The value of intraoperative smear examination of stereotaxic brain specimens

This study was conducted to evaluate the importance of intraoperative smear examinations for the final diagnosis of intracerebral stereotaxic procedures. 125 consecutive patients with suspect intracerebral lesions underwent stereotaxic frame-based biopsies after acquisition of computer tomographic and magnetic resonance images. After secondary image processing, including multiplanar visualization of the target region and target definition, a serial biopsy was realized using an aspiration Sedan needle. Biopsy taking was repeated as long as pathological tissue samples were obtained according to the visual impression of the neurosurgeon (group I) or to the first neuropathological result of a smear examination (group II). Retrospective analysis of all cases showed that intraoperative microscopic diagnostics could improve the conditions for a definitive neuropathological diagnosis from 91.8% (56/61 patients, group I) to 96.9% (62/64 patients, group II) (t>0.05). The number of biopsy specimens and the rate of CT-detectable small bleedings differed slightly between both groups and were higher in group II. The duration of surgery and anaesthesia as well as the final neurological outcomes were comparable in both groups. In conclusion, intraoperative smear examination as a kind of "bedside" diagnostics confers a better diagnostic safety and improves the reliability of this minimal invasive manoeuvre.