The 980-nm diode laser for brain surgery: histopathology and recovery period

The 980-nm diode laser has been under investigation for neurosurgery because of a local peak in the absorption spectra of water around this wavelength. This work was carried out to examine the extent of thermal changes and the recovery process of laser-induced brain lesions. In order to study the quality of the lesions, a conventional monopolar electrocoagulation technique was applied comparatively. An in vivo stereotaxic neurosurgical procedure was performed on Wistar rats. Bilateral brain lesions of the same size (2–3 mm diameter) were created with a diode laser and via electrocoagulation. Subjects were sacrificed 0, 2 and 7 days after surgery in order to observe the healing process of the necrotic tissue. The surgical after-effects of both types of lesions were identified through immunohistochemical staining with CD68 macrophage marker and haematoxylin eosin (H&E). CD68 was found to be more efficient than H&E in determining the thermally altered areas. Histological examinations showed that the 980-nm diode laser system has a remarkable ablating ability with minimal thermal damage of nearby tissue.