Longitudinal risk of meningitis after cochlear implantation associated with the use of the positioner

In 2002, the electrode combined with positioner was identified as a significant risk factor for postimplantation meningitis and was voluntarily discontinued by the manufacturer. The ongoing risk of meningitis with passage of time with the positioner remains unknown. The objective of this study was to determine the current risk of meningitis in patients implanted with the positioner. Data regarding the date of implantation, report of meningitis, and presence or absence of risk factors for meningitis (otitis media, inner ear malformation) were obtained from the clinical database maintained by the manufacturer. There were 8,329 devices implanted that may have used a positioner, yielding a cumulative postimplantation time of 74,976 patient-years. The incidence of meningitis during the 3-year spans of 1999 to 2001, 2002 to 2004, 2005 to 2007, and 2008 to 2010 was 33, 40, 11, and 2, respectively; the risk of meningitis in cases per patient-years has decreased significantly from 0.0044 at its peak in 2001 to 0.0011 in 2010. Only a single case of positioner-related meningitis 96 months or longer after implantation has been reported. More than 40% of children had otitis media within 1 week of developing meningitis; less than 10% had a history of meningitis or inner ear malformation. The risk of meningitis with the use of positioner is highest within the first 24 months after implantation and is frequently associated with otitis media. The risk of meningitis more than 96 months after implantation is significantly reduced. Thus, the prophylactic removal of the positioner is not recommended in patients who underwent implantation more than 8 years ago.