A 4-year-old child with bilateral profound sensorineural hearing loss and absent otoacoustic emissions is evaluated for cochlear implantation. High-resolution CT of the temporal bone shows bilateral Mondini malformation (incomplete partition type II). Which of the following is the most significant implant-related risk in this patient?
- A Facial nerve injury during electrode insertion
- B Inability to achieve full electrode insertion
- C Electromagnetic interference with the device
- D Perilymphatic gusher during cochleostomy ✓
Explanation
Mondini malformation (incomplete partition type II) is characterized by a dilated vestibule and absent interscalar septum in the apical turns with a deficient modiolus. The deficient modiolus creates a communication between the subarachnoid space and the cochlea via the internal auditory canal, resulting in a perilymphatic gusher during cochleostomy. This is a well-recognized surgical hazard: the surgeon must pack the cochleostomy firmly with tissue immediately. Facial nerve injury and incomplete insertion are risks in all cochlear implants but are not specifically heightened by Mondini malformation.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.