International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Experience of bone-anchored hearing aid implantation in children younger than 5 years of age Kwamena Amonoo-Kuofi a, Andrea Kelly b, Michel Neeff a, Colin R.S. Brown a,* a b
Starship Children’s Hospital, Park Road, Grafton, Auckland 1024, New Zealand Starship Children’s Hospital, Green Lane Hospital, Auckland, New Zealand
A R T I C L E I N F O
A B S T R A C T
Article history: Received 18 November 2014 Accepted 26 December 2014 Available online 3 January 2015
Objective: To assess the practicality and benefit of Bone-anchored hearing aid (BAHA1) implantation in children younger than 5 years of age. FDA approval for use of BAHA1 only exists for children 5 years of age and older. Their use in Australia is also rare, however their use for younger children is approved by the European Union. We wish to share our experience of implantation in an antipodean setting in this age group. Methods: Institutional board approval was obtained for this study. All children undergoing BAHA1 implantation under 5 years old were included from our prospective database. We examined the variety of surgical techniques, (including skin grafting, limited soft tissue reduction and no soft tissue reduction), BAHA1 implants and abutments used, and use of the new series 400 hydroxyapatite coatings. Demographic data obtained included age at surgery, follow up duration, gender, ethnicity and indication for surgery. Anonymous benefit questionnaires (Glasgow children’s benefit inventory (GCBI) and parents’ evaluation of aural performance of children (PEACH)) were completed online as well as a questionnaire on device use. Complications recorded included soft tissue reactions, implant loss/ removal, abutment replacement/removal. We also assessed whether patient weight, ethnicity or socioeconomic status were risk factors for these complications. Results: 24 Children (26 ears/26 implants) under five years were identified from the database and included in the study. There was a 14:10 male to female ratio. Patient caregivers reported subjective benefit and improved quality of life (QOL) despite setbacks and complications related to BAHA1 usage. 10/24 (42%) of children required treatment for significant peri-implant skin reactions whilst 25% required replacement of their abutments and/or implants. An increased risk of major complication was associated with socioeconomic deprived backgrounds and in patients of New Zealand Maori and Pacific Island ethnicity but not in patients with increased weight centiles. Conclusions: The BAHA1 implant and hearing aid system is of value to children under age 5 years. Parents tolerate the skin reactions and complications because of the perceived benefit in hearing and quality of life. Careful counselling of parents of potential young BAHA1 implant candidates is necessary in light of this. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Bone-anchored hearing aids BAHA1 complications Soft tissue hypertrophy Bone hypertrophy Osseo-integration Pediatric
Introduction Bone anchored hearing aids (Baha1) were developed by Tjellstrom and Carlsson and first utilized in adults in 1977 in Gothenburg, Sweden. Use in children occurred nearly two decades later in 1983. The BAHA1 is indicated for use in treating conductive hearing loss (e.g. in children with aural atresia, chronic otitis media, ossicular abnormalities) and mild to moderate
* Corresponding author. Tel.: +0064 96311965; fax: +0064 96311966. E-mail address: [email protected] (Colin R.S. Brown). http://dx.doi.org/10.1016/j.ijporl.2014.12.033 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
sensorineural hearing loss as well as single sided sensorineural deafness. The Food and Drug Administration (FDA) approved its use in adults in 1996 and in children over 5 years old in 1999 [1]. Approval for its use in single sided deafness was granted in 2002. There is no current approval for use in children under 5 years of age. Numerous studies have outlined beneficial outcomes encompassing improved quality of life, improved hearing outcomes as well as compliance with device usage [2–4]. Some advantages of the BAHA1 over conventional headband worn bone conducted (BC) hearing aids include improved aesthetics, reduced pressure headaches, skin ulcers and improved user compliance [4].
K. Amonoo-Kuofi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480
Complications occurring at the interface between the soft tissue and the titanium implant are well described in the literature [5,6]. Immunochemical studies have demonstrated increased inflammatory cells surrounding the implant following insertion of the BAHA1 device even when the soft tissues remain clinically non-inflamed and non-infected [7–9]. A number of surgical techniques for managing the skin and soft tissues with BAHA1 implant insertion have been described to reduce inflammatory responses including split skin grafting, limited soft tissue reduction and no soft tissue reduction [10]. Method All children undergoing BAHA1 implant surgery in the tertiary Otolaryngology unit at the Starship Children’s Hospital in the North Island of New Zealand were operated on by the two senior authors (CB, MN). Operative details were prospectively recorded on a password-protected database. We reviewed the clinical records and identified all children under the age of five fitted with a BAHA1 from 2002 to 2013. Institutional approval was sought and obtained for the purpose of the study. Demographic data obtained included age at surgery, patient weight, gender, ethnicity, indication for surgery and follow up duration. Deprivation index (socioeconomic status) and patient weight were also recorded. Complications recorded included soft tissue reactions, implant loss or removal, abutment removal or replacement and failure of osseo-integration. The New Zealand Deprivation Index 2006 (NZDep2006) is an updated version of an index of socioeconomic deprivation derived from the patient’s address and census variables (educational qualifications, home ownership and income in the immediate locale). This is an ordinal scale ranging from 1 to 10, with 1 representing areas of least deprivation and 10, areas with most deprivation [11]. Weight percentile based on age was derived based on US centre for disease control and prevention growth charts 2000. This data was obtained from recorded weight measurement against age at Stage I BAHA1 surgery. For the purpose of this study this was converted to standard deviation score (SDS) for statistical analysis. SDS is based on US centre for disease control and prevention 2000 sex-specific weight for age reference population data [12]. Improvement of quality of life (QOL) was evaluated using the validated Glasgow Children’s Benefit Inventory (GCBI). This is comprised of 24 questions with five possible responses (with score ranging from –2 to +2). The total overall score is divided by 24 (number of questions) and then multiplied by 50, yielding a final score ranging from 100 to +100. The Parents’ Evaluation of Aural/Oral Performance of Children (PEACH) is a questionnaire designed to evaluate children’s hearing and communication when using their hearing implant. It is comprised of 11 questions with five possible responses (scoring ranging from 2 to +2). The total score is divided by 48 and multiplied by 100 to give a percentage score. Children with 70% and above scores tend to be performing as expected with lower scores requiring review of the hearing devices. Parents were surveyed using an online anonymous selfreporting questionnaire developed for this study. We obtained information regarding whether or not devices were still being utilized and whether any devices had undergone repairs in the study period. Surgical description Insertion of the BAHA1 was performed in two stages in the majority of patients. For the two-stage technique, skin and subcutaneous tissues were elevated during the first stage leaving
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periosteum intact. A burr hole was drilled utilizing a high-speed drill with copious irrigation. A 3 mm or 4 mm implant (flange fixture) was inserted depending on skull bone thickness. In many patients a sleeper fixture was inserted at the time of the first stage procedure. A 3–6 month period to enable osseo-integration was allowed prior to second stage implantation surgery. Patients had osseointegration assessed and verified clinically at the time of 2nd stage surgery. Initially, we used a skin graft technique using the BAHA1 dermatome with soft tissue reduction. A 5.5 mm titanium abutment was secured and the skin graft sutured down to the periosteum. If revision surgery was required an 8.5 mm titanium abutment was used. Latterly we utilized a single skin incision with limited soft tissue reduction, and most recently no soft tissue reduction. Since 2013, hydroxyapatite (BAHA1 400 series) coated abutments (according to skin thickness) have been utilized with primary insertions and also following revision surgery. Follow up was arranged 3–6 monthly once the BAHA1 site had fully healed and all families were counselled about abutment and peri-abutment cleaning and maintenance. Follow up data recorded included minor and major wound complications. Major complications were defined as requiring revision surgery. Minor complications were defined as local wound infections not requiring revision surgery. Clinical information was used to assign a highest Holgers grade for wound complications. Audiological assessment included functional benefit whilst using the BAHA1 as well as audiometric hearing assessments. Statistical analysis Continuous data (e.g. age, follow up time) was reported as means or medians as appropriate. Categorical variables (e.g. gender) were reported as frequencies with percentages. Comparisons were made between patients that had major complications versus those that did not. Differences in weight were compared using the Wilcoxon’s rank sum test. Differences in the frequency of upper or lower socioeconomic status as well as ethnicity were compared using the Fisher’s exact test. Results A total of 24 children (26 ears/26 implants) younger than 5 years were identified from the database and included in the study. There were 14 males and 10 females. One patient (a bilateral implantee) emigrated and was lost to follow up and therefore not included in the analysis. The mean duration of follow up was 2.8 years (range 6 months to 10.2 years). Fig. 1 depicts the age distribution of children at the first and second stages of surgery. The mean age at 1st stage was 40 months with a range 24–59 months. The mean time interval between first and second stage surgery was 6 months (Fig. 2). 1 patient had their BAHA1 implanted as a single stage procedure. Two patients had bilateral implants inserted. These were done simultaneously. There were 11 patients of New Zealand Maori ethnicity, 10 European, 2 South East Asian and 1 Pacific Islander (Fig. 3). The surgical indications for BAHA1 insertions are shown in Table 1 with concomitant syndromes shown in Table 2 and Fig. 4. 20 patients (22 implants) had a 3 mm implant with 4 patients (4 implants) fitted with a 4 mm implant. The patient undergoing a single stage procedure had a 4 mm implant. Patients with bilateral implants had 3 mm implants inserted. In our series, no sleeper implant was used in the single stage BAHA1 insertion. 12 patients (12 implants) received the generation 2 BAHA1 implant, 7 patients (8 implants) had a generation 3 (BIA 300 series)
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K. Amonoo-Kuofi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480 Table 1 Indication for BAHA. Diagnosis
Patients (n)
Bilateral atresia Unilateral atresia Single sided deafness Chronic otitis media
12 10 1 1
Table 2 Associated syndromes.
Fig. 1. Age distribution at first and second stage surgery.
Syndromes
Patients (n)
Goldenhaar Treacher Collins Cornelia de Lange 18q Syndrome Charge syndrome Congenital spinal cord anomalies
4 2 1 1 1 1
their follow up duration. Thirteen patients (54%) (14 implants— 53%) had grade 2 or 3 (redness, moistness and/or granulation tissue were present). Most of these required local (topical) treatment with or without oral antibiotics. Seven patients (29%) (8 implants— 31%) had a grade 4 Holgers score with extensive soft-tissue reactions. There were 2 patients (8.5%) (2 implants—8%) without complications.
Fig. 2. Interval time (months between stages I + II).
implant, and 5 patients (6 implants) received the generation 4 (BIA 400 series) implant.15 patients (16 implants) had a skin thinning technique, 2 patients (3 implants) had minimal soft tissue reduction and 7 patients (7 implants) had no soft tissue reduction. The most severe soft tissue/skin reaction for each patient was recorded based on Holgers grade/modification; Figs. 5 and 6a and b [5,7,13]. Four patients (17%) (4 implants—16%) had grade 0 or 1 Holgers score ratings (minimal or no reaction around the abutment) over
Fig. 4. Distribution of syndrome diagnoses.
Fig. 3. Range of ethnicity.
Fig. 5. Soft tissue reaction—Holgers grade.
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Fig. 6. (a) BAHA1 implant demonstrating soft tissue overgrowth over abutment. (b) BAHA1 implant with complete soft tissue overgrowth over abutment.
Fig. 7a and b flow charts demonstrate all complications identified in the study. Ten patients (42%) (46% implants) underwent revision surgery during the study period for ‘major’ soft tissue/BAHA1 related complications. We could not demonstrate superiority of the non-skin reduction technique in this group, with 42% of these children having major complications. 17 patients (19 implants had soft tissue reduction performed at surgery. Within this group, 12 implants had minor complications and 12 implants had major complications. Minor complications occurred in 12 patients (50%), 12 implants (46%) with 6 patients experiencing recurrent infections. Three patients (11%), 3 implants (10%) required soft tissue reduction for treatment of overgrowth around the abutment site. Three patients lost their flange fixtures. These were related to infection (2 patients) and trauma (1 patient). 3 patients were no longer using their BAHA1 devices due to longstanding soft tissue reactions resistant to local treatments and soft tissue reduction attempts. Alternative modalities of hearing rehabilitation are being considered. 14 patients required their BAHA1 processor to be repaired and in the majority, this occurred more than once. The main reasons were due to aid failure as well as following traumatic events. 2 patients had lost their devices. 60% (6/10) of major complications occurred in children with a syndromic diagnosis with 40% occurring in patients with isolated microtia. 1/10 (10%) of syndromic children had no complications with 3/10 (30%) and 6/10 (60%) experiencing minor and major complications, respectively.
Weight distribution is described in Figs. 8 and 9. Over 2/3 of our patients had a weight >50–75th centile with approximately a third over the 90th centile. 3 patients who had major complications had weight percentiles >90th centile. Fig. 10 represents the association between socioeconomic score (SES) and complications. 11 patients were in the most deprived group (NZDep score 8–10), 9 patients in the mid deprived (NZDep score 5–7), and 4 patients in the least deprived (NZDep score 1–4). There was a non-statistically significant trend (P = 0.41) towards an increased rate of complications for patients in the most deprived group (lowest socioeconomic group). Fig. 11 represents rate of complications assessed against ethnicity comparing Maori/Pacific Island against non-Maori/ Pacific Island ethnic groups. There was a non-statistically significant (P = 0.21) trend towards an increased rate of complications in the Maori/Pacific Island ethnic group compared to the non-Maori/Pacific Island ethnic group. 18/24 Quality of Life (QOL) completed responses were returned. All children had parental assistance with regards to answering the GCBI questionnaire. The final mean score was +40 (range 100 to +100) indicating an increase in parental perception of patient’s QOL. There were no scores below 0. This compares favourably to a previous study with mean scores ranging from 26 to 32 [2]. 14/24 patients returned questionnaires with the PEACH assessment. Score ranges were 24/44 to 42/44. Mean score was 35 with calculated final percentage score of 72% indicating performance of the device fell within the range of normal auditory perception in noisy and quiet environments.
Fig. 7. (a) Flow chart of distribution of complications [patients]. (b) Flow chart of distribution of complications [Implants].
K. Amonoo-Kuofi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480
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Fig. 8. Weight percentiles.
Discussion The BAHA1 device is not yet FDA approved in the USA for children under 5 years of age. Our series of children in this age group demonstrates that that the BAHA1 implant and abutment system can be used safely in this group, with a high rate of successful osseo-integration, even in bone less than 3 mm in thickness. The PEACH results of a mean score of 72% showed the parents were finding their children’s auditory performance fell within the range of auditory perception equivalent to those of children with normal hearing. The GCBI score of +40 indicated overall pleasing parental satisfaction with BAHA1 use. Whilst we and most parents believe the BAHA1 implant to be beneficial, soft tissue complications occurred frequently in our patient group, putting additional demands also upon parents and clinic services. A number of changes have been made in order to reduce this, including the use of longer abutments [14] and the use of a linear incision without soft tissue reduction at the time of implantation [15,16]. Soft tissue reduction techniques have not resulted in clinically significant reduction in skin complications in our cohort (10 minor, 7 major complications) although the numbers in our study are small. Newer hydroxyapatite implants (400 BAHA1) have also been utilised but we have not yet seen a reduction in skin complications using these, although our numbers with this abutment in this age group are small (n = 5). A number of studies have grouped complications similarly into major complications (requiring revision surgery) and minor
Fig. 9. Rate of complications associated with patients’ standardized.
Fig. 10. Rate of complications associated with socioeconomic deprivation scores. Top 70% SES (socioeconomic score) = Mid–High SES = NZDep score 01–03 and 04– 07 (least deprived). Bottom 30% SES = Low SES NZDep 08–10 (most deprived). P = 0.41 status
complications (wound infections not requiring revision surgical intervention) [17–19]. One series found no difference in soft tissue complications when comparing single versus double stage surgery and skin graft type [20]. Complications are suggested to be higher in children with a diagnosis of craniofacial syndrome with the risk of complications increasing over a prolonged period of time [21]. In our study, 22 patients out of 24 had a recorded complication. 50% of recorded complications were minor skin reactions not requiring surgical intervention. 42% of patients in our study group suffered major complications requiring surgical intervention (soft tissue reduction, abutment revision or abutment removal). There are very significant variations in reported studies related to complication rates and in perceptions of what constitute complications [21,22]. 83% of our patients (84% of implants) had a Holgers grade 2 or greater. Previously reported rates include 37% [4] and 78% [17]. Our Holgers grade 3–4 (50% patients, 53% of implants) is higher compared to reported rates of 17% [3] and 38% [17]. Failure of osseo-integration, the most common reason for loss of implant is estimated to range from 0 to 15% in the paediatric population [13,14]. This compares with 10% in this study. There were 2 patients (8%) (2 implants—8% of implants) without complications, described in some articles as a ‘reaction free penetration site’. This compares to 11%, 54% and 91% in reported studies, respectively [4,13,18]. Implantation in children less than 5 years has raised concerns relating to the adequacy of skull thickness. Concerns raised also suggest that increased skull water content as well as reduced
Fig. 11. Rate of complication associated with ethnicity.
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mineral content, have a potential negative impact on osseointegration [20,23]. In this study we have not found initial integration to be a problem, even into bone less than 3 mm in thickness. One patient under 5 years of age had a 4 mm BAHA1 inserted as a single stage procedure. This implant has survived without major complications. The current cost of BAHA1 insertion was calculated in order to assess the financial burden relating to our case mix. We also wished to assess the financial burden in cases resulting in revision of abutment and or implant due to skin and soft tissue complications. The cost of hardware for a flange fixture (implant) plus abutment insertion as a single staged procedure is $NZ 2390.00. If we implant a spare flange fixture (abutment), typically as we have done in our two stage procedures the hardware costs alone are $NZ4161.00 Should a replacement abutment be required, this increases the hardware costs by 49% (single stage with one fixture) and 28% (two stage procedure with two fixtures). Notwithstanding the cost of the operating facility, there is additional burden on the family of the child, associated with major and minor complications which may render the patient temporarily unable to utilize their BAHA1 device with additional costs of medicines, and transport for medical care, and time off school for the children and work for their parents. A previous article reviewing USA Medicare billing costs of revising BAHA in adults and children suggested an overall increase of 16% over and above original costings [24]. New Zealand may have environmental socioeconomic/ethnic factors that might play a role in increased susceptibility to soft tissue skin reactions [25]. There appears to be increased risk of soft tissue infections in ethnic Pacific and Maori children [26,27]. We observed a non-statistically significant trend in our study with major complications increased in the Maori and Pacific group compared to non-Maori and Pacific groups. We were not able to show a statistically significant trend reported in a previous publication on BAHA in children [17]. In adults, an increased trend of soft tissue complications requiring surgical reduction/abutment replacement in association with high BMI has been reported [28]. Also reported has been an association of complications relating to increased weight percentiles (>90th centiles) in a paediatric population [17]. This association was not identified in our study group (P = 0.84). In our current review major complications were identified within all the different weight categories. From a practical point of view, we recognize the potential benefit of implanting patients with elevated weight centiles (for respective ages) with longer abutments at second stage surgery. In a prior article we demonstrated NZDep score to be the most important risk factor in determining risk of complications [17]. In order to analyse outcomes based on socioeconomic score, major complications in patients with a higher NZDep score (most deprived) were compared to those in patients with a lower NZDep score (least deprived). We observed a non-statistically significant trend with major complications increased in the patients in the lower socioeconomic group (P = 0.41). In future, we believe non skin penetrating devices along the lines of as the Vibrant Sound Bridge and Bone Bridge (MedelTM), and to a lesser degree, the Sophono Otomag1, BAHA1 4 Attract system (Cochlear1), amongst others may have a greater role in managing the hearing deficit in children with aural atresia [29,30]. Conclusions This study reports observed complications in BAHA1 implantation within a group of children implanted under age 5 years. Osseo-integration in children in this age group was not a significant problem however outpatient and surgical interventions
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are often required. Despite this complication burden and morbidity, parental self-reporting and questionnaire results showed perceived benefit in hearing and quality of life from the use of the BAHA1 implant. An honest discussion with careful counselling of parents of potential young BAHA1 implant candidates is important in light of these results. Acknowledgements We acknowledge assistance from Dr Peter Reed, PhD, of the Children’s Research Centre (supported by the Starship Foundation and Auckland District Health Board).
References [1] G. Ricci, A.D. Volpe, M. Faralli, et al., Bone-anchored hearing aids (Baha) in congenital aural atresia: Personal experience, Int J. Pediatr. Otorhinolaryngol. 75 (2011) 342–346. [2] M.J.F. de Wolf, M.K.S. Hol, E.A.M. Mylanus, A.F.M. Snik, W.R.J. Cremers, Benefit and quality of life after bone-anchored hearing aid fitting in children With unilateral or bilateral hearing impairment, Arch. Otolaryngol. Head Neck Surg. 137 (2) (2011) 130–138. [3] A. McDermott, M. Williams, A. Kuo, D. Reid, D. Proops, Quality of life in children fitted with a bone- anchored hearing aid, Otol. Neurotol. 30 (2009) 344–349. [4] S. Lloyd, J. Almeyda, K.S. Sirimanna, D.M. Albert, C.M. Bailey, Updated surgical experience with bone anchored hearing aids, J. Laryngol. Otol. 121 (2007) 826– 831. [5] K.M. Holgers, A. Tjellstrom, L.M. Bjursten, et al., Soft tissue reactions around percutaneous implants: a clinical study of soft tissue conditions around skin penetration titanium implants for bone anchored hearing aids, Am. J. Otol. 9 (1988) 56–59. [6] S. Roman, R. Nichollas, J.M. Triglia, Practical guidelines for bone-anchored hearing aids in children, Eur. Ann. Otorhinolaryngol., Head Neck Dis. 128 (2011) 253–258. [7] K.M. Holgers, Characteristics of the inflammatory process around skin penetrating titanium implants for aural rehabilitation, Audiology 39 (2000) 253–259. [8] P. Bonding, Titanium implants for bone anchored hearing aids- host reaction, Acta Otolaryngol. Sup. 543 (2000) 105–107. [9] A. Tjellstrom, B. Ha˚kansson, J. Lindstrom, et al., Analysis of the mechanical impedance of bone-anchored hearing aids, Acta Otolaryngol. 89 (1980) 85–92. [10] G.K. Lekakis, A. Najuko, P.G. Gluckmann, Wound related complications following full thickness versus split thickness skin grafts on patients with bone anchored hearing aids, Clin. Otol. 30 (4) (2005) 324–327. [11] hhttp://koordinates.com/layer/1066-nz-deprivation-index-2006i (last accessed March 2014). [12] hhttp://www.cdc.gov/nchs/data/series/sr_11/sr11_246.pdfi (last accessed April 2014). [13] R.F. Yellon, Bone anchored hearing aid in children—prevention of complications, Int J. Pediatr. Otorhinolaryngol. 71 (2007) 823–826. [14] T.J. Allis, B.D.O. Owen, B. Chen, D.T. Jones, G.F. Moore, et al., Longer length Baha abutments decrease wound complications and revision surgery, Laryngoscope 124 (4) (2014) 989–992. [15] S.P. Cass, P.A. Mudd, Bone-anchored hearing devices: indications, outcomes and the linear surgical technique, Oper. Tech. Otolaryngol. 21 (2010) 197–206. [16] A. Lanis, M. Hultcrantz, Percutaneous osseointegrated implant surgery without skin thinning in children: a retrospective case review, Otol. Neurootol. 34 (2013) 715–722. [17] T. Kraii, C. Brown, M. Neeff, K. Fisher, Complications of bone-anchored hearing aids in paediatric patients, Int. J. Pediatr. Otorhinolaryngol. 75 (2011) 749–753. [18] M.J.F. de Wolf, M.K.S. Hol, P.L.M. Huygen, E.A.M. Mylanus, W.R.J. Cremers, Nijmegan results with application of a bone-anchored hearing aid in children: simplified surgical technique, Ann. Otol. Rhinol. Laryngol. 117 (11) (2008) 805–814. [19] T. Davids, K.A. Gordon, D. Clutton, B.C. Papsin, Bone-anchored hearing aids in infants and children younger than 5 years, Arch. Otolaryngol. Head Neck Surg. 133 (2007) 51–55. [20] I. Saliba, P. Froehlich, S. Bouhabel, One-stage vs. two-stage BAHA implantation in a paediatric population, Int. J. Pediatr. Otorhinolaryngol. 76 (2012) 1814–1818. [21] J.B. Ida, S. Mansfield, J.K. Meinzen-Derr, D.I. Choo, Complications in pediatric osseointegrated implantation, Otolaryngol. Head Neck Surg. 144 (4) (2011) 586–591. [22] R. Kiringoda, L.R. Lustig, A meta-analysis of the complications associated with osseointegrated hearing aids, Otol. Neurootol. 34 (2013) 790–794. [23] S. Ali, L. Hadoura, A. Carmichael, N.K. Geddes, Bone-anchored hearing aid; a single stage procedure in children, Int. J. Pediatr. Otorhinolaryngol. 73 (8) (2009) 1076–1079. [24] S.E. Pross, A. Layton, K. Tong, L.R. Lustig, Cost of placement and complications associated with osseointegrated bone-conducting hearing prosthesis: a retrospective analysis of medicare billing data, Otol. Neurootol. 35 (3) (2014) 476–481.
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[25] A. Leversha, Risk factors for cellulitis and hospitalisation with cellulitis among Auckland children: Is the ethnic inequality explained by socioeconomic factors or is there more? 2013, Unpublished PhD Thesis, University of Auckland, New Zealand. [26] A. Leversha, Skin infections in Maori and Pacific families, Best Pract. J. 45 (2012) 14–20. [27] P.S. Morris, A.J. Leach, Acute and chronic otitis media, Paediatr. Clin. North Am. 56 (6) (2009) 1383–1399.
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Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Experience of bone-anchored hearing aid implantation in children younger than 5 years of age Kwamena Amonoo-Kuofi a, Andrea Kelly b, Michel Neeff a, Colin R.S. Brown a,* a b
Starship Children’s Hospital, Park Road, Grafton, Auckland 1024, New Zealand Starship Children’s Hospital, Green Lane Hospital, Auckland, New Zealand
A R T I C L E I N F O
A B S T R A C T
Article history: Received 18 November 2014 Accepted 26 December 2014 Available online 3 January 2015
Objective: To assess the practicality and benefit of Bone-anchored hearing aid (BAHA1) implantation in children younger than 5 years of age. FDA approval for use of BAHA1 only exists for children 5 years of age and older. Their use in Australia is also rare, however their use for younger children is approved by the European Union. We wish to share our experience of implantation in an antipodean setting in this age group. Methods: Institutional board approval was obtained for this study. All children undergoing BAHA1 implantation under 5 years old were included from our prospective database. We examined the variety of surgical techniques, (including skin grafting, limited soft tissue reduction and no soft tissue reduction), BAHA1 implants and abutments used, and use of the new series 400 hydroxyapatite coatings. Demographic data obtained included age at surgery, follow up duration, gender, ethnicity and indication for surgery. Anonymous benefit questionnaires (Glasgow children’s benefit inventory (GCBI) and parents’ evaluation of aural performance of children (PEACH)) were completed online as well as a questionnaire on device use. Complications recorded included soft tissue reactions, implant loss/ removal, abutment replacement/removal. We also assessed whether patient weight, ethnicity or socioeconomic status were risk factors for these complications. Results: 24 Children (26 ears/26 implants) under five years were identified from the database and included in the study. There was a 14:10 male to female ratio. Patient caregivers reported subjective benefit and improved quality of life (QOL) despite setbacks and complications related to BAHA1 usage. 10/24 (42%) of children required treatment for significant peri-implant skin reactions whilst 25% required replacement of their abutments and/or implants. An increased risk of major complication was associated with socioeconomic deprived backgrounds and in patients of New Zealand Maori and Pacific Island ethnicity but not in patients with increased weight centiles. Conclusions: The BAHA1 implant and hearing aid system is of value to children under age 5 years. Parents tolerate the skin reactions and complications because of the perceived benefit in hearing and quality of life. Careful counselling of parents of potential young BAHA1 implant candidates is necessary in light of this. ß 2015 Elsevier Ireland Ltd. All rights reserved.
Keywords: Bone-anchored hearing aids BAHA1 complications Soft tissue hypertrophy Bone hypertrophy Osseo-integration Pediatric
Introduction Bone anchored hearing aids (Baha1) were developed by Tjellstrom and Carlsson and first utilized in adults in 1977 in Gothenburg, Sweden. Use in children occurred nearly two decades later in 1983. The BAHA1 is indicated for use in treating conductive hearing loss (e.g. in children with aural atresia, chronic otitis media, ossicular abnormalities) and mild to moderate
* Corresponding author. Tel.: +0064 96311965; fax: +0064 96311966. E-mail address: [email protected] (Colin R.S. Brown). http://dx.doi.org/10.1016/j.ijporl.2014.12.033 0165-5876/ß 2015 Elsevier Ireland Ltd. All rights reserved.
sensorineural hearing loss as well as single sided sensorineural deafness. The Food and Drug Administration (FDA) approved its use in adults in 1996 and in children over 5 years old in 1999 [1]. Approval for its use in single sided deafness was granted in 2002. There is no current approval for use in children under 5 years of age. Numerous studies have outlined beneficial outcomes encompassing improved quality of life, improved hearing outcomes as well as compliance with device usage [2–4]. Some advantages of the BAHA1 over conventional headband worn bone conducted (BC) hearing aids include improved aesthetics, reduced pressure headaches, skin ulcers and improved user compliance [4].
K. Amonoo-Kuofi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480
Complications occurring at the interface between the soft tissue and the titanium implant are well described in the literature [5,6]. Immunochemical studies have demonstrated increased inflammatory cells surrounding the implant following insertion of the BAHA1 device even when the soft tissues remain clinically non-inflamed and non-infected [7–9]. A number of surgical techniques for managing the skin and soft tissues with BAHA1 implant insertion have been described to reduce inflammatory responses including split skin grafting, limited soft tissue reduction and no soft tissue reduction [10]. Method All children undergoing BAHA1 implant surgery in the tertiary Otolaryngology unit at the Starship Children’s Hospital in the North Island of New Zealand were operated on by the two senior authors (CB, MN). Operative details were prospectively recorded on a password-protected database. We reviewed the clinical records and identified all children under the age of five fitted with a BAHA1 from 2002 to 2013. Institutional approval was sought and obtained for the purpose of the study. Demographic data obtained included age at surgery, patient weight, gender, ethnicity, indication for surgery and follow up duration. Deprivation index (socioeconomic status) and patient weight were also recorded. Complications recorded included soft tissue reactions, implant loss or removal, abutment removal or replacement and failure of osseo-integration. The New Zealand Deprivation Index 2006 (NZDep2006) is an updated version of an index of socioeconomic deprivation derived from the patient’s address and census variables (educational qualifications, home ownership and income in the immediate locale). This is an ordinal scale ranging from 1 to 10, with 1 representing areas of least deprivation and 10, areas with most deprivation [11]. Weight percentile based on age was derived based on US centre for disease control and prevention growth charts 2000. This data was obtained from recorded weight measurement against age at Stage I BAHA1 surgery. For the purpose of this study this was converted to standard deviation score (SDS) for statistical analysis. SDS is based on US centre for disease control and prevention 2000 sex-specific weight for age reference population data [12]. Improvement of quality of life (QOL) was evaluated using the validated Glasgow Children’s Benefit Inventory (GCBI). This is comprised of 24 questions with five possible responses (with score ranging from –2 to +2). The total overall score is divided by 24 (number of questions) and then multiplied by 50, yielding a final score ranging from 100 to +100. The Parents’ Evaluation of Aural/Oral Performance of Children (PEACH) is a questionnaire designed to evaluate children’s hearing and communication when using their hearing implant. It is comprised of 11 questions with five possible responses (scoring ranging from 2 to +2). The total score is divided by 48 and multiplied by 100 to give a percentage score. Children with 70% and above scores tend to be performing as expected with lower scores requiring review of the hearing devices. Parents were surveyed using an online anonymous selfreporting questionnaire developed for this study. We obtained information regarding whether or not devices were still being utilized and whether any devices had undergone repairs in the study period. Surgical description Insertion of the BAHA1 was performed in two stages in the majority of patients. For the two-stage technique, skin and subcutaneous tissues were elevated during the first stage leaving
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periosteum intact. A burr hole was drilled utilizing a high-speed drill with copious irrigation. A 3 mm or 4 mm implant (flange fixture) was inserted depending on skull bone thickness. In many patients a sleeper fixture was inserted at the time of the first stage procedure. A 3–6 month period to enable osseo-integration was allowed prior to second stage implantation surgery. Patients had osseointegration assessed and verified clinically at the time of 2nd stage surgery. Initially, we used a skin graft technique using the BAHA1 dermatome with soft tissue reduction. A 5.5 mm titanium abutment was secured and the skin graft sutured down to the periosteum. If revision surgery was required an 8.5 mm titanium abutment was used. Latterly we utilized a single skin incision with limited soft tissue reduction, and most recently no soft tissue reduction. Since 2013, hydroxyapatite (BAHA1 400 series) coated abutments (according to skin thickness) have been utilized with primary insertions and also following revision surgery. Follow up was arranged 3–6 monthly once the BAHA1 site had fully healed and all families were counselled about abutment and peri-abutment cleaning and maintenance. Follow up data recorded included minor and major wound complications. Major complications were defined as requiring revision surgery. Minor complications were defined as local wound infections not requiring revision surgery. Clinical information was used to assign a highest Holgers grade for wound complications. Audiological assessment included functional benefit whilst using the BAHA1 as well as audiometric hearing assessments. Statistical analysis Continuous data (e.g. age, follow up time) was reported as means or medians as appropriate. Categorical variables (e.g. gender) were reported as frequencies with percentages. Comparisons were made between patients that had major complications versus those that did not. Differences in weight were compared using the Wilcoxon’s rank sum test. Differences in the frequency of upper or lower socioeconomic status as well as ethnicity were compared using the Fisher’s exact test. Results A total of 24 children (26 ears/26 implants) younger than 5 years were identified from the database and included in the study. There were 14 males and 10 females. One patient (a bilateral implantee) emigrated and was lost to follow up and therefore not included in the analysis. The mean duration of follow up was 2.8 years (range 6 months to 10.2 years). Fig. 1 depicts the age distribution of children at the first and second stages of surgery. The mean age at 1st stage was 40 months with a range 24–59 months. The mean time interval between first and second stage surgery was 6 months (Fig. 2). 1 patient had their BAHA1 implanted as a single stage procedure. Two patients had bilateral implants inserted. These were done simultaneously. There were 11 patients of New Zealand Maori ethnicity, 10 European, 2 South East Asian and 1 Pacific Islander (Fig. 3). The surgical indications for BAHA1 insertions are shown in Table 1 with concomitant syndromes shown in Table 2 and Fig. 4. 20 patients (22 implants) had a 3 mm implant with 4 patients (4 implants) fitted with a 4 mm implant. The patient undergoing a single stage procedure had a 4 mm implant. Patients with bilateral implants had 3 mm implants inserted. In our series, no sleeper implant was used in the single stage BAHA1 insertion. 12 patients (12 implants) received the generation 2 BAHA1 implant, 7 patients (8 implants) had a generation 3 (BIA 300 series)
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K. Amonoo-Kuofi et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 474–480 Table 1 Indication for BAHA. Diagnosis
Patients (n)
Bilateral atresia Unilateral atresia Single sided deafness Chronic otitis media
12 10 1 1
Table 2 Associated syndromes.
Fig. 1. Age distribution at first and second stage surgery.
Syndromes
Patients (n)
Goldenhaar Treacher Collins Cornelia de Lange 18q Syndrome Charge syndrome Congenital spinal cord anomalies
4 2 1 1 1 1
their follow up duration. Thirteen patients (54%) (14 implants— 53%) had grade 2 or 3 (redness, moistness and/or granulation tissue were present). Most of these required local (topical) treatment with or without oral antibiotics. Seven patients (29%) (8 implants— 31%) had a grade 4 Holgers score with extensive soft-tissue reactions. There were 2 patients (8.5%) (2 implants—8%) without complications.
Fig. 2. Interval time (months between stages I + II).
implant, and 5 patients (6 implants) received the generation 4 (BIA 400 series) implant.15 patients (16 implants) had a skin thinning technique, 2 patients (3 implants) had minimal soft tissue reduction and 7 patients (7 implants) had no soft tissue reduction. The most severe soft tissue/skin reaction for each patient was recorded based on Holgers grade/modification; Figs. 5 and 6a and b [5,7,13]. Four patients (17%) (4 implants—16%) had grade 0 or 1 Holgers score ratings (minimal or no reaction around the abutment) over
Fig. 4. Distribution of syndrome diagnoses.
Fig. 3. Range of ethnicity.
Fig. 5. Soft tissue reaction—Holgers grade.
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Fig. 6. (a) BAHA1 implant demonstrating soft tissue overgrowth over abutment. (b) BAHA1 implant with complete soft tissue overgrowth over abutment.
Fig. 7a and b flow charts demonstrate all complications identified in the study. Ten patients (42%) (46% implants) underwent revision surgery during the study period for ‘major’ soft tissue/BAHA1 related complications. We could not demonstrate superiority of the non-skin reduction technique in this group, with 42% of these children having major complications. 17 patients (19 implants had soft tissue reduction performed at surgery. Within this group, 12 implants had minor complications and 12 implants had major complications. Minor complications occurred in 12 patients (50%), 12 implants (46%) with 6 patients experiencing recurrent infections. Three patients (11%), 3 implants (10%) required soft tissue reduction for treatment of overgrowth around the abutment site. Three patients lost their flange fixtures. These were related to infection (2 patients) and trauma (1 patient). 3 patients were no longer using their BAHA1 devices due to longstanding soft tissue reactions resistant to local treatments and soft tissue reduction attempts. Alternative modalities of hearing rehabilitation are being considered. 14 patients required their BAHA1 processor to be repaired and in the majority, this occurred more than once. The main reasons were due to aid failure as well as following traumatic events. 2 patients had lost their devices. 60% (6/10) of major complications occurred in children with a syndromic diagnosis with 40% occurring in patients with isolated microtia. 1/10 (10%) of syndromic children had no complications with 3/10 (30%) and 6/10 (60%) experiencing minor and major complications, respectively.
Weight distribution is described in Figs. 8 and 9. Over 2/3 of our patients had a weight >50–75th centile with approximately a third over the 90th centile. 3 patients who had major complications had weight percentiles >90th centile. Fig. 10 represents the association between socioeconomic score (SES) and complications. 11 patients were in the most deprived group (NZDep score 8–10), 9 patients in the mid deprived (NZDep score 5–7), and 4 patients in the least deprived (NZDep score 1–4). There was a non-statistically significant trend (P = 0.41) towards an increased rate of complications for patients in the most deprived group (lowest socioeconomic group). Fig. 11 represents rate of complications assessed against ethnicity comparing Maori/Pacific Island against non-Maori/ Pacific Island ethnic groups. There was a non-statistically significant (P = 0.21) trend towards an increased rate of complications in the Maori/Pacific Island ethnic group compared to the non-Maori/Pacific Island ethnic group. 18/24 Quality of Life (QOL) completed responses were returned. All children had parental assistance with regards to answering the GCBI questionnaire. The final mean score was +40 (range 100 to +100) indicating an increase in parental perception of patient’s QOL. There were no scores below 0. This compares favourably to a previous study with mean scores ranging from 26 to 32 [2]. 14/24 patients returned questionnaires with the PEACH assessment. Score ranges were 24/44 to 42/44. Mean score was 35 with calculated final percentage score of 72% indicating performance of the device fell within the range of normal auditory perception in noisy and quiet environments.
Fig. 7. (a) Flow chart of distribution of complications [patients]. (b) Flow chart of distribution of complications [Implants].
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Fig. 8. Weight percentiles.
Discussion The BAHA1 device is not yet FDA approved in the USA for children under 5 years of age. Our series of children in this age group demonstrates that that the BAHA1 implant and abutment system can be used safely in this group, with a high rate of successful osseo-integration, even in bone less than 3 mm in thickness. The PEACH results of a mean score of 72% showed the parents were finding their children’s auditory performance fell within the range of auditory perception equivalent to those of children with normal hearing. The GCBI score of +40 indicated overall pleasing parental satisfaction with BAHA1 use. Whilst we and most parents believe the BAHA1 implant to be beneficial, soft tissue complications occurred frequently in our patient group, putting additional demands also upon parents and clinic services. A number of changes have been made in order to reduce this, including the use of longer abutments [14] and the use of a linear incision without soft tissue reduction at the time of implantation [15,16]. Soft tissue reduction techniques have not resulted in clinically significant reduction in skin complications in our cohort (10 minor, 7 major complications) although the numbers in our study are small. Newer hydroxyapatite implants (400 BAHA1) have also been utilised but we have not yet seen a reduction in skin complications using these, although our numbers with this abutment in this age group are small (n = 5). A number of studies have grouped complications similarly into major complications (requiring revision surgery) and minor
Fig. 9. Rate of complications associated with patients’ standardized.
Fig. 10. Rate of complications associated with socioeconomic deprivation scores. Top 70% SES (socioeconomic score) = Mid–High SES = NZDep score 01–03 and 04– 07 (least deprived). Bottom 30% SES = Low SES NZDep 08–10 (most deprived). P = 0.41 status
complications (wound infections not requiring revision surgical intervention) [17–19]. One series found no difference in soft tissue complications when comparing single versus double stage surgery and skin graft type [20]. Complications are suggested to be higher in children with a diagnosis of craniofacial syndrome with the risk of complications increasing over a prolonged period of time [21]. In our study, 22 patients out of 24 had a recorded complication. 50% of recorded complications were minor skin reactions not requiring surgical intervention. 42% of patients in our study group suffered major complications requiring surgical intervention (soft tissue reduction, abutment revision or abutment removal). There are very significant variations in reported studies related to complication rates and in perceptions of what constitute complications [21,22]. 83% of our patients (84% of implants) had a Holgers grade 2 or greater. Previously reported rates include 37% [4] and 78% [17]. Our Holgers grade 3–4 (50% patients, 53% of implants) is higher compared to reported rates of 17% [3] and 38% [17]. Failure of osseo-integration, the most common reason for loss of implant is estimated to range from 0 to 15% in the paediatric population [13,14]. This compares with 10% in this study. There were 2 patients (8%) (2 implants—8% of implants) without complications, described in some articles as a ‘reaction free penetration site’. This compares to 11%, 54% and 91% in reported studies, respectively [4,13,18]. Implantation in children less than 5 years has raised concerns relating to the adequacy of skull thickness. Concerns raised also suggest that increased skull water content as well as reduced
Fig. 11. Rate of complication associated with ethnicity.
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mineral content, have a potential negative impact on osseointegration [20,23]. In this study we have not found initial integration to be a problem, even into bone less than 3 mm in thickness. One patient under 5 years of age had a 4 mm BAHA1 inserted as a single stage procedure. This implant has survived without major complications. The current cost of BAHA1 insertion was calculated in order to assess the financial burden relating to our case mix. We also wished to assess the financial burden in cases resulting in revision of abutment and or implant due to skin and soft tissue complications. The cost of hardware for a flange fixture (implant) plus abutment insertion as a single staged procedure is $NZ 2390.00. If we implant a spare flange fixture (abutment), typically as we have done in our two stage procedures the hardware costs alone are $NZ4161.00 Should a replacement abutment be required, this increases the hardware costs by 49% (single stage with one fixture) and 28% (two stage procedure with two fixtures). Notwithstanding the cost of the operating facility, there is additional burden on the family of the child, associated with major and minor complications which may render the patient temporarily unable to utilize their BAHA1 device with additional costs of medicines, and transport for medical care, and time off school for the children and work for their parents. A previous article reviewing USA Medicare billing costs of revising BAHA in adults and children suggested an overall increase of 16% over and above original costings [24]. New Zealand may have environmental socioeconomic/ethnic factors that might play a role in increased susceptibility to soft tissue skin reactions [25]. There appears to be increased risk of soft tissue infections in ethnic Pacific and Maori children [26,27]. We observed a non-statistically significant trend in our study with major complications increased in the Maori and Pacific group compared to non-Maori and Pacific groups. We were not able to show a statistically significant trend reported in a previous publication on BAHA in children [17]. In adults, an increased trend of soft tissue complications requiring surgical reduction/abutment replacement in association with high BMI has been reported [28]. Also reported has been an association of complications relating to increased weight percentiles (>90th centiles) in a paediatric population [17]. This association was not identified in our study group (P = 0.84). In our current review major complications were identified within all the different weight categories. From a practical point of view, we recognize the potential benefit of implanting patients with elevated weight centiles (for respective ages) with longer abutments at second stage surgery. In a prior article we demonstrated NZDep score to be the most important risk factor in determining risk of complications [17]. In order to analyse outcomes based on socioeconomic score, major complications in patients with a higher NZDep score (most deprived) were compared to those in patients with a lower NZDep score (least deprived). We observed a non-statistically significant trend with major complications increased in the patients in the lower socioeconomic group (P = 0.41). In future, we believe non skin penetrating devices along the lines of as the Vibrant Sound Bridge and Bone Bridge (MedelTM), and to a lesser degree, the Sophono Otomag1, BAHA1 4 Attract system (Cochlear1), amongst others may have a greater role in managing the hearing deficit in children with aural atresia [29,30]. Conclusions This study reports observed complications in BAHA1 implantation within a group of children implanted under age 5 years. Osseo-integration in children in this age group was not a significant problem however outpatient and surgical interventions
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are often required. Despite this complication burden and morbidity, parental self-reporting and questionnaire results showed perceived benefit in hearing and quality of life from the use of the BAHA1 implant. An honest discussion with careful counselling of parents of potential young BAHA1 implant candidates is important in light of these results. Acknowledgements We acknowledge assistance from Dr Peter Reed, PhD, of the Children’s Research Centre (supported by the Starship Foundation and Auckland District Health Board).
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