Standardization of the Punch Technique for the Implantation of Bone Anchored Auditory Devices: Evaluation of the MIPS Surgical Set.

OBJECTIVE: To describe and assess intraoperative and postoperative outcomes in the insertion of osseointegrated auditory implants with a newly designed surgical instrumentation set through a punch type technique. STUDY DESIGN: Retrospective case series. METHODS: Patients who underwent bone anchored auditory implant surgery using the Minimally Invasive Ponto Surgery (Oticon Medical, Somerset, NJ) surgical set through a punch technique at nine neurotology tertiary referral based practices were identified. Demographic data, skin thickness at implant site, implant used, duration of surgery, adverse intraoperative events, and postoperative outcomes were recorded. RESULTS: Seventy-five patients comprised the study cohort (32 males, 43 females). Most patients (57. 3%) were aged 51 to 75 years while 30.7% of the cohort comprised those aged 18 to 50 years and 12% were over 75 years. All but two patients received 4 mm fixtured implants and 68% received the Oticon Medical BioHelix implant. Two patients received 3 mm fixture implants and 32% received the Oticon Medical Wide Ponto implant. Mean surgical time was 12.2 minutes (6-45 min, standard deviation of 6.88 min). In three instances, surgery was converted to a linear incision to control brisk bleeding. Skin condition was Holgers 0 to 1 in 91.8%, while 5.5% had Holgers 2, and 2.7% had Holgers 3 at the first postoperative visit. At second postoperative visit, 94.3% had Holgers 0 to 1, 4.3% had Holgers 2, and 1.4% had Holgers 3. All instances of adverse skin reactions were treated with topical or systemic antibiotics and/or local debridement. There were no instances of implant loss. One patient had his implant traumatically displaced to a 45-degree angle necessitating implant replacement at a second site. CONCLUSION: Punch technique placement of osseointegrated auditory implants using the Minimally Invasive Ponto Surgery surgical set represents a safe technique that further simplifies a progressively minimally invasive surgery.

Enhanced dopamine uptake in the striatum following repeated restraint stress.

In mice administered chronic stress--repeated overnight restraint stress for 7 days--there was a prolonged enhancement of dopamine (DA) uptake into synaptosomes. The mRNA for the DA transporter (DAT) was found to be concomitantly increased in the midbrain, as was the binding of the transporter ligand mazindol to DAT in the nucleus accumbens and caudate-putamen. Kinetic analysis showed an increase in Vmax for DA, with little change in Km. No changes in tyrosine hydroxylase activity and tissue DA or 3,4-dihydroxyphenylacetic acid (DOPAC) content were observed. However, homovanillic acid (HVA) was found to be increased in the striatum of the stressed animals. Enhanced DAT activity attributable to chronic stress was still observed in animals treated with the DA D2 receptor antagonist haloperidol or the glucocorticoid receptor antagonist mifepristone. Modulation of DAT activity may be a physiological mechanism for regulating the concentration of DA that reaches receptors, following periods of stress.

The accuracy of computer-aided surgery in neurotologic approaches to the temporal bone: a cadaver study.

OBJECTIVE: To assess the accuracy of computer-aided surgery for common neurotologic approaches to the temporal bone. STUDY DESIGN AND SETTING: Cadaveric heads were dissected by using standard neurotologic approaches to the temporal bone including translabyrinthine, middle fossa, and retrosigmoid. Dissected anatomic landmarks from each approach were compared with CT images that were obtained before dissection on the VectorVision 2 system (BrainLAB Corp, Munich, Germany) and the variability measured from digital images. Each approach was performed 5 times, with each anatomic landmark measured 3 times from each approach. RESULTS: The accuracy of the computer-aided surgery system was less than 1 mm for all anatomic points measured. Forty-two of the 49 measured points were accurate to less than 0.5 mm. CONCLUSIONS: Computer-aided surgery of the temporal bone using common neurotologic approaches can be performed accurately and reliably in cadaver specimens. SIGNIFICANCE: The utility and limitations of computer-aided surgery in the temporal bone are discussed. EBM RATING: B-2.

Prospective evaluation of intraoperative cochlear implant radiographs.

OBJECTIVE: To investigate the clinical utility of intraoperative plain radiographs in cochlear implant surgery. STUDY DESIGN: Prospective. SETTING: Tertiary referral center. PATIENTS: Eighty consecutive adult and pediatric cochlear implant operations at a facility capable of intraoperative radiographs were evaluated over 12 months. INTERVENTIONS: Intraoperative plain radiographs to assess implant location and surgeon questionnaire. MAIN OUTCOME MEASURES: Plain radiographic image interpretation and surgeon questionnaire. RESULTS: In one revision surgery, the intraoperative plain radiograph was useful for confirming the cochleostomy site. In the remaining 79 operations, no changes in the electrode arrays were made on the basis of the information provided by intra-operative plain radiographs. CONCLUSIONS: In this cohort, intraoperative plain radiographs were not useful for uncomplicated implant operations; however, they may be useful for complicated operations. These results may have implications for surgical cost and patient radiation exposure.

Cochlear implantation in children with congenital inner ear malformations.

OBJECTIVE/HYPOTHESIS: To assess the audiologic and surgical outcomes for pediatric cochlear implant patients with inner ear malformations. STUDY DESIGN: Retrospective review of 315 pediatric cochlear implant cases from 1994 to 2002. METHODS: Twenty-eight pediatric cochlear implant patients with known inner ear malformations determined on high-resolution computed tomography (HRCT) of the temporal bone were the subjects of review. Results of HRCT findings, intraoperative findings, postoperative complications, and objective measures of both closed- and open-set testing of speech perception were analyzed. RESULTS: Patients with the constellation of an incompletely partitioned (IP) cochlea, enlarged vestibular aqueduct (EVA), and a dilated vestibule (i.e., Mondini's malformation) as well as those with an isolated EVA or partial semicircular canal aplasia have relatively good levels of speech perception. Patients with total semicircular canal aplasia, isolated IP, cochlear hypoplasia, or common cavity demonstrated lower levels of performance. Poor performance may be related to associated developmental delays rather than labyrinthine anatomy alone. Complications of surgery were relatively limited. CONCLUSIONS: Cochlear implantation can be successfully performed in children with inner ear malformations. These children and their parents can expect significant auditory benefits from this intervention. The various types of inner ear malformations may have quite different prognoses for good auditory performance.

Cochlear implantation for the treatment of deafness.

Cochlear implants have dramatically changed the treatment and prognosis for patients with profound sensorineural hearing loss. Deaf adults and children can be successfully (re)integrated into the hearing world through a multidisciplinary approach involving otolaryngologists, audiologists, and speech/language pathologists. As the technology of the cochlear prosthesis advances, the candidacy for these devices continues to broaden. This review addresses the basic technology, candidacy criteria, and important issues in the fields of adult and pediatric cochlear implantation. Cost utility and future directions in the treatment of the profoundly hearing impaired are discussed.

Management of labyrinthine fistulae in chronic ear surgery.

The appropriate management of labyrinthine fistulae has been debated in the literature for years. After several recent cases of labyrinthine fistulae at our institution, a review of the published data regarding hearing outcome with fistula management was undertaken. Results of this critical review were presented at departmental grand rounds. The grand rounds presentation, data and discussion are presented to better illuminate the topic of labyrinthine fistula management.