Objective: To evaluate the utility of frameless stereotaxy in minimally invasive neurosurgery.
Methods: A retrospective review of 200 cases of craniotomy and laminotomy procedures using frameless stereotaxy systems performed from December 1999 to June 2001 was made, including 43 cases of AVM, 39 cases of aneurysm, 30 of meningioma, 27 of cavenous malformation, 19 of glioma, 8 of neuronoma, 5 of pituitary tumor, 4 of angioreticuloma, 3 of metastatic tumor, 14 cases of craniotomy with other causes, and 8 spinal tumors. Data of MRI or CT, conducted one day before the operation, were entered into the neuronavigation systems and analyzed. A 3-D simulation of model of cranium or spinal cord was reestablished and operative approach was designed. During the operation, the lesion can be located accurately.
Results: The lesions and important anatomical structures were accurately located and the location errors of lesions were within the limit of 2 mm. Postoperative neurological complications occurred only in 10 cases (5.0%). No operative death occurred.
Conclusion: The frameless stereotaxy is very helpful for brain and spinal surgery, especially for the cases with lesions located deep in the brain. Its accuracy of location is very important in protecting normal brain tissues. The neuronavigation systems are changing the pattern of traditional neurosurgical procedures and serve as the guarantee of minimally invasive neurosurgery.