Frameless navigated biopsy with the BrainLAB® VarioGuide system: a technical note.

Objective: Implementation of a new neuronavigation system in the department included the opportunity to change the brain biopsy procedures from a frame-based system to a frameless system--the BrainLAB® VarioGuide. We report our first 20 consecutive procedures within 2 years, analyzing the effectiveness of this new tool.

Patients, Materials, And Methods: 15 men and 5 women with various intracerebral lesions were biopsied. Their average age was 62 years (range, 41-83 years). Preoperative planning was performed using computed tomography (CT) or magnetic resonance imaging (MRI) data provided by a radiological picture archiving and communication system (PACS) sent to the planning station. Planning was based on either MRI or CT in 14 and 4 cases, respectively, and a combination of both in 2 cases.

Results: The lesions had a mean maximal diameter of 42.97 mm (range, 5.8-109.8 mm). 19 lesions were supratentorial, 1 of those intraventricular, and 1 lesion was infratentorial, within the cerebellar peduncle and brainstem. During surgery, the samples were sent to neuropathological examination, and the procedure was completed after confirmation that pathological tissue was obtained. In 18 of 20 cases, definitive pathological tissue was harvested. Histopathology confirmed 8 glioblastomas, 1 oligoastrocytoma, 4 anaplastic astrocytomas, 1 astrocytoma, and 2 primary central nervous system lymphomas, as well as 1 encephalitis and 1 necrotic tissue of unknown origin. In 3 cases, including the case of necrotic tissue, there was no final diagnosis possible. Referencing the BrainLAB® navigation system and software-wizard guided sterile adjustment of the VarioGuide arm over the entry point took 5 to 10 minutes. The mean operation time was 49 minutes (range, 24-69 minutes) including the time until first neuropathological examination was completed. No adverse events occurred during or after the operation.