A systematic review of electrode array scalar dislocation after cochlear implant surgery

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neurosurgery

Background:

• Scalar dislocation (SD) is a potential complication following cochlear implant surgery.
• Understanding SD rates associated with different electrode array designs and manufacturers is crucial for optimizing surgical outcomes and patient safety.

Purpose of the Study:

• To systematically review and quantify the incidence of scalar dislocation (SD) after cochlear implant surgery.
• To compare SD rates between lateral wall (LW) and pre-formed (PF) electrode array types.
• To analyze SD rates across three different cochlear implant manufacturers.

Main Methods:

• Systematic literature search of databases for relevant studies published between August 2014 and December 2023.
• Quantitative synthesis of data from 66 publications, encompassing 4,729 cochlear implantations.
• Statistical analysis to compare SD rates based on array type and manufacturer.

Main Results:

• Overall scalar dislocation (SD) rate was 19.5% (923/4,729 implantations).
• Lateral wall (LW) arrays had a significantly lower SD rate (8.1%) compared to pre-formed (PF) arrays (25.0%).
• MED-EL arrays exhibited the lowest SD rate (6.4%), significantly lower than Manufacturer A (23.2%) and Manufacturer B (21.3%) arrays. LW arrays were associated with lower SD rates than PF arrays within Manufacturer A and B.

Conclusions:

• Cochlear implant electrode array type and manufacturer significantly influence scalar dislocation (SD) rates.
• Lateral wall (LW) arrays demonstrate a lower incidence of SD compared to pre-formed (PF) arrays.
• MED-EL cochlear implant arrays show the lowest SD rates among the manufacturers studied.