EFFECT OF ND-YAG LASER ON EXPERIMENTAL DISC DEGENERATION .2. HISTOLOGICAL AND MR-IMAGING FINDINGS

The potential advantages of percutaneous procedures over traditional d iscectomy are multiple, but the use of laser energy to ablate disc tis sue appears entirely empirical. To date, no experimental study exists investigating the results of laser on degenerated intervertebral disc. The present study was therefore undertaken to determine the histologi cal and radiological changes induced by neodymium-yttrium-aluminum-gar net (Nd:YAG) laser on such disc tissue. It was shown that the vaporiza tion of disc tissue was caused by Nd:YAG laser in the early period, bu t this was gradually replaced by cartilaginous fibrous tissue at 60 da ys after laser irradiation as a result of the proliferation of cartila ginous cells and fibrous tissues. Accordingly the magnetic resonance ( MR) imaging index histogram moved to the left in the early period, but it moved to the right again at 60 days after laser irradiation. In vi ew of these data, we conclude that the use of laser in degenerated dis c disease does not represent an effective treatment as an alternative to conventional surgical methods.