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Bone Conduction Implant Devices
Abstract
Bone conduction implants (BCIs) are semi-implantable devices for the treatment of hearing losses in patients who either cannot wear or underperform with conventional hearing AIDS. These devices have to be surgically implanted, are based on the principle of osseointegration, and work by enhancing natural bone conduction. Since their first introduction in 1977, they have evolved in their external design and functionality. Even the surgical technique has undergone several modifications. Today, they are available as percutaneous and transcutaneous devices.
... El implante transforma la energía acústica entregada por el botón externo hacia energía mecánica que mueve los huesecillos del oído medio. Su indicación es en hipoacusia sensorio neurales moderada a severa y en hipoacusia mixtas (2)(3)(4)(13)(14)(15). ...
... Aquí entramos en esa área gris entre colocar un implante coclear o este tipo de prótesis. Solo la publicación de resultados que sean comparables nos permitirá decidir cuál es la prótesis indicada en cada caso (2)(3)(4)(13)(14)(15). ...
Si bien aún la mayoría de los pacientes con hipoacusia se siguen beneficiando con los audífonos convencionales, las prótesis auditivas implantables han evolucionado vertiginosamente, existiendo en el presente una gran variedad de ellas.
Los implantes cocleares siguen siendo las más usadas y en las que se tiene mayor experiencia. Las prótesis de conducción ósea implantables o semi implantables cambiaron el manejo de las atresias y malformaciones de oído externo y medio. Pese a lo prometedor que se visualiza el presente y futuro con el uso de estos dispositivos, siempre se debe tener presente que requieren de un acto quirúrgico para su implantación y que no están exentas de complicaciones, por lo cual se debe elegir juiciosamente la prótesis a usar.
Electroacoustics is a rapidly growing field formed by the confluence of implantation otology, audiology, electronics and robotics. The currently available devices can rehabilitate numerous parts of the auditory pathway, ranging from bone anchored hearing solutions, middle ear implants, cochlear implants through to brainstem implants. The development of the cochlear implant has been deemed one of the miraculous inventions of the twentieth Century, restoring the gift of hearing and enabling patients to communicate. This chapter is an overview of the current electroacoustic implantation devices available and discusses the future direction of the technology.
The protocol for bone-anchored hearing implants (e.g., Baha) surgery involves reduction of soft tissues around the abutment to minimize the risk of skin-related complications. It is hypothesized that good soft tissue outcomes may be achieved without performing skin reduction if improved abutment designs and/or materials are used that provide enhanced integration with surrounding soft tissues. The aim of the study was to investigate soft tissue response to different abutment designs/materials.
Thirty-six Baha implants and abutments were inserted in the skull of six sheep without performing soft tissue reduction. Four different abutments were used: 1) standard Baha abutments, 2) hydroxyapatite-coated standard Baha abutments, 3) concave titanium abutments, and 4) hydroxyapatite-coated concave abutments. Healing times of 1, 2, and 4 weeks were used (2 animals per time point). Samples were analyzed using descriptive histology and morphometric measurements, and results were compared using Wilcoxon's signed-ranked test.
Histologic assessment showed healthy soft tissues around the abutments with limited or no signs of inflammation. Hydroxyapatite-coated abutments showed tight adherence with dermis and limited epidermal downgrowth and pocket formation. Weaker adherence, often associated with significant epidermal downgrowth and pocket formation, was noted for noncoated titanium abutments. The mean pocket depth for abutment types A, B, C, and D was 1.38, 0.42, 1.51, and 0.24 mm, respectively. The difference between C and D was statistically significant (p = 0.031).
The results showed enhanced dermal adherence and reduced epidermal downgrowth and pocket formation for hydroxyapatite-coated abutments, with the most significant effect recorded for the hydroxyapatite-coated abutments with a concave shape.
Percutaneous bone-anchored hearing aid (BAHA) is an important rehabilitation alternative for patients who have conductive or mixed hearing loss. However, these devices use a percutaneous and bone-anchored implant that has some drawbacks reported. A transcutaneous bone conduction implant system (BCI) is proposed as an alternative to the percutaneous system because it leaves the skin intact. The BCI transmits the signal to a permanently implanted transducer with an induction loop system through the intact skin. The aim of this study was to compare the electroacoustic performance of the BAHA Classic-300 with a full-scale BCI on a cadaver head in a sound field. The BCI comprised the audio processor of the vibrant sound bridge connected to a balanced vibration transducer (balanced electromagnetic separation transducer).
Implants with snap abutments were placed in the parietal bone (Classic-300) and 15-mm deep in the temporal bone (BCI). The vibration responses at the ipsilateral and contralateral cochlear promontories were measured with a laser Doppler vibrometer, with the beam aimed through the ear canal.
Results show that the BCI produces approximately 5 dB higher maximum output level and has a slightly lower distortion than the Classic-300 at the ipsilateral promontorium at speech frequencies. At the contralateral promontorium, the maximum output level was considerably lower for the BCI than for the Classic-300 except in the 1-2 kHz range, where it was similar.
Present results support the proposal that a BCI system can be a realistic alternative to a BAHA.
A total of 2895 threaded, cylindrical titanium implants have been inserted into the mandible or the maxilla and 124 similar implants have been installed in the tibial, temporal or iliac bones in man for various bone restorative procedures. The titanium screws were implanted without the use of cement, using a meticulous technique aiming at osseointegration--a direct contact between living bone and implant. Thirty-eight stable and integrated screws were removed for various reasons from 18 patients. The interface zone between bone and implant was investigated using X-rays, SEM, TEM and histology. The SEM study showed a very close spatial relationship between titanium and bone. The pattern of the anchorage of collagen filaments to titanium appeared to be similar to that of Sharpey's fibres to bone. No wear products were seen in the bone or soft tissues in spite of implant loading times up to 90 months. The soft tissues were also closely adhered to the titanium implant, thereby forming a biological seal, preventing microorganism infiltration along the implant. The implants in many cases had been allowed to permanently penetrate the gingiva and skin. This caused no adverse tissue effects. An intact bone-implant interface was analyzed by TEM, revealing a direct bone-to-implant interface contact also at the electron microscopic level, thereby suggesting the possibility of a direct chemical bonding between bone and titanium. It is concluded that the technique of osseointegration is a reliable type of cement-free bone anchorage for permanent prosthetic tissue substitutes. At present, this technique is being tried in clinical joint reconstruction. In order to achieve and to maintain such a direct contact between living bone and implant, threaded, unalloyed titanium screws of defined finish and geometry were inserted using a delicate surgical technique and were allowed to heal in situ, without loading, for a period of at least 3--4 months.
Recent studies with adults have suggested that amplification at 4 kHz and above fails to improve speech recognition and may even degrade performance when high-frequency thresholds exceed 50-60 dB HL. This study examined the extent to which high frequencies can provide useful information for fricative perception for normal-hearing and hearing-impaired children and adults. Eighty subjects (20 per group) participated. Nonsense syllables containing the phonemes /s/, /f/, and /O/, produced by a male, female, and child talker, were low-pass filtered at 2, 3, 4, 5, 6, and 9 kHz. Frequency shaping was provided for the hearing-impaired subjects only. Results revealed significant differences in recognition between the four groups of subjects. Specifically, both groups of children performed more poorly than their adult counterparts at similar bandwidths. Likewise, both hearing-impaired groups performed more poorly than their normal-hearing counterparts. In addition, significant talker effects for /s/ were observed. For the male talker, optimum performance was reached at a bandwidth of approximately 4-5 kHz, whereas optimum performance for the female and child talkers did not occur until a bandwidth of 9 kHz.
Objectives:
The purpose of this study is to evaluate the effectiveness of Bone Anchored Cochlear Stimulator (BAHA) in transcranial routing of signal by implanting the deaf ear. Study design and settings Eighteen patients with unilateral deafness were included in a multisite study. They had a 1-month pre-implantation trial with a contralateral routing of signal (CROS) hearing aid. Their performance with BAHA was compared with the CROS device using speech reception thresholds, speech recognition performance in noise, and the Abbreviated Profile Hearing Benefit and Single Sided Deafness questionnaires.
Results:
Patients reported a significant improvement in speech intelligibility in noise and greater benefit from BAHA compared with CROS hearing aids. Patients were satisfied with the device and its impact on their quality of life. No major complications were reported. Conclusion and significance BAHA is effective in unilateral deafness. Auditory stimuli from the deaf side can be transmitted to the good ear, avoiding the limitations inherent in CROS amplification.
The aim of this study is the evaluation of results of using new Baha abutment covered by hydroxyapatite (Baha® BA400, Cochlear Ltd.) which enables new surgical technique without soft tissue reduction.
Material and methods
The results of treatment of 9 adult patients were compared with results of 126 patients implanted earlier by standard technique with soft tissue reduction.
Results
In analyzed group we find: slight shortening of time of surgery, similar results of implant stability (RFA) before sound processor connection, very good cosmetic results in 6 patients, some soft tissue overhanging in 2 and retraction pocket formation and inflammation (Holgers 2) in 1, no numbness and pain in operated area in all operated.
Conclusions
New Baha abutment covered by hydroxyapatite (Baha® BA400) enables to safely use new surgical technique without soft tissue reduction. In authors’ opinion the most important benefit from this technique is limited bleeding during operation, reduction of using of coagulation and less risk of lesion of nerves and numbness or pain after operation. This technique required less time, but the need of measuring of soft tissue and choosing of proper abutment cause longer preoperative time, so the time of all procedure is only slightly shorter. The esthetic results and healing process confirm the advantage of technique without soft tissue reduction over standard technique. However in patients with a thick soft tissue there is a risk of soft tissue overhanging, so in such cases it is better to make a partial soft tissue reduction.
To describe the clinical characteristics of a 70-year-old female with occipital neuropathy following bone conduction device surgery.
A 65-year-old woman underwent bone conduction device placement surgery on the left temporal bone. Postoperatively she progressively developed chronic pain at the implantation site. The pain led to minimal neck movement, which resulted in complaints of the shoulder and arm on the left side. She was treated by an orthopaedic surgeon for a frozen shoulder. Pain medication and occipital nerve blocking had no sustained effect on the pain.
Occipital neuropathy is a syndrome with continuous aching involving the occipital and parietal scalp caused by trauma or peripheral compression of the occipital nerves. The most common causes of occipital neuropathy are probably direct trauma to the nerve and hypertrophic fibrosis of subcutaneous tissue surrounding the nerve. Scar formation after surgery may therefore cause entrapment of the nerve.
We describe a case of occipital neuropathy as a complication of BAHA surgery.
Introduction and objectiveThe most common postoperative complications related to BAHA prosthetic surgery are skin complications. In this study we compare and evaluate these reactions with two different surgical techniques, the BAHA dermatome and the U-graft technique.Material and methodFifty-three patients who underwent implantation of a BAHA at our hospital between 2001 and 2008 were studied. The comparison of the skin reactions was carried out according to Holgers' classification. We also recorded the number of cures required until the skin was stabilized.ResultsWe used the dermatome in 27 patients and the U-graft in 26 patients. In the dermatome group we have reported a total of 74% of skin reactions (20 patients), in contrast with the 34% (9 patients) observed in the U-graft group. The average number of cures for patients in the dermatome group and those in the U-graft group was 4.1 and 2.7, respectively. The differences found were statistically significant and had a 95% confidence interval.Conclusions
In our experience, the use of the electric dermatome in BAHA surgery offers a higher incidence of skin complications in comparison with the U-graft technique. Since both techniques have a number of advantages and disadvantages, it may be that the selection of the technique to be employed according the individual characteristics of each patient may offer better results in the future.
Objective
To describe and evaluate a novel technique for the implantation of bone conduction hearing devices as compared with a common, conventional technique.Study DesignCase series with chart review.SettingTertiary referral otology and neurotology practice.Methods
Individuals who underwent the implantation of bone-anchored hearing devices between January 1, 2004, and December 31, 2011, were identified. Demographic data, surgical indications, surgical technique used, surgical time, and complications were recorded. Soft tissue complications were graded on the Holgers classification scheme. Group 1 was defined as those undergoing a traditional technique using a dermatome with subcutaneous tissue reduction. Group 2 was defined as those undergoing the described technique for implantation of the coupling hardware with minimal subcutaneous soft tissue reduction.ResultsForty patients underwent the procedure, with 11 patients comprising group 1 and 29 patients comprising group 2. Group 2 required a shorter operative time (32.3 vs 56.1 minutes, P < .0001). Of patients in group 1, 2 of 11 developed soft tissue complications, whereas 5 of 29 in group 2 developed soft tissue complications (P = 1.000). Most soft tissue complications were reversed with conservative wound care.Conclusion
Surgery was performed faster with similar postoperative outcomes in individuals undergoing implantation of bone-anchored hearing devices using the described technique that necessitated minimal soft tissue reduction.
During the last 20 years, bone-anchored hearing aids (Baha(®)) became a familiar solution in the treatment of some types of hearing loss. The aim of this chapter is to present the different historical steps which have permitted the production of this new bone conduction hearing device. The recognition of bone conduction hearing is old and was known at least in Antiquity. During the Renaissance, Girolamo Cardano demonstrated a method by which sound may be transmitted to the ear by means of a rod or the shaft of a spear held between one's teeth: this was the beginning of teeth stimulators to improve hearing, firstly in connection with a musical instrument and then, in the second part of the 19th century, with the speaker. The development of the carbon microphone at the beginning of the 20th century allowed the construction of the bone conduction vibrator placed on the mastoid area, notably supported by eyeglasses since the 1950s. Confronted by various problems, and notably the loss of part of sound in the soft tissue of the external mastoid, the idea to implant the vibrator into the mastoid bone was developed in Göteborg, and the first Baha was implanted in 1977 by Anders Tjellström. From that date, various improvements allowed the development of the actual Baha. These different steps are presented in this study, supported by original documentation.
A study performed in the 1990s with analogue linear hearing aids showed that in patients with mixed hearing loss and an air-bone gap that exceeded 25 to 30 dB, speech perception was better with a bone-anchored hearing aid (Baha) than with a conventional behind-the-ear (BTE) device. The objective of the present study was to investigate whether this conclusion applies to today's digital BTEs with feedback cancellation and whether the crossover point still occurs at an air-bone gap of 25 to 30 dB.
Case control.
Experienced unilateral Baha users with the latest digital Baha processors were fitted with a powerful BTE with feedback cancellation. After an acclimatization period of 4 weeks, aided thresholds and speech recognition scores were determined and compared to those recorded previously with the Baha. To obtain patients' opinions, a disability-specific questionnaire was used. Participants comprised 16 subjects with bilateral mixed hearing loss participated
Audiometric and speech recognition data showed similar trends to those described previously, but the crossover point had shifted to an air-bone gap of 30 to 35 dB. In the questionnaire, the BTE was rated higher than the Baha, except by the patients with an air-bone gap that exceeded an average of 45 dB.
In patients with mixed hearing loss whose air-bone gap exceeded 35 dB, speech recognition is likely to be better with a Baha than with a BTE. Therefore, the Baha should receive greater consideration when mixed hearing loss is combined with a significant air-bone gap, even when there are no contraindications for BTEs.
Up to now, treatment modalities of unilateral deafness consist of no treatment, conventional contralateral routing of signal (CROS), or Bone-Anchored Hearing Aid (BAHA) hearing aid. Cochlear implantation makes a new treatment modality available for patients with single-sided deafness. The aim of this study is to evaluate the use of unilateral electrical stimulation with normal hearing on the contralateral side after a period of 6 months compared with the preoperative unaided situation, conventional CROS, or BAHA hearing aids.
Prospective design.
Tertiary referral center; cochlear implant (CI) program.
Eleven adult subjects with unilateral deafness of various causes were enrolled in the study. Only those patients were included in whom therapy with CROS hearing aid or BAHA was not successful and in whom the auditory nerve was found to be intact and the cochlea patent for cochlear implantation.
All subjects were fitted in random order with a BAHA Intenso mounted on the softband/tension clamp or with a CROS hearing aid. After test periods with both devices, the subjects received a CI.
The Hochmair-Schulz-Moser sentence test and the Oldenburg sentence test were used to test speech comprehension in 3 presentation configurations in the unaided situation, with conventional CROS and BAHA hearing aids before cochlear implantation as well as after 6 months with CI. Localization was assessed using an array of 7 speakers at head level in a frontal semicircle. Subjective improvement in daily life was evaluated using the Speech, Spatial and Qualities of Hearing Scale, the Health Utilities Index 3 and the International Outcome Inventory for Hearing Aids questionnaires. Tinnitus distress was measured with a tinnitus scale before and after CI implantation.
The results show significant improvement in localization ability as well as in speech comprehension in most presentation configurations with the CI. Especially, there is no negative effect on speech comprehension if the noise is presented to the CI ear and speech to the normal hearing ear. With the CI, the summation and squelch effects are not significant, but a significant combined head shadow effect is seen. Speech, Spatial and Qualities of Hearing results show an overall benefit of wearing the CI compared with the other treatment options. The tinnitus scale revealed a positive effect of CI stimulation in cases of preoperative tinnitus.
The results in these patients suggest that cochlear implantation improves hearing abilities in people with single-sided deafness and is superior to the alternative treatment options. The use of the CI does not interfere with speech understanding in the normal hearing ear. Our data suggest that the binaural integration of electric and acoustic stimulation is possible even with unilateral normal hearing.
Epidural hematoma (EDH) has never been reported as a complication after placement of a bone-anchored hearing aid (BAHA). To our knowledge, this is the first case report of an EDH after placement of a BAHA.
We report the case of a 15-year-old girl with an EDH after placement of a BAHA. Initially, she presented with a history of right ear conductive hearing loss and had a tympanomastoidectomy and placement of a BAHA at an outpatient surgical facility. Postoperatively, the patient was transferred to the postoperative care unit in stable neurological condition but was subsequently noted to be lethargic with dilated, nonreactive pupils and extensor posturing. A computed tomography scan revealed a large right temporal EDH with midline shift. She was then taken to the operating room emergently for craniotomy and evacuation of the EDH. After evacuation, she was admitted to the pediatric intensive care unit and slowly emerged from her coma with supportive care. She was discharged to inpatient rehabilitation and has made a good recovery.
This report emphasizes the need for a high index of suspicion of this rare, but life-threatening complication of an EDH after the placement of a BAHA.
Since the introduction of the BAHA (bone-anchored hearing aid), two main different surgical procedures have been used to insert the implant: the skin flap technique and the linear incision technique.
The aim of this retrospective study is to compare the short terms results (3 months after the implantation, the usual period of skin healing) of the skin healing process in the surgical field and around the BAHA implant of these two different techniques.
113 implantations were done from January 2004 to mid May 2008. Between January 2004 to December 2006, 62 were inserted with the skin flap technique and between January 2007 to mid May 2008, followed by 51 with the linear incision technique. All cases were done by the same surgeon.
Four implanted BAHA with the skin flap technique necessitated a revision of the operating field because skin necrosis around the implant and only 1 with the linear incision technique. For the other cases and outside the normal range of fixed controls, the cases with the skin flap technique necessitated 25 unforeseen visits by 21 patients for cleaning and removal of crusts, in contrast to 2 visits by 2 patients for the cases with the linear incision technique.
This study clearly demonstrates that the linear incision technique has statistically lower risks of skin problems than the skin flap technique in the first three months post-implantation.
To determine which bone-anchored hearing aid (BAHA) implantation surgical technique is associated with the fewest major postoperative complications and shortest time between surgery and use of the BAHA. The techniques evaluated were 1) a free retroauricular "full-thickness" skin graft, 2) a pedicled parieto-occipital epidermal graft, 3) a dermatome-pedicled parieto-occipital dermal graft, and 4) two broad pedicled local epidermal skin envelopes/skin flaps.
Retrospective case study.
Tertiary referral center.
One hundred forty-three patients who received a BAHA at Maastricht University Medical Center between November 1996 and January 2007. Number and mean age of patients in each group: Technique 1 (n = 30; mean age, 55 yr), Technique 2 (n = 45; mean age, 54 yr), Technique 3 (n = 47; mean age, 55 yr), and Technique 4 (n = 21; mean age, 54 yr).
Cumulative proportion of implants that remained free of major complications versus follow-up interval, time between surgery and use of BAHA.
Technique 4 (2 broad pedicled local epidermal envelopes/skin flaps) has a significantly higher proportion of implants that remained free of major complications during first year of follow-up (91%; p = 0.021). Pairwise comparisons revealed that Technique 4 also has a significantly shorter time until use (2 mo) than Techniques 1 (2.5 mo), 2, and 3 (both 2.3 mo).
Two broad pedicled, local epidermal envelopes/flaps are associated with significantly fewer major complications and have one of the shortest times between surgery and use of the BAHA. The use of a dermatome is not associated with fewer major complications. We recommend Technique 4 as the preferred standard in BAHA surgery to minimize complications, postoperative medication, discomfort, and cost.
The most common postoperative complications related to BAHA prosthetic surgery are skin complications. In this study we compare and evaluate these reactions with two different surgical techniques, the BAHA dermatome and the U-graft technique.
Fifty-three patients who underwent implantation of a BAHA at our hospital between 2001 and 2008 were studied. The comparison of the skin reactions was carried out according to Holgers' classification. We also recorded the number of cures required until the skin was stabilized.
We used the dermatome in 27 patients and the U-graft in 26 patients. In the dermatome group we have reported a total of 74% of skin reactions (20 patients), in contrast with the 34% (9 patients) observed in the U-graft group. The average number of cures for patients in the dermatome group and those in the U-graft group was 4.1 and 2.7, respectively. The differences found were statistically significant and had a 95% confidence interval.
In our experience, the use of the electric dermatome in BAHA surgery offers a higher incidence of skin complications in comparison with the U-graft technique. Since both techniques have a number of advantages and disadvantages, it may be that the selection of the technique to be employed according the individual characteristics of each patient may offer better results in the future.
To determine the predictive ability of the Jahrsdoerfer grading scale score in congenital aural atresia surgery.
Retrospective review of medical records.
Tertiary referral center.
One hundred eight patients with aural atresia.
Demographic data, preoperative Jahrsdoerfer score, and postoperative audiometric outcomes were reviewed. One month postoperative, 4-tone pure-tone averages and speech reception thresholds were compared between ears scoring 6 or lower, 7, and 8 or higher on the Jahrsdoerfer grading scale. The percentage of ears with a speech reception threshold of 30 dB hearing level or lower for each group was calculated and compared between groups. Individual anatomical structures on the Jahrsdoerfer grading scale were evaluated for their ability to predict postoperative audiometric success.
Of 116 ears evaluated, postoperative 4-tone pure-tone averages and speech reception thresholds were significantly poorer in ears scoring 6 or less on the Jahrsdoerfer grading scale compared with ears scoring 7 or higher (P < .02, t test). Ears scoring 6 or less had a 45% chance of achieving a postoperative speech reception threshold of 30 dB hearing level or lower, while ears scoring 7 or higher had an 89% chance (P < .01, chi(2) test). Lack of middle ear aeration was the only anatomical factor predictive of poor audiometric outcome.
Compared with patients with a Jahrsdoerfer score of 6 or lower, patients with a score of 7 or higher had significantly better hearing postoperatively. Middle ear aeration may be the most important predictor of postoperative hearing outcome. The Jahrsdoerfer grading scale is an invaluable tool in the preoperative evaluation of patients with congenital aural atresia.
It is generally recognized that surgery for congenital aural atresia is difficult. In an effort to select those patients who have the greatest chance of success, we have developed a grading scheme based on the preoperative temporal bone CT scan and the appearance of the external ear. Patients are graded on a possible best score of 10. The stapes is assigned the highest rating (2 points), while all other entrees on the scale are 1 point. The grade assigned preoperatively has been shown to correlate well with the patient's chance of success, herein defined as a postoperative speech reception threshold of 15 to 25 dB. A patient with a preoperative grade of 8/10 would, therefore, have a 80 percent chance of achieving this threshold. Patients with scores of 5/10, or less, are not considered surgical candidates, because the risk of the operation would outweigh the potential benefits. We have found that the grading system allows us to avoid impossible surgical cases while allowing for a reasonable prediction of the hearing outcome.
Some patients with hearing impairment cannot use conventional hearing aids. One solution for these patients is the use of bone conduction hearing aids; however, this kind of equipment is associated with several problems related to the necessity for a good contact between the transducer and the temporal bone. Direct bone contact would be an ideal solution provided that safe and reaction-free skin penetration and a safe and permanent bone anchorage could be achieved. Brånemark et al have developed a procedure to furnish edentulous patients with fixed bridges using titanium implants. This report is focused on the clinical status of the soft tissue adjacent to the 67 skin-penetrating devices in 60 patients. The patients have been followed between 3 and 96 months on 313 occasions, which represents a total observation time of 1515 months of clinical performance. Only one implant was extracted due to adverse skin reaction, giving a failure rate of 0.07% per month. This is comparable with the failure rate of cardiac pacemakers 0.02-0.04% per month).
The study goal was to evaluate the hearing follow up results in patients who underwent surgery for congenital aural atresia. We studied hearing results and correlated them with Jahrsdoerfer prognostic classification. Protocols management of unilateral and bilateral atresia auris are written considering to our results and other authors.
We conducted a retrospective review of 12 ears who underwent surgery for congenital aural atresia between 1989 and 2002. CT scan was used to evaluate Jahrsdoerfer prognostic classification and the correlation with the hearing results.
There are significant statistical differences (p = 0.003) in air-bone gap closure before and after surgery, also a lineal significant correlation (p = 0.016) between Jahrsdoerfer prognostic classification and air-bone gap closure.
Atresiaplasty surgery in individuals with congenital aural atresia can yield good hearing results in selected cases.
To discuss perioperative complications associated with the bone-anchored hearing aid (BAHA) and their management.
A retrospective review of 58 patients who underwent implantation of BAHA for unilateral conductive, mixed, or sensorineural hearing losses was performed at a tertiary referral center.
Between September 2003 and June 2005, 58 patients underwent implantation of a BAHA. There were 30 female and 28 male patients, with a mean age of 48 years (range 8-80 years). Complications occurred in 19% (11/58) of patients. Most adverse events were seen early in the series. The most common complication, partial or complete loss of the skin graft, occurred in 10% (6/58) of patients. These were managed successfully with local wound care. Five percent (3/58) of patients had skin growth over the abutment. Two of these cases were managed with office debridement, whereas 1 patient required revision under general anesthesia. There was implant extrusion in 3% (2/58) of patients, and both of these patients later underwent successful reimplantation. All patients had their implant activated 3 months after surgery. There were no perioperative or postoperative deaths.
Complications related to BAHA implantation are relatively minor and usually involve partial or complete loss of the skin graft. Most complications were successfully managed in the office.
To determine the incidence of complications associated with implantation of the bone-anchored hearing aid (BAHA) and the management of these complications.
Retrospective case review.
Tertiary referral center.
One hundred forty-nine consecutive patients between October 25, 2001, and June 29, 2005, underwent implantation of a BAHA. The majority of patients had unilateral profound sensorineural hearing loss after removal of an acoustic neuroma or skull base tumor (59.1%) with the next most common etiology of deafness secondary to sudden sensorineural hearing loss (16.1%).
Implantation of a BAHA.
Incidence of complications occurring after implantation of a BAHA.
There were no intraoperative or perioperative complications. Significant postoperative complications requiring intervention occurred in 19 (12.8%) patients. Skin overgrowing the abutment occurred in 11 (7.4%) patients, and 10 of these patients required revision in the operating room. Skin overgrowth was a late complication, occurring an average of 12 months after the initial procedure. Implant extrusion occurred in 5 (3.4%) patients, with 3 requiring revision surgery. Two patients elected not to have the device reimplanted. Two patients had local wound infections requiring oral antibiotics.
Significant complications are uncommon after implantation of a BAHA; however, these complications may require local wound care, antibiotics, or revision surgery.
To report cases of long-term surgical complications, implant failure and revision surgery, within a large bone-anchored hearing aid programme.
Retrospective, case-cohort study.
Tertiary referral centre.
One hundred and sixty-five adults and children who had undergone a total of 177 bone-anchored hearing aid implantations.
Diagnosis and explanation of adverse events and device failure.
Operative complications and survival analysis, surgical challenges related to revisions, and causes of failure.
Twenty-one per cent of patients (3.4 per cent of those observed) suffered from skin reactions; this rate did not increase over time. Seventeen per cent had loss of osseointegration at a median interval of 6.3 months. Loss of osseointegration was observed more frequently in patients with a 3 mm compared with a 4 mm fixture (p < 0.001). Intra-operatively, the only complication was bleeding, occurring in 3 per cent of patients. Post-operative complications included: primary bleeding (2 per cent); severe skin reactions requiring intravenous antibiotics, cautery or grafting (8 per cent); thickening or overgrowth of skin requiring excision (8 per cent); failure of osseointegration requiring a new fixture (18 per cent); and graft necrosis requiring revision (1 per cent). In two patients, it was necessary to explore the area to remove overgrowth of bone. In 16 patients (10 per cent), the bone-anchored hearing aid had to be abandoned due to failure of osseointegration (n = 4), dissatisfaction with the aid (n = 6), intolerable pain (n = 4), hair growth around the abutment (n = 1) or recurrent infections (n = 1). In 12 of these patients, the bone-anchored hearing aid was removed surgically. Overall, 57 patients (34 per cent) underwent revision surgery.
Awareness of complications is becoming increasingly important in bone-anchored hearing aid programme. A substantial workload of device maintenance should be anticipated, and patients should be appropriately counselled beforehand. Ninety per cent of our patients chose to persevere with this form of hearing rehabilitation.