Lateral wall or perimodular? Perimodular!
Reviewed by Hassan Mohammed

In cochlear implant (CI) surgery, both lateral wall (LW) and perimodular (PM) electrodes have their advantages and disadvantages. The PM electrode was shown to have superior hearing outcomes. The disadvantages of the PM electrode, except for tip fold-over, were reduced even more by introducing the slim PM. Authors compared the audiometric outcomes and electrode performance in 32 patients implanted with PM electrode in one ear and a LW in the other ear. The study spanned 20 years and 75% of the patients were implanted with Advanced Bionics (AB) electrodes. The median time interval between implants was 65 months, with PM electrodes placed first in around 70% of subjects. PM electrodes resulted in a significantly better performance on CNC word testing. However, PM electrodes did not offer a significant improvement in battery life or AzBio scores. Authors addressed the limitations of the study, including a small sample size and the grouping of different types of electrodes under one subtype. They concluded that the better outcomes associated with PM electrodes should be considered when counselling patients on cochlear implant selection. This study adds to the available literature supporting the superiority of PM electrodes in terms of speech understanding outcomes and the reduced rates of tip fold-over and electrode translocation to the scala vestibuli.

A Unique Perspective: Intrapatient Comparison of Perimodiolar and Lateral Wall cochlear Implant Electrodes.
Ewer N, Espahbodi M, Durham AR, et al.
OTOL NEUROTOL
2026;47(5):678–83.