[Intracochlear electrode position: evaluation after deep insertion using cone beam computed tomography]

Area of Science:

• Otolaryngology
• Neurosurgery
• Radiology

Background:

• Cochlear implantation (CI) is increasingly common, necessitating accurate postoperative assessment of electrode placement for quality control.
• Radiological verification is crucial for ensuring optimal CI outcomes and patient safety.

Purpose of the Study:

• To evaluate the intracochlear position of deep-inserted electrodes using cone beam computed tomography (CBCT).
• To assess the reliability of CBCT in determining electrode array location within the cochlea.

Main Methods:

• Retrospective analysis of CBCT data from 22 patients (28 ears) who underwent CI with deep electrode insertion via a round window approach.
• Evaluation of electrode position within the scala vestibuli, scala tympani, or between scalae, and assessment of the certainty of this evaluation.

Main Results:

• CBCT provided certain or relatively certain evaluation of electrode position in the basal turn of the cochlea for all analyzed ears.
• The electrode array was accurately placed in the scala tympani in 93% of cases in the basal turn.
• Evaluation of electrode position in the apical cochlear turns was only possible with relative certainty in 32% of cases, with malpositions noted in 3.5%.

Conclusions:

• CBCT is effective for verifying cochlear implant electrode position in the basal turn.
• Current CBCT technology has limitations in precisely determining electrode placement in the medial and apical cochlear regions for deep insertions.
• The round window approach facilitates reliable implantation of electrodes into the scala tympani.