Researchers Improve Success Rates for Chronic Rhinitis Treatments with Modified Surgical Technique

Targeting a sometimes obscured nerve improves the success rate of cryotherapy and radiofrequency therapy for chronic rhinitis, according to a recent Houston Methodist Hospital study that is extending the game-changing treatments to a minority of patients previously not helped by them.

The study showed that the temperature-controlled, office-based therapies benefitted initially unresponsive patients when doctors following up treated the posterior nasal nerve (PNN), hidden in certain people because of anatomic differences.

"Not only were we able to dramatically improve the procedures' success rate, now we're able to offer these safer, less invasive treatments as an alternative to the surgical options we often turn to for patients with a high symptom burden," said Dr. Omar Ahmed, a Houston Methodist otolaryngologist and the study's principal investigator.

The study, published in Laryngoscope Investigative Otolaryngology earlier this year, reported symptoms improved in more than 90% of participants — up from 70% historically — as a result of the hidden PNN being treated. Such outcomes now have been replicated in over 200 surgeries at Houston Methodist, and the technique is being adopted by surgeons nationwide.

In the past five years, cryotherapy (ClariFix®) and radiofrequency therapy (RhinAer™) have emerged as effective, minimally invasive options for many individuals suffering from near-constant runny nose, post-nasal drip, congestion, sneezing, coughing and nasal itching.

The procedures have been a watershed for the 70% of patients who respond favorably. But 30% of patients who underwent treatment received no noticeable improvements in their symptoms.

"We expected to see a gradual tapering off of benefits, but in these early studies it was more of a binary yes or no — either the treatment worked or it was like they never underwent the treatment at all," said Dr. Ahmed. "That clued us in to the fact that anatomic differences might be driving these results, and there might be a better way to ensure we're not missing the mark."

In an attempt to understand why the treatment was failing, Dr. Ahmed and Dr. Mas Takashima, chair of Otolaryngology – Head and Neck Surgery at Houston Methodist, first conducted research focused on patients who previously had not responded to the procedures.

"What we discovered was a significant variation in the anatomy of patients whose treatments were unsuccessful," said Dr. Ahmed.

Specifically, the team determined that the PNN, a key target in the procedures, is often missed because it's located behind the middle turbinate, a bony structure in the nasal cavity. Traditional approaches target nerves in front of this structure, leading to incomplete treatment in certain patients.

By using computed tomography (CT) scans, the researchers were able to identify these anatomical differences, particularly in the middle turbinate's attachment to the sphenopalatine foramen (SPF), the opening where PNN enters the nasal cavity.

Patients with an unfavorable attachment, where the turbinate attached anterior to the SPF, were more likely to experience treatment failure. In the team's study, published in the International Forum of Allergy and Rhinology in 2022, 90.9% of patients with this unfavorable attachment had no improvement from their initial treatments.

The research team modified their surgical technique to account for these anatomical variations, treating both the front and back of the middle turbinate.

The subsequent findings underscore the importance of personalizing treatment approaches based on individual anatomy and conducting follow-up studies when treatments fail.

Drs. Ahmed, Takashima and team first presented these findings at the 2022 American Rhinologic Society meeting. Their work has since gained national recognition, with clinicians across the country reaching out to the team for guidance on how to modify their technique.