Robot-assisted Versus Manual: Intracochlear Forces During and After Cochlear Implant Electrode Insertion Show Benefits of Automation and Electrode Guidance.

Abstract

Hypothesis: Smooth and steady cochlear implant electrode insertions with minimal manual interactions during and after insertion positively impact intracochlear forces.

Background: Inserting the electrode array is a critical step during cochlear implant surgery, as associated trauma can influence hearing outcomes. Automated insertions have shown the potential to reduce trauma while enhancing insertion consistency. This study aims to compare the intracochlear effects of manual and automated insertions, focusing on forces and factors affecting insertion reproducibility.

Methods: In total, 90 implantation experiments into an artificial temporal bone phantom were conducted, consisting of the insertion of the electrode array into the cochlea, its release from the tool and subsequent lead fixation. Three different insertion techniques were compared: manual insertion and automated insertion with and without an additional electrode guide tube. Intracochlear forces were measured along with time-synchronized video recordings during the entire process.

Results: The data confirms that automation significantly reduces maximum forces and force fluctuation. This positive effect is counteracted through manual interactions, such as electrode buckling corrections and lead manipulations in the postinsertion phase. Both induce significant intracochlear force peaks. The use of a guide tube can effectively prevent electrode buckling and associated manual manipulations, resulting in a smoother insertion with higher reproducibility.

Conclusion: Besides confirming the force-reducing effect of automated insertions, we present aspects that should be considered to enhance insertion reproducibility using robotic devices. Since clinical data does not conclusively reflect the advantages of automation observed in lab experiments, reducing manual interactions could improve the clinical transferability of these benefits.