A HOLLOW SAPPHIRE WAVE-GUIDE FOR STEREOTAXIC INTRAVENTRICULAR CO2-LASER NEUROSURGERY - A RAT MODEL

A hollow sapphire waveguide was used for stereotactic delivery of CO2 laser radiation through the cerebro-spinal fluid to the ventricular surface of rat brains. The tissue was irradiated with single pulses (spot size similar to 0.5 mm) ranging from 0.125 to 0.5 s in duration and from 1.68 to 5.2 W in power. The radius, depth and variation in histological appearance of the lesions were measured as a function of energy density, and the repair response was evaluated by observing changes in the laser-induced lesions from 1 to 28 days post-injury. A lack of charring and limited size of the lesions were noted, and the lesions were repaired in a normal manner over the course of observation. Our results demonstrate that hollow sapphire waveguides are both safe and effective for the transmission of CO2 laser light for intraventricular neurosurgical applications.