Pre-operative routine tests: routine blood, coagulation series, liver and kidney function, blood electrolytes, fasting glucose, electrocardiogram, chest X-ray, ultrasound. Other special examinations will be decided according to individual conditions. Pre-operative precautions: 1. Pre-operative treatment of diseases causing increased abdominal pressure, such as constipation, prostate enlargement, chronic cough; 2. Fasting blood sugar should be controlled at about 7 mmol/l; 6. The night before the surgery, the stool should be excreted to avoid postoperative bloating; 7. Do not leave without permission so that you can contact them in time.