[Laser ablation of the nucleus pulposus: optical properties of degenerated intervertebral disk tissue in the wavelength range 200 to 2200 nm].

Percutaneous ablation of degenerative disk material by laser has been introduced recently as an alternative to enzymatic or mechanical discectomy. The optical properties of degenerative disk material were evaluated in the range from 200 to 2200 nm, which includes most of the laser wavelengths used for medical purposes. Remittance rate was determined in 16 post-mortem disks using a spectrophotometric unit and rate of absorption and scatter were calculated. High rates of diffuse remittance were found for classical laser wavelengths such as the argon or the Nd:YAG II laser indicating only low rates of absorption. In contrast, much higher rates of absorption were determined for excimer or mid-infrared lasers as well as for the Nd:YAG I (1320 nm), which appear more appropriate for laser discectomy than the Nd:YAG (1064 nm) laser.