The Alexandria Cochlear Implant Program: A Multisystem Program (1983–2001)

Abstract

Objective: This study reviews 51 cases of cochlear implantation done over a period of 18 years (1983–2001) in Alexandria, Egypt. Study Design: Retrospective case review on patients implanted in the period 1983–2001. Setting: Tertiary referral medical center, Alexandria University Hospitals. Patients: The study group consisted of 51 profoundly deaf patients, 24 adults and 27 children. Intervention: Five types of cochlear implants were used. Three types were short, single-electrode implants: 3M-House (n = 5), Med-El (n = 6) and All-Hear (n = 24). Two types were long, multiple-electrode implants: Nucleus-22 (n = 14), and Combi-40 (n = 2). Main Outcome Measures: Preoperative air conduction thresholds and speech perception tests with and without hearing aids, postoperative aided thresholds and speech perception tests repeated at 3, 6 and 12 months after implantation, then semiannually. Results: Although marked individual differences were seen in the performance of the different implants, both short and long electrode implants provided almost similar results for sound field warble tone thresholds, and patient’s satisfaction with sound alertness. The long, multiple-electrode implants provided better speech understanding than single-electrode implants, but the difference was not statistically significant due to the small number of cases. The new generation of short electrode implants (All-Hear) provided better scores of speech understanding than the older generations (3M-House and Med-El). Retrofitting an All-Hear speech processor on 1 patient with 3M-House electrode led to improvement in speech understanding scores. Preservation of residual hearing in the implanted cases was much higher with short than with long electrode implants. Functional failure of speech processor, microphone and connecting wires was higher among long electrode implants. Conclusions: We recommend long electrode implants for postlingual profoundly deaf adults who do not benefit from conventional hearing aids, who are mentally sane, whose ears are radiologically free and are committed to a long-term follow-up program. Short electrode implants are indicated particularly when preservation of hearing remnants is essential, when there is a need for a cost-effective, easily programmable and maintenance-free cochlear implant, for the fitting of prelingual adults, and in implanting some difficult cases like Mondini dysplasia and labyrinthitis ossificans.