Meningitis and a safe dexamethasone-eluting intracochlear electrode array

AbstractObjectivesTo evaluate the potential risk of pneumococcal meningitis associated with the use of a dexamethasone-eluting intracochlear electrode array as compared with a control array.MethodsIn two phases, adult Hooded–Wistar rats were implanted via the middle ear with an intracochlear array and were inoculated with Streptococcus pneumoniae 5 days post-surgery. Phase I created a dosing curve by implanting five groups (n = 6) with a control array, then inoculating 5 days later with different numbers of S. pneumoniae: 0 CFU, 103 CFU, 104 CFU, 104 CFU repeated, or 105 CFU (colony forming units). A target infection rate of 20% was aimed for and 104 CFU was the closest to this target with 33% infection rate. In phase II, we implanted two groups (n = 10), one with a dexamethasone-eluting array, the other a control array, and both groups were inoculated with 104 CFU of S. pneumoniae 5 days post-surgery.ResultsThe dexamethasone-eluting array group had a 40% infection rate; the control array group had a 60% ...