Craniotomy is a major surgery. There are many problems involved in opening the skull and brain. The first is the risk of bleeding after the surgery, because the human body has countless blood vessels on top of the skull, and every 1cm performed may damage various blood vessels. Therefore, if electrocoagulation is not adequate at this time and abnormalities such as high blood pressure occur after surgery, brain hemorrhage may occur again after surgery, which may be fatal. The second is the risk of intracranial infection, because after opening the cranium, the original cranial cavity is an absolutely sterile situation. If the cranial cavity is opened, it is possible for bacteria to enter the cranium at this time. If postoperative antibiotics are not applied in a timely manner and changes in the condition are observed, it is easy to form intracranial infections, and once the intracranial infection is severe, it may be fatal. So these are also fundamental to major surgery, and there are some other corresponding complications, such as cerebral infarction, epilepsy, and a host of other conditions. This can all cause an unpleasant experience for the patient as well as death, so it must be taken seriously.