Consistency of Using an Auditory Prosthesis Device Post a Sequentially Implanted Cochlear Implant: Data-Logging Evidence.

Objectives The aim of this study was to explore: 1) the average use of each device in sequentially implanted cochlear implants; 2) whether the inter-implant duration between implants produced any significant difference in the average use of the second implant; and 3) whether wearing hearing aids before the implantation of the second cochlear implant affects its average use. Materials and methods The study included 20 participants with bilateral Nucleus 24 implants (Cochlear Corporation, Lone Tree, CO). Data regarding various variables were extracted and then analyzed with IBM SPSS Statistics for Mac, version 23 (IBM Corp., Armonk, NY). Results The pediatric group included 14 subjects (average age 7.5 years) while the adult group comprised six subjects (average age 37.5 years). The average use of the second device was 0.9 hours per day more than the first in the pediatric group while it was 1.22 hours per day more in the adult group. We also divided the subjects on the basis of duration between the first and second devices and calculated the average use of each device by them. There was no significant difference (p>0.05). The average use by subjects who did and did not use hearing aids before implantation was also insignificant (p>0.05). Conclusions No significant difference between the average use of the first and second implants, between the inter-implant duration of the first and second implants, the average use of the second implant, and between using hearing aids before the implantation of the second device and the average use was observed.

Direct measurement of cochlear parameters for automatic calculation of the cochlear duct length.

BACKGROUND: Cochlear morphology and cochlear duct length (CDL) play important roles in the selection of appropriate electrodes. Cochlear parameters such as diameter (A value) and width (B value) are used as inputs for calculating the CDL. Current measurements of these parameters are inefficient and time consuming. Recently developed otological planning software (OTOPLAN) allows surgeons to directly measure these parameters and then automatically calculate the CDL. OBJECTIVES: The primary objective was to validate this new software for measuring the cochlear parameters and CDL. The secondary aim was to investigate the correlation between each cochlear parameter with the calculated CDL. DESIGN: Retrospective. SETTINGS: Ear specialist hospital. PATIENTS AND METHODS: The measurement of cochlear diameter (A value) was chosen as the validation parameter. To do this, the A value was measured by a neurotologist on the new OTOPLAN planning software and was validated to the one measured on the currently used DICOM viewer. Upon the validation of the OTOPLAN software, the other two cochlear parameters, namely width (B value) and height (H value) were measured, and CDL was automatically calculated. Finally, the correlation of all parameters with the CDL was statistically analyzed. MAIN OUTCOME MEASURES: Validation of OTOPLAN and CDL estimation. SAMPLE SIZE: 88 ears. RESULTS: There was no significant difference between the A-value measured on the DICOM viewing software and that on the new planning software by the two independent neurotologists (P=.27). Both A-and B-values showed a high positive correlation to the CDL. However, the B-value showed a stronger correlation to the CDL than the A-value (r=0.63 for A, and r=0.96 for B). CONCLUSION: The direct measurement of cochlea parameters and automatic calculation of the CDL could improve the efficiency of clinical workflow and make otology surgeons more independent. Moreover, the cochlear width (B) has a strong correlation to the CDL. Thus, we suggest using the combination of A and B to accurately estimate the CDL rather than using only one. LIMITATIONS: Single center and small sample size. CONFLICT OF INTEREST: None. No relationship with manufacturers.

Age as a Factor of Growth in Mastoid Thickness and Skull Width.

OBJECTIVES: To understand the growth rate of mastoid thickness and skull width associated with the age for both normal and malformed inner-ear anatomy groups. Also, to determine if there is any mathematical relation between cochlear size as measured by the "A" value against the age, mastoid thickness, and skull width. METHODS: Ninety-two computed tomography image datasets of human temporal bone were made available that contained normal (n = 44) and malformed inner-ear (n = 48) anatomies. The age of the subjects ranged from 6 months to 79 years. CE marked OTOPLAN preplanning otology software was used to load the patient's preoperative images for making all the measurements including mastoid thickness, skull width, and the cochlear size as measured by the "A" value. Mastoid thickness was measured both in axial and coronal planes starting from the cochlear entrance to the skull surface, with the line in plane with the basal turn of the cochlea. Skull width was measured from side to side in both axial and coronal planes from the image slice that gave the highest width. The cochlear size in terms of basal turn diameter "A" was measured from "Cochlear View" in the oblique coronal plane. RESULTS: Mastoid thickness and skull width increased with age in a logarithmic manner. The mastoid thickness increased from a minimum of 17 mm to around 34 mm and the skull width increased from 105 mm to around 146 mm as the age increased from 6 months to 20 years. At the age of around 20, both the mastoid thickness and skull width reached the plateau and thereafter with a very little growth. The skull width was linearly correlated with the mastoid thickness conveying the fact that bigger the head size is, thicker will be the mastoid. The size of the cochlea as measured by the "A" value did not have any meaningful correlation with the age, mastoid thickness, and skull width. This conveys the message that the cochlear size is independent of the overall size of head and the age of patient. CONCLUSIONS: Mastoid thickness and skull width increased with age, while the cochlear size was independent of age, mastoid thickness, and the size of the skull.

Value of Routine Magnetic Resonance Imaging for the Preoperative Assessment of Cochlear Implant Candidates.

Background The selection of an appropriate imaging technique for assessment before cochlear implantation is critical for precise diagnosis and management. While magnetic resonance imaging (MRI) is used for the diagnosis of several conditions, such as labyrinthitis ossificans, cochlear nerve deficiency, and neoplasms, high-resolution computed tomography (HRCT) provides excellent details of the temporal bone. However, it remains unclear whether routine MRI provides any additional benefits over HRCT. Objectives To assess the added value of MRI as a screening tool for temporal bone abnormalities in cochlear implant candidates through comparisons of its findings with those of HRCT. Materials and method It is a retrospective analysis of preoperative HRCT and MR images in a tertiary referral center. A total of 308 patients who underwent MRI and HRCT examinations before cochlear implantation between 2013 and 2015 were included. Preoperative HRCT and MR images were screened for temporal bone abnormalities by a senior neurotologist and a neuroradiologist. Results HRCT detected inner ear deformities in 51 of the 308 (16.6%) subjects, whereas MRI revealed abnormalities in only 18 (5.8%) of subjects. HRCT detected the same inner abnormalities in 16 of the 18 (88.9%) subjects diagnosed by MRI, whereas it showed normal results for the remaining two subjects. MRI detected cochlear nerve aplasia/hypoplasia in 13 subjects, 11 of whom had associated inner ear deformities that were detected by HRCT. The MR images of nine subjects showed cochlear fibrosis, which was confirmed by HRCT in all nine subjects. Conclusion In this study, MRI did not exhibit significant additional benefits over HRCT, and its routine use for the preoperative assessment of CI candidates was not justified. However, MRI is warranted for subjects at an increased risk of cochlear nerve aplasia due to an inner ear deformity or a narrow internal auditory canal. The establishment of criteria that facilitate the performance of MRI only when absolutely needed will reduce healthcare costs, prevent unnecessary exposure to the risks associated with general anesthesia, and shorten delays before cochlear implantation.

Trans-aditus approach: an alternative technique for cochlear implantation.

The objective of this study was to report our preliminary experience with an alternative technique for cochlear implantation. Twenty patients underwent cochlear implantation via a trans-aditus ad antrum approach to the round window. The main steps involved in the surgical procedure are cortical mastoidectomy, elevation of tympanomeatal flap, incudostapedial joint dislocation, incus removal, preparation of a bed for the implant, cochleostomy via the external auditory canal, and finally insertion of the electrode into the cochlea via the aditus. Twenty-five implants were performed on 20 patients, 18 children (mean age of 3.2 years) and 2 adults. Twelve patients were males and eight were females. All the children were pre-lingual while the adults were post-lingual. Nucleus freedom cochlear implant system (Cochlear, Lane Cover, NSW, Australia) was used in four patients and a cochlear Nucleus 5 was used in six patients. A Med-el SONATA implant (MED-EL, Innsbruck, Austria) was used in 15 patients. The minimum follow-up was 5 months. Here, we describe a new alternative technique for cochlear implantation and report our preliminary results. The procedure has advantages over the existing techniques and avoids the potential complications of posterior tympanotomy, transcanal, and transmeatal techniques.

Conservative management of acoustic neuroma.

AIM OF STUDY: To identify those patients with vestibular schwannoma (acoustic neuroma) in whom treatment becomes necessary. METHOD: Retrospective chart review. RESULT: A total of 205 patients with small tumors were followed for a mean of 40.8 months. The longest follow-up was 180 months. One hundred and ninety-seven patients had a follow-up of more than 12 months. Eight patients with a follow-up of less than 12 months were excluded from the study. In 136 patients (66.3%) the tumor did not grow. Forty-seven patients (23.9%) showed some evidence of slow growth. Eight of 197 patients (4%) had rapid growth and 6 patients (3%) had radiological evidence of tumor regression. Fifteen patients came to surgery. Five of these showed rapid growth, four developed ataxia in whom tumor growth was slow, three had ataxia without tumor growth, two patients developed brainstem compression, and one patient elected to proceed to surgery, although there were no tumor growth or symptoms. CONCLUSION: Few patients with small tumors will come to surgery in the short term. Perhaps the majority of patients with such small tumors will not need surgery. Long-term follow-up studies of 20 years or more are required to be come more confident about the natural history of these tumors. This study continues.