Experimentelle untersuchungen zur gewebereduzierenden wirkung and zu morphologischen veränderungen an der leichenbandscheibe durch den holmium- und den neodym-yag-laser

Abstract

We examined 12 human autopsy specimen in order to compare the mass reduction and morphological alterations of the intervertebral disc using an Holmium- and an Neodym-YAG-laser. The mass reduction was represented by the difference between the pre- and postlasing weights, morphological alterations were examinated at different disc sections, evaluating macroscopic changes. The mass reduction of the Neodym-laser was superior with 0,73 g compared 0.35 g achieved with the Holmium-laser at 1000 J. The Holmium-laser caused clearly visible lesions within the disc with a small zone of carbonisation. After Neodym-laser treatment no such lesions could be observed and the area of structural changes involved diffusly the surrounding tissue. The reason for the differences in mass reduction and morphological changes have to be seen in close connection with the different physical effects of the Neodym- (thermal reaction) and the Holmium-laser (photoablation).