XeCl Excimer Laser Ablation of Rabbit Tibia Bone: Morphology of the Irradiated Site and Self-Limiting Effect

Abstract

The purpose of this work is to investigate the morphological changes of the rabbit tibia bone submitted to osteotomy with XeCl excimer laser. Laser ablation of tissue is a relevant clinical application of high-power lasers. Due to the variety of laser wavelengths and properties of biological targets, the subject has not yet been completely explored. In this study, four tibias were irradiated with six different durations. The applied energy density was 6.7 J/cm(2) per pulse at a 4-Hz repetition rate. The 24 samples had similar and well-defined craters that were free of carbonization. The ablation rates per pulse, at 60-120 seconds, were 3.8 and 1.9 microm at the compact bone and the marrow tissue, respectively. The ablation process ceased after 120 sec, with a 1.6-mm crater depth. In the present study, the laser used showed a self-limiting characteristic, which is a phenomenon that can be of great value in preserving important structures close to the working area, giving a margin of safety to the surgeon, in case of over-irradiation. This self-limiting effect is attributed to liquid filling the cavity by the bleeding and irrigation process.