Any operation is risky. The so-called safety is based on professional practical skills and strict operating environment. Doing a variety of routine physical examinations before operation can eliminate the basic safety hazards during and after operation. There are two sides to one thing. Using the best technology only tries to control the risk within the controllable range, but it does not mean zero risk, selling clothes and pressing goods. A bottle of antibiotics in a routine clinic may also be life-threatening. Trust the doctor, believe now.