Noel L. Cohen

Complications of Cochlear Implant Surgery in Adults and Children

Surgery for cochlear prosthesis insertion exposes the patient to several potential risks. We review the surgical complication experience with cochlear implants in the United States. There have been no deaths attributable to these devices, few serious major complications, and relatively few minor complications. Major complications usually have to do with surgical technique and include flap necrosis, improper electrode placement, and rare facial nerve problems. Minor complications include dehiscence of incisions, infection, facial nerve stimulation, dizziness, and pedestal problems with the Ineraid device. Complications were less frequent in children than adults and were more likely to occur in the younger children than those above the age of 7 years. Complications were still fewer in groups of patients operated on within tightly controlled protocols. There was no increased incidence of otitis media in children who received the Nucleus Mini-22 device, and no reported sequelae from such otitis when it occurred.

Long-term effects of cochlear implants in children

OBJECTIVE: Since 1987, when the use of multichannel cochlear implants was initiated in children, candidacy has expanded; many thousands of children have received these devices, and results have revealed a wide range of performance. However, few long-term studies exist on a large population of these children. There have been concerns expressed that cochlear implant function might degrade over time, that devices and electrodes might migrate and extrude in the growing child, or that there might even be a deleterious effect of long-term stimulation of the cochlear nerve. The purpose of this study was to explore the long-term effects of implantation as a function of performance over time, reimplantation, and educational factors. STUDY DESIGN AND SETTING: We studied 81 children who received implants at a major academic medical center and were followed for 5 to 13 years. RESULTS: Results revealed significant gains in speech perception, use of oral language, and ability to function in a mainstream environment. There was no decrease in performance over time and no significant incidence of device or electrode migration or extrusion, and device failure did not cause a deterioration in long-term outcome. CONCLUSIONS: Multichannel cochlear implants in children provide perception, linguistic, and educational advantages, which are not adversely affected by long-term electrical stimulation.

Systematic approach to electrode insertion in the ossified cochlea

Ossification of the fluid spaces of the cochlea occurs often in candidates for cochlear implantation, especially children. When noted before surgery on computerized tomography, ossification previously was thought to contraindicate cochlear implantation because of possible mechanical obstruction and uncertainty about the level of function that could be achieved by stimulating an ossified cochlea. However, during the preceding 6 years, techniques have been developed that permit implantation in ossified cochleas. We present a systematic approach that has been developed to treat the three clinically important categories of cochlear ossification: round window niche obliteration, inferior segment obstruction, and upper segment obstruction. Case reports are presented for each of these three drill-out procedures, demonstrating results often similar to those expected for implantation of the nonossified cochlea.

Cochlear Reimplantation: Surgical Techniques and Functional Results

Objectives/Hypothesis The most common indication for cochlear reimplantation is device failure. Other, less frequent indications consist of “upgrades” (e.g., single to multichannel), infection, and flap breakdown. Although the percentage of failures has decreased over time, an occasional patient requires reimplantation because of device malfunction. The varying designs of internal receiver/stimulators and electrode arrays mandate an examination of the nature and effects of reimplantation for the individual designs. The purpose of the current study was to investigate the reimplantation of several implant designs and to determine whether differences in surgical technique, anatomical findings, and postoperative performance exist.

Delayed implantation in congenitally deaf children and adults.

Objective To determine the efficacy of cochlear implants with current processing strategies in children and adults with long-term congenital deafness, and to determine whether the growth of auditory perceptual skills in these patients is similar to the data reported for patients who have undergone implantation with earlier devices and coding strategies. Study Design A prospective study of children and adults fulfilling the study inclusion criteria. Setting University medical center. Patients Thirty-five congenitally deaf children who received implants after the age of 8 years and 14 congenitally deaf adults who received implants as adults participated in this study. Length of device use ranged from 6 months to 3 years. Main Outcome Measures Open set phoneme, word recognition tests, and sentence recognition tests were administered in quiet and noise auditory only conditions preoperatively and postoperatively. Changes in test scores were examined by paired t tests, and differences between groups were compared by Students t tests. Spearman correlation coefficients were calculated to identify associations between scores and subject characteristics. A two-sided &agr; of less than 0.05 was considered statistically significant. Results The results indicated significant improvement in open set speech perception skills in the children after implantation; the adults demonstrated improved mean scores on both word and sentence recognition. A shorter length of deafness correlated with better postoperative performance, but all subjects continued to improve over time. The improvement in test scores was similar between the devices, and no significant differences were detected between the different processing strategies. Conclusion Children and adults with long-term congenital deafness can obtain considerable open set speech understanding after implantation. Length of deafness (age at implantation), length of device use, and mode of communication contribute to outcome.

Use of a multichannel cochlear implant in the congenitally and prelingually deaf population

Fourteen children and three adults, each congenitally and prelinguistically deaf, received the Nucleus® multichannel implant. All underwent extensive evaluations and rehabilitation. The surgery was uneventful, and no patients have been lost to follow‐up.

Acoustic Neuroma Surgery: An Eclectic Approach with Emphasis on Preservation of Hearing The New York University—Bellevue Experience

During the past 10 years, 157 patients have been operated on at the New York University-Bellevue Medical Center for acoustic neuromas and other cerebellopontine angle tumors. We describe our diagnostic protocol with joint neurosurgical evaluation leading to either translabyrinthine (otology only) or suboccipital-transmeatal (combined otology-neurosurgery) surgery. The decision is made on the basis of tumor size, level of hearing, age, and health of the patient. Using these criteria, 105 suboccipital and 59 translabyrinthine operations were performed with eight patients having had two-stage operations. In 12 of 29 patients, hearing was successfully preserved. Of 18 patients with good hearing and extracanalicular tumors less than 2 cm, hearing was preserved in 11. We describe the surgical technique used in this suboccipital-transmeatal operation and present illustrative cases in detail.

Cochlear implantation in the neurofibromatosis type 2 patient: long-term follow-up.

Objective: To evaluate the long‐term hearing outcomes of neurofibromatosis type 2 (NF2) patients with cochlear implants.

Cerebrospinal Fluid Drainage in the Management of CSF Leak Following Acoustic Neuroma Surgery

A retrospective analysis was performed on 174 patients operated on from 1992 to 1995 to evaluate the safety and efficacy of continuous lumbar cerebrospinal fluid drainage (CLCFD) in the management of cerebrospinal fluid (CSF) leaks following acoustic neuroma surgery. There was a 17% incidence of CSF leak. CLCFD stopped the leak in 87% of cases. There were no cases of meningitis associated with CLCFD. One deep vein thrombosis was treated without sequelae. It is concluded that CLCFD is safe and efficacious. The authors recommend that CLCFD be implemented immediately when indicated, foregoing a trial of conservative therapy. Indications and precautions are discussed.

The benefits of cochlear implantation in the geriatric population.

The deterioration of speech-understanding abilities in the aged that results from factors such as reduced speed and accuracy in processing has been well documented. The purpose of this study was to evaluate whether the geriatric population could benefit from a cochlear implant, despite the possibility of reduced processing abilities. Twenty patients, ages 65 to 85 years, with bilateral profound sensorineural hearing loss received the Nucleus multichannel cochlear prosthesis at NYU Medical Center. All patients underwent extensive preoperative medical and audiologic assessments to determine candidacy. The surgical procedure was well-tolerated by all patients. Mean postoperative test results revealed significant improvements in both auditory performance and quality of life as a result of implant usage. These data support the concept that although a reduction in the processing of sensory stimulation might exist, the elderly can process a new auditory code delivered by means of a cochlear implant.