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Bone anchored hearing aid in children—Prevention of complications
International Journal of Pediatric Otorhinolaryngology (2007) 71, 823—826
www.elsevier.com/locate/ijporl
CASE REPORT
Bone anchored hearing aid in children–— Prevention of complications§ Robert F. Yellon a,b,* a b
Department of Pediatric Otolaryngology, Children’s Hospital of Pittsburgh, United States Department of Otolaryngology, University of Pittsburgh School of Medicine, United States
Received 4 August 2006; received in revised form 3 January 2007; accepted 6 January 2007
KEYWORDS Bone anchored hearing aid; Children; Complications; Congenital aural atresia; Conductive hearing loss; Microtia
Summary To report results with the bone anchored hearing aid (BAHA) in children. Retrospective medical record review. Tertiary care children’s hospital. Fourteen children with microtia/aural atresia underwent BAHA surgery. Mean age was 5.8 years. Data were collected concerning age, diagnoses, surgery, success of implantation, hearing, complications use of BAHA, speech reception thresholds (SRT), complications BAHA surgeries and revisions. Fifteen implants were placed by the author in 13 children. Eleven of 13 (84.6%) children are successfully using BAHAs (one bilateral) with a mean post operative SRT of 18.5 dB (range 14—25 dB). Mean interval between first and second stages was 7.3 months (n = 12). Three unilateral implants were placed by a different surgeon in a child with severe hemifacial microsomia who developed complications treated by the author. Complications included poor healing requiring removal of three implants in one child, recurrent cellulitis of flap requiring revision (n = 4), loss of implant (n = 2), tearing of flap with dermatome due to tenting by healing screw (n = 1), thin skull necessitating multiple drilling sites (n = 1). BAHA surgery has a high success rate in children. The following recommendations may decrease complications: (1) 6-month period between stages in children with thin skulls, (2) thin flap with scalpel when it is tented by healing screw or infiltrate flap with local anesthetic to balloon it prior to using the dermatome for second stage cases, and (3) create extremely thin flap to prevent cellulitis. # 2007 Elsevier Ireland Ltd. All rights reserved.
1. Introduction §
Presented in part at the American Society of Pediatric Otolaryngology Annual Meeting, Las Vegas, NV, May 2005 * Correspondence address: Department of Pediatric Otolaryngology, Children’s Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, United States. Tel.: +1 412 692 5902; fax: +1 412 692 6074. E-mail address: [email protected].
The bone anchored hearing aid (BAHA) (Cochlear Americas, Engelwood, CO) is a significant advance for conductive hearing loss that requires modifications for the pediatric population when compared with the procedure in adults. In infants and children the procedure is performed in two stages [1—4] while the procedure is performed in a single
0165-5876/$ — see front matter # 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2007.01.006
824
R.F. Yellon
Table 1 Data collected from medical records of BAHA patients
Table 2 Characteristics of 14 children who underwent BAHA
Age Other diagnoses Number and type of surgeries Length of time between first and second stage surgeries Computed tomography of the skull Angiography results Successful use of BAHA Hearing thresholds Complications
Mean age = 5.8 years (range 2.4—14.9 years)
stage in older children and adults. Two stages are required in the pediatric population since the skulls are thinner and more time is required for osseointegration of the implant. There has been a significant ‘‘learning curve’’ for BAHA surgery in children that will be reported here to help increase success of implantation and decrease complications. In this manuscript, information will be presented regarding length of time between stages, avoidance of the use of the dermatome for second stage cases unless the flap is ballooned first with local anesthetic, and the importance of extreme thinning of the skin flap.
2. Methods This study was approved by the Institutional Review Board of Children’s Hospital of Pittsburgh. The design of this study was a retrospective review of medical records. The study group included 14 children with microtia, congenital aural atresia and maximal conductive hearing loss who underwent BAHA implantation. Data available in the medical records were collected concerning the items listed in Table 1. The main outcome measures were successful osseointegration and use of BAHA, hearing thresholds, and complications.
3. Results The characteristics of the group of children studied are shown in Table 2. Fifteen osseointegrated implants were placed by the author in 13 children. There was one bilateral placement and one reimplantation of the BAHA during the planned second stage for failure of osseointegration. Eleven of these 13 (84.6%) children are successfully using their BAHAs (12 of 14 sides, 85.7%, one bilateral case) with mean post operative speech reception threshold of 18.5 dB (range 14—25 dB).
Syndromes Treacher-Collins = 4 (28.6%) Nager = 2 (14.3%) Oculoauriculovertebral = 2 (14.3%) Mean follow up period = 1.5 years (range 0.1—4.4 years)
Congenital aural atresia repair was successful in one child who spontaneously lost a functioning BAHA. BAHA was successful for one child in whom an initially successful congenital aural atresia repair failed due to recurrent infection. Replacement of the BAHA was successful for one child who had removal of the implant at the planned second stage procedure due to failure of osseointegration. The interval between the two stages in this child was only 2 months. Thus two children had failure of osseointegration (14.3%). Mean interval between first and second stage procedures (n = 12 procedures in 10 children) was 7.3 months (range 2—18 months). One child had his second stage procedure and is awaiting activation of the BAHA. There were two single-stage procedures in older children with thick skulls. Three simultaneous first stage procedures (one for a BAHA and two for an auricular prosthesis) were performed by a different surgeon in one young child with severe hemifacial microsomia who developed the complication of poor healing with exposure of the implants and surrounding skull that was treated by the author. If major complications are defined as those which require a return to the operating room, there were 6 (42.9%) major complications. For the overall group, complications included poor healing requiring surgical removal of three unilateral implants placed in one child (7.1%), loss of implant (n = 2, 14.3%) with one reimplantation (7%), recurrent cellulitis of the flap around the BAHA requiring revision surgery for flap thinning (n = 4, 28.6%), spontaneous loss of the implant (n = 2, 14.3%), tearing of the flap with the manufacturers dermatome due to tenting up of the flap by the healing screw on the implant (n = 1, 7.1%), and very thin skull bone that necessitated multiple drilling sites (n = 1, 7.1%).
4. Discussion Our study has confirmed that BAHA surgery can be safely performed in the pediatric population with a high success rate, excellent hearing outcomes,
Bone anchored hearing aid in children and only limited complications. Other groups have reported similar results in children [1—6]. The conclusions of this study are limited by the small number of patients and relatively short follow up period. The child with severe hemifacial microsomia who had poor healing of three first stage implants placed by a different surgeon was quite instructive. At presentation, there was inadequate soft tissue coverage of the three implants with exposure of fixtures and a small amount of surrounding bone. The second stage was never performed due to poor healing. The angiogram showed that there was congenital absence of the superficial temporal artery. Thus it is possible that insufficient blood supply was the cause of poor healing. It is also possible that poor soft tissue handling, postoperative trauma, or some other event led to poor healing in this case. Drilling out of the exposed fixtures allowed complete healing. Reimplantation has not been attempted. The mean interval between first and second stages was 7.3 months (n = 12). Although there is no prospective study, anecdotal reports (A. Tjellstrom, MD, PhD, personal communication 2005) suggest that a longer period (at least 6 months) between the two stage procedures allows for adequate osseointegration. The need for revision surgery for replacement of lost fixtures may be reduced by placement of a second ‘‘sleeper’’ fixture at the time of initial surgery that may be used if the primary fixture fails to osseointegrate [5]. Sleepers were not placed in this group of patients. Skin reactions around the BAHA site have been previously reported to occur [7]. Recurrent cellulitis and thickening of the flap that requires thinning may be reduced by making the flap extremely thin at the time the flap is first thinned. The flap may be easily thinned with the manufacturer’s dermatome for single stage procedures. However, for two-stage procedures, the dermatome should not be used due to tearing of flap caused by tenting by healing screw, unless the flap is first ballooned with local anesthetic [8]. As an alternative, the flap must be carefully thinned with a scalpel (including removal of hair follicles) for second stage procedures. Very young children (<3 years) and those with syndromes such as Treacher-Collins, may have very thin skulls that necessitates multiple drilling sites. If the skull is very thin at the usual planned site of drilling (5.5 cm posterior—superior to the planned site of the external auditory canal) then another location with thicker skull bone, such as a skull suture line may be selected. Previous investigators have determined that the average skull thickness in young children undergoing BAHA had an average
825 skull thickness of 2.5 mm [4]. Dura and sigmoid sinus were exposed during BAHA surgery in 70.5% of pediatric cases. Granstrom and Tjellstrom [9], recommend placement of a polytetrafluoroethylene membrane to protect the dura and stimulate bone growth over the exposed areas. Special consideration for the site of BAHA placement should also be given for patients who have a BAHA placed prior to planned microtia reconstruction. Bajaj et al. [10] determined that the optimal position for BAHA placement was 6.5—7.0 cm from the planned site of the external auditory canal rather than the usual 5.5 cm, for such patients. The method used for microtia reconstruction may influence the site of BAHA placement and preoperative consultation with the microtia reconstructive surgeon is suggested. Bilateral BAHA placement may be considered for children with bilateral aural atresia. A small number of children with bilateral aural atresia were found to have significantly improved sound localization following bilateral BAHA placement [11]. In conclusion, BAHA surgery has a high success rate in children with acceptable complications. The following recommendations may decrease complications and the need for revision surgery: (1) for two stage procedures, allow at least 6 months between stages for children with thin skulls to allow for adequate osseointegration, (2) thin the flap with a scalpel rather than the manufacturer’s dermatome to avoid tearing when the flap is tented by the healing screw during second stage procedures or balloon the flap with local anesthetic and then use the dermatome, and (3) creation of extremely thin flaps to prevent recurrent cellulitis and flap thickening to avoid the need for flap revision.
References [1] G. Granstrom, K. Bergstrom, M. Odersjo, A. Tjellstrom, Osseointegrated implants in children: experience from our first 100 patients, Otolaryngol. Head Neck Surg. 125 (1) (2001) 85—92. [2] B.C. Papsin, T.K. Sirimanna, D.M. Albert, C.M. Bailey, Surgical experience with bone-anchored hearing aids in children, Laryngoscope 107 (6) (1997) 801—806. [3] I. Bejar-Solar, M. Rosete, M. de Jesus Madrazo, C. Baltiera, Percutaneous bone-anchored hearing aids at a pediatric institution, Otolaryngol. Head Neck Surg. 122 (6) (2000) 887—891. [4] C. Priwin, G. Granstrom, The bone-anchored hearing aid in children: a surgical and questionnaire follow-up study, Otolaryngol. Head Neck Surg. 132 (4) (2005) 559—565. [5] H. Zeitoun, S.D. Thompson, D.W. Proops, Osseointegrated implants in the management of childhood ear abnormalities: with particular emphasis on complications, J. Laryngol. Otol. 116 (2) (2002) 87—91.
826 [6] R. Seeman, R. Liu, J. Toppa, Results of pediatric boneanchored hearing aid implantation, J. Otolaryngol. 33 (2) (2004) 71—74. [7] R.A. Reyes, A. Tjellstrom, G. Granstrom, Evaluation of implant losses and skin reactions around extra-oral boneanchored implants: a 0- to 8-year follow-up, Otolaryngol. Head Neck Surg. 122 (2) (2000) 272—276. [8] T.J. Woolford, D.P. Morris, S.R. Saeed, M.P. Rothera, The implant-site split-skin graft technique for the boneanchored hearing aid, Clin. Otolaryngol. 24 (1999) 177— 180.
R.F. Yellon [9] G. Granstrom, A. Tjellstrom, Guided tissue generation in the temporal bone, Ann. Otol. Rhinol. Laryngol. 108 (4) (1999) 349—354. [10] Y. Bajaj, M.E. Wyatt, D. Gault, C.M. Bailey, D.M. Albert, How we do it: BAHA positioning in patients with microtia requiring auricular reconstruction, Clin. Otolaryngol. 30 (5) (2005) 468—471. [11] K.T. Van der Pouw, A.F. Snik, C.W. Cremers, Audiometric results of bilateral bone-anchored hearing aid application in patients with bilateral congenital aural atresia, Laryngoscope 108 (4 Part 1) (1998) 548—553.
www.elsevier.com/locate/ijporl
CASE REPORT
Bone anchored hearing aid in children–— Prevention of complications§ Robert F. Yellon a,b,* a b
Department of Pediatric Otolaryngology, Children’s Hospital of Pittsburgh, United States Department of Otolaryngology, University of Pittsburgh School of Medicine, United States
Received 4 August 2006; received in revised form 3 January 2007; accepted 6 January 2007
KEYWORDS Bone anchored hearing aid; Children; Complications; Congenital aural atresia; Conductive hearing loss; Microtia
Summary To report results with the bone anchored hearing aid (BAHA) in children. Retrospective medical record review. Tertiary care children’s hospital. Fourteen children with microtia/aural atresia underwent BAHA surgery. Mean age was 5.8 years. Data were collected concerning age, diagnoses, surgery, success of implantation, hearing, complications use of BAHA, speech reception thresholds (SRT), complications BAHA surgeries and revisions. Fifteen implants were placed by the author in 13 children. Eleven of 13 (84.6%) children are successfully using BAHAs (one bilateral) with a mean post operative SRT of 18.5 dB (range 14—25 dB). Mean interval between first and second stages was 7.3 months (n = 12). Three unilateral implants were placed by a different surgeon in a child with severe hemifacial microsomia who developed complications treated by the author. Complications included poor healing requiring removal of three implants in one child, recurrent cellulitis of flap requiring revision (n = 4), loss of implant (n = 2), tearing of flap with dermatome due to tenting by healing screw (n = 1), thin skull necessitating multiple drilling sites (n = 1). BAHA surgery has a high success rate in children. The following recommendations may decrease complications: (1) 6-month period between stages in children with thin skulls, (2) thin flap with scalpel when it is tented by healing screw or infiltrate flap with local anesthetic to balloon it prior to using the dermatome for second stage cases, and (3) create extremely thin flap to prevent cellulitis. # 2007 Elsevier Ireland Ltd. All rights reserved.
1. Introduction §
Presented in part at the American Society of Pediatric Otolaryngology Annual Meeting, Las Vegas, NV, May 2005 * Correspondence address: Department of Pediatric Otolaryngology, Children’s Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, United States. Tel.: +1 412 692 5902; fax: +1 412 692 6074. E-mail address: [email protected].
The bone anchored hearing aid (BAHA) (Cochlear Americas, Engelwood, CO) is a significant advance for conductive hearing loss that requires modifications for the pediatric population when compared with the procedure in adults. In infants and children the procedure is performed in two stages [1—4] while the procedure is performed in a single
0165-5876/$ — see front matter # 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2007.01.006
824
R.F. Yellon
Table 1 Data collected from medical records of BAHA patients
Table 2 Characteristics of 14 children who underwent BAHA
Age Other diagnoses Number and type of surgeries Length of time between first and second stage surgeries Computed tomography of the skull Angiography results Successful use of BAHA Hearing thresholds Complications
Mean age = 5.8 years (range 2.4—14.9 years)
stage in older children and adults. Two stages are required in the pediatric population since the skulls are thinner and more time is required for osseointegration of the implant. There has been a significant ‘‘learning curve’’ for BAHA surgery in children that will be reported here to help increase success of implantation and decrease complications. In this manuscript, information will be presented regarding length of time between stages, avoidance of the use of the dermatome for second stage cases unless the flap is ballooned first with local anesthetic, and the importance of extreme thinning of the skin flap.
2. Methods This study was approved by the Institutional Review Board of Children’s Hospital of Pittsburgh. The design of this study was a retrospective review of medical records. The study group included 14 children with microtia, congenital aural atresia and maximal conductive hearing loss who underwent BAHA implantation. Data available in the medical records were collected concerning the items listed in Table 1. The main outcome measures were successful osseointegration and use of BAHA, hearing thresholds, and complications.
3. Results The characteristics of the group of children studied are shown in Table 2. Fifteen osseointegrated implants were placed by the author in 13 children. There was one bilateral placement and one reimplantation of the BAHA during the planned second stage for failure of osseointegration. Eleven of these 13 (84.6%) children are successfully using their BAHAs (12 of 14 sides, 85.7%, one bilateral case) with mean post operative speech reception threshold of 18.5 dB (range 14—25 dB).
Syndromes Treacher-Collins = 4 (28.6%) Nager = 2 (14.3%) Oculoauriculovertebral = 2 (14.3%) Mean follow up period = 1.5 years (range 0.1—4.4 years)
Congenital aural atresia repair was successful in one child who spontaneously lost a functioning BAHA. BAHA was successful for one child in whom an initially successful congenital aural atresia repair failed due to recurrent infection. Replacement of the BAHA was successful for one child who had removal of the implant at the planned second stage procedure due to failure of osseointegration. The interval between the two stages in this child was only 2 months. Thus two children had failure of osseointegration (14.3%). Mean interval between first and second stage procedures (n = 12 procedures in 10 children) was 7.3 months (range 2—18 months). One child had his second stage procedure and is awaiting activation of the BAHA. There were two single-stage procedures in older children with thick skulls. Three simultaneous first stage procedures (one for a BAHA and two for an auricular prosthesis) were performed by a different surgeon in one young child with severe hemifacial microsomia who developed the complication of poor healing with exposure of the implants and surrounding skull that was treated by the author. If major complications are defined as those which require a return to the operating room, there were 6 (42.9%) major complications. For the overall group, complications included poor healing requiring surgical removal of three unilateral implants placed in one child (7.1%), loss of implant (n = 2, 14.3%) with one reimplantation (7%), recurrent cellulitis of the flap around the BAHA requiring revision surgery for flap thinning (n = 4, 28.6%), spontaneous loss of the implant (n = 2, 14.3%), tearing of the flap with the manufacturers dermatome due to tenting up of the flap by the healing screw on the implant (n = 1, 7.1%), and very thin skull bone that necessitated multiple drilling sites (n = 1, 7.1%).
4. Discussion Our study has confirmed that BAHA surgery can be safely performed in the pediatric population with a high success rate, excellent hearing outcomes,
Bone anchored hearing aid in children and only limited complications. Other groups have reported similar results in children [1—6]. The conclusions of this study are limited by the small number of patients and relatively short follow up period. The child with severe hemifacial microsomia who had poor healing of three first stage implants placed by a different surgeon was quite instructive. At presentation, there was inadequate soft tissue coverage of the three implants with exposure of fixtures and a small amount of surrounding bone. The second stage was never performed due to poor healing. The angiogram showed that there was congenital absence of the superficial temporal artery. Thus it is possible that insufficient blood supply was the cause of poor healing. It is also possible that poor soft tissue handling, postoperative trauma, or some other event led to poor healing in this case. Drilling out of the exposed fixtures allowed complete healing. Reimplantation has not been attempted. The mean interval between first and second stages was 7.3 months (n = 12). Although there is no prospective study, anecdotal reports (A. Tjellstrom, MD, PhD, personal communication 2005) suggest that a longer period (at least 6 months) between the two stage procedures allows for adequate osseointegration. The need for revision surgery for replacement of lost fixtures may be reduced by placement of a second ‘‘sleeper’’ fixture at the time of initial surgery that may be used if the primary fixture fails to osseointegrate [5]. Sleepers were not placed in this group of patients. Skin reactions around the BAHA site have been previously reported to occur [7]. Recurrent cellulitis and thickening of the flap that requires thinning may be reduced by making the flap extremely thin at the time the flap is first thinned. The flap may be easily thinned with the manufacturer’s dermatome for single stage procedures. However, for two-stage procedures, the dermatome should not be used due to tearing of flap caused by tenting by healing screw, unless the flap is first ballooned with local anesthetic [8]. As an alternative, the flap must be carefully thinned with a scalpel (including removal of hair follicles) for second stage procedures. Very young children (<3 years) and those with syndromes such as Treacher-Collins, may have very thin skulls that necessitates multiple drilling sites. If the skull is very thin at the usual planned site of drilling (5.5 cm posterior—superior to the planned site of the external auditory canal) then another location with thicker skull bone, such as a skull suture line may be selected. Previous investigators have determined that the average skull thickness in young children undergoing BAHA had an average
825 skull thickness of 2.5 mm [4]. Dura and sigmoid sinus were exposed during BAHA surgery in 70.5% of pediatric cases. Granstrom and Tjellstrom [9], recommend placement of a polytetrafluoroethylene membrane to protect the dura and stimulate bone growth over the exposed areas. Special consideration for the site of BAHA placement should also be given for patients who have a BAHA placed prior to planned microtia reconstruction. Bajaj et al. [10] determined that the optimal position for BAHA placement was 6.5—7.0 cm from the planned site of the external auditory canal rather than the usual 5.5 cm, for such patients. The method used for microtia reconstruction may influence the site of BAHA placement and preoperative consultation with the microtia reconstructive surgeon is suggested. Bilateral BAHA placement may be considered for children with bilateral aural atresia. A small number of children with bilateral aural atresia were found to have significantly improved sound localization following bilateral BAHA placement [11]. In conclusion, BAHA surgery has a high success rate in children with acceptable complications. The following recommendations may decrease complications and the need for revision surgery: (1) for two stage procedures, allow at least 6 months between stages for children with thin skulls to allow for adequate osseointegration, (2) thin the flap with a scalpel rather than the manufacturer’s dermatome to avoid tearing when the flap is tented by the healing screw during second stage procedures or balloon the flap with local anesthetic and then use the dermatome, and (3) creation of extremely thin flaps to prevent recurrent cellulitis and flap thickening to avoid the need for flap revision.
References [1] G. Granstrom, K. Bergstrom, M. Odersjo, A. Tjellstrom, Osseointegrated implants in children: experience from our first 100 patients, Otolaryngol. Head Neck Surg. 125 (1) (2001) 85—92. [2] B.C. Papsin, T.K. Sirimanna, D.M. Albert, C.M. Bailey, Surgical experience with bone-anchored hearing aids in children, Laryngoscope 107 (6) (1997) 801—806. [3] I. Bejar-Solar, M. Rosete, M. de Jesus Madrazo, C. Baltiera, Percutaneous bone-anchored hearing aids at a pediatric institution, Otolaryngol. Head Neck Surg. 122 (6) (2000) 887—891. [4] C. Priwin, G. Granstrom, The bone-anchored hearing aid in children: a surgical and questionnaire follow-up study, Otolaryngol. Head Neck Surg. 132 (4) (2005) 559—565. [5] H. Zeitoun, S.D. Thompson, D.W. Proops, Osseointegrated implants in the management of childhood ear abnormalities: with particular emphasis on complications, J. Laryngol. Otol. 116 (2) (2002) 87—91.
826 [6] R. Seeman, R. Liu, J. Toppa, Results of pediatric boneanchored hearing aid implantation, J. Otolaryngol. 33 (2) (2004) 71—74. [7] R.A. Reyes, A. Tjellstrom, G. Granstrom, Evaluation of implant losses and skin reactions around extra-oral boneanchored implants: a 0- to 8-year follow-up, Otolaryngol. Head Neck Surg. 122 (2) (2000) 272—276. [8] T.J. Woolford, D.P. Morris, S.R. Saeed, M.P. Rothera, The implant-site split-skin graft technique for the boneanchored hearing aid, Clin. Otolaryngol. 24 (1999) 177— 180.
R.F. Yellon [9] G. Granstrom, A. Tjellstrom, Guided tissue generation in the temporal bone, Ann. Otol. Rhinol. Laryngol. 108 (4) (1999) 349—354. [10] Y. Bajaj, M.E. Wyatt, D. Gault, C.M. Bailey, D.M. Albert, How we do it: BAHA positioning in patients with microtia requiring auricular reconstruction, Clin. Otolaryngol. 30 (5) (2005) 468—471. [11] K.T. Van der Pouw, A.F. Snik, C.W. Cremers, Audiometric results of bilateral bone-anchored hearing aid application in patients with bilateral congenital aural atresia, Laryngoscope 108 (4 Part 1) (1998) 548—553.