Robot-assisted vs. manual cochlear implant electrode array insertion in four children.

Purpose: Evaluate the feasibility and safety of a robotic electrode insertion in pediatric cochlear implantation and compare the results with manually inserted electrodes in the same subject.

Methods: Retrospective case series review of four children who underwent bilateral cochlear implantation with the same array: on one side, the array was inserted using the robot, while on the other side the array was inserted manually. Behavioural and electrophysiological measures were compared.

Results: The duration of surgery when the robot was adopted was significantly longer than when a manual insertion was performed (161.15 ± 27.59 minutes vs. 122.6 ± 37.71 min, paired t-test: p = 0.029). Moreover, robotic electrode insertion was significantly slower (average insertion speed 0.3 mm/second vs. 0.52 ± 0.17 mm/s, paired t-test: p = 0.0055). On radiologic examination, none of the arrays was misplaced. Impedance, both at activation and at one year of cochlear implant use, was significantly lower on the robotic side in monopolar mode compared to the manual side (mean 9.64 ± 2.41kΩ and 9.97 ± 1.39 kΩ vs. 10.43 ± 2.69 kΩ and 10.94 ± 1.11 kΩ, paired t test, p = 0.0251 and p = 0.0061, respectively). Both the threshold stimulation level and the most comfortable loud stimulation level were significantly lower in the robotic inserted ear compared to the manually inserted ear (mean 108.1 ± 5.98 and 169 ± 4.84 vs. 112.1 ± 7.43 and 172.7 ± 6.83, respectively, paired t test p < 0.0001).

Conclusions: Although we present a small group of cases, our results show how robot-based array insertion is associated with lower impedance and stimulation levels compared to manually inserted arrays.