Objectives of our project were to determine the affects of Ho:YAG laser energy on canine intervertebral (IV) discs by thermography, and histology. Multiple IV discs in three cadaveric nonchondrodystrophoid spines were treated with 20 J to 180 J of energy and evaluated by thermography and histology. Histologic evaluation revealed thermal affects at all doses including potential acoustic wave affects, increased eosinophilia, carbonization, and in some cases a large defect due to laser irradiation. Laser affects were confined only to the nucleus pulposus and annulus fibrosus with adjacent structures unaffected. In an acute study, two nonchondrodystrophoid dogs were sacrificed after IV discs were treated with 20 - 180 J of Ho:YAG laser radiation, following an extensive dorsal laminectomy to allow placement of thermoprobes in spinal and spinal cord structures. Heating occurred in only the nucleus pulposus and annulus fibrosus with minimal temperature changes in the adjacent structures including the spinal cord.

Date Published: 7 September 1994
PDF: 7 pages
Proc. SPIE 2128, Laser Surgery: Advanced Characterization, Therapeutics, and Systems IV, (7 September 1994); doi: 10.1117/12.184943

Published in SPIE Proceedings Vol. 2128:
Laser Surgery: Advanced Characterization, Therapeutics, and Systems IV
R. Rox Anderson M.D.; R. Rox Anderson M.D., Editor(s)