Minimally invasive scoliosis treatment with a Ho:YAG laser

摘要

Today most surgical treatment of spinal deformations is concetrated on invasive mechanical techniques with long operation times and major effects on the patient's mobility. The proposed minimally invasive technique using laser light for tissue abaltion offers a possibility of gentle scoliosis treatment. It is thought that an early removal of the epiphysial growth zone on the convex side over several vertebrae results in a straightening of the spine. In a first evaluation, four different laser systems including argon ion, Nd:YAG (Q-switched), Nd:YAG (cw), and Ho:YAG laser were compared with respect to thermal damage to adjacent tissue, ablation rates, efficiency and laser handling. For in-vivo investigation, fresh lamb spine was used. Comparison showed that the Ho:YAG laser is the most appropriate laser for the given goal, providing efficient photoablation with moderate thermal effects on the adjacent tissue. In a second step the proposed minimally invasive operation technique was performed in in-vivo experiments on young foxhounds using 3D-thoracoscopic operation techniques. During these operations temperature mapping was done as MRI was performed on the spine. First results show a positive effect of scoliotic growth in two cases. Beeing able to produce a scoliosis by hemieiphysiodesis on the vertebra, it is thought that this technique is successful for a straightening of the spine on pateitns with scoliosis.