Frameless stereotactic drainage of intracranial abscesses.

Our preliminary experience is presented in the use of the Aachen Computer-Assisted Surgery device for frameless stereotactic puncture and drainage of intracranial abscesses through a 2.1-mm twist-drill hole. The apparatus and technique are described, along with the results of its use in 2 patients. Intraoperatively the semiactive system presents a schematic display of the drainage probe projected into a 3D model of the situs on the monitor screen corresponding to the instrument's position. As the surgeon directs the probe into the abscess the corresponding section is displayed. Thereby drainage is easily achieved under visual control.