MAUDE Adverse Event Report: COCHLEAR LTD NUCLEUS CI522 COCHLEAR IMPLANT WITH SLIM STRAIGHT ELECTRODE; NUCLEUS 24 COCHLEAR IMPLANT SYSTEM

Model Number	CI522
Medical Device Problem Codes	Circuit Failure (1089); Positioning Failure (1158); Output Problem (3005); Therapeutic or Diagnostic Output Failure (3023)
Health Effect - Clinical Code	Pain (1994)
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Device analysis report attached.
Event or Problem Description
Per the clinic, the patient was implanted at a late stage following meningitis, resulting in cochlear closure and incomplete electrode insertion into the cochlea.The clinicians initially elected to monitor the patient to determine whether responses could be obtained from the implanted electrodes over time; however, no response was observed.The clinic also reported that the patient experienced pain/non-auditory sensations and poor device performance since activation.Prior to explantation, device testing confirmed that the device was functioning; however, 15 electrodes were reported as open circuit due to meningitis, while the impedance of the remaining 7 electrodes was within normal limits.Additionally, the patient required an mri of the head region due to ongoing health issues unrelated to the cochlear device.Subsequently, the device was explanted on (b)(6) 2026.As of the date of this report, there are no plans to reimplant the patient with a new device.

• Brand Name: NUCLEUS CI522 COCHLEAR IMPLANT WITH SLIM STRAIGHT ELECTRODE
• Common Device Name: NUCLEUS 24 COCHLEAR IMPLANT SYSTEM
• Manufacturer (Section D): COCHLEAR LTD; 1 university avenue; macquarie university, nsw 2109 ; AS 2109
• Manufacturer (Section G): COCHLEAR LTD; 1 university avenue; macquarie university, nsw 2109 ; AS 2109
• Manufacturer Contact: nur fitrahana mohd yusop ; unit ug-1, vertical podium; no. 8 jalan kerinchi; kuala lumpur, wilayah persekutuan 59200 ; MY 59200
• MDR Report Key: 25237329
• Report Number: 6000034-2026-01827
• Device Sequence Number: 10548293
• Product Code: MCM
• UDI-Device Identifier: 09321502032599
• UDI-Public: (01)09321502032599(11)231115(17)251114
• Combination Product (Y/N): N
• Initial Reporter Country: TU
• PMA/510(K) Number: P970051
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2024
• Device Explanted Year: 2026
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Other
• Type of Report: Initial
• Report Date (Section B): 05/19/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Lay User/Patient
• Device Expiration Date: 11/14/2025
• Device Model Number: CI522
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 04/22/2026
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 04/29/2026
• Initial Report FDA Received Date: 05/20/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 11/15/2023
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Sex: Female