According to the American Association of Neurological Surgeons, the risk of death during brain surgery is about 0.5% to 1%. However, this risk varies depending on the type of surgery, the patient's overall health, and the surgeon's experience. For example, the risk of death is higher for surgeries that are performed to remove tumors that are located near critical brain structures, such as the brainstem or the optic nerve. The risk of death is also higher for patients who are older, who have other medical conditions, or who are undergoing surgery for the first time.