Faculty Bibliography

PURPOSE: To present the postoperative radiographic appearance of the multichannel cochlear implant and to suggest criteria for the radiographic evaluation of postimplant patients. METHODS: One hundred forty-one patients, 73 female and 68 male, had multichannel cochlear implants inserted. One hundred thirty-five intraoperative radiographs, 31 postoperative radiographic examinations, and 10 postoperative CT examinations were retrospectively reviewed. RESULTS: In 135 patients, a Stenver's or anteroposterior projection confirmed the normal placement of the implant by demonstrating the electrodes to be regularly spaced and gently curved within the first turn of the cochlea. The insertion depth was determined by counting the number of electrodes that projected medial to the cochlear promontory. In 5 patients in whom intracochlear placement of the electrode array could not be confirmed on plain radiographs, CT demonstrated the location of the electrode array. In 3 patients with postoperative infections, CT either correctly identified or excluded the presence of a collection beneath the implant. CONCLUSION: Plain radiographs of the temporal bone are sufficient for the postoperative treatment of the majority of postimplant patients. CT should be performed when plain radiographs cannot adequately show the location of the electrode array or if postoperative infection is suspected

A cochlear lubricant may facilitate the surgeon's ability to place the electrode array deep within the cochlea. Patient performance with the multichannel cochlear implant may be enhanced with a deeper electrode insertion. Theoretically, deeper insertion and stimulation will recruit and activate more surviving spiral ganglion neurons. Several studies have shown that neuron survival is a factor for cochlear implant success, especially in the postmeningitis patient. We studied the histologic and electrophysiologic effects of the intracochlear injection of three potential lubricants in the guinea pig: glycerin, hyaluronic acid, and hydroxypropyl methylcellulose. All three have approved medical uses, reduce friction, and are readily available. Results show that when compared to surgical controls (cochleostomy without injection), there is no significant reduction in the spiral ganglion neuronal count at 2 and 8 weeks postinjection, and the dendrite and axon histology is well preserved. Injection of any of the substances within the cochlea causes severe hearing loss (detected by direct round window electrocochleographic responses to auditory stimuli) that only partially recovers with time. These findings suggest that any of the three tested substances could be considered as lubricants for intracochlear electrode insertion

Otologic disease often extends into the hypotympanum, posterior mesotympanum, and infralabyrinthine compartments. Surgical access to these areas can be difficult because of the proximity of the facial nerve. In patients with a normal bone anatomy, these regions can be accessed by a retrofacial approach, which spares the posterior canal wall and avoids transposition of the facial nerve. The anatomy of the hypotympanum, posterior mesotympanum, and infralabyrinthine compartments will be reviewed emphasizing gross anatomic documentation. We will detail the surgical approach to these areas along the retrofacial air cell tract, and will present an appropriate case history

Massive skull base injuries require detailed preoperative neurological and neurovascular assessment prior to undertaking surgical repair of isolated cranial nerve deficits. We present the management of a patient with traumatic facial paralysis, cerebrospinal fluid leak, and carotid artery cavernous sinus fistula as the result of a gunshot wound to the skull base. The carotid artery cavernous sinus fistula was ultimately controlled with super-selective embolization via the vertebral artery. The facial nerve injury was then safely treated with mobilization of the labyrinthine and vertical segments to allow a primary anastomosis

Eight patients 45 years of age and under (range, 29 to 45) with squamous cell carcinoma of the head and neck and infection with the human immunodeficiency virus are reported. Primary tumor sites include nasopharynx, oral cavity, oropharynx, and larynx. Probes for the human papillomavirus were positive in two of the patients. Therapy consisted of surgery followed by radiation therapy in five patients, surgery alone in one patient, and radiation therapy in the remaining two patients. Follow-up ranged up to 2 years and revealed four deaths, three patients alive without disease, and one patient recently posttreatment with residual disease. The significance of the presence of the human papillomavirus in these individuals remains to be determined. The incidence of squamous cell carcinoma of the head and neck under age 45 is low, and whether there may be a higher incidence in HIV-positive patients cannot be determined from this small series