Our ears are a delicate instrument, composed of a variety of elegant structures. Less than a millimeter thick, the eardrum or tympanic membrane receives information from our surroundings and transmits them to the minuscule bones or ossicles of the middle ear. Those tiny structures then propel sound into the inner ear as vibrations. This incredible ability to conduct sound has a tradeoff; the eardrum is also fragile. Hearing ability is lost when the eardrum breaks, and can no longer move sound from the outer ear to the inner ear.
New work may help torn eardrums. As the video above describes, a new procedure has been developed by researchers in Japan aiming to help the eardrum heal under its own power. Results from a July 2016 clinical trial are due to be reported soon.
Eardrums can burst simply because of trauma, or from an infection. Most tend to heal by themselves over the course of about ten days, but there are some that cannot heal naturally. With that kind of chronic rupture, there is an increased risk of hearing loss and middle ear infections, which can be a serious problem.
For these chronically injured eardrums, a surgery called tympanoplasty is the only treatment. It involves harvesting graft material from the patient, which is then used to patch up the rupture. While it does have a good success rate, it is very expensive, it requires the attention of specialists, and like any surgery carries a risk of complications including a slight chance of nerve damage. In poor countries where infection rates are high, the procedure is rarely or never performed.
The technique has to be improved if we are to bring better therapeutics to more people. Investigators working on tissue engineering saw the need. They created a sponge scaffold of gelatin that has been infused with a molecule called basic fibroblast growth factor (bFGF). The eardrum then gets assistance in regenerating the eardrum without relying on a surgical patch.
A phase II study of the technique was done in 2011; of 53 patients, 52 displayed total healing in the eardrum and improvement in their hearing, compared with one of ten in a control group. Scientists were intrigued by these results; a commentary from Robert Jackler, a head and neck surgeon at Stanford University, California, stated that a confirmation of the procedure’s efficacy by replicating it would be “potentially the greatest advance in otology since the invention of the cochlear implant.”
Jackler noted that “it could bring a simple and inexpensive remedy to the many millions of patients around the world for whom capital intensive microsurgery is not available.”
Other studies that have backed up the concept. Preclinical assessment of skin grafts and scarred vocal chords indicate that bFGF in a gelatin scaffold can aid healing of those wounds. Other molecular infusions, like epidermal growth factor, are also being tested.