The expanding domain of implantable hearing devices: an update on current status in the United States.

Several implantable devices are now approved in the United States for rehabilitation of conductive, mixed, and sensorineural hearing loss. This paper will review current rehabilitative options including middle ear implants, used for mild to severe sloping sensorineural loss, and bone-anchored hearing aids, for conductive or mixed hearing loss. The indications for these devices differ, as do the bases for exclusion. Audiologic evaluation parameters will be reviewed as a guideline to selection, and as a baseline to determine potential rehabilitative impact. We will also describe emerging applications, based on our ongoing research projects, for these devices that are anticipated to broaden the indications.

A radiation-shielding device for craniofacial implant placement.

The use of radiation shields in the head and neck cancer patient receiving adjuvant radiation therapy is a treatment alternative for protecting anticipated prosthetic implant sites. Shields can be fabricated easily as part of an interdisciplinary treatment protocol. In this article, the methods used to fabricate an extraoral radiation shield are described, and a patient treatment that illustrates possible uses of the shield for both extraoral and intraoral sites is presented.

Results of the bone-anchored hearing aid in unilateral hearing loss.

OBJECTIVES: The advantages of binaural hearing are well established and universally accepted. However, a tendency remains to withhold the benefits of binaural hearing to adults and children with one normal ear. The purpose of this study is to demonstrate the benefit of the bone-anchored hearing aid (BAHA) in a group of patients with unilateral conductive or mixed hearing loss. STUDY DESIGN: This is a prospective study of nine patients (five males and four female patients) with conductive or mixed hearing loss who met the criteria for BAHA except for having normal hearing in the other ear. They had congenital aural atresia or mastoidectomies secondary to chronic ear infections with or without cholesteatoma or had a temporal bone tumor excised METHODS: Patients had evaluations before and after implantation, including audiological testing and responses to a standardized hearing handicap questionnaire. Statistical analyses of the data were made using the Wilcoxon signed rank test and the paired Student t test for repeated measures. RESULTS: All patients had tonal and spondee threshold improvement with BAHA when compared with thresholds before treatment. Speech recognition performance in BAHA-aided conditions was comparable to the patient's best score in unaided condition. Patients reported a significant improvement in their hearing handicap scores with the BAHA. CONCLUSIONS: The use of BAHA has significantly improved the hearing handicap scores in patients with unilateral conductive or mixed hearing loss. The proven safety and efficacy of the device promote its use in unilateral cases that traditionally had been left unaided.

Cranioplasty in acoustic neuroma surgery.

OBJECTIVES: To measure the incidence of postoperative headaches after retrosigmoid resections of acoustic neuromas and to evaluate the impact of cranioplasty on the prevention and management of these headaches. STUDY DESIGN: A prospective evaluation was performed on 30 consecutive patients who underwent a cranioplasty after retrosigmoid excision of their acoustic neuroma. The results were compared with 30 historical control patients who underwent the same procedure but did not have reconstruction with a cranioplasty. The patients were evaluated by review of office records and via telephone questionnaire. METHODS: One group of patients (30 patients) had no cranioplasty, and the other group of 30 patients had primary reconstruction with a titanium mesh-acrylic cranioplasty. All 60 patients were asked to report on the duration and severity of their headaches by means of a standard questionnaire, grading their symptoms on a scale of 1 to 4. The data were subjected to chi2 and Student t test statistical analyses. RESULTS: New-onset, postoperative headaches occurred in 27% of patients, 23% in the cranioplasty group compared with 30% in the group without cranioplasty (a difference that was not statistically significant [P = .158]). However, there was a statistically significant difference in the severity of the headaches (P<.03). The headaches in the cranioplasty group were less severe and were not disabling. There were no complications, infections, or extrusions related to the cranioplasty. CONCLUSIONS: Cranioplasty has not been able to eliminate postoperative headaches. However, the use of cranioplasty has significantly decreased the severity of postoperative headaches after retrosigmoid excision of acoustic neuromas.

Multidisciplinary treatment for an implant retained auricular prosthesis rehabilitation.

Retention of a facial prosthesis is the most important factor in creating a useful prosthesis for the patient. This paper presents a detailed case study of an auricular defect that was rehabilitated using two types of prosthetic retention: adhesive and osseointegration. We present the patient selection criteria, the surgical considerations prior to implant placement, retention component selection, prosthetic fabrication techniques and patient management after prosthetic delivery. The osseointegrated prosthesis made a large improvement in the patient's quality of life.

Auricular rehabilitation with bone-anchored titanium implants.

OBJECTIVE: To evaluate the effectiveness of the bone-anchored titanium implants in auricular reconstructions. STUDY DESIGN: Six patients who received implants for an auricular reconstruction were followed prospectively. Four patients had lost their ears to cancer, and the other two had congenital aural atresia. METHODS: All patients were thoroughly evaluated by the reconstruction team, which included a surgeon, a prosthodontist, and a facial prosthetist. Three patients were evaluated audiologically for a bone-anchored hearing aid. Four patients received implants in a single-stage procedure, and two underwent a two-stage procedure. A gold bar with retaining clips was used to anchor the prosthetic ear in four patients, and magnets were used in the remaining two. RESULTS: All six patients are completely satisfied with their reconstructions. No failures, extrusions, or bony complications were encountered. One patient had recurrent dermatitis, which subsided when his gold bar was replaced with magnets. CONCLUSION: Implanted under the guidance of an appropriate prosthetic team, bone-anchored titanium implants provide patients with a safe, reliable, adhesive-free method to anchor auricular prostheses with recovery of their normal appearance.

Ciprofloxacin versus cefuroxime axetil in the treatment of acute bacterial sinusitis. Sinusitis Infection Study Group.

OBJECTIVE: This study was conducted to compare the efficacy and safety of ciprofloxacin to cefuroxime axetil for the management of acute bacterial sinusitis or acute exacerbations of chronic sinusitis. METHOD: In this prospective, multicentre, randomized, double-blind clinical trial, 501 adult outpatients seen in 17 otolaryngology offices with both symptoms and radiographic evidence of acute maxillary sinusitis randomly received oral ciprofloxacin (500 mg b.i.d.) or cefuroxime axetil (250 mg b.i.d.), each for 10 days. Patients were further subclassified as having either acute sinusitis or an acute exacerbation of chronic sinusitis. All patients underwent maxillary sinus aspiration at study entry to establish a microbiologic etiology. The primary measure of efficacy was the rate of clinical success in the efficacy-valid population at the end of therapy. Secondary measures included bacteriologic response at the end of therapy, and 2- to 4-week clinical and bacteriologic follow-up response rates in both efficacy-valid and intent-to-treat groups. RESULTS: Haemophilus influenzae (21%), Streptococcus pneumoniae (19%), Moraxella catarrhalis (14%), and Staphylococcus aureus (9%) were the most commonly isolated pathogens (target organisms) among the 225 causative organisms identified from 189 patients. Of 453 adults valid for clinical efficacy (228 ciprofloxacin, 225 cefuroxime axetil), ciprofloxacin treatment was statistically equivalent to cefuroxime axetil at the end of treatment (87% vs. 83%; CI95 = -0.021 ... 0.106) and at follow-up (91% vs. 88%; CI95 = -0.044 ... 0.080). The clinical response was similar for subgroups of patients with positive cultures, including the subset with target organisms. Bacteriologic eradication at end of therapy was similar between the two groups (97% ciprofloxacin, 95% cefuroxime axetil). Both treatments were equally well tolerated. CONCLUSION: Ciprofloxacin is as effective as cefuroxime axetil in the treatment of community-acquired acute sinusitis.

Fabrication and use of a surgical template for placing implants to retain an auricular prosthesis.

A procedure is described for the fabrication of a 3-dimensional surgical template to guide the placement of implants to retain an auricular prosthesis. This procedure requires a diagnostic wax pattern that is checked while on the patient to ensure it is positioned correctly and is also the correct size. The wax pattern is processed into a clear, methyl methacrylate resin, 3-dimensional surgical template. The most effective type of surgical template for planning implant placement is a 3-dimensional acrylic template that closely resembles the final prosthesis. This template will direct the implant placement where the retentive elements are most easily concealed, under the thickest areas of the prosthesis, which are the antihelix and antitragus. This location allows the best esthetic and functional results. An additional advantage of this technique is that it allows the retrieval of the diagnostic wax pattern of the auricle so that it can be used to fabricate the definitive prosthesis.

Long-term results with the titanium bone-anchored hearing aid: the U.S. experience.

OBJECTIVE: The purpose of this study is to evaluate the long-term safety and efficacy of the titanium bone-anchored hearing aid (BAHA). STUDY DESIGN: A retrospective review of 24 patients implanted with the BAHA between 1984 and 1987 in a multiinstitutional study designed to evaluate the device in the United States was performed, including detailed clinical and audiologic evaluations of the 10 patients implanted at the Columbia-Presbyterian Medical Center in New York. The data were collected from patients' charts, questionnaires, and the Nobel Biocare patient contact and repair records. PATIENTS: Candidates for the BAHA are unable to use a conventional air conduction hearing aid because of congenital aural atresia, draining mastoid cavities, or recurrent otitis externa. The audiologic indications are a conductive or a mixed hearing loss with a bone conduction average of 45 db or better and a speech discrimination score of 60% or better. INTERVENTION: A BAHA was implanted in a two-stage procedure under local anesthesia on an outpatient basis. MAIN OUTCOME MEASURES: Patients' satisfaction with the device, hearing improvement, and complication rates were reviewed. RESULTS: The majority of the patients analyzed (78%) are still using the device an average of 15.6 hours/day 10 to 13 years after implantation. The overall satisfaction score was 4.5 (1, worst; 5, best). In sound field testing, the mean speech reception threshold improved from 52 db to 27 db (p < 0.05). There were no major complications. CONCLUSION: The BAHA is a safe and effective bone conduction hearing aid with wide applications for patients with bone conduction hearing levels of 45 db and discrimination scores of 60% or better.

Long-term hearing results following vestibular surgery in Meniere's disease.

OBJECTIVES: The purpose of this study is to evaluate the long-term hearing changes following vestibular surgery in patients with Meniere's disease. STUDY DESIGN: This is a retrospective analysis of patients operated on in a tertiary referral center setting. METHODS: Preoperative, postoperative, and 3- to 9-year postoperative audiograms were analyzed in two patient groups. Twenty-one patients underwent posterior fossa vestibular neurectomy (VN) and five, mastoid endolymphatic sac decompression and shunt (ELS). All frequencies, four-frequency pure-tone averages (PTAs), spondee thresholds, and speech recognition scores were compared for operated ear against nonoperated ear of VN subjects. The results were subjected to a covariance analysis. VN and ELS patients whose hearing deteriorated from "serviceable" (PTA < or =70 dB hearing level) and speech recognition > or =30%) to nonserviceable status were compared using nonparametric statistics. RESULTS: Progressive hearing loss beyond the rate of change of the normal contralateral ear was evident in all patients. Serviceable hearing dropped from 81% to 43% of patients an average of 4 years following VN. CONCLUSIONS: VN patients have significant hearing deterioration over time in the operated ear. This finding suggests that continued postoperative medical management is necessary for patients undergoing VN.

Intra-operative electrocochleography in stapedectomy and ossicular reconstruction.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of intraoperative electrocochleography (ECOG) in predicating the postoperative hearing improvement in surgery for conductive hearing loss. STUDY DESIGN: This study was a prospective study of 22 patients undergoing intraoperative electrocochleography during a stapedectomy. SETTING: The study was performed in a tertiary referral center. PATIENTS: Intraoperative electrocochleography was performed in 22 patients 27-73 years of age undergoing a stapedectomy for otosclerosis under general anesthesia. INTERVENTION: For each patient, the N1 threshold to click stimulation was measured intraoperatively, before and after the reconstruction. MAIN OUTCOME MEASURES: The intraoperative ECOG thresholds were compared with the pre and postoperative audiograms. RESULTS: Postreconstruction ECOG's demonstrated improvements in the N1 threshold in 19 cases, and were unchanged in 1 case. In each of these cases, improvement in the intraoperative N1 threshold corresponded with improvement in the postoperative audiogram compared with the preoperative studies. In two other cases the postreconstruction ECOG was nearly unobtainable, despite improved hearing postoperatively. CONCLUSION: Intraoperative ECOG appears to be an effective tool for verifying the functional integrity of ossicular reconstructions as in stapedectomies. We speculate that intraoperative ECOG may allow the surgeon to "fine tune" the reconstruction to optimize the hearing results.

Selective cochlear neurectomy for debilitating tinnitus.

Eighth nerve sections have been performed to control debilitating tinnitus, with various success rates (45% to 76%). Patients with a unilateral profound sensorineural hearing loss and disabling tinnitus perceived in that ear are candidates for such surgery. The concept of a selective cochlear neurectomy with preservation of the vestibular nerve is introduced with two case presentations. The indications for surgery, surgical technique, and results are described. Advantages of preserving the vestibular nerve fibers include the lack of postoperative vertigo and disequilibrium and thus a shorter length of hospital stay, and the conservation of a symmetric vestibular input, obviating the lengthy compensation process that might otherwise be needed, particularly in the elderly. A selective cochlear neurectomy for the control of debilitating tinnitus has proven to be successful in controlling tinnitus in the two patients presented, with the added advantage of preservation of their vestibular function. Further controlled studies are necessary to confirm the advantages and effectiveness of this technique.

Dural closure with laser tissue welding.

This study investigates the use of tissue-soldering techniques to substitute or reinforce traditional suture closure of dural incisions. Fresh human cadaveric dura was incised and subsequently closed by use of three techniques: (1) conventional interrupted suture with 4-0 silk (n = 25), (2) laser solder reinforced suture closure (n = 25), and (3) laser solder closure alone (n = 25). Anastomosis tensile strength and hydrostatic leak pressures were measured. Dural repair was also performed in 15 live Lewis rats. Dural closure was accomplished with 9-0 Prolene sutures (n = 5), laser-reinforced suture closure (n = 5), and laser solder closure alone (n = 5). Histologic examination of the closure immediately after soldering and 2 weeks later was performed. Suture closure alone had the lowest leak pressure, 9.4 +/- 1.7 mm Hg, and an intermediate break point, 13.3 +/- 2.1 Kgf/cm2. Measurements with laser solder alone revealed a mean leak pressure of 26.2 +/- 3.7 mm Hg and a break point of 4.6 +/- 1.4 Kgf/cm2. Solder-reinforced suture closure leak pressure measured 64.0 +/- 6.7 mm Hg and 21.4 +/- 2.4 Kgf/cm2. There was a statistically significant increase in leak pressure and tensile strength in the closures performed with laser weld reinforcement of traditional suture technique (p = 0.0001). Dural closure with laser tissue welding alone provided an immediate leak-free closure, but with poor tensile strength. Histologic examination of welded dura and underlying brain tissue showed no evidence of thermal injury in four of five animals studied. Laser welding may significantly decrease the incidence of cerebrospinal fluid leak after dural closure. In addition, laser tissue welding also makes dural closure possible where space constraints make traditional suture closure difficult.

Intraoperative monitoring of auditory function: experimental observations and new applications.

The three different methods of intraoperative monitoring, namely, auditory brainstem response evaluation (ABR), electrocochleography (ECoG), and direct eighth nerve compound action potentials monitoring are reviewed. Both ECoG and direct eighth nerve monitoring surpass the ABR in their ability to provide fast, almost instantaneous, large, reproducible potentials in response to click stimuli. Changes in the amplitude and the latency of these potentials alert the surgeon of an impending eighth nerve injury. Human clinical observations revealed instances of persistence of the ECoG despite a total eighth nerve section in the cerebellopontine angle. Animal and human experiments were conducted to evaluate the effectiveness of ECoG and direct eighth nerve monitoring in hearing preservation. Twelve cats underwent progressive sectioning of the eighth nerve with simultaneous monitoring of changes in their ECoG and direct eighth nerve potentials. ECoG thresholds were obtained intraoperatively in eight patients undergoing surgery for conductive hearing loss. The results of these experiments suggest that recording directly from the eighth nerve is a more accurate technique during cerebellopontine angle and eighth nerve surgery. ECoG, however, appears to have a promising role in the intraoperative monitoring of middle ear reconstruction procedures under general anesthesia.

Advances in otology and neurotology.

During the last few years many advances occurred in the field of Otolaryngology. In this article we will present significant advances in the fields of otology and neurotology. The adaptation of laser energy to surgery is a significant event in the evolution of ear microsurgery. Lasers in otology reduce trauma and increase accuracy. Implantable hearing devices are used to rehabilitate patients with mild to moderately severe hearing loss. Cochlear implants have secured a permanent role in the management of selected profoundly deaf patients. Intraoperative cranial nerve monitoring is a major advance in ear surgery. Facial nerve and auditory nerve monitoring are now widely used and are the basis for facial and hearing conservation.

Referred otalgia.

The diagnosis and management of otalgia may be a very simple task or a very complex and frustrating experience for both physician and patient. A thorough understanding of the anatomy of the head and neck is required. A basic knowledge of neuroanatomy, with emphasis on the cranial nerves, their course, distribution, and function, is also necessary. The complexity of this field may sometimes require the treating physician to call for consultations from colleagues in the fields of oral surgery, neurology, or neurosurgery. It is often through the collaboration of different specialists that patients are provided with the appropriate medical care they deserve. This has never been more true than in the area of the head and neck.

Clinical results with a percutaneous bone-anchored hearing aid.

During a 2-year period ending in July 1987, nine patients were implanted with a percutaneous bone-anchored hearing aid developed at the University of Gothenburg and Chalmers University of Technology, Sweden. Patients selection was based on the presence of conductive or mixed hearing loss in patients who are unable to wear a conventional hearing aid because of infection or ear canal problems. Patients had speech discrimination scores of at least 60% for phonetically balanced monosyllables (CID lists) at 40 dB above threshold, and a pure tone bone conduction average of 45 dB hearing loss or better. Patients were evaluated in sound field, preoperatively and postoperatively using warble tones, speech reception threshold, speech discrimination, and synthetic speech identification. The patient's unaided hearing and hearing with a bone-anchored hearing aid were compared with the patient's hearing with a standard bone conduction hearing aid. Signal to noise ratio testing with the synthetic speech identification test demonstrated that the bone-anchored hearing aid was comparable to a standard bone conduction aid. There were no complications in our series. Five patients who reported otorrhea with conventional hearing aids experienced no otorrhea after implantation. Patient satisfaction, as assessed by questionnaire, revealed that all patients preferred the bone-anchored hearing aid to previously worn hearing aids.

Intraoperative BAER monitoring and hearing preservation in the treatment of acoustic neuromas.

We treated 20 cases of acoustic neuromas in the last 2 1/2 years using the suboccipital approach with intraoperative monitoring of eighth nerve function in an attempt to preserve hearing. Total tumor removal was accomplished in 18 cases. Three tumors were small (less than 2 cm in size); 3 tumors were moderate sized (2 to 3 cm) and 14 tumors were large (greater than 3 cm). In 15 cases, all BAER components were lost during surgery. These patients had no postoperative hearing. In five patients there was intraoperative preservation of some or all BAER components. These included the three patients with small tumors and two other patients with moderate sized tumors. One patient with a moderate size tumor had preservation of wave 1 only, and had no postoperative speech discrimination. One patient with a small tumor retained all 5 BAER components, but had no postoperative hearing. Three patients in our series retained functional hearing after surgery, including 3 of 5 patients with tumors 2 cm or smaller. Intraoperative BAER monitoring appears to be useful in predicting postoperative hearing. Tumor size seems to be the primary factor in preservation of hearing following acoustic neuroma surgery.