Introduction: Neuroendoscopy is technically challenging due to the limited accuracy, dexterity, and reachability of the instruments. Surgical robots offer a potential solution, however the unique and critically constrained workspace within the ventricle system poses major challenges. We have developed a novel concentric tube endoscopic robot - used as a suction/irrigation tool - as a solution and implemented it on a validated silicone hydrocephalic brain phantom.
Methods: Telescoping, pre-curved, superelastic nitinol tubes, 2.5 mm in diameter and driven by 1 stepper motor and 2 linear actuators, were controlled via a Novint Falcon master system. An analysis of the robot’s reachable workspace and positioning accuracy was performed. The robot was positioned within a silicone phantom ventricle system and its dexterity and reachability was evaluated. Endoscopic third ventriculostomies (ETV) were performed using the robot in an analogous fashion to standard endoscopic techniques.
Results: The reachable workspace was an inverted cone with base diameter 18.4 mm and height 40 mm. The positioning accuracy was 0.99 mm. The observed accuracy, dexterity and reachability of the robotic tools exceeded that of standard endoscopic instruments, however at reduced velocity. The robot was able to successfully perform an ETV in the phantom brain without apparent "injury" to critical structures including the basilar artery.
Conclusions: We have successfully developed a miniaturized, teleoperated, concentric tube robot for intraventricular neuroendoscopy with improved accuracy, dexterity, and reachability. An ETV in a brain phantom was successfully performed. Future work will focus on improvements in positioning accuracy, system responsiveness, and reachability and additional phantom and animal testing.
Patient Care: It is expected that several advantages will be realized with this robotic tool including: 1) improved miniaturization and decreased OR footprint, 2) increased dexterity, reachability, and accuracy over standard neuroendoscopic tools, 3) improved visualization and localization, 4) the use of a patient- and task-specific design and motion planning algorithm, and 5) the use of interchangeable end-effector instruments. As a result, this tool has the potential to broaden the scope of neuroendoscopy to more complex and comprehensive procedures that more effectively reduce the morbidity and mortality of intraventricular disease and hydrocephalus. In addition, this device has the potential to minimize treatment-related complications by using its shape-shifting capabilities to navigate around critical neuroanatomical structures and within the small confines of the ventricles. Lastly, by reducing the physical and mental workload placed upon the neurosurgeon, this device may be able to reduce fatigue and error and consequently reduce operating room times, hospital stays, and healthcare costs.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the limitations of standard neuroendoscopic tools.
2) Understand the design and control of a novel concentric tube endoscopic robot.
3) Identify the capabilities and performance advantages of using concentric tube robots in intraventricular neuroendoscopic procedures.