Photoablation of meningiomas and neurinomas by Holmium Yag laser radiation

Cranial rat bone was irradiated by 2.1 microns Holmium Yag laser radiation. Quantitative edge rates were calculated. Histologic sections were investigated by light and electron microscopy. Eighteen 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 0.3-0.5 mm per pulse. Perifocal thermal damage was observed in a zone of 20-90 microns around the lesion. In all human cases tumors could be removed totally without additional neurological deficit. In vivo heat development was measured by an i.r.-camera.