gms | German Medical Science

Objective: To prove the safety and efficacy of a minimally invasive frameless stereotactic biopsy technique.

Methods: Stereotactic biopsy techniques are widely used to procure tissue samples for pathological analysis of brain tumours. The frame-based surgical technique can be a time-consuming procedure with the patient going from the ward or surgery ward to the radiology department and back to the surgery ward. Since 1986, the era of frameless image guided neurosurgery was launched and in recent years, frameless biopsy techniques have gained interest as a minimal invasive and fast technique to acquire material for anatomic pathological diagnosis. Between September 2000 and December 2007, a total of 535 patients with intracranial tumoural pathologies were biopsied with a frameless technique for which a custom made flexible arm was developed in cooperation with Philips. Instead of a burr hole, a small opening is made in the skull using a 3.2mm diameter burr, so that there is no need for shaving nor incisioning.

Results: A diagnostic yield of 96.8% was found in the patients biopsied, while 3.2% of the patients had a non-diagnostic tissue sample. A total of 17 patients had a negative pathological result, meaning they had to undergo a second biopsy. Of these patients, 11 were re-operated again with the frameless technique, while 6 had a frame-based biopsy. In each group, 1 ‘redo’ operation revealed no diagnosis again. Operating skin-to-skin time ranged from 136 to 18 minutes, with a mean of 30,76 minutes. 2 patients had a clinically significant haemorrhage. Death occurred in 2 patients.

Conclusions: The authors show a diagnostic yield of 96.8%, with a low complication and mortality rate. It proves to be an accurate and safe technique, which reduces operating time and stress for the patient. It combines flexibility, simplicity and precise access to the brain.