Chronic Pseudomonas infections of cochlear implants

Objective: To discuss chronic, refractory Pseudomonas infections of cochlear implants and their management. Design: Retrospective case series. Setting: Two university-based cochlear implant programs. Patients: Twenty-eight-year-old (Case 1) and 4-year-old (Case 2), different devices. Interventions: Medical and surgical management. Main Outcome Measures: Clinical course. Results: Both patients had delayed presentations, 4 months and 3 years postimplantation, respectively, with fluctuating scalp edema and pain resistant to multiple courses of oral antibiotics. Infections began as localized granulation and progressed to complete encasement of both devices with rubbery, poorly vascularized tissue. In each case, two different strains of multiresistant Pseudomonas aeruginosa were cultured. Infections progressed despite local debridement and targeted antipseudomonal antibiotic coverage, and sensitive organisms continued to appear in cultures of refractory granulation tissue. Both patients underwent partial explantation, with the electrode array left in the cochlea, then received 2 to 3 more months of further medical therapy and observation and then were reimplanted successfully with new devices. Both have shown excellent performance and no sign of recurrent infection. Conclusions: Infections of cochlear implants are uncommon, and cases of successful conservative management without device explantation have been reported. However, our experience and the implanted device literature suggest that chronic Pseudomonas infections may represent a distinct clinical entity, likely to fail protracted therapy and ultimately require device removal. Fortunately, successful reimplantation is possible.