1, patients and doctors should have a comprehensive and in-depth preoperative conversation to understand the size, steps, pain, recovery speed, possible effects and possible risks of the operation; The doctor should know the patient's face, the motivation of the operation and whether the expectation of the operation is realistic.

2. Physical health examination: exclude possible medical diseases such as heart, lung, liver and blood, previous surgical history, medication history and allergic history.

3. Stop drinking and taking vasodilators such as aspirin and vitamin E one week before the operation.

4. Sleeping pills can be taken properly one night before surgery, and sedatives and painkillers can be used as appropriate half an hour before surgery; According to the anesthesia, decide whether fasting is needed.