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Sept. 18, 2001 -- No.441
UNC study provides hope for habitual snorers
By LESLIE H. LANG
UNC School of Medicine
CHAPEL HILL -- A new study at the University of North Carolina at Chapel Hill School of Medicine offers new hope for habitual snorers and those who must endure their nighttime cacophonies.
How many people habitually snore is difficult to pin down, but epidemiological surveys indicate that the number may be high, affecting an estimated 30 percent of women and 40 percent of men. Moreover, the percentage of people who snore increases as people age.
"Most snoring questionnaires depend on patients being aware of their own snoring, which may not be the case," said Dr. Wendell G. Yarbrough, assistant professor in the division of otolaryngology-head and neck surgery at UNC. "In any event, subjective snoring often goes underreported."
In a journal report published Sept. 10 in the Archives of Otolaryngology, Yarbrough and co-authors described how a relatively new outpatient treatment for snoring can be modified to significantly boost the chances of success, cause less pain and result in fewer relapses than older methods.
The UNC researchers tackled the ubiquitous problem by attacking one of its common culprits: vibrations of the soft palate in the roof of the mouth that are caused by the breath during sleep. This region, along with the uvula that dangles at the back of the palate, the base of the tongue and the tonsillar pillars (the soft side walls near the tonsils) are collapsible regions of the upper airway that can change configuration during sleep.
"Basically, itís the palate thatís the main cause of snoring in people, the main vibrator that makes the noise," Yarbrough said. "If you can create scarring in it, then it becomes stiffer and tighter and wonít vibrate as much."
The method the researcher studied involved heating a needle electrode with radiofrequency energy to create lesions in the soft palate. The needle is placed through the mucosa and into the
muscular portions of the palate where pain nerve fibers are few. A heat lesion is created around the needle, a scar the size of which can be controlled by the energy level used.
Unlike other surgical treatments for snoring, including laser procedures, tissue is not removed and there is no raw surface to heal. "Those treatments work but are very painful and can require multiple procedures. Often, patients wonít come back for the second or third treatment because it hurt so much the first time," Yarbrough said.
Somnus Medical Technologies Inc., of Sunnyvale, Calif., developed the technology for radiofrequency tissue volume reduction. It has been studied in the last three years in cardiology and urology for soft tissue ablation. Studies in otolaryngology last year showed it could be useful for treatments to reduce or eliminate snoring.
But as Yarbrough pointed out, the original procedure involved creating only a single lesion. While less painful than older treatments and not requiring general anesthesia, the single lesion method did have a drawback in common with the others.
"With the single lesion technique, people had to get multiple treatments before their snoring would improve. So we started giving more energy per session and creating multiple lesions. We went from three, then to four, and now five."
The new study compared single versus multiple lesions for safety and effectiveness. Results clearly favored the multiple lesion approach.
Each group showed significant reduction in snoring as measured by a 10-point scale completed by the spouse. "We were able to show that the more energy you give with each treatment, the more improvement you get," Yarbrough said.
The single lesion group showed 1.46 improvement, triple lesion 1.68, 4 lesion 2.3.
As to the number of treatments per cure: The percentage of single lesion patients cured after two treatments was 25 percent, compared with 61 percent for the triple lesion patients and 71 percent for the four lesion group. "So what weíre doing is decreasing the number of treatments people must go through before their snoring is cured. And this means snoring that is not bothersome to the partner," Yarbrough said.
In terms of pain, the study did show increased pain with an increased number of lesions, "but still at a level that doesnít require narcotic pain medication," Yarbrough said. "We treat people on Friday and by Monday they go back to work. We recommend partially inclined sleep for the first night or two."
About 20 percent of habitual snorers will not be helped by this or any other procedures. "Theyíre making noise with something besides the palate; for example, the pharyngeal side walls. As there is no reliable way to differentiate these patients and there is no accepted procedure to address areas other than the palate, all current treatments focus on the palate," Yarbrough said.
"Our study included a 16-month follow-up, the longest in the literature. In a previous single lesion study, a 14-month follow-up showed significant worsening of snoring. We didnít see that in our multi-lesion group. Our ultimate goal is to decrease the number of procedures as much as we can so patients donít have to incur increase costs or suffer more morbidity."
Study co-authors are Dr. Michael Ferguson, a resident in otolaryngology-head and neck surgery; and Adam Zanation, a UNC medical student.
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Note: Contact Yarbrough at (919) 966-3344 or firstname.lastname@example.org
School of Medicine contact: Leslie Lang at (919) 843-9687 or email@example.com