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Dynamic Behavior and Insertional Forces of a Precurved Electrode Using the Pull-Back Technique in a Fresh
Miriam R Smetak1, Katherine E Riojas2, Noah Whittenbarger1
1Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center.
Summary
The pull-back technique safely improves cochlear implant electrode array perimodiolar positioning. This method enhances electrode array placement without increasing insertion forces, benefiting hearing outcomes.
Area of Science:
- Otolaryngology
- Neurosurgery
- Biomedical Engineering
Background:
- Precurved electrode arrays (EAs) offer improved cochlear implant (CI) outcomes.
- Perimodiolar positioning is key for CI efficacy.
- The pull-back technique's benefit for perimodiolar positioning and insertion forces is not well-established.
Purpose of the Study:
- Evaluate the pull-back technique's utility in enhancing perimodiolar positioning of precurved CI EAs.
- Measure insertion force profiles during the pull-back technique.
- Observe dynamic EA behavior during insertion.
Main Methods:
- Robotic insertion of EAs into 15 cadaveric temporal bones.
- Simultaneous measurement of insertion forces and video recording.
- CT scans for calculating angular depth, mean perimodiolar distance (Mavg), and cochlear duct length.
Main Results:
- Overinsertion did not significantly increase peak insertion forces compared to standard insertion.
- 40% of specimens showed visibly improved perimodiolar positioning post-pull-back.
- Mavg significantly improved after the pull-back technique (0.34 ± 0.07 mm) versus standard insertion (0.41 ± 0.10 mm; p < 0.01).
Conclusions:
- The pull-back technique is safe, not increasing insertion forces.
- This technique significantly improves perimodiolar positioning, visually and quantitatively.
- Improved positioning is independent of cochlear size.
