Freezing the posterior nasal nerve can reduce the symptoms of chronic rhinitis, researchers say.
In what they believe to be the most rigorous study yet of cryotherapy for chronic rhinitis, the researchers showed that the ClariFix cryotherapy device (Stryker) was more efficacious than a sham procedure in improving the symptoms patients reported on questionnaires.
"This was the first time we were able to get placebo control, using the blinding method we developed here, to test whether the device worked," said Anthony Del Signore, MD, PharmD, an assistant professor of otolaryngology at Mount Sinai Hospital in New York City. He and his colleagues published their findings this month in International Forum of Allergy & Rhinology .
About 10%–22% of patients with chronic rhinitis don't get relief from any of the medical treatments available, according to estimates the researchers cited.
A surgical procedure called vidian neurectomy is designed to disrupt parasympathetic innervation of the nasal mucosa and can help these patients. But this must be done under general anesthesia and frequently causes dry eye because it also disrupts parasympathetic innervation to the lacrimal gland.
More recently, device manufacturers have focused on ablating the posterior nasal nerve because it is distal to the parasympathetic fibers for lacrimal innervation, making dry eye an unlikely side effect.
The ClariFix impairs this nerve by freezing it. A rival product, the RhinAer Stylus (Aerin Medical) impairs the nerve through radiofrequency ablation.
The US Food and Drug Administration ruled in 2017 that the ClariFix could be marketed because it was similar to devices already on the market. It gave the same approval to the RhinAer 2 years later. Nonrandomized trials produced promising results for both devices, and both companies began randomized controlled trials, with the ClariFix results now available.
For the ClariFix trial, the investigators recruited 133 people with chronic rhinitis at 12 centers in the United States. Of these, 43% had allergic rhinitis and 94% had endured their symptoms for more than 2 years. The researchers randomly assigned 68 to treatment with the ClariFix and 65 to a sham procedure. The groups were similar except that those assigned to the active treatment had a mean age of 6 years younger than those in the sham group.
The investigators blindfolded all the patients. Then they treated those assigned to ClariFix according to the manufacturer's instructions: after administering local and topical anesthesia, physicians inserted the cryoprobe into the posterior middle meatus of the patient's nasal cavity and administered a 30-second freeze followed by a 60-second thaw, then repeated at their discretion.
For the sham procedure, the investigators applied the same anesthetics and placed the cryoprobe in the same positions in the patients' nasal passages for the same durations of time. They released gas from a cannister near the patients' heads to simulate the sound of the ClariFix treatments.
The results suggest that the benefits of the procedure include a placebo effect, but that the nerve ablation causes a longer-lasting effect, the investigators found.
After 90 days, 73.4% of those receiving the ClariFix treatments reported at least a 30% reduction in their symptoms on the reflective Total Nasal Symptom Score (rTNSS), compared with 36.5% of those receiving the sham treatment, a statistically significant difference (P > .001). On this scale, patients rate their symptoms from 0 (no symptoms) to 3 (severe symptoms) on four domains, yielding a range of 0-12.
The active treatment group improved from a baseline score of 8.1 to 4.8 at 30 days and reached 4.3 at 90 days. The sham group improved from a baseline of 8.1 to 5.7 at 30 days, then worsened again to 6.3 at 90 days. The differences between the two groups in the change in symptoms was not statistically significant at 30 days (P < .088) but it was at 90 days (P < .001) .
The changes in scores and differences between the two groups were similar on the Rhinoconjunctivitis Quality of Life Questionnaire standardized (RQLQs) and Nasal Obstruction Symptom Evaluation (NOSE).
The investigators planned to measure the change in the patients' mucus flow themselves, but had to scratch those plans because of COVID-19.
One patient experienced a panic attack after the procedure, but improved after spending a day under observation. Just under half (32 of 68) of the people in the active treatment group and 3 in the sham group reported less serious adverse events. The most common was pain or discomfort at the treatment site, and four reported headaches. These reactions typically resolved within 2 hours of the procedure.
Previous studies have shown the benefits can last at least 24 months, Del Signore told Medscape Medical News. He counsels his patients that it's possible the effects will wane after about 2 years because of nerve regeneration. "I tell them we could just play it by ear and see how their quality of life is impacted and at that point we could decide whether to re-treat," he said.
Patients are hearing about the procedure and contacting specialists who offer it, said Zachary Michael Soler, MD, MSc, an associate professor of otolaryngology at Medical University of South Carolina in Charleston, who enrolled some of his patients in the trial. "I don't think the average primary care doctor knows this exists," he told Medscape Medical News. "Patients are untreated and they kind of find you. I saw a guy today; he came from 2 hours away."
The procedure requires endoscopy and primary care physicians should not attempt it themselves, he said.
"Every patient has a different response, but some of my patients when they are candidates, they are using tissues 24/7, said Jivianne K. Lee, MD, an associate professor of rhinology and endoscopic skull-based surgery at UCLA David Geffen School of Medicine in Los Angeles. "Some have said it's been transformative in their quality of life because they no longer need to carry a tissue around with them all the time," she told Medscape Medical News.
Not all patients can undergo the procedure in the office, she said. "You have to have somewhat favorable anatomy. A deviated septum would make it difficult to do under local anesthesia."
She has also treated patients with the RhinAer. "I think they both work well," she said. "The one benefit of the radiofrequency ablation is that the patients don't get an 'ice cream headache.' "
Del Signore and Soler have disclosed no relevant financial relationships. Lee reported relationships to Stryker and Aerin Medical.
Int Forum Allergy Rhinol. Published online August 6, 2021. Abstract
Laird Harrison writes about science, health and culture. His work has appeared in national magazines, in newspapers, on public radio and on websites. He is at work on a novel about alternate realities in physics. Harrison teaches writing at the Writers Grotto. Visit him at lairdharrison.com or follow him on Twitter: @LairdH
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Cite this: Cryotherapy Found Efficacious for Chronic Rhinitis - Medscape - Aug 27, 2021.