Cochlear Implant With Translabyrinthine Acoustic Neuroma Resection
Michigan Ear Institute is one of the few centers around the globe beginning to study the benefits of performing a cochlear implant at the time of acoustic neuroma resection. Both short-term and long-term performance results are being studied and the preliminary data is encouraging.
The Congress of Neurological Surgeons recently looked at long-term hearing results of patients with acoustic neuroma. They found a low likelihood of long-term serviceable hearing preservation with observation, radiosurgery, and microsurgery. While patients with unilateral hearing loss have other options for hearing rehabilitation (traditional hearing aid, CROS aid, and BAHA), a cochlear implant is the only option that provides binaural stimulation by improving hearing in the poorer hearing ear.
Along with improved hearing in noise, reduction in both tinnitus and vertigo have been seen in those who have undergone this procedure. For this reason, we are so excited to offer this unique, cutting edge technique for our patients.
Surgical Innovations: Reducing CSF Leaks
As a center of excellence, the Michigan Ear Institute employs and pioneers a variety of the latest techniques in the treatment of Acoustic Neuromas. Our surgeons may repair the craniotomy, or opening in the skull, which allows for surgical access to your tumor with fat grafting and possibly other materials such as hydroxyapatite (HA) cement. Fat graft repair outcomes from MEI have been published in peer reviewed journals demonstrating excellent results with extremely low risk for CSF leakage. Hydroxyapatite (HA) is a biocompatible substance that integrates with bone and mimics the strength and durability of the body’s natural skeleton. Our surgeons have significant experience in this closure technique and are leaders in the field having published extensively on the topic.
A major advantage of hydroxyapatite closure is the avoidance of an abdominal incision, which is generally required for fat harvest for standard closure techniques. Hydroxyapatite cement may also reduce the risk of spinal fluid leak following surgery and reduce postoperative pain and less need for pain medications, including opioids. Your surgeon may discuss this option with you as well.
Intraoperative Facial Nerve Monitoring
One of the major advances in otologic and neurotologic surgery, facial nerve monitoring (FNM), was pioneered at the Michigan Ear Institute beginning in the late 1980’s. It has become the worldwide standard of care in all neurotologic procedures and in many otologic surgeries. Facial nerve monitoring has led to markedly improved facial nerve functional outcomes, especially in acoustic neuroma surgery.
Both passive and active facial nerve monitoring provide the surgeon with valuable information as to facial nerve location and function. Continuous electromyography (EMG) monitoring gives the surgeon feedback in real time during the course of surgery. With passive monitoring, EMG activity can be detected due to mechanical manipulation of the nerve. Direct electrical stimulation of the nerve (active monitoring) allows for facial nerve identification and confirmation of neural integrity. In acoustic tumor surgery, FNM is especially useful in mapping out the course of the nerve and determining the nerve/ tumor interface.
A more recent development in facial nerve monitoring, pioneered at MEI, has been the introduction of Kartush stimulus dissectors. These are surgical dissecting instruments acting as monopolar stimulating probes that allow for direct nerve stimulation during continuous dissection. The use of FNM using stimulus dissectors has led to outstanding facial nerve functional outcomes in both otologic and neurotologic surgery.