Totally implantable active middle-ear implants: a large, single-surgeon cohort.

OBJECTIVES: This study aimed to evaluate hearing outcomes and device safety in a large, single-surgeon experience with the totally implantable active middle-ear implants. METHODS: This was a retrospective case series review of 116 patients with moderate-to-severe sensorineural hearing loss undergoing implantation of active middle-ear implants. RESULTS: Mean baseline unaided pure tone average improved from 57.6 dB before surgery to 34.1 dB post-operatively, signifying a mean gain in pure tone average of 23.5 dB (p = 0.0002). Phonetically balanced maximum word recognition score improved slightly from 70.5 per cent to 75.8 per cent (p = 0.416), and word recognition score at a hearing level of 50 dB values increased substantially from 14.4 per cent to 70.4 per cent (p < 0.0001). Both revision and explant rates were low and dropped with increasing surgeon experience over time. CONCLUSION: This study showed excellent post-operative hearing results with active middle-ear implants with regard to pure tone average and word recognition score at a hearing level of 50 db. Complication rates in this case series were significantly lower with increasing experience of the surgeon. Active middle-ear implants should be considered in appropriate patients with moderate-to-severe sensorineural hearing loss who have struggled with conventional amplification and are good surgical candidates.

Tympanic membrane perforation repair using AlloDerm.

BACKGROUND: Some patients lack quality autologous tissue for tympanic membrane (TM) grafting. AlloDerm (LifeCell Corp, The Woodlands, TX) is a preserved allograft that has been effective in nonotologic applications. OBJECTIVE: The goal of this study was to investigate AlloDerm in the repair of chronic TM perforations. METHODS: Ten adult chinchillas underwent a controlled, 2-stage procedure for creation and repair of bilateral TM perforations. Myringoplasties were performed. The control side (left) was repaired with autologous fascia; AlloDerm was used in all right ears. Grafts were assessed at 3 to 8 weeks. RESULTS: Complete TM perforation closure was noted in 9 of 10 (90%) control ears and 8 of 10 (80%) AlloDerm-treated ears. Fascia and AlloDerm integrated consistently with host tissues. No variables demonstrated statistical significance. CONCLUSIONS: AlloDerm appeared to be an ideal substitute for grafting of the TM. It was equally effective as fascia. Clinical trials in human beings appear warranted. Potential health care savings are discussed.

Central nervous system metabolic activity after cochlear implantation in the feline neonatal model.

OBJECTIVE: To determine the effects of deafening and cochlear implant stimulation on central nervous system (CNS) metabolic activity in the feline neonate model. BACKGROUND: Deafening of fetal animals has been shown to result in acute, profound depression of CNS glucose metabolism, in both auditory structures and the cerebral hemispheres. Preliminary studies have suggested that electrical stimulation of the auditory system may increase central nervous metabolic activity after deafening. The purpose of this study was to investigate this possibility. METHODS: This was a prospective, randomized, blinded, and controlled animal study of 13 random-source newborn kittens. It was set in an animal research facility for otologic disorders. OUTCOME: Deoxyglucose metabolism (assessed with autoradiograph densitometry) of brain cross-sections of normal, deafened, and deafened and cochlear-implanted animals after 6 weeks of auditory stimulation or deprivation. RESULTS: Chronic deafening did not result in a profound reduction in CNS metabolic activity. Cochlear implantation and electrical stimulation did not significantly raise the level of CNS metabolic activity within either auditory pathways or the cerebral hemispheres. CONCLUSIONS: Deafening is not associated with significant chronic reduction in CNS metabolic activity. Other parameters of CNS activity and maturation may be necessary to assess the effects of cochlear implantation and stimulation in animal models.

Otologic injuries caused by airbag deployment.

Airbags are clearly successful at mitigating injury severity during motor vehicle accidents. Deployment unfortunately has introduced new injury-causing mechanisms. A retrospective review of 20 patients who sustained otologic injuries resulting from airbag inflation was conducted. The most common symptoms were hearing loss in 17 (85%) and tinnitus in 17 (85%). Objective hearing loss was documented in 21 of 24 (88%) subjectively affected ears; this included unilateral and bilateral sensorineural, unilateral conductive, and mixed hearing losses. Ten patients (50%) had dysequilibrium. Four subjects (20%) had a tympanic membrane perforation; each required surgical closure. Ear orientation toward the airbag was found to be associated with hearing loss (P = 0.027), aural fullness (P = 0.039), and tympanic membrane perforation (P = 0.0004). A wide variety of airbag-induced otologic injuries occur and may have long-term sequelae. It is important for health care personnel to be aware of these potential problems.

Somatosensory phenomena after multichannel cochlear implantation in prelingually deaf adults.

OBJECTIVES: Central auditory system development in thought to be dependent on normal auditory nerve excitation. Central auditory disorganization may differ between prelingual and postlingual deafness. One possible clinical manifestation of such central auditory disorganization is somatosensory perception with cochlear implant stimulation. The purpose of this study was to investigate the incidence and characteristics of somatosensory phenomena in prelingually and postlingually deafened adult cochlear implant subjects. STUDY DESIGN: The study design was a retrospective analysis. SETTING: The study was performed at an academic tertiary referral center. PATIENTS: This study included 32 adult multichannel cochlear implant recipients. MAIN OUTCOME MEASURES: Subjective patient reporting of sensory perception after cochlear implant stimulation was reviewed. RESULTS: All 10 prelingually deaf subjects noted somatosensory phenomena distant from the implanted ear (e.g., chest, abdomen) on implant stimulation. These sensations resolved gradually for all patients. No subject deafened after the age of 2 years reported somatosensory perceptions. CONCLUSIONS: Somatosensory phenomena experienced by prelingually deafened adults suggest that disorganization of central auditory system pathways is more severe in these individuals. Earlier auditory deprivation appears to produce greater central auditory alterations, and perceptible crossover between somatosensory and auditory signals may be the end result.

Intratympanic gentamicin treatment for Meniere's disease.

OBJECTIVES: The purpose of this study was to evaluate the safety and efficacy of a modified intratympanic gentamicin technique in patients with intractable unilateral or bilateral Meniere's disease. METHODS: A retrospective review of 25 consecutive patients who underwent gentamicin treatment for Meniere's disease was conducted between 1992 and 1996. Two separate delivery systems were used during this study, with the last 13 subjects undergoing placement of the new system (flanged polyethylene tubing). RESULTS: Follow-up averaged 23 months. Absence of vertigo spells was reported in 88%, and substantial control was achieved in 12%. Four of five patients with bilateral disease achieved complete control. Results for the two delivery systems were not significantly different. Absence of ice-water caloric response was seen in 75% (15 of 20) patients. Clinically significant sensorineural hearing loss occurred in 5 (20%) of 25 ears. Nonserviceable hearing developed in only two (8%) patients. CONCLUSIONS: Our results support the previously reported efficacy and relative safety of gentamicin infusion therapy for intractable Meniere's disease. Polyethylene tubing may be more advantageous than T-tube delivery because of anatomic concerns in certain patients.