For different types of diseases, its mortality rate after craniotomy is different. If it is caused by heavy craniocerebral injury, the mortality rate is very high and may reach 30% or even higher. For some patients with brain hemorrhage, the mortality rate is also around 10% to 20%. The mortality rate is just a statistical figure for research purposes, it doesn’t mean much to individuals because, after craniotomy every individual patient either dies or survives, so basically the probability is 1/2.