F
Cochlear Implants in Children: A Review of Reported Complications, Patterns of Device Failure, and Assessment of Current Approaches to Surveillance

John K. Niparko M.D.,* Janice Leung A.B.,* Debara L. Tucci M.D.,** Martin J. Burton M.D., F.R.C.S.,*** Eric A. Mann M.D., Ph.D.****

INTRODUCTION

Impairment of hair cell function induces profound deafness in approximately 0.3 percent of children younger than 5 years.1,2 In deafness, hair cells of the inner ear fail to trigger auditory nerve fibers in the presence of sound. However, large reserves of auditory nerve fibers exist even in the ear of the profoundly deaf. Furthermore, these nerve fibers retain the ability to respond to electrical activation. Cochlear implants could potentially affect the auditory rehabilitation of an estimated 200,000 United States children with advanced levels of deafness as indicated by a failure to achieve critical milestones in speech and language using conventional hearing aids.

While the impact of hearing loss in an adult varies considerably with the severity of hearing loss and with lifestyle choices, the impact of an advanced level of hearing loss in infancy and early childhood can dramatically affect developmental learning. Because most domains of communication and language learning are subserved by early access to the phonology of speech, deafness effects can extend to the acquisition of visual-language reception (reading) and visual-language production (writing), as well as the constructs of spoken language. A hearing 5-year-old child, for example, has

*  

Johns Hopkins University.

**  

Duke University.

***  

Oxford University.

****  

Center for Devices and Radiological Health, U.S. Food and Drug Administration.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 382
Safe Medical Devices for Children F Cochlear Implants in Children: A Review of Reported Complications, Patterns of Device Failure, and Assessment of Current Approaches to Surveillance John K. Niparko M.D.,* Janice Leung A.B.,* Debara L. Tucci M.D.,** Martin J. Burton M.D., F.R.C.S.,*** Eric A. Mann M.D., Ph.D.**** INTRODUCTION Impairment of hair cell function induces profound deafness in approximately 0.3 percent of children younger than 5 years.1,2 In deafness, hair cells of the inner ear fail to trigger auditory nerve fibers in the presence of sound. However, large reserves of auditory nerve fibers exist even in the ear of the profoundly deaf. Furthermore, these nerve fibers retain the ability to respond to electrical activation. Cochlear implants could potentially affect the auditory rehabilitation of an estimated 200,000 United States children with advanced levels of deafness as indicated by a failure to achieve critical milestones in speech and language using conventional hearing aids. While the impact of hearing loss in an adult varies considerably with the severity of hearing loss and with lifestyle choices, the impact of an advanced level of hearing loss in infancy and early childhood can dramatically affect developmental learning. Because most domains of communication and language learning are subserved by early access to the phonology of speech, deafness effects can extend to the acquisition of visual-language reception (reading) and visual-language production (writing), as well as the constructs of spoken language. A hearing 5-year-old child, for example, has *   Johns Hopkins University. **   Duke University. ***   Oxford University. ****   Center for Devices and Radiological Health, U.S. Food and Drug Administration.

OCR for page 382
Safe Medical Devices for Children a vocabulary that ranges between 5,000 and 26,000 words. In comparison, a deaf child of the same age usually has access to a vocabulary of about 200 words and limited ability to structure a spoken sentence.3 Given the substantial impact of deafness on development and the potential benefit of restored hearing, there are risks of underestimating the importance of potential complications associated with a device-oriented approach to deafness. Complications associated with the implantation procedure and device malfunction may arise during critical stages of language acquisition, before a child can be expected to report on their experience with an implanted device. The cochlear implant is best characterized as a device that provides access to sound. The device enables the hearing pathway to respond to environmental and speech sounds, providing informational cues from the surroundings and from others through direct, electrical activation of auditory nerve fibers tuned to frequencies that span the spectrum of practical hearing. In October 2004, the U.S. Food and Drug Administration (FDA) developed a website that contains general information on hearing physiology (including animated graphics), information on how a cochlear implant functions, as well as FDA regulatory approvals for these devices. The reader is referred to this website as a comprehensive resource for background information on cochlear implants: http://www.fda.gov/cdrh/cochlear/index.html. Three different manufacturers of cochlear implant systems provide currently available devices. All three product devices consist of similar component parts An external unit comprised of a microphone, speech processor (Figures F.1 and F.2), and batteries to drive the system. An implanted receiver and electronics package (Figure F.3) with connecting leads that feed an electrode array (Figure F.4). The design of the electrode array must incorporate biocompatibility, mechanical stability, practical fabrication, and minimize insertion trauma. From a surgical point of view, efforts to reduce insertion trauma must be accomplished at the materials and design levels, as well as through the surgical technique. For the past two decades, mastoid-implantable internal devices with leads to electrical arrays placed in the basal turn of the cochlea have been applied to deaf children as an increasingly large proportion of all cochlear implants placed (Figures F.5 and F.6). As of 2003, more than half of all newly implanted devices have been placed in children under age 5. It is estimated that approximately 7,500 to 10,000 United States children have received a multichannel cochlear implant prior to the age of 5 years out of

OCR for page 382
Safe Medical Devices for Children FIGURE F.1 Ear-level processor. (Courtesy of Cochlear Americas Corporation.) FIGURE F.2 Body-worn processor. (Courtesy of Cochlear Americas Corporation.) a worldwide population of approximately 90,000 recipients as of February 2005 (synthesis of verbal communication with the three major cochlear implant manufacturers: Advanced Bionics Corporation, Cochlear Corporation, and Med El Corporation, February 2005). Auditory thresholds of cochlear-implanted children allow access to auditory information beyond that available to deaf children who routinely use conventional amplification (hearing aids). Lowered hearing thresholds offer a substrate for auditory therapy.4 Through developmental learning in the early, formative years, auditory centers of the brain appear capable of processing the additional information from the implant in ways that are not possible at later developmental stages. Speech comprehension and oral lan-

OCR for page 382
Safe Medical Devices for Children FIGURE F.3 An implanted receiver and electronics package. (Courtesy of Advanced Bionics Corporation.) FIGURE F.4 An electrode ray. (Courtesy of Advanced Bionics Corporation.) guage development after implantation occur at a rate that parallels that of normal hearing peers, although gaps due to early deprivation often persist. Phonologic access afforded by of the cochlear implant to children has set the stage for several global perceptions of the intervention: the cochlear implant represents one of many innovative technologies that enable the rapid transfer of processed information from sound to comprehension; implant technology represents an alliance of informational processing strategies that utilize both manufactured and natural neural circuits;

OCR for page 382
Safe Medical Devices for Children FIGURE F.5 An implanted electronics and receiver package connected to an electrode ray, which is inserted through the cochlea. (Used with permission of Lippincott Williams & Wilkins. Originally appeared in Cochlear Implants: Principles and Practices, 2000. Niparko J, Kirk KI, Mellon NK, eds.) FIGURE F.6 The cochlear implant system comprised of its internal and external components. (Courtesy of Medmovie.com.)

OCR for page 382
Safe Medical Devices for Children to the extent that a cochlear implant can encode the sounds of speech with precision, the device can provide opportunities for developmental and oral language learning in young children with implications for psychosocial development, scholastic achievement, and life chances; and potentially dramatic, life-altering outcomes following early cochlear implantation have fostered high media visibility and enthusiasm about the benefits of early implantation. Against a two-decade old background of a generally positive global perception of clinical effects of cochlear implants in deaf children, a more open acknowledgement of potential harms has emerged in recent years. This summary provides background, peer-reviewed information regarding current risks posed to implant recipients and suggests approaches to improve surveillance of complications associated with cochlear-implantable devices in children. We begin with a description of considerations for candidacy selection and then review current understanding of complications and underlying mechanisms. We close with an assessment of the current state of device surveillance and propose several approaches to addressing the considerable challenge of tracking the health of children with cochlear implants. CANDIDACY EVALUATION: MEDICAL, OTOLOGIC AND RADIOLOGIC ASSESSMENT General Medical and Otologic Assessment To date, most cochlear implantations have been performed in children over the age of 2, though recent trends have shifted applications to ever younger patients. The main concerns with implanting infants and toddlers relate to the unreliability of audiologic testing at these ages, the prevalence of otitis media, challenges in the rehabilitation process, surgical obstacles posed by smaller tolerances in surgically approaching the cochlea. Nonetheless, centers have demonstrated promising results with few surgical complications.5,6,7,8,9 Moreover, outcome analyses seem to suggest the value in implanting at earlier ages. Zwolan and colleagues reviewed their series of 295 children implanted between 12 months and 10 years of age and observed that children implanted at younger ages experienced greater gains in speech perception over time than children implanted at a later stage.10 Robbins and colleagues11 noted that children implanted prior to the age of 19 months carry the highest potential for acquiring auditory skills at rates

OCR for page 382
Safe Medical Devices for Children that are not statistically different from their normal-hearing peers. Likewise, Schauwers and colleagues12 found smaller delays in the onset of babbling with earlier implantation, and Govaerts and colleagues13 found that implantation before the age of 2 was important in achieving optimal results. These case series of children suggest that implant-based percepts promote developmental learning in keeping with constructs of critical-period dictates of early language development. It does not appear that earlier implantation is associated with higher device-related complications. For example, a review of 34 cochlear implant complications in the Johns Hopkins cohort of 1,030 patients found that 51 percent of implants were placed in children under the age of 4 years. Device failure was found to occur in children under the age of 5 years in 11 of the 34 cases (33 percent). In addition to age considerations, the child must undergo a series of tests to ensure the proper candidacy for the procedure. Evaluation should include a complete medical history with appropriate laboratory studies and an assessment of the patient’s general health and ability to endure a general anesthetic for the necessary mastoid surgery. For children under the age of 9 to 12 months, general anesthetic may carry increased risk;14 therefore, the benefits of earlier implantation must be carefully assessed against these risks. Although implantation under a local anesthetic has been described, this approach is usually not recommended because it constrains the soft tissue dissection behind the mastoid required for embedding the internal device. Patients must be physically and psychologically capable of completing the course of recommended programming and therapy. Personality traits and family dynamics that predict program engagement should be assessed. Psychological assessment may be indicated to screen for psychopathology and organic brain disease. However, children with developmental delays and other limitations or disabilities should not be barred from implantation. While such children may not experience the same gains as deaf children without other functional limitations, numerous studies have shown considerable benefit is still possible.15,16,17,18 Both the chronology of deafness and the history of amplification use can help determine the choice of ear to be implanted. Previous otologic operations should be documented, as well as any abnormalities or diseases. In particular, a history of meningitis should prompt a discussion of methods for implanting a cochlea that may be partially or fully ossified as a result of meningitic-related inflammation. While post-meningitic deaf children were previously thought to perform at less impressive levels after implantation due to the neuropathologic consequences of the disease at the level of the inner ear, Francis and colleagues19 found no significant delays in their cognitive or speech perception performance, with the exception of

OCR for page 382
Safe Medical Devices for Children those children who exhibited evidence of meningitic-related hydrocephalus. Data from this case series of 30 meningitis-deafened children suggest that central factors hold sway in predicting audiologic performance and that ossification of the cochlea does not prevent good outcomes. Most children who present for cochlear implantation will likely have some history of acute otitis media (AOM). However, this does not constitute a clinical contraindication currently, as long as the condition is under control at surgery. The surgeon, however, should be prepared for an inflamed middle ear mucosa that may complicate and lengthen the surgery.20 Based on clinical experience, ventilation tubes may be removed before implantation, but should be left in if the child has frequent recurrent episodes of AOM. Luntz and colleagues21 suggest the continuous use of ventilation tubes until the child has outgrown susceptibility to AOM based on a study. In audiologic testing, the cochlear implant candidate should have puretone averages (PTA) greater than 90 dB and speech understanding scores of up to 50 percent on sentence testing, though recent work has suggested that children who retain greater residual hearing may still also significantly benefit from implantation.22 Such guidelines, however, are less compelling as younger candidates are considered. The required testing may prove difficult in young children. For such children, severe to profound levels of hearing loss, severe delays in verbal language acquisition, and substantial elevations in thresholds even with the use of hearing aids may indicate the need for an implant.23 Special consideration should be given to patients for whom magnetic resonance imaging (MRI) may be needed in the future. MRI is conventionally contraindicated in patients with magnetic devices. Recently, devices compatible with low-strength MRI (0.2 Tesla) and devices which can be rendered MRI compatible (by a minor surgical procedure to remove the magnet should the need for an MRI arise) have become available from some of the manufacturers.24,25,26 Even with magnetic devices left in place and intact, though, at least three reports have suggested that MRI can be safely performed.27,28,29 Nonetheless, at least three adverse events are under investigation. Etiologic Assessment Determining the cause of a child’s hearing loss can reveal information about the expected histopathology of the inner ear. Although many patient factors are deemed important in predicting success of speech recognition with the cochlear implant, survival of the first-order neurons is thought to be of particular importance. Second, recognition of factors that are associated with cochlear abnormalities (e.g., congenital malformations or ossifi-

OCR for page 382
Safe Medical Devices for Children cation) is critical for surgical planning and for patient and family counseling before implantation. Nadol’s studies30 of almost 100 temporal bones from patients with documented profound sensorineural hearing loss reveal patterns of spiral ganglion cells (SGC) survival that are consistent across diagnostic categories. Residual SGC counts were highest in individuals who were deafened by aminoglycoside ototoxicity or sudden idiopathic sensorineural hearing loss and least in those deafened by postnatal viral labyrinthitis or congenital causes. Counts for the two other etiologic categories—temporal bone neoplasms and bacterial labyrinthitis—fall in between. Age at time of death and duration of deafness were less predictive of SGC survival than was the cause of hearing loss. Labyrinthitis ossificans, or new bone formation in the inner ear, is a common finding in the temporal bones of patients who are deafened by bacterial meningitis. Quantitative assessment of 11 temporal bones of these patients by Nadol revealed a significant negative correlation between SGC survival and the presence of bony occlusion.30 However, even in segments with severe bony occlusion, significant numbers of SGCs remained. In a study of temporal bones from previously implanted patients, Linthicum and colleagues31 found that useful auditory sensations are reported by individuals whose temporal bones were found to have as few as 10 percent of the normal complement of cells. Although the presence of ossification is not considered a contraindication to implantation, the degree of ossification as demonstrated on imaging studies preoperatively should correlate with SGC survival and help guide the implant team in selecting an ear for implantation. Radiologic Assessment Radiologic imaging is an essential part of the evaluation of the cochlear implant candidate. High-resolution computerized tomography (HRCT) scans of the temporal bone help to define the surgical anatomy and provide information about cochlear abnormalities that can aid the surgeon in surgical planning and patient counseling. Temporal bone CT scans should be obtained and reviewed for evaluation of temporal bone anatomy with attention to the degree of mastoid pneumatization, position of vascular structures, middle ear anatomy, and position of the facial nerve.32 Scans are also examined for evidence of cochlear malformation, cochlear ossification, enlarged vestibular aqueduct, and other inner ear and skull base anomalies. An absolute contraindication to cochlear implantation detectable by HRCT is the absence of the cochlea in Michel’s aplasia. Although HRCT is the gold standard for evaluating most aspects of temporal bone anatomy, MRI is ideal in imaging soft tissue structures such as the membranous labyrinth and nerves. MRI can identify the presence or

OCR for page 382
Safe Medical Devices for Children absence of fluid within the cochlear turns and the size of the cochlear and vestibular nerves within the internal auditory canals. MRI is superior to HRCT in determining cochlear obstruction due to non-ossified scarring. One disadvantage to using MRI in children, though, is the need for sedation. CRITERIA FOR DEFINING COMPLICATIONS IN COCHLEAR IMPLANTATION A number of classification schemes have been developed to help define complications in the cochlear implantation process. Cohen and colleagues33 labeled “major” complications as those requiring additional surgery or hospitalization for treatment or correction, while “minor” complications resolve with minimal or no treatment. Exceptions to this distinction include facial nerve palsy or paralysis, considered to be a “major” complication even if no further surgery or inpatient treatment is required. As examples, they cite flap necrosis and improper electrode placement as “major” complications and dehiscence of incisions, infection, facial nerve stimulation, dizziness, and pedestal problems as “minor” complications. The initial reports revealed the rate of “major” and “minor” complications to be 8 percent and 4.3 percent, respectively, but later analyses found the rates to be 5 percent and 7 percent, suggesting a decrease in major complications with experience over time.34 Determining the stage at which complications arise can also be helpful. Luetje and Jackson35 separated “surgical” complications from “nonsurgical” complications. “Surgical” complications were identified as skin flap problems, facial nerve injury and stimulation, and infection. “Non-surgical” complications consisted of device failure, delayed stimulation, educational deficiencies, poor compliance by the family unit, behavioral problems, and socioeconomic disadvantages. In a review of 55 children, no “surgical” complications were found whereas “non-surgical” problems occurred, the most common being device failure in 10.9 percent of the group. Finally, the timing of events is of interest. Kempf and colleagues36 characterized “early” complications as those that arose within 3 months of surgery and “delayed” complications as those that occurred after this time period. In their retrospective analysis of 366 children, “early” complications such as flap problems, electrode dislocation, facial nerve problems, and incorrect insertion of the electrode, were found in 1–2.5 percent of children. “Delayed” complications, for example, otitis media and facial nerve stimulation, occurred in 14 percent of the children. Although children were indeed once thought to be at greater risk than adults of major and minor complications from cochlear implantation, stud-

OCR for page 382
Safe Medical Devices for Children ies have, in fact, suggested no significantly heightened risk in the pediatric population. In a series of 309 children who were implanted with the Nucleus device by 25 surgeons in North America before 1991, the total complication rate (major and minor) was 7 percent, which compared favorably with the adult rate of 12 percent. The incidence of complications was lower in children older than 7 years of age. However, the relatively low rate of operative complications in the pediatric population as reported in this study may have reflected the greater experience of surgeons who initially performed pediatric cochlear implants.44,37 SURGICAL ISSUES RELATED TO COMPLICATIONS Cochlear Implantation Surgical Procedures Implantation of the young child requires specific knowledge of the unique anatomy of the temporal bone in this age group and of the impact of skull growth on the implanted device. Although temporal bone growth has been shown to continue through adolescence, anatomy of the facial recess is fully developed at birth.38,39 The most significant developmental changes are in the size and configuration of the mastoid cavity, which has been shown to expand in width, length, and depth from birth until at least the teenage years. Growth of the mastoid during this time parallels the growth patterns of the skull, with two periods of rapid development: one starts at birth and continues through early childhood, and the other occurs at puberty. From 1 year of age to adulthood, the average mastoid can be expected to grow 2.6 cm in length, 1.7 cm in width, and 0.9 cm in depth for males and 2.0 cm in length, 1.7 cm in width, and 0.8 cm in depth for females. Based on these measurements, it has been recommended that 2.5 cm of electrode lead redundancy in the mastoid is necessary to accommodate head growth while avoiding electrode extrusion.40,41 Investigation in the young primate has demonstrated that cochlear implantation had no adverse effects on skull growth.42,43 Moreover, the electrode appears to remain in a stable position with no migration over time.44 These observations strongly suggest that lateral skull base development occurs in a pattern that circumscribes the implanted device, with soft-tissue anchoring of connecting leads. As for all otologic surgery in children, the surgeon should remember that the lack of development of the mastoid tip, narrow tympanic ring, and lack of subcutaneous tissue in infants and toddlers place the main trunk of the facial nerve just below the skin, where it is easily injured by an incorrectly placed incision. Design of the postauricular skin flap is particularly important. In younger children, who have a thin scalp, elevation of the postauricular tissue in continuity with the skin flap may protect from flap

OCR for page 382
Safe Medical Devices for Children meningitis in children in 2002 indicated that complications of particular concern to children can arise and that trends can go undetected for years.91 It also appears that complications unique to children can arise after highly variable periods of time following surgical implantation, thus necessitating follow-up for indefinite periods of time. For example, the current database on pediatric cochlear implant users is not sufficiently robust to enable a formal determination of meningitis risk going forward as new implant types are introduced. These observations emphasize the need for mandatory reporting requirements and better quality reporting to facilitate the early detection of health-related complications in cochlear implant users. Manufacturer-based reports on cochlear implant complications are often supplied in direct correspondences and in newsletters to clinicians. However, such reports are often provided in the context of marketing device durability, suggesting that some datasets may go unreported in manufacturer communications. In addition to reports, independently-tracked data are needed to provide a more useful profile. The above summary of pediatric cochlear implant complications from the peer-reviewed literature represents the best efforts of clinicians to gather information about complications from case series, and manufacturer and FDA datasets. The cornerstone for FDA’s postmarket surveillance of medical devices is the information provided by both voluntary and mandatory device-related adverse event reports to the Agency. (For additional description, see Chapters 3 and 4 of the Institute of Medicine report in which this appendix appears.151) Voluntary reporting to FDA began in 1973, and the current MedWatch Program, created in 1993, provides a mechanism for consumers and health care professionals to voluntarily report problems with medical devices by phone, mail, or online completion of an adverse event form. More recently, FDA has developed partnerships with major health care organizations in the United States to promote reporting adverse events through this program, particularly those of a serious nature. In 1984 FDA implemented the MDR (Medical Device Reporting) regulation, which requires manufacturers and importers to report all device-related deaths, serious injuries, and malfunctions to the Agency. Additionally, under the Safe Medical Devices Act of 1990 and other subsequent legislation, user facilities (e.g., hospitals, nursing homes) are also now required to report: (1) device-related deaths to both FDA and the manufacturer, (2) device-related serious injuries to the manufacturer (or to the FDA if the manufacturer is unknown), and (3) an annual summary report of deaths and serious injuries to FDA. Although legal enforcement of these mandatory reporting requirements is possible and FDA does inspect manufacturer facilities for compliance with adverse event record keeping and reporting, FDA has relied on the goodwill and cooperation of manufacturers and user facilities to ensure compliance with the regulation and charac-

OCR for page 382
Safe Medical Devices for Children terization of the potential sources of the complication. Of note, individual health professionals are not required to report events. This is not an insignificant source of cochlear implant surgeries for children in the United States. The specific requirements for device-related adverse event reporting are outlined in federal regulation at 21 CFR 803. Briefly, manufacturers are required to report deaths, serious injuries, and malfunctions to FDA within 30 calendar days. When an adverse event requires remedial action to prevent an unreasonable risk to public health (or when another event designated by FDA occurs), manufacturers must report the event to the agency within 5 work days. User facilities must report deaths and serious injuries within 10 work days, and must also file an annual report to FDA of deaths and serious injuries. In actual practice, reporting from user facilities has been low (less than 3 percent of adverse event reports to the Agency in 1999). Recognizing the value and importance of adverse event reporting experience from user facilities in postmarket surveillance, Congress mandated, under the FDA Modernization Act of 1997, that a focused network of well-trained and highly motivated user facilities be created to enhance detection of emerging device problems and to act as a two-way communication channel between FDA and the clinical community. This network, known as the Medical Product Surveillance Network (MedSun), is currently under development and will consist of at least 250 hospitals and approximately 50 nursing homes. MedSun aims to achieve a reasonably representative sample of user facilities (primarily hospitals) that may allow for national estimates on certain device issues in the future. This network could eventually provide a consistent, reliable source of postmarket clinical experience in children with cochlear implants. Adverse events, whether from voluntary or mandatory reports, are entered into the FDA’s Manufacturer User Facility and Distributor Experience (MAUDE) database. MAUDE contains reports from user facilities since 1991, voluntary reports to the Agency since June 1993, distributor (e.g., importers) reports since 1993, and manufacturer reports since August 1996. Within FDA’s Center for Devices and Radiological Health (CDRH), the Office of Surveillance and Biometrics routinely monitors and analyzes incoming reports to detect signals of significant postmarket safety and effectiveness concerns. Information from these reports is disclosed to the public and is available on the web in the MAUDE database (www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/search.CFM). An informal analysis of MAUDE suggests that in its current state, the database lacks sensitivity for complications that can be managed medically or are related to surgical technique; such complications would seem to be unlikely to be reported to FDA.152 The MAUDE dataset is intended for

OCR for page 382
Safe Medical Devices for Children serious complications that result from errors in the use of a device or device malfunction. Even for complications such as device failure, however, there is often an absence of data, such as device lifespan prior to failure and uniform terminology regarding failure modes (e.g., hermeticity breach, electrode wire breakage). These data would likely prove invaluable in analyzing trends. Information such as patient age, date of implant, surgical approach and relevant surgical anatomy, prior surgeries, and characteristics of the implant center are often not included in the MAUDE reports. To be effective, the MAUDE database will need to be structured to provide detailed information on individual medical devices. This will require a priori form design that offers heightened sensitivity and specificity in characterizing device-related complications. Form 3500A (www.fda.gov/medwatch/safety/3500a.pdf) is quite detailed. One problem, however, is that it often is not filled out completely by the manufacturer or user facility—due either to lack of information or other issues. For cochlear implants, the MAUDE database might be strengthened with regular, timely provision to FDA of manufacturer and distributor data on the number of devices implanted (i.e., denominator data) and trends with respect to recipient demographics could construct a crucial background of device distributional patterns. For example, when cases of meningitis were reported at an alarming rate in 2002, it was completely unclear as to whether the higher incidence of this complication may have coincided with clinical trends of implantation of younger ages. Epoch analyses are likely to be extremely instructive in determining the source(s) of device-related complications. Such analyses would be afforded with updated, high-quality epidemiologic datasets. It is apparent, however, that the establishment of a uniform, comprehensive, and up-to-date national database of device-related complications faces monumental obstacles. For example, manufacturers may be reluctant to publicly provide data on devices implanted for defined time periods (i.e., denominator data) because this would reveal potentially sensitive information regarding market share. Another very practical issue that hampers ongoing tracking is that families of children with cochlear implants are young and highly likely to change their address within any 5 to 10 year period. A recent experience is instructive. The Advanced Bionics Corporation made a concerted effort to contact every user of its cochlear implant systems (n = ~12,000) in association with the meningitis reports of 2002 with direct, registered mail. Despite using updated address information based on warranty registration, the corporation was able to contact less than 90 percent of users at a cost of over $300,000. While the inability to contact more than 10 percent of users is less than ideal, it is higher than might be expected. Because children and most adults with cochlear implants require regular follow-up, their regular contact with clinics may

OCR for page 382
Safe Medical Devices for Children promote high rates of information updating and thus relatively high access when compared with patient groups using other implants. The above experience underscores that some cochlear implant device users and their families appear to go without close, regular follow-up by a medical facility. Moreover, address changes are not always available from manufacturer and patient records. This experience, however, does suggest that ongoing manufacturer to FDA communications and warranty-related contact information can provide an important means of informing trends in device-related complications. This would seem to be particularly important with respect to childhood recipients. The establishment of a dedicated, pediatric database that draws on multiple sources of information deserves further consideration. In addition to adverse event reporting requirements, FDA may also mandate that manufacturers perform postmarket studies either as a condition of the original FDA approval or under the FDA Modernization Act (Section 522) authorities. High-risk implantable devices (e.g., cochlear implants) require FDA approval of a premarket approval application (PMA) prior to marketing to ensure their safety and effectiveness. Along with the specific adverse event reporting requirements listed in the PMA Conditions of Approval, the Agency may also include an additional “condition” for the manufacturer to address specific safety and/or effectiveness issues through a postapproval study. For example, cochlear implant manufacturers have often been required to collect additional long-term clinical data on pediatric patients to demonstrate safety and effectiveness of the device in this population. Alternatively, the Agency may impose postmarket study requirements for certain devices under Section 522 of the Federal Food, Drug, and Cosmetic Act. This authority allows FDA, under its discretion and for good reason, to order manufacturers to conduct postmarket surveillance on Class II or III devices that are implanted in the human body for more than 1 year, life-sustaining or life-supporting devices used outside of a device user facility, or devices the failure of which would be reasonably likely to have serious adverse health consequences. These studies are generally reserved for potential device failure situations that would be reasonably likely to have serious adverse health consequences. Under these circumstances, FDA can require prospective surveillance period of up to 36 months. Reviews of major complications associated with implantable devices suggest that two approaches to monitoring device safety might be expanded: (1) the role of clinicians in reporting potential device-related complications, and (2) the visibility of a centralized data coordination center. Health care providers are the likely contact for virtually all complications related to device use. The responsibility of clinicians to report major device complications is in the interest of the public’s health and should be underscored in licensing requirements. Successful completion of web-based training mod-

OCR for page 382
Safe Medical Devices for Children ules used recently to inform clinicians of new Health Insurance Portability and Accountability Act and Effort-Reporting regulations could be used to develop new approaches to device-use surveillance and may be held as a requirement for licensure. Such training should also promote complete understanding of mechanisms of reporting to a data coordination center that is singularly recognized as the site for the accrual of data on device complications. REFERENCES 1Reis R. Prevalence and characteristics of persons with hearing trouble: United States, 1990–1991. National Center for Health Statistics. Vital Health Stat 10 1994:1–134. 2Blanchfield B, Dunbar J, Feldman J, Gardner E. The Severely to Profoundly Hearing Impaired Population in the United States: Prevalence and Demographics. Bethesda, Md: Project HOPE Center for Health Affairs, 1999. 3Berliner K, Eisenberg L. Methods and issues in the cochlear implantation of children: an overview. Ear Hear 1985;6:(Suppl 3) 6S–13S. 4Ling D. Foundations of Spoken Language for Hearing Impaired Children. Washington, DC: Alexander Graham Bell Assoc for the Deaf, 1989. 5Parisier SC, Chute PM, Popp AL, et al. Surgical techniques for cochlear implantation in the very young child. Otolaryngol Head Neck Surg 1997;117:248–254. 6Waltzman SB, Cohen NL. Cochlear implantation in children younger than 2 years old. Am J Otolaryngol 1998;19:158–162. 7Lenarz T. Cochlear implantation in children under the age of two years. Adv Otorhinolaryngol 1997;52:204–210. 8Novak MA, Firszt JB, Rotz LA, et al. Cochlear implants in infants and toddlers. Ann Otol Rhinol Laryngol Suppl 2000;185:46–49. 9Hehar SS, Nikolopoulos TP, Gibbin KP, et al. Surgery and functional outcomes in deaf children receiving cochlear implants before age 2 years. Arch Otolaryngol Head Neck Surg 2002;128:11–14. 10Zwolan TA, Ashbaugh CM, Alarfaj A, et al. Pediatric cochlear implant patient performance as a function of age at implantation. Otol Neurotol 2004;25:112–120. 11Robbins AM, Koch DB, Osberger MJ, et al. Effect of age at cochlear implantation on auditory skill development in infants and toddlers. Arch Otolaryngol Head Neck Surg 2004; 130:570–574. 12Schauwers K, Gillis S, Daemers K, et al. Cochlear implantation between 5 and 20 months of age: the onset of babbling and the audiologic outcome. Otol Neurotol 2004;25:263–270. 13Govaerts PJ, De Beukelaer C, Daemers K, et al. Outcome of cochlear implantation at different ages from 0 to 6 years. Otol Neurotol 2002;23:885–890. 14Young NM. Infant cochlear implantation and anesthetic risk. Ann Otol Rhinol Layngol Suppl 2002;189:49–51. 15Waltzman SB, Scalchunes V, Cohen NL. Performance of multiply handicapped children using cochlear implants. Am J Otol 2000;21:349–335. 16Hamzavi J, Baumgartner WD, Egelierler B, et al. Follow up of cochlear implanted handicapped children. Int J Ped Otorhinolaryngol 2000;56:169–174. 17Fukuda S, Fukushima K, Maeda Y, et al. Language development of a multiply handicapped child after cochlear implantation. Int J Ped Otorhinolaryngol 2003;67:627–633. 18Donaldson AI, Heavner KS, Zwolan TA. Measuring progress in children with autism spectrum disorder who have cochlear implants. Arch Otolaryngol Head Neck Surg 2004;130: 666–671.

OCR for page 382
Safe Medical Devices for Children 19Francis HW, Pulsifer MB, Chinnici J, et al. Effects of central nervous system residua on cochlear implant results in children deafened by meningitis. Arch Otolaryngol Head Neck Surg 2004;130:604–611. 20Luntz M, Teszler CB, Shpak T, et al. Cochlear implantation in healthy and otitis–prone children: a prospective study. Laryngoscope 2001;111:1614–1618. 21Luntz M, Teszler CB, Shpak T. Cochlear implantation in children with otitis media: second stage of a long-term prospective study. Int J Pediatr Otorhinolaryngol 2004;68:273–280. 22Dettman SJ, D’Costa, WA, Dowell RC, et al. Cochlear implants for children with significant residual hearing. Arch Otolaryngol Head Neck Surg 2004;130:612–618. 23Mecklenburg D. Cochlear implants and rehabilitative practices. In: Handbook of Hearing Aid Amplification. Sandlin R, ed. Boston: College Hill Press, 1990, pp. 179–188. 24Weber BP, Neuburger J, Goldring JE, et al. Clinical results of the CLARION magnetless cochlear implant. Ann Otol Rhinol Laryngol Suppl 1999;177:22–26. 25Youssefzadeh S, Baumgartner W, Dorffner R, et al. MR compatibility of Med EL cochlear implants: clinical testing at 1.0 T. J Comput Assist Tomogr 1998;22:346–350. 26Heller JW, Brackmann DE, Tucci DL, et al. Evaluation of MRI compatibility of the modified nucleus multichannel auditory brainstem and cochlear implants. Am J Otol 1996; 17:724–729. 27Baumgartner WD, Youssefzadeh S, Hamzavi J, et al. Clinical application of magnetic resonance imaging in 30 cochlear implant patients. Otol Neurotol 2001;22:818–822. 28Schmerber S, Reyt E, Lavieille JP. Is magnetic resonance imaging still a contraindication in cochlear-implanted patients? Eur Arch Otorhinolaryngol 2003;260:293–294. 29Teissl C, Kremser C, Hochmair ES, et al. Cochlear implants: in vitro investigation of electromagnetic interference at MR imaging—compatibility and safety aspects. Radiology 1998;208:700–708. 30Nadol JB. Patterns of neural degeneration in the human cochlea and auditory nerve: implications for cochlear implantation. Otolaryngol Head Neck Surg 1997;117:220–228. 31Linthicum FH, Fayad J, Otto SR, et al. Cochlear implant histopathology. Am J Otol 1991;12:245–311. 32Woolley AL, Oser AB, Lusk RP, et al. Pre-operative temporal bone computed tomography scan and its use in evaluating the pediatric cochlear implant candidate. Laryngoscope 1997;108:1100–1106. 33Cohen NL, Hoffman RA, Stroschein M. Medical or surgical complications related to the Nucleus multichannel cochlear implant. Ann Otol Rhinol Laryngol Suppl 1988;135:8–13. 34Cohen NL, Hoffman RA. Complications of cochlear implant surgery in adults and children. Ann Otol Rhinol Laryngol 1991;100:708–711. 35Luetje CM, Jackson K. Cochlear implants in children: what constitutes a complication? Otolaryngol Head Neck Surg 1997;117:243–247. 36Kempf HG, Johann K, Weber BP, et al. Complications of cochlear implant surgery in children. Am J Otol 1997;18:S62–S63. 37Gysin C, Papsin BC, Daya H, Nedzelski J. Surgical outcome after paediatric cochlear implantation: diminution of complications with the evolution of new surgical techniques. J Otolaryngol 2000 Oct;29(5):285–289. 38Bielamowiez SA, Coker NJ, Jenkins HA, et al. Surgical dimensions of the facial recess in adults and children. Arch Otolaryngol Head Neck Surg 1988;114:534–537. 39Eby TL. Development of the facial recess: implications for cochlear implantation. Laryngoscope 1996;106(Suppl 80):1–7. 40Eby TL, Nadol JB. Postnatal growth of the human temporal bone: implications for cochlear implants in children. Ann Otol Rhinol Laryngol 1986;95:356–382. 41Dahm MC, Shepherd RK, Clark GM. The postnatal growth of the temporal bone and its implications for cochlear implantation in children. Acta Otolaryngol Suppl 1993;505:1–39.

OCR for page 382
Safe Medical Devices for Children 42Xu J, Shepherd RK, Xu SA, Seldon HL, Clark GM. Pediatric cochlear implantation: radiologic observations of skull growth. Arch Otolaryngol Head Neck Surg 1993;119:525–534. 43Burton MJ, Shepherd RK, Xu SA, et al. Cochlear implantation in young children: histological studies on head growth, leadwire, design, electrode fixation in the monkey model. Laryngology 1994;104:167–175. 44Roland JT Jr, Fishman AJ, Waltzman SB, et al. Stability of the cochlear implant array in children. Laryngoscope 1998;108:1119–1123. 45Wang RC, Parisier SC, Weiss MH, et al. Cochlear implant flap complications. Ann Otol Rhinol Laryngol 1990;99:791–795. 46O’Donoghue GM, Nikolopoulos TP. Minimal access surgery for pediatric cochlear implantation. Otol Neurotol 2002;23:891–894. 47Green JD, Marion MS, Hinojosa R. Labyrinthitis ossificans: histopathologic consideration for cochlear implantation. Otolaryngol Head Neck Surg 1991;104:320–326. 48Telian SA, Zimmerman-Phillips S, Kileny PR. Successful revision of failed cochlear implants in severe labyrinthitis ossificans. Am J Otol 1996;17:53–60. 49Nadol JB. Patterns of neural degeneration in the human cochlea and auditory nerve: implications for cochlear implantation. Otolaryngol Head Neck Surg 1997;117:220–228. 50Balkany T, Gantz B, Nadol JB. Multichannel cochlear implants in obstructed and obliterated cochleas. Otolaryngol Head Neck Surg 1988;98:72–81. 51Linthicum FH, Fayad J, Otto SR, et al. Cochlear implant histopathology. Am J Otol 1991;12:245–311. 52El-Kashlan HK, Ashbaugh C, Zwolan T, et al. Cochlear implantation in prelingually deaf children with ossified cochleae. Otol Neurotol 2003;24:596–600. 53Steenerson RL, Gary LB. Multichannel cochlear implantation in children with cochlear ossification. Am J Otol 1999;20:442–444. 54Hodges AV, Balkany TJ, Gomez-Marín O, et al. Speech recognition after implantation of the ossified cochlea. Am J Otol 1999;20:453–456. 55Dodds A, Tyszkiewicz E, Ramsden R. Cochlear implantation after bacterial meningitis: the dangers of dealy. Arch Dis Child 1997;76:139–140. 56Balkany T, Gantz BJ, Steenerson RL, et al. Systematic approach to electrode insertion in the ossified cochlea. Otolaryngol Head Neck Surg 1996;114:4–11. 57Gantz BJ, McCabe BF, Tyler RS. Use of multichannel cochlear implants in obstructed and obliterated cochleas. Otolaryngol Head Neck Surg 1988;98:72–81. 58McClay JE, Tandy R, Grundfast K, et al. Major and minor temporal bone abnormalities in children with and without congenital sensorineural hearing loss. Arch Otolaryngol Head Neck Surg 2002;128:664–671. 59Ohlms LA, Edwards MS, Mason EO, et al. Recurrent meningitis and Mondini dysplasia. Arch Otolaryngol Neck Surg 1990;116:608–612. 60Tucci DL, Telian SA, Zimmerman-Phillips S, et al. Cochlear implantation in patients with cochlear malformations. Arch Otolaryngol Head Neck Surg 1995;21:833–838. 61Jackler RK, Luxford WM, House WF. Congenital malformations of the inner ear: a classification based on embryogenesis. Laryngoscope 1987;97(Suppl 40):15–17. 62Shelton C, Luxford WM, Tonokawa LL, et al. The narrow internal auditory canal in children: a contraindication for cochlear implants. Otolaryngol Head Neck Surg 1989;100: 227–231. 63Casselman JW, Offeciers FE, Govaerts PJ, et al. Aplasia and hypoplasia of the vestibulocochlear nerve: diagnosis with MR imaging. Radiology 1997; 202:773–781. 64Otte G, Schuknecht HF, Kerr AG. Ganglion cell populations in normal and pathological human cochleae: implications for cochlear implantation. Laryngoscope 1978;88:1231–1246. 65Johnsson LG, Hawkins JE, Rouse RC, et al. Four variations of the Mondini inner ear malformations as seen in microdissections. Am J Otol 1984;5:242–257.

OCR for page 382
Safe Medical Devices for Children 66Monsell EM, Jackler RK, Motta G, et al. Congenital malformations of the inner ear. Laryngoscope 1987;97(Suppl 40):18–24. 67Zheng Y, Schachern PA, Cureoglu S, et al. The shortened cochlea: its classification and histopathologic features. Int J Pediatr Otorhinolaryngol 2002;63:29–39. 68Molter DW, Pate BR, McElveen JT. Cochlear implantation in the congenitally malformed ear. Otolaryngol Head Neck Surg 1993;108:174–177. 69Hoffman RA, Downey LL, Waltzman SB, et al. Cochlear implantation in children with cochlear malformations. Am J Otol 1997;18:184–187. 70Weber BP, Dillo W, Dietrich B, et al. Pediatric cochlear implantation in cochlear malformations. Am J Otol 1998;19:747–753. 71Woolley AL, Jenison V, Stroaer BS, et al. Cochlear implantation in children with inner ear malformations. Ann Otol Rhinol Laryngol 1998;107:492–500. 72Eisenman DJ, Ashbaugh C, Zwolan TA, et al. Implantation of the malformed cochlea. Otol Neurotol 2001;22:834–841. 73Incesulu A, Vural M, Erkan U, et al. Cochlear implantation in children with inner ear malformations: report of two cases. Int J Pediatr Otorhinolaryngol 2002;65:171–179. 74Buchman CA, Copeland BJ, Yu KK, et al. Cochlear implantation in children with congenital inner ear malformations. Laryngoscope 2004;114:309–316. 75Govaerts PJ, Casselman J, Daemers K, et al. Cochlear implants in aplasia and hypoplasia of the cochleovestibular nerve. Otol Neurotol 2003;24:887–891. 76Mylanus EAM, Rotteveel LJC, Leeuw RL. Congenital malformation of the inner ear and pediatric cochlear implantation. Otol Neurotol 2004;25:308–317. 77Cohen NL. Cochlear implant soft surgery: fact or fantasy? Otolaryngol Head Neck Surg 1997;117:214–216. 78Clark GM. An evaluation of per-scalar cochlear electrode implantation techniques: a histopathological study in cats. J Laryngol Otol 1977;91:185–199. 79Shepherd RK, Clark GM, Black RC. Chronic electrical stimulation of the auditory nerve in cats. Acta Otolaryngol (Stockh) Suppl 1983;399:19–31. 80Kennedy DW. Multichannel intracochlear electrodes: mechanism of insertion trauma. Laryngoscope 1987;97:42–49. 81Cohen NL, Hoffman RA. Complications of cochlear implant surgery. In: Complications in Head and Neck Surgery. Krespi YP, Ossoff RH, eds. Baltimore, Md.: Mosby, 1993. 82House JR, Luxford WM. Facial nerve injury in cochlear implantation. Otolaryngol Head Neck Surg 1993;109:1078–1082. 83Fayad JN, Wanna GB, Micheletto JN, et al. Facial nerve paralysis following cochlear implant surgery. Laryngoscope 2003;113:1344–1346. 84House WF, Luxford WM, Courtney B. Otitis media in children following cochlear implant. Ear Hear 1985;6:24S–26S. 85Luntz M, Hodges AV, Balkany T, et al. Otitis media in children with cochlear implants. Laryngoscope 1996;106:1403–1405. 86Fayad JN, Tabaee A, Micheletto JN, et al. Cochlear implantation in children with otitis media. Laryngoscope 2003;113:1224–1227. 87Kempf HG, Stöver T, Lenarz T. Mastoiditis and acute otitis media in children with cochlear implants: recommendations for medical management. Ann Otol Rhinol Laryngol Suppl 2000;185:25–27. 88Papsin BC, Bailey CM, Albert DM, et al. Otitis media with effusion in paediatric cochlear implantees: the role of peri-implant grommet insertion. Int J Pediatr Otorhinolaryngol 1996; 38:13–19. 89Nadol JB, Eddington DK. Histologic evaluation of the tissue seal and biologic response around cochlear implant electrodes in the human. Otol Neurotol 2004;25:257–262.

OCR for page 382
Safe Medical Devices for Children 90Antonelli PJ, Lee JC, Burne RA. Bacterial biofilms may contribute to persistent cochlear implant infection. Otol Neurotol 2004 Nov;25(6):953–957. 91Reefhuis J, Honein MA, Whitney CG, et al. Risk of bacterial meningitis in children with cochlear implants. N Engl J Med 2003;349:435–445. 92Callanan V, Poje C. Cochlear implantations and meningitis. Int J Pediatr Otorhinolaryngol 2004;68:545–550. 93Page EL, Eby TL. Meningitis after cochlear implantation in Mondini malformation. Otolaryngol Head Neck Surg 1997;116:104–106. 94Suzuki C, Sando I, Fagan JJ, et al. Histopathological features of a cochlear implant and otogenic meningitis in Mondini dysplasia. Arch Otolaryngol Head Neck Surg 1998;124: 462–466. 95O’Donoghue GM, Balkany T, Cohen N, et al. Meningitis and cochlear implantation. Otol Neurotol 2002;23:823–824. 96Cohen NL, Roland JT, Marrinan M. Meningitis in cochlear implant recipients: the North American experience. Otol Neurotol 2004;25:275–281. 97Pneumococcal vaccination for cochlear implant candidates and recipients: updated recommendations of the advisory committee on immunization practices. MMWR Morb Mortal Wkly Rep 2003;52(31):739–740. 98Ito J, Sakakihara J. Tinnitus suppression by electrical stimulation of the cochlear wall and by cochlear implantation. Laryngoscope 1994;104:752–754. 99Souliere CRJ, Kileny PR, Zwolan TA, et al. Tinnitus suppression following cochlear implantation: a multifactorial investigation. Arch Otolaryngol Head Neck Surg 1992;118: 1291–1297. 100Tyler RS. Tinnitus in the profoundly hearing-impaired and the effects of cochlear implants. Ann Otol Rhinol Laryngol Suppl 1995;165:25. 101Ruckenstein MJ, Hedgepeth C, Rafter KO, et al. Tinnitus suppression in patients with cochlear implants. Otol Neurotol 2001;22:200–204. 102Miyamoto RT, Bichey BG. Cochlear implantation for tinnitus suppression. Otolaryngol Clin North Am 2003;36:345–352. 103Aschendorff A, Pabst G, Klenzner T, et al. Tinnitus in cochlear implant users: the Freiburg experience. Int Tinnitus J 1998;4:162–164. 104Vibert D, Hausler R, Kompis M, et al. Vestibular function in patients with cochlear implantation. Acta Otolaryngol Suppl 2001;545:29–34. 105Dobie R, Jenkins H, Cohen N. Surgical results. Ann Otol Rhinol Laryngol 1995; 104(Suppl 165):6–8. 106Kubo T, Yamamoto K, Iwaki T, et al. Different forms of dizziness occurring after cochlear implant. Eur Arch Otorhinolaryngol 2001;258:9–12. 107Ito J. Influence of the multichannel cochlear implant on vestibular function. Otolaryngol Head Neck Surg 1998;118:900–902. 108Fina M, Skinner M, Goebel JA, et al. Vestibular dysfunction after cochlear implantation. Otol Neurotol 2003;24:234–242. 109Steenerson RL, Cronin GW, Gary LB. Vertigo after cochlear implantation. Otol Neurotol 2001;22:842–843. 110Hoffman RA, Cohen NL. Complications of cochlear implant surgery. Ann Otol Rhinol Laryngol 1995;166:420–422. 111Gibson WPR, Harrison HC. Further experience with a straight, vertical incision for placement of cochlear implants. J Laryngol Otol 1997;111:924–927. 112Harris JP, Cueva RA. Flap design for cochlear implantation: avoidance of a potential complication. Laryngoscope 1987;97:755–757. 113Gibson WPR, Harrison HC, Prowse C. A new incision for placement of cochlear implants. J Laryngol Otol 1995;109:821–825.

OCR for page 382
Safe Medical Devices for Children 114Cohen NL, Hoffman RA. Complications of cochlear implant surgery. In: Complications in Head and Neck Surgery. Baltimore, Md.: Mosby, 1993:723. 115Wang RC, Parisier SC, Weiss MH, et al. Cochlear implant flap complications. Ann Otol Rhinol Laryngol 1990;99:791–795. 116Haberkamp TJ, Schwaber MK. Management of flap necrosis in cochlear implantation. Ann Otol Rhinol Laryngol 1992;101:38–41. 117Kennedy DW. Multichannel intracochlear electrodes: mechanism of insertion trauma. Laryngoscope 1987;97:42–49. 118Fayad J, Linthicum FH, Otto SR, et al. Cochlear implants: histopathologic findings related to performance in 16 human temporal bones. Ann Otol Rhinol Laryngol 1991;100: 807–811. 119Zappia JJ, Niparko JK, Oviatt DL, et al. Evaluation of the temporal bones of a multichannel cochlear implant patient. Ann Otol Rhinol Laryngol 1991;100:914–921. 120Nadol JB, Ketten DR, Burgess BJ. Otopathology in case of multichannel cochlear implantation. Laryngoscope 1994;104:299–303. 121Zappia JJ, Niparko JK, Oviatt DL, et al. Evaluation of the temporal bones of a multichannel cochlear implant patient. Ann Otol Rhinol Laryngol 1991;100:914–921. 122Shepherd RK, Clark GM, Black RC. Chronic electrical stimulation of the auditory nerve in cats. Acta Otolaryngol (Stockh) Suppl 1983;399:19–31. 123Clark FM, Shepherd RK, Franz BK-H. The histopathology of the human temporal bone and auditory central nervous system following cochlear implantation in a patient. Acta Otolaryngol (Stockh) Suppl 1988;448:6–65. 124Linthicum, FH, Fayad J, Otto SR, et al. Cochlear implant histopathology. Am J Otol 1991;12:245–311. 125Nadol JB Jr, Shiao JY, Burgess BJ, et al. Histopathology of cochlear implants in humans. Ann Otol Rhinol Laryngol 2001;110:883–891. 126Leake PA, Hradek GT, Snyder RL. Chronic electrical stimulation by a cochlear implant promotes survival of spiral ganglion neurons after neonatal deafness. J Comp Neurol 1999; 412:543–562. 127Li L, Parkins CW, Webster DB. Does electrical stimulation of deaf cochleae prevent spiral ganglion degeneration? Hear Res 1999;133:27–39. 128Cochlear Americas Technology Update, Vol.1, Ed. 2, October 2004. 129Weise JB, Muller-Deile J, Brademann G, Meyer JE, Ambrosch P, Maune S. Impact to the head increases cochlear implant reimplantation rate in children. Auris Nasus Larynx 2005 May 26; [Epub ahead of print]. 130Alexiades G, Roland JT, Fishman AJ, et al. Cochlear reimplantation: surgical techniques and functional results. Laryngoscope 2001;111:1608–1613. 131Luetje CM, Jackson K. Cochlear implants in children: what constitutes a complication. Otolaryngol Head Neck Surg 1997;117:243–247. 132Parisier SC, Chute PM, Popp AL. Cochlear implant mechanical failures. Am J Otol 1996;17:730–734. 133Miyamoto RT, Svirsky MA, Myres WA, et al. Cochlear implant reimplantation. Am J Otol 1997;18:S60–S61. 134Balkany TJ, Hodges AV, Gómez-Marín O, et al. Cochlear reimplantation. Laryngoscope 1999;109:351–355. 135Alexiades G, Roland JT, Fishman AJ, et al. Cochelar reimplantation: surgical techniques and functional results. Laryngoscope 2001;111:1608–1613. 136Parisier SC, Chute PM, Popp AL, et al. Outcome analysis of cochlear implant reimplantation in children. Laryngoscope 2001;111:26–32. 137Haensel J, Engelke JC, Dujardin H, et al. Cochlear reimplantation—experiences and results. Laryngorhinootologie 2004;83:83–87.

OCR for page 382
Safe Medical Devices for Children 138Brackett D, Zara CV. Communication outcomes related to early implantation. Am J Otol 1998;19:453–460. 139Nikolopoulos TP, O’Donoghue GM, Archbold S. Age at implantation: its importance in pediatric cochlear implantation. Laryngoscope 1999;109:595–599. 140Hammes DM, Novak MA, Rotz LA, et al. Early identification and cochlear implantation: critical factors for spoken language development. Ann Otol Rhinol Laryngol Suppl 2002;189:74–78. 141Robbins AM, Koch DB, Osberger MJ. Effect of age at cochlear implantation on auditory skill development in infants and toddlers. Arch Otolaryngol Head Neck Surg 2004;130:570–574. 142Geers AE. Speech, language, and reading skills after early cochlear implantation. Arch Otolaryngol Head Neck Surg 2004;130:634–638. 143Dowell RC, Dettman SJ, Hill K, et al. Speech perception outcomes in older children who use multichannel cochlear implants: older is not always poorer. Ann Otol Rhinol Laryngol Suppl 2002;189:97–101. 144Staller SJ, Beiter AL, Brimacombe JA, et al. Pediatric performance with the Nucleus 22-channel cochlear implant system. Am J Otol 1991;12 Suppl:126–136. 145Tobey EA, Rekard D, Buckley K, et al. Mode of communication and classroom placement impact on speech intelligibility. Arch Otolaryngol Head Neck Surg 2004;130:639–643. 146Dillon C, Pisoni DB, Cleary M, et al. Nonword imitation by children with cochlear implants. Arch Otolaryngol Head Neck Surg 2004;130:587–591. 147Nikolopoulos TP, Gibbin KP, Dyar D. Predicting speech perception outcomes following cochlear implantation using Nottingham children’s implant profile (NChIP). Int J Pediatr Otorhinolaryngol 2004;68:137–141. 148Spahn C, Richter B, Zschocke I, et al. The need for psychosocial support in parents with cochlear implanted children. Int J Pediatr Otorhinolaryngol 2001;57:45–53. 149O’Neill C, O’Donoghue GM, Archbold SM, et al. A cost-utility analysis of pediatric cochlear implantation. Laryngoscope 2000;110:156–160. 150Cheng AK, Rubin HR, Powe NR, et al. Cost-utility analysis of the cochlear implant in children. JAMA 2000;284:850–856. 151Institute of Medicine, Committee on Postmarket Surveillance of Pediatric Medical Devices. Safe Medical Devices for Children. Field M, and Tilson H, eds. Washington, DC: The National Academies Press, 2005. 152 Tambyraja EM, Gutman MA, Megerian CA Cochlear implant complications: Utility of federal database in systematic analysis. Archives of Otolaryngology-Head & Neck Surgery, 2005, Mar;131(3):245-250.