Unilateral auditory performance before and after bilateral sequential cochlear implantation

Objective: The relationship between unilateral preimplantation and postimplantation auditory performance in patients undergoing sequential cochlear implantation (SCI) has not been clearly defined. A greater understanding of this relationship could affect preoperative counseling to patients regarding choice of initial side to implant. Study Design: Retrospective case series. Setting: Tertiary otologic practice. Patients: Adult/pediatric SCI recipients. Outcome Measures: Unilateral auditory performance preimplantation and postimplantation was assessed. To compare interaural preimplantation performance, we defined a "better-hearing ear" as better pure tone average or speech awareness/reception threshold by at least 10 dB or open/closed-set speech perception score at least 10 percentage points higher. Results: Ninety patients underwent SCI from 1997 to 2011; 34 children and 22 adults with at least 6 months of bilateral implant use underwent further analysis. Preoperatively, the first-implanted ear was better hearing in 6 cases, poorer hearing in 15 cases, and equal hearing in 35 individuals. The proportion of SCI recipients exhibiting better long-term performance of the first-implanted ear was not significantly different from the proportion exhibiting equal or better performance of the second-implanted ear (p = 0.79, χ²), irrespective of preoperative hearing status. The first-implanted ear exhibited better closed/open-set speech perception scores in 41% (9/22) adult and 59% (20/34) pediatric patients at a mean most recent test point of 25 and 39 months, respectively. Conclusion: Preimplantation unilateral hearing status was not found to influence relative interaural performance differences after SCI. This finding highlights the relative unimportance of preoperative audiometry and speech recognition scores for guiding clinical decisions regarding implant ear selection.