Long-term results of cochlear implantation in children.

OBJECTIVES: Since the first implantation of a multichannel cochlear implant over 15 years ago there have been improvements in implant devices, surgical techniques, speech coding strategies and rehabilitation matters. There also have been concerns, whether the first implanted systems are stable and the benefit for the patients is constant over a long time. This study analyzes long-term results of prelingually deaf children who were implanted at Aachen University Hospital. STUDY DESIGN AND SETTING: We examined 16 prelingually deaf children, who underwent cochlear implantation at our department between 1990 and 1993 over a time period of 10 to 13 years. The indication, perioperative complications, technical parameters, speech test results as well as the psychosocial development of the children were analyzed. A questionnaire containing questions about the daily use, expectations and the personal evaluation of the procedure was sent to all patients. RESULTS: The mean age of all patients was 9 years at time of implantation. In two cases we saw postoperative complications which needed an intervention. The speech test results remained stable after reaching a plateau after 5 years. Eighty-eight percent of all patients would undergo the procedure again and 94% would recommend cochlear implantation to others. CONCLUSION: Cochlear implantation in cases of prelingual deafness is feasible without severe complications and leads to an increasing quality of life demonstrated by long-term observation.     

Reliability of cochlear implants.

BACKGROUND: The long-term reliability of cochlear implants over time is an important issue for patients and cochlear implant teams. The calculation of cumulative survival rates including all hard failures of cochlear implants is suitable to report objectively about cochlear implant reliability. METHODS: This is a report of 192 cochlear implants from different manufacturers in adults (n = 58) and children (n = 134). RESULTS: The overall cumulative implant survival rate was 91.7% for a period of 11 years. The main reasons for hard failures were design errors of the products and direct or indirect trauma to the cochlea implant site (especially in children) with consecutive breaks of the implant body or electrodes. CONCLUSIONS: To improve our knowledge about reliability of cochlear implants more studies on cumulative long time survival of cochlear implants are needed, where functional failures and complications for whatever reason (design, mechanical, electronic, medical) are included. Cochlear implant reliability data should be considered during the choice of an implant for each individual patient.     

Speech perception results in children with cochlear implants: contributing factors.

Speech perception test results were obtained from a group of 40 pediatric cochlear implant users. Half of the children participated in oral-only habilitation programs, which included both traditional oral and auditory-verbal approaches, and half participated in programs that used a combination of oral and manual communication referred to as total communication (TC). Analysis of the scores showed that children enrolled in oral-only habilitation programs scored significantly higher on the speech perception measures than did children who were enrolled in total communication based programs. These results were inconsistent with those of other reports, which suggested that communication methods had little effect on implant outcomes. To further examine the reasons for the differences in performance, we analyzed 7 additional factors, including length of implant use, age at surgery, device type, socioeconomic status, bilingualism, school setting, and participation in private therapy, which may affect implant performance. Multiple-regression analysis again showed communication mode to be the factor most highly correlated with speech perception abilities among this group of children.     

Early speech changes in children with multichannel cochlear implants

A number of studies have demonstrated that cochlear implants provide an improved auditory signal and enhance the development of speech-perception and production skills for profoundly deaf children. However, exactly when these early speech skills begin to develop remains unclear. To explore this issue, we observed, for a 1-year period, four prelingually deaf children who underwent implantation consecutively within 1 month of each other, and we paid particular attention to the first few months of rehabilitation. We found immediate speech scores as early as the first day of implant tune-up. Speech production continued to improve rapidly throughout the first 4 months but exhibited a generally slower rate of progress in some of the speech-production skills at 1 year. We also found vowel-production skills to be the easiest to achieve, with word-pattern recognition and consonant voicing of intermediate difficulty. Consonant placing and manner of consonant production were the hardest skills to achieve. Results of speech-perception tests 1 year after implantation were markedly improved over preimplantation levels in three of the four children. These early speech changes stress the need for maximization of the capability of the cochlear implant by institution of immediate and intensive speech rehabilitation efforts for prelingually deaf children. (Otolaryngol Head Neck Surg 1996;115:508-12.)     

Pediatric cochlear implants

Indications for cochlear implants have been widened since 1995. Most implant candidates are children with severe congenital deafness. The cochlear implant must be inserted as early as possible for these children in order to optimize development of perception and language. A cochlear implant can also be discussed in certain particular cases for children with associated diseases, malformation of the inner ear, or severe deafness. The educational project must be realistic and take into account the future difficulties as well as an established set of criteria for successful language acquisition.     

Resolution of facial stimulation in otosclerotic cochlear implants.

OBJECTIVES: We examined the incidence of facial nerve stimulation in a population of patients with otosclerosis implanted with the Nucleus 22, Clarion 1.2, or Clarion High Focus (CHF) device. STUDY DESIGN AND SETTING: A retrospective chart review was used for 147 patients who had been implanted with electronic cochlear devices at the University of Minnesota between June 1986 and February 2001. Seventy-four patients were implanted with the Nucleus 22, 41 patients were implanted with the Clarion 1.2 (without a positioner), and 32 patients were implanted with the CHF I or II. RESULTS: Eleven (14.9%) of the 74 patients implanted with the Nucleus 22 device had facial stimulation. There were 9 patients with otosclerosis. Seven (78%) of the 9 patients with otosclerosis had facial stimulation. One (2.4%) of the 41 patients implanted with the Clarion 1.2 device (without a positioner) had facial stimulation and that 1 (100%) patient in the group had otosclerosis. There were 4 patients in the CHF group with otosclerosis. One patient experienced stimulation, but it was possible to decrease maximum current levels and still use the electrode pair. CONCLUSION: Facial stimulation appears to be less problematic in patients with otosclerosis implanted with the CHF devices.     

Cognitive skills and academic achievement of deaf children with cochlear implants

Objective To compare cognitive performance between children with cochlear implants (CI) and normal-hearing peers; provide information about correlations between cognitive performance, basic academic achievement, and medical/audiological and social background variables; and assess the predictor quality of these variables for cognition. Study Design Cross-sectional study with comparison group, diagnostic test assessment. Setting Data were collected in the authors' clinic (children with CI) and in Austrian schools (normal-hearing children). Subjects and Methods Forty children with CI (of the initial 65 children eligible for this study), aged 7 to 11 years, and 40 normal-hearing children, matched by age and sex, were tested with (a) the Culture Fair Intelligence Test (CFIT); (b) the Number Sequences subtest of the Heidelberger Rechentest 1-4 (HRT); (c) Comprehension, (d) Coding, (e) Digit Span, and (f) Vocabulary subtests of HAWIK III (German WISC III); (g) the Corsi Block Tapping Test; (h) the Arithmetic Operations subtests of the HRT; and (i) Salzburger Lese-Screening (SLS, reading). In addition, medical, audiological, social, and educational data from children with CI were collected. Results The children with CI equaled normal-hearing children in (a), (d), (e), (g), (h), and (i) and performed significantly worse in (b), (c) and (f). Background variables correlate significantly with cognitive skills and academic achievement. Medical/audiological variables explain 44.3% of the variance in CFT1 (CFIT, younger children). Social variables explain 55% of CFT1 and 24.5% of the Corsi test. Conclusions This study augments the knowledge about cognitive skills and academic skills of children with CI. Cognitive performance is dependent on the early feasibility to hear and the social/educational background of the family.     

The narrow internal auditory canal in children: a contraindication to cochlear implants

We suggest a new explanation for the lack of auditory response to electric stimulation in children with cochlear implants: the very narrow internal auditory canal, 1 to 2 mm in diameter, and the probable absence of the cochlear nerve. This defect can be seen on high-resolution computed tomographic x-ray studies and may represent aplasia of the auditory-vestibular nerve. We report on eight children with this anomaly, three of whom have received implants and failed to respond with a sensation of sound. Identification of this problem on screening x-ray films is a contraindication to cochlear implantation for auditory stimulation.     

Biofilm formation in cochlear implants with cochlear drug delivery channels in an in vitro model.

BACKGROUND: Cochlear implant (CI) drug delivery (DD) may improve electrophysiological outcomes, but it may also increase the risk of suppurative complications. The aim of this study was to evaluate the development of bacterial biofilms on DD ports when subjected to varying types of penetration. METHODS: Silastic models were constructed to represent CIs with a DD channel, with an intact port, a widely opened port, a noncoring needle penetrating the port, and a noncoring needle removed from the port. CIs were exposed to a culture of a biofilm-forming strain of Staphylococcus aureus for 5 days. Biofilm formation was assessed with quantitative bacterial counts (after eliminating planktonic bacteria) and scanning electron microscopy. RESULTS: Bacterial counts were significantly higher in CIs with widely fenestrated ports than all other port conditions (P = 0.0003). CONCLUSIONS: Biofilm formation may be minimized on CIs with DD by using fine, noncoring needles and limiting the duration of port penetration.     

Comparison of speech perception abilities in deaf children with hearing aids or cochlear implants

The speech perception abilities of deaf children with a single- or multi-channel cochlear implant are compared with those of deaf children who derive substantial benefit from conventional hearing aids. The children with hearing aids have unaided pure-tone thresholds ranging from 90- to 110-dB HL through at least 2000 Hz, and aided thresholds of 30- to 60-dB HL. The group data show that the speech perception scores of the subjects with hearing aids were significantly higher than those of the subjects with implants on a range of speech perception measures. Although a few subjects with implants achieved scores as high as those who used hearing aids, the majority did not. Even though the children with implants receive substantial benefit from their devices, they continue to have limited auditory perception abilities relative to their peers who derive benefit from conventional hearing aids. The data highlight the importance of establishing hearing aid benefit in potential candidates for implant.     

Long-term follow-up of pyrolytic carbon metacarpophalangeal implants.

BACKGROUND: The metacarpophalangeal joint is the most commonly involved joint when rheumatoid arthritis affects the hand. Many prosthetic implants have been designed for the replacement of this joint. Although studies of these implants have shown relief of pain, they have generally demonstrated a poor range of motion, progression of ulnar drift, and bone loss, as well as failure, fracture, and dislocation of the implant. METHODS: From December 1979 to February 1987, 151 pyrolytic carbon metacarpophalangeal implants were inserted in fifty-three patients. The implants had an articulating, unconstrained design with a hemispherical head and grooved, offset stems. Forty-four patients had rheumatoid arthritis; five, posttraumatic arthritis; three, osteoarthritis; and one, systemic lupus erythematosus. Three patients (eleven implants) were lost to long-term follow-up, and twenty patients (fifty-one functioning implants) died after the implant had been in situ for an average of 7.2 years. Eighteen implants (12 percent) in eleven patients were revised. Fourteen of the eighteen implants were replaced with a silicone-elastomer or another type of implant, and the remaining four were removed and a pyrolytic carbon implant was reinserted with the addition of bone cement or bone graft, or both. Twenty-six patients (seventy-one implants) were available for long-term review at an average of 11.7 years (range, 10.1 to 16.0 years) after implantation. RESULTS: The implants improved the arc of motion of the fingers by an average of 13 degrees and elevated the arc by an average of 16 degrees. As a result, fingers were in a more functional, extended position. A complete set of preoperative, postoperative, and follow-up radiographs was available for fifty-three of the seventy-one implants that were followed long term. There was a high prevalence of joint stability: fifty (94 percent) of the fifty-three implants were in a reduced position postoperatively, and forty-one (82 percent) of those fifty implants were still in the postoperative reduced position at the time of long-term follow-up. Ulnar deviation averaged 20 degrees preoperatively and 19 degrees at the time of follow-up, with only the long finger having an increase in deviation. No adverse remodeling or resorption of bone was seen. Fifty (94 percent) of the fifty-three implants had evidence of osseointegration, with sclerosis around the end and shaft of the prosthetic stems. Radiolucent changes were seen adjacent to twelve implants. There was minimum-to-moderate subsidence (four millimeters or less) of thirty-four implants; most of the subsidence occurred immediately postoperatively. Survivorship analysis demonstrated an average annual failure rate of 2.1 percent and a sixteen-year survival rate of 70.3 percent. The five and ten-year survival rates were 82.3 percent (95 percent confidence interval, 74.6 to 88.2 percent) and 81.4 percent (95 percent confidence interval, 73.0 to 87.8 percent), respectively. None of the revised implants had any visible changes of wear or deformity of the surfaces or stems. Four instances of chronic inflammatory tissue and three instances of proliferative synovitis were noted histologically. Focal pigment deposits were seen in three fingers, one of which had removal of the implant two months after a fracture. No evidence of intracellular particles or particulate synovitis was found. CONCLUSIONS: The results of this study demonstrate that pyrolytic carbon is a biologically and biomechanically compatible, wear-resistant, and durable material for arthroplasty of the metacarpophalangeal joint.     

Long-term results with hydroxylapatite middle ear implants.

PURPOSE: This study evaluated long-term results in patients who had ossicular reconstruction with a Goldenberg hydroxylapatite implant. METHODS: A total of 233 patients underwent implantation; of these, 77 had 5-year or longer follow-up and are the subjects of this study of long-term hearing results. All 233 patients were included for analysis of extrusion rate and postoperative otorrhea. RESULTS: The hearing success rate at long-term follow-up was 56.8%; the mean air-bone gap was 21.1 dB. Prosthesis extrusion occurred in 5.29% of the 233 patients, and visible slippage occurred in 7.7%. Overall, 50. 6% of patients met the criteria for successful hearing, which included no extrusion and a dry ear. Better hearing before surgery and presence of the malleus long process were factors associated with a successful hearing result, as was tympanoplasty alone and canal wall up tympanomastoidectomy. CONCLUSION: Hydroxylapatite hybrid prostheses provide stable hearing results over time with low extrusion and a dry ear overall.     

Long-term results of palatal implants for primary snoring.

OBJECTIVE: To determine the safety and efficacy of the Pillar Palatal Implant System over a 1-year follow-up period. STUDY DESIGN AND SETTING: In this prospective study, 40 healthy adult patients with primary snoring due to palatal flutter were treated after clinical, polysomnographic, and endoscopic examination. Under local anesthesia 3 implants were placed into the soft palate. Postoperative morbidity and functional parameters were assessed. Snoring and daytime sleepiness were assessed before and 90, 180, and 360 days after surgery. Objective data were obtained by polysomnography and SNAP-recording before and 90 days after treatment. RESULTS: All implants were placed without complications. A total of 13 implants partially extruded uneventfully in 10 patients. Functional parameters remained unchanged. After 1 year, snoring was reduced from 7.1 +/- 1.9 to 4.8 +/- 2.5 (Visual-Analogue-Scale, P < 0.05) and daytime sleepiness from 6.1 +/- 3.2 to 4.9 +/- 3.1 (Epworth-Sleepiness-Scale, P < 0.05). SNAP data and polysomnography parameters showed clinically irrelevant changes. CONCLUSION: Our data demonstrate a significant decrease in snoring and daytime sleepiness over a period of one year.     

Biofilm formation in an in vitro model of cochlear implants with removable magnets.

BACKGROUND: Cochlear implant (CI) recesses, such as the removable magnet pocket, appear to harbor more biofilm than smooth surfaces. The aim of this study was to examine the impact of removable magnets on biofilm formation in an in vitro model. METHODS: Silastic models were constructed to represent CIs with and without a magnet pocket and with and without a titanium blank in the pocket. CIs were exposed to a culture of a biofilm forming strain of Staphylococcus aureus. Adherence of planktonic bacteria and biofilm formation were assessed with quantitative bacterial counts and scanning electron microscopy. RESULTS: Adherent bacterial counts were significantly higher in CI models with an empty magnet pocket (P = 0.0097). Biofilm formation was significantly lower in CI models without a magnet pocket (P = 0.0121). CONCLUSIONS: CI magnet pockets harbor bacteria that can increase biofilm development in an in vitro model.