Nucleus N5 CI500 series implant recall: hard failure rate at a major Cochlear implantation center

Abstract

Objectives/hypothesis: To compare the cumulative failure percentage of the Cochlear Nucleus N5 CI500 series implant observed, both before and after the voluntary recall of unimplanted devices, to that of the Cochlear Nucleus Freedom CI24RE series implant.

Study design: Retrospective review of 411 patients implanted with either the Nucleus Freedom or the Nucleus N5 device.

Methods: Cochlear implantation was performed in standard fashion. A database was created by combining information obtained from operative case logs, an integrated clinical electronic medical records system, and an external database of devices maintained by Cochlear Corporation.

Results: Of the 289 implants of the Nucleus Freedom CI24RE series device at this institution, the cumulative failure percentage was 0%. There were 122 implants of the Nucleus N5 CI500 series device, yielding a 9.8% cumulative failure percent; 82 were manufactured before the voluntary recall and 40 were produced afterward. The 82 implants manufactured before the recall had two associated failures, while the 40 produced afterward had 10 failures.

Conclusions: It is possible that the cumulative failure percentage (CFP) of the Cochlear Nucleus N5 CI500 series implant is not fully defined. While the CFP of the Nucleus Freedom CI24RE series implant at this institution was 0%, it was 9.8% for the Nucleus N5. The CFP of Nucleus N5 devices manufactured before the voluntary recall was 2.4%, while the CFP afterward was 25.0%-nearly 6-fold higher than the company-published value of 4.2% for all Nucleus N5 implants registered globally.

Keywords: CI24RE; CI512; Cochlear implant; Nucleus Freedom; Nucleus N5; cumulative failure percentage; diode; hard failure; hermetic seal; hermeticity; microcrack; recall.