Photoablation of meningeomas and neurinomas by holmium YAG laser radiation

Cranial rat bone was irradiated by 2.1 micrometers Holmium YAG laser radiation. Quantitative edge rates were calculated. Histologic sections were investigated by light and electron microscopy. 18 cases of hard fibrous or calcified spinal and cranial meningiomas and neurinomas were operated upon using pulsed laser beam. In rat cranial bone ablation rate ranged between 3 - 5/10 mm per pulse. Perifocal thermal damage was observed in a zone of 20 - 90 micrometers around the lesion. In all human cases tumors could be removed totally without additional neurological deficit. In vivo heat development was measured by an IR-camera.