Dr. Poe is the principal investigator of a clinical trial mandated by the U.S. Food and Drug Administration (FDA) comparing balloon dilation with nasal steroid spray for Eustachian tube dilatory dysfunction in an effort to get the device approved by the agency. The FDA requested that the trial be performed in comparison to medical management, which is commonly used in clinical practice despite a lack of evidence that medical therapy influences dilatory dysfunction.
Explore This IssueJanuary 2016
As a rhinologist, Dr. Metson often combines balloon dilation with a microdebrider to perform Eustachian tube and sinus surgery. This thin hollow tube has a rotating blade at the tip that shaves swollen tissue from the opening of the Eustachian tube to enlarge it. He has had fairly good success with this procedure. The microdebrider can also be used alone and is ideal for patients with polyps, hypertrophic tissue, and adenoid tissue that may be contributing to Eustachian tube or sinus obstruction.
Obliteration for Cerebrospinal Fluid Leak Repair
Obliteration for cerebrospinal fluid (CSF) leak repair is used for lateral skull base or posterior fossa lesions that result in a spinal fluid leak that drips down the Eustachian tube. Spinal fluid leaks occur in 5% to 10% of skull base surgeries, such as vestibular schwannomas.
The surgery involves a transnasal, transoral endoscopic approach. The endoscope is inserted into the tip in the nose. A tonsil mouth gag is inserted into the mouth to provide greater access to the Eustachian tube, which facilitates dissection and suturing. Dr. Poe uses an angled microdebrider blade passed through the mouth to remove mucosa 360 degrees around the Eustachian tube and as high as possible in the lumen. The lumen is filled with AlloDerm (a cadaveric dermis product) and oversewn shut.
“It’s important to only remove surface mucosa and not allow the microdebrider to dig deeper into tissue, which can create significant bleeding,” Dr. Poe said. “We have to always be aware of the location of the internal carotid artery in this area, but keeping the dissection within the cartilaginous Eustachian tube provides an adequate margin of safety.” The complete obliteration will normally scar over fully, and long-term outcomes are excellent, because it shouldn’t recur, Dr. Poe said.
The surgery is a useful alternative to inserting a lumbar drain for three to five days or trying to plug the neurosurgical wound from the inside. In addition, patients tolerate it much better and spend fewer days in the hospital. Although a lumbar drain is still required in order to keep the seal dry for the first few days, less time is necessary.
Patulous Eustachian Tube Repair
Patulous Eustachian tube is an uncommon condition in which the Eustachian tube is a persistently open, causing the disturbing symptoms of autophony and respiratory-synchronous tinnitus. Incidence of patulous Eustachian tube ranges from 0.3% to 10% of the general population (J Am Acad Audiol. 2011;22:201-207). Physically, it involves a defective concavity in the lumen that causes a leak in the valve. Consequently, the Eustachian tube doesn’t close completely.