Scala vestibuli cochlear implantation: exploring feasibility and outcomes- a systematic review.

Purpose: While the scala tympani (ST) is usually the preferred site for electrode insertion in cochlear implantation, anatomical variations and cochlear ossification may require scala vestibuli (SV) insertion. This systematic review evaluates the feasibility, techniques, and clinical outcomes of SV insertions compared to ST insertions, focusing on their impact on auditory performance.

Methods: A systematic review was conducted using PRISMA guidelines. Studies on SV cochlear implantation were identified from databases like PubMed and EMBASE. The review included research articles reporting on anatomical feasibility, surgical methods, postoperative outcomes, and complications. Data extraction focused on demographic details, electrode types, insertion depths, and clinical outcomes of SV insertions. A two-stage selection process was applied, and 17 studies with 72 cases were included.

Results: The review covered 72 cases of SV insertions, with patients aged 18 months to 65 years. Bacterial meningitis was the leading cause of hearing loss (28%). Various electrode types were used, with insertion depths ranging from 12 to 31 mm. Approximately 75% of patients showed improved auditory performance. Complications, including vertigo and tinnitus, were reported in 10% of cases, with no significant difference between SV and ST insertions.

Conclusion: SV cochlear implantation is a feasible and effective alternative in cases where ST is inaccessible. Auditory outcomes are comparable to ST insertions, and the technique shows promise in challenging anatomical situations such as cochlear ossification. Further studies are required to optimize surgical approaches and confirm long-term outcomes.