Navigated, Robot-Driven Laser Craniotomy for SEEG Application Using Optical Coherence Tomography in an Animal Model

Area of Science:

• Neurosurgery
• Medical Robotics
• Biomedical Engineering

Background:

• Introduced a navigated, robot-driven laser beam craniotomy as an alternative to traditional drills for stereoelectroencephalography (SEEG).
• Previous studies focused on ex vivo applications; this study evaluates in vivo feasibility.

Purpose of the Study:

• Acquire data for the laser device's depth control unit.
• Assess the feasibility of cutting bone channels using a robot-driven laser.
• Evaluate dura perforation and potential cortex damage from cold ablation.

Main Methods:

• Planned multiple SEEG bone channel trajectories on pig craniums using surgical planning software and frameless navigation.
• Utilized magnetic resonance angiography to avoid cortical blood vessels.
• Employed two cutting modes: remaining bone thickness (using optical coherence tomography - OCT) and cut through (CTR) mode (using real-time video).

Main Results:

• Successfully executed 19 bone channels using the robot-driven laser system without irregularities.
• Observed minor to severe dura damage with increasing laser beams; no cortex damage occurred.
• Cerebrospinal fluid leakage interfered with OCT-based depth control and visualization, impacting cutting efficiency; video identified bone cut-through in 84%.

Conclusions:

• Inflowing cerebrospinal fluid disrupted OCT signals, limiting the reliability of the current CTR method for depth control.
• Video imaging shows promise for monitoring successful bone cut-through.
• Future strategies may integrate OCT and video imaging for enhanced SEEG bone channel creation.