The perceived angle of the round window affects electrode insertion trauma in round window insertion - an anatomical...

Area of Science:

• Otolaryngology
• Neurosurgery
• Biomedical Engineering

Background:

• Cochlear implantation aims to restore hearing but can cause trauma.
• Minimizing electrode insertion trauma is crucial for patient outcomes.
• Round window (RW) insertion is explored as a less traumatic approach.

Purpose of the Study:

• To systematically evaluate the potential for reducing electrode insertion trauma using the round window (RW) approach.
• To analyze surgical vectors and their impact on insertion trauma.

Main Methods:

• Fifteen temporal bones were used with a 0.5 mm electrode analog.
• Computerized morphometric software analyzed the point of first contact and RW dimensions.
• Insertions were classified as 'traumatic' or 'less traumatic' based on contact point.

Main Results:

• Less traumatic insertion was achieved in 13 out of 15 cases (86.6%).
• The mean RW angle in less traumatic insertions was 137°, compared to 147° in traumatic insertions.
• The difference in RW angles between traumatic and less traumatic groups was statistically significant.

Conclusions:

• Round window (RW) insertion of cochlear implants can be performed with significantly less trauma in selected patients.
• This technique is a valid option, particularly when hearing preservation is a primary goal.
• Surgical modification, including drilling overhangs, is frequently required for optimal RW insertion.