Tumor surgery under local anesthesia

Resection, or even biopsy, of an intraaxial mass lesion in close relation to eloquent cortex carries a major risk for neurologic deficit. In such lesions, craniotomy under local anesthesia and monitored sedation is a safe technique that allows maximal resection of the lesion, with a low risk of new neurologic deficit. We have assessed the safety and effectiveness of this technique, demonstrated its usefulness in gross total or substantial tumor resection, found that there was no additional operative morbidity or usage of hospital resources. The technique also involves a level of stress that remains within the tolerance level of the average adult. Operating under local anesthesia proved an important tool for localization of function and exploration of eloquent cortex, as well as for the safe removal of epileptogenic areas. A number of other noninvasive strategies have been described and are currently the subject of great interest. Although these are promising new techniques, cortical mapping under local anesthesia was one of the most important steps in our progress toward a more exact localization of function in the cerebral cortex, and apart from a research tool in neurophysiology remains an important adjunct for the management of brain tumors by defining the limits of safe resection.