Use of a Novel Robotic System for Retrosigmoid Internal Auditory Canal Decompression

Introduction: (1) Determine whether a 7 degrees of freedom robotic arm can be useful for retrosigmoid (RS) acoustic neuroma resection; (2) understand the complexities of adapting robotics to skull base surgery.

Methods: In a prospective manner, eight cadaveric temporal bones were used to perform RS internal auditory canal (IAC) decompressions. The procedures were performed under visualization with a microscope. A joystick was used to control the robotic arm; a foot pedal was used to operate the drill. Suction/irrigation was controlled manually. Maximum velocity of the robotic arm was 2 mm/sec.

Results: The RS IAC decompressions were performed in all eight specimens. There were numerous technical difficulties (e.g., burr falling into porus acusticus) with potential for neurovascular injury, mainly related to inadequate stabilization of the temporal bone. Average time to perform decompression: 19.3 minutes (range, 9 to 40 min).

Conclusion: Although skull base surgery, including RS approaches, may eventually be performed by robotic systems, the delicate nature of such an approach, the instruments required, and the limited confines preclude easy adaptation. Benefits of robotics include tremor reduction, audible proximity warnings, and automatic avoidance behaviors. Future developments include an improved handpiece, utilization of mounted cameras, and integration with image-guidance systems.