A New Procedure for Frameless Computer Navigated Stereotaxy

Summary¶ Objective. Stereotactic procedures using frame-based systems have become well established in neurosurgery. Later, stereotactic computers have provided the neurosurgeon with a broader range of applications. A new, frameless stereotactic guide which utilizes the navigational abilities of a computer has been developed. This clinical study evaluates the accuracy and safety of the system when applied for puncture of tumours and abscesses in the cerebrum. Methods. Using a frameless setup 36 patients were operated on for a total of 39 intracranial processes over a period of two years. Three patients were operated on twice. Computer data, time of surgery, anesthesia, complications, tumour localization and tissue examinations were recorded. Results. Biopsies were obtained from all lobes of the cerebrum and a diagnosis established in all cases except two. Mean age and total range was 52 years and 15–82 years, respectively. Median time of surgery was approximately 60 minutes including positioning of the patient and the registration process on the stereotactic computer. Local anesthesia was used for 25 operations and general anesthesia for 14 operations. There was one postoperative abscess formation in a previously immunosupressed patient and a per-operative epileptic seizure caused by electrocoagulation of the dura in a second patient. Conclusions. Based on this clinical study a new procedure for obtaining stereotactic biopsies of intracranial processes is introduced. All tumours were successfully reached with two cases of complications.