Abstract
The excirner laser has the possibility of being a valuable tool which can precisely ablate a specific location within central nervous (CN) tissue without heat-injury effects. We have examined the morphological changes of excirner laser irradiated injured tissue in the dorsal column of rat spinal cord. Excimer laser (Kr-F: 248nm) irradiation with 10, 20 and 30 mJ energy produced sharp spinal cord transection without edema and axonal destruction around the lesion. At the energy of 50 mJ and 75 mJ laser irradiation the edges of tra.nsected lesion flared over the surface of the spinal cord with loss of glial cells and spliting of myelin sheaths of axons. Transmission and scanning electron microscope revealed that the excimer laser can sharply and uniformly transect the various types of composed elements (i. e., rnielin sheaths, glial cell, meningial cells, and axons), of CN tissue, in situ through out this experiment. No morphplogical abnormalities caused by thermal effects were detected. These results suggested that the excimer laser is a valuable tool for making sharp transections in spinal cord when employing appropriate power setting.
