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 su rface of rat brains. The tissue was irradiated with single pulses (spo t 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 histol ogical appearance of the lesions were measured as a function of energy density, and the repair response was evaluated by observing changes i n the laser-induced lesions from 1 to 28 days post-injury. A lack of c harring and limited size of the lesions were noted, and the lesions we re repaired in a normal manner over the course of observation. Our res ults demonstrate that hollow sapphire waveguides are both safe and eff ective for the transmission of CO2 laser light for intraventricular ne urosurgical applications.