Object. Stereotactic brain biopsy has played an integral role in the diagnosis and management of brain lesions. At most centers, imaging studies following biopsy are rarely performed. The authors prospectively determined the acute hemorrhage rate after stereotactic biopsy by performing immediate postbiopsy intraoperative computerized tomography (CT) scanning. They then analyzed factors that may influence the risk of hemorrhage and the diagnostic accuracy rate.
Methods. Five hundred consecutive patients undergoing stereotactic brain biopsy underwent immediate postbiopsy intraoperative CT scanning. Before surgery, routine preoperative coagulation studies were performed in all patients. All medical charts, laboratory results, preoperative imaging studies, and postoperative imaging studies were reviewed.
In 40 patients (8%) hemorrhage was detected using immediate postbiopsy intraoperative CT scanning. Neurological deficits developed in six patients (1.2%) and one patient (0.2%) died. Symptomatic delayed neurological deficits developed in two patients (0.4%), despite the fact that the initial postbiopsy CT scans in these cases did not show acute hemorrhage. Both patients had large intracerebral hemorrhages that were confirmed at the time of repeated imaging. The results of a multivariate logistic regression analysis of the risk of postbiopsy hemorrhage of any size showed a significant correlation only with the degree to which the platelet count was below 150,000/mm3 (p = 0.006). The results of a multivariate analysis of a hemorrhage measuring greater than 5 mm in diameter also showed a correlation between the risk of hemorrhage and a lesion location in the pineal region (p = 0.0086). The rate at which a nondiagnostic biopsy specimen was obtained increased as the number of biopsy samples increased (p = 0.0073) and in accordance with younger patient age (p = 0.026).
Conclusions. Stereotactic brain biopsy was associated with a low likelihood of postbiopsy hemorrhage. The risk of hemorrhage increased steadily as the platelet count fell below 150,000/mm3. The authors found a small but definable risk of delayed hemorrhage, despite unremarkable findings on an immediate postbiopsy head CT scan. This risk justifies an overnight hospital observation stay for all patients after having undergone stereotactic brain biopsy.