MINIMALLY INVASIVE SURGERY .7. NEUROSURGERY

The introduction of minimally invasive techniques has greatly improved results for intracranial neurosurgery. Stereotaxy and improved imagin g techniques have reduced surgical trauma by allowing surgeons to plan the least damaging route to operative sites and by increasing surgica l precision. Stereotaxy has also allowed brain biopsies to be taken fr om sites such as the brain stem, which were rarely sampled before beca use free hand biopsy was so dangerous. Brain tumours can now be treate d by interstitial radiotherapy-stereotactic insertion of catheters int o the lesion for loading of radioactive iodine or radiosurgery-focusin g of intense beams of radiation on lesions without needing surgical in cisions. Endoscopic neurosurgery can be used to reach cavities such as the ventricular system or cystic tumours. With interventional neurora diology fine catheters can be introduced into most vessels in the cran ium for embolisation or dilatation. The development of augmentative fu nctional neurosurgery means that movement disorders, epilepsy, and int ractable pain can be treated with implanted neurostimulating electrode s. Future developments will probably include frameless stereotaxy, whe n the rigid attachment of stereotactic apparatus to the patient's head can be dispensed with, and at least partial automation of procedures such brain biopsy.