The risk of haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours--a prospective study

OBJECTIVE: To analyze prospectively the frequency and the risk of symptomatic and asymptomatic haemorrhage after image guided stereotactic biopsy of intra-axial brain tumours. METHODS: The study was conducted within a time frame of 24 months (April 1998-April 2000). 326 patients (150 males, 176 females; mean age 56.8 years) were included and 345 computerized tomography (CT)-guided stereotactic biopsies were performed/supervised by a specialized stereotactic neurosurgeon. A modified Riechert Stereotaxy System and a workstation for multiplanar trajectory planning were used in all patients. Serial biopsies (median, 5 samples) were done with small forceps (diameter 1 mm), smear preparations of the biopsy specimens were intra-operatively examined. Frequency, size, and location of any detectable bleeding were analyzed by post-biopsy CT-scan investigation. For risk estimation, logistic regression analysis was performed. The chi-square statistic was used for comparative analysis of the study results with available data from the literature. RESULTS: A conclusive tissue diagnosis could be achieved in 98%. Overall treatment morbidity was 3.1%. There was no mortality. Haemorrhage related morbidity was 0.9%. Age, Karnofsky score, mass effect of the tumour, tumour histology, tumour location and the number of specimens taken did not have any prognostic significance. The clinically silent bleeding rate was 9.6% and more often seen in patients with high grade gliomas (p = 0.03). Both the silent and non-silent bleeding rate were significantly lower as compared to available prospective data in the literature (p < 0.01). CONCLUSION: Using multiplanar image guided trajectory planning, small biopsy forceps and intra-operative smear preparations the risk of major haemorrhage related morbidity after stereotactic brain tumour biopsy is extremely low (<1%) in experienced hands.