussing new treatment options of any disorder, one must consider the current gold-standard therapy. As it relates to OSA, the current gold-standard is considered to be Continuous Positive Airway Pressure (CPAP). Unfortunately patients’ abilities to tolerate using CPAP has been historically poor.
Comparing CPAP & RFA
Since CPAP is widely recognized as the standard for treatment, studies have been conducted to compare the efficacy of CPAP to RFA. One such study in 2003 looked at 90 patients and showed, that for those with mild to moderate sleep apnea, RFA was equally effective in improving daytime sleepiness, sleep-related quality of life, and global quality of life over a several month period.
Additional studies have further evaluated the ability of RFA to reduce a patient’s respiratory disturbance index (RDI). This is important because RDI is the scale that determines whether a patient even has OSA or not, and if so, how severe it is. One study in 2008 showed that over a period of 12 months, RFA alone reduced patients’ RDI by 31%, this percentage increased to 45% over 24 months. On average, they reported ~4.5 procedures needed to achieve those results (4).
The RFA Procedure
RFA is generally conducted in the outpatient setting, using either local anesthetics or conscious sedation anesthesia. The procedure itself generally lasts under 3 minutes. The desired tissue (either the tongue or the palate) is generally approached through the mouth, without the need for incisions, although one case report has relayed going through the neck using assisted imaging. If the tongue is being targeted, this can be done either from on top (dorsal) of the tongue or underneath (ventral). Respective approaches are usually at the discretion of the treating physician. Reported complications associated with RFA procedures include ulcerations, infection, nerve weakness or numbness and swelling. All complications that were reported, occured in less than 1% of patients being treated.
1. Powell NB, Riley RQ, Troell RJ, Blumen MB, Guilleminault C. Radiofrequency volumetric reduction of the tongue: a porcine pilot study for the treatment of obstructive sleep apnea syndrome. Chest 1997; 111: 1348-1355.
2. ”Submucosal Ablation of the Tongue Base for OSAS.” Submucosal Ablation of the Tongue Base for OSAS. AAO, 8 Dec. 2012. Web. 15 Aug. 2013. http://www.entnet.org/Practice/Submucosal-ablation-of-the-tongue-base-for-OSAS.cfm.
3. Farrar J, Ryan J, Oliver E, Gillespie MB. Radiofrequency ablation for the treatment of obstructive sleep apnea: a meta-analysis. Laryngoscope. 2008 Oct;118(10):1878-83.
4. Woodson BT, Nelson L, Mickelson SA, Huntley T, Sher A. A multi-institutional study of radiofrequency volumetric tissue reduction for OSAS. Otol H&N Surg. 125(4):303-311, 2001.
Written by Dr. Nugent