Quantifying Soft-Surgery in Cochlear Implantation: Multimodal Data From 30 International Specialists

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Surgical Science

Background:

• Cochlear implantation (CI) is a complex procedure requiring precise surgical technique.
• Minimizing intracochlear mechanical stress is vital for preserving residual hearing and optimizing auditory outcomes.
• Variability in surgical behavior among specialists may lead to inconsistent outcomes.

Purpose of the Study:

• To objectively quantify the influence of surgical behavior on intracochlear mechanical stress during CI.
• To identify specific surgical actions associated with increased mechanical stress.
• To correlate surgical experience and self-assessment with objective measures of surgical performance.

Main Methods:

• Thirty specialist CI surgeons performed bilateral insertions in artificial temporal bone models.
• Objective multi-sensor data (force, pressure, kinematics) were captured during insertions.
• Six trauma-related metrics were combined into a composite soft-surgery score; nonparametric statistics were used for analysis.

Main Results:

• Significant variability in surgical performance and intracochlear stress was observed.
• Surgeons with less than 50 lifetime insertions demonstrated poorer performance.
• Excessively slow insertions, frequent electrode regrasping, and post-insertion handling increased mechanical stress.

Conclusions:

• Surgical behavior is a critical determinant of intracochlear mechanical stress during CI.
• Steady, uninterrupted insertion at moderate speeds and avoidance of regrasping reduce mechanical load.
• Structured training with quantitative feedback is essential due to unreliable self-assessment in refining surgical technique.