Bilateral Cochlear Implantation (CI) in Children

Summary and Conclusions

Technology and target group

Among the 100 000 (approximate) children born in Sweden each year, between 1 and 2 per 1000 have a hearing loss that requires some form of habilitation. Also, some children who can hear at birth may lose their hearing at an early age, eg, resulting from severe infection or head trauma. In most cases, conventional hearing aids, other devices, and psychosocial and communicative support are helpful in habilitating these children. Cochlear implantation (CI) is an option if conventional hearing aids do not yield satisfactory results in habilitating children with profound hearing loss or deafness.

This assessment assumes that a decision has been made to use cochlear implantation. Hence, the aim is not to compare the value of cochlear implantation versus other aural habilitation methods, but to compare a single (unilateral) implant versus dual (bilateral) implants.

Cochlear implants are devices that electrically stimulate the auditory nerve, and potentially allow people with profound hearing loss or deafness to recognize sounds. A cochlear implant consists of an internal component with a receiver and electrodes, and an external component with a microphone, speech processor, and transmitter. The internal component is implanted in the ear during a surgical procedure that lasts several hours. Following insertion of a cochlear implant, the patient begins a lifelong habilitation process. In children who previously have been unable to hear, the brain must learn to interpret sound, ie, the children must be given opportunities to learn listening skills and train their hearing. Also, the implant itself must be checked and maintained. Cochlear implants enable children to develop speech communication skills, depending on individual abilities. Maintaining sign language in these children, and in their environment, is important since the outcome of implantation varies by individual and because implants cannot be used in some situations (eg, while bathing or during a technical malfunction). Earlier, the devices were implanted in only one ear (unilateral cochlear implantation). Implanting devices in both ears (bilateral cochlear implantation) is being introduced to help children improve speech perception, primarily in complex listening situations, and to develop directional hearing. This assessment focuses on a potential target group of approximately 60 children per year diagnosed with congenital, or early acquired, profound hearing loss or deafness.

Primary question

Is there scientific evidence to show that patients benefit more from bilateral CI than from unilateral CI? This assessment is based on a systematic review of the literature.

Patient benefit

Only a few scientific studies (none of which included a control group) have assessed bilateral cochlear implants. Studies using children as their own controls have reported improvements in speech perception and directional hearing when children used both implants instead of only one. However, these studies provide only low-quality evidence because of their design. Results from clinical studies on complications of unilateral CI in children showed that complication rates varied from 2 percent to 16 percent. A second cochlear implant would double the risk for complications. No studies have specifically investigated the complications or side effects from bilateral cochlear implantation.

Economic aspects

A single cochlear implant costs approximately 220 000 Swedish kronor (SEK). The total cost for unilateral cochlear implantation is estimated to be around 350 000 SEK, including evaluation, surgery, fitting of the speech processor, and followup visits for the first year. Insertion of two implants during a simultaneous operation would add the cost of the second device, but the associated costs would not increase substantially. Hence, the total cost for bilateral implantation would be approximately 600 000 SEK. If the two devices were implanted sequentially, with an interval of several months, the cost would be higher (at least 700 000 SEK). No studies were identified that addressed the cost effectiveness of bilateral CI in children.

SBU's appraisal of the evidence

Scientific documentation on the benefits of bilateral cochlear implantation in children is insufficient*. Well-designed, scientific studies are needed to determine whether the method yields positive effects that outweigh the increased risk for complications. Given the uncertainty of current knowledge, there is an urgent need to systematically compile national data on clinical experience.

*Criteria for Evidence Grading SBU's Conclusions
Evidence Grade 1 - Strong Scientific Evidence. The conclusion is corroborated by at least two independent studies with high quality and internal validity, or a good systematic overview.
Evidence Grade 2 - Moderately Strong Scientific Evidence. The conclusion is corroborated by one study with high quality and internal validity, and at least two studies with medium quality and internal validity.
Evidence Grade 3 - Limited Scientific Evidence. The conclusion is corroborated by at least two studies with medium quality and internal validity.
Insufficient Scientific Evidence - No conclusions can be drawn when there are not any studies that meet the criteria for quality and internal validity.
Contradictory Scientific Evidence - No conclusions can be drawn when there are studies with the same quality and internal validity whose findings contradict each other.

This summary is based on a report prepared at SBU in collaboration with Elina Mäki-Torkko (expert), MD, PhD, Linköping University Hospital, and Radi Jönsson (reviewer), MD, PhD, Sahlgrenska University Hospital, Göteborg.

The complete report is available only in Swedish.

SBU Alert is a service provided by SBU in collaboration with the Medical Products Agency, the National Board of Health and Welfare, and the Swedish Association of Local Authorities and Regions.

References

1. EU Work Group on Genetics of Hearing Impairment. In: Martini A (redactor) Deafness, Epidemiology and Clinical Research (HEAR), Infoletter 1996;2:8-9.
2. Roush J, Holcomb MA, Roush PA, Escolar ML. When hearing loss occurs with multiple disabilities. Semin Hear 2004;25:333-45.
3. Yoshinaga-Itano C, Sedey AL, Coulter DK, Mehl AL. Language
   of early- and later-identified children with hearing loss. Pediatrics 1998;102(5):1161-71.
4. Yoshinaga-Itano C, Coulter D, Thomson V. Developmental outcomes of children with hearing loss born in Colorado hospitals with and without universal newborn hearing screening programs. Semin Neonatol 2001;6(6):521-9.
5. Cochlear implants in adults and children. NIH Consens Statement 1995;13(2):1-30. Review.
6. James AL, Papsin BC. Cochlear implant surgery at 12 months of age or younger. Laryngoscope 2004;114(12):2191-5.
7. Schauwers K, Gillis S, Daemers K, de Beukelaer C, Govaerts PJ. Cochlear implantation between 5 and 20 months of age: the onset of babbling and the audiologic outcome. Otol Neurotol 2004;25(3):263-70.
8. Colletti V, Carner M, Miorelli V, Guida M, Colletti L, Fiorino FG. Cochlear implantation at under 12 months: report on 10 patients. Laryngoscope 2005;115(3):445-9.
9. Vårdprogram för behandling av döva barn med cochleaimplantat. Stimulansbidrag för habilitering och rehabilitering: Socialstyrelsen, Stockholm; 2000. Artikelnr: 2000-19-6.
10. ODonoghue GM, Nikolopoulos TP, Archbold SM. Determinants of speech perception in children after cochlear implantation. Lancet 2000;356(9228):466-8.
11. Kirk KI, Miyamoto RT, Lento CL, Ying E, ONeill T, Fears B. Effects of age at implantation in young children. Ann Otol Rhinol Laryngol Suppl 2002;189:69-73.
12. Nikolopoulos TP, Dyar D, Archbold S, ODonoghue GM. Development of spoken language grammar following cochlear implantation in prelingually deaf children. Arch Otolaryngol Head Neck Surg 2004;130(5):629-33.
13. Svirsky MA, Teoh SW, Neuburger H. Development of language and speech perception in congenitally, profoundly deaf children as a function of age at cochlear implantation. Audiol Neurootol 2004;9(4):224-33.
14. Geers AE, Nicholas JG, Sedey AL. Language skills of children with early cochlear implantation. Ear Hear 2003;24(1 Suppl):46S-58S.
15. Willstedt-Svensson U, Lofqvist A, Almqvist B, Sahlen B. Is age at implant the only factor that counts? The influence of working memory on lexical and grammatical development in children with cochlear implants. Int J Audiol 2004;43(9):506-15.
16. Gravel JS, OGara J. Communication options for children with hearing loss. Ment Retard Dev Disabil Res Rev 2003;9(4):243-51.
17. Donaldson AI, Heavner KS, Zwolan TA. Measuring progress in children with autism spectrum disorder who have cochlear implants. Arch Otolaryngol Head Neck Surg 2004;130(5):666-71.
18. Filipo R, Bosco E, Mancini P, Ballantyne D. Cochlear implants in special cases: deafness in the presence of disabilities and/or associated problems. Acta Otolaryngol Suppl 2004;(552):74-80.
19. Mueller J, Schoen F, Helms J. Bilateral cochlear implant--new aspects for the future? Adv Otorhinolaryngol 2000;57:22-7.
20. Winkler F, Schon F, Peklo L, Muller J, Feinen Ch, Helms J. [The Wurzburg questionnaire for assessing the quality of hearing in CI-children (WH-CIK)]. Laryngorhinootologie 2002;81(3):211-6.
21. Kuhn-Inacker H, Shehata-Dieler W, Muller J, Helms J. Bilateral cochlear implants: a way to optimize auditory perception abilities in deaf children? Int J Pediatr Otorhinolaryngol 2004;68(10):1257-66.
22. Litovsky RY, Parkinson A, Arcaroli J, Peters R, Lake J, Johnstone P et al. Bilateral cochlear implants in adults and children. Arch Otolaryngol Head Neck Surg 2004;130(5):648-55.
23. Cohen NL, Hoffman RA. Complications of cochlear implant surgery in adults and children. Ann Otol Rhinol Laryngol 1991;100(9 Pt 1):708-11.
24. Collins MM, Hawthorne MH, el-Hmd K. Cochlear implantation in a district general hospital: problems and complications in the first five years. J Laryngol Otol 1997;111(4):325-32.
25. Kempf HG, Johann K, Lenarz T. Complications in pediatric cochlear implant surgery. Eur Arch Otorhinolaryngol 1999;256(3):128-32.
26. Bhatia K, Gibbin KP, Nikolopoulos TP, ODonoghue GM. Surgical complications and their management in a series of 300 consecutive pediatric cochlear implantations. Otol Neurotol 2004;25(5):730-9.
27. Luetje CM, Jackson K. Cochlear implants in children: what constitutes a complication? Otolaryngol Head Neck Surg 1997;117(3 Pt 1):243-7.
28. Reefhuis J, Honein MA, Whitney CG, Chamany S, Mann EA, Biernath KR et al. Risk of bacterial meningitis in children with cochlear implants. N Engl J Med 2003;349(5):435-45.
29. Meningitprofylax för personer som ska opereras med cochleärt implantat: Socialstyrelsen, Stockholm; 2005. Artikelnr: 2005-130-3.
30. Carter R, Hailey D. Economic evaluation of the cochlear implant. Int J Technol Assess Health Care 1999;15(3):520-30.
31. Cheng AK, Rubin HR, Powe NR, Mellon NK, Francis HW, Niparko JK. Cost-utility analysis of the cochlear implant in children. JAMA 2000;284(7):850-6.
32. ONeill C, ODonoghue GM, Archbold SM, Normand C. A cost-utility analysis of pediatric cochlear implantation. Laryngoscope 2000;110(1):156-60.
33. Summerfield AQ, Marshall DH, Barton GR, Bloor KE. A cost-utility scenario analysis of bilateral cochlear implantation. Arch Otolaryngol Head Neck Surg 2002;128(11):1255-62.
34. European Group on Ethics in Science and New Technologies. Opinion Nº 20. Ethical aspects of ICT implants in the human body. Adopted March 16, 2005.
35. Sharma A, Dorman MF, Kral A. The influence of a sensitive period on central auditory development in children with unilateral and bilateral cochlear implants. Hear Res 2005;203(1-2):134-43.