Effects of Epidural Block on the Prognosis in Patients With Pancreatic Cancer Undergoing Distal Pancreatectomy

Inclusion Criteria: 1. Undergoing elective distal pancreatectomy for pancreatic cancer . 2. ASA statusⅠ-Ⅲ. 3. 18 years to 80 years （adults）. 4. Able to understand, communicate and sign an informed consent form. Exclusion Criteria: 1. Laparoscopic surgery. 2. Preoperative chemotherapy or radiotherapy. 3. Pregnancy. 4. Allergic to any drugs used during the study. 5. Long-term receiving β-blockers. 6. Complicated with chronic inflammatory diseases, autoimmune diseases, or long-term receiving glucocorticoids or other immunosuppressants before surgery. 7. Abnormal coagulation functions (platelet count prior to surgery \<100000/ μL , APTT value is more than the normal value, INR \> 1.3 or clopidogrel that cannot be discontinued 7 days prior to surgery). 8. Complicated with severe heart disease (NYHA classification \>3), severe renal insufficiency (serum creatinine \>1.8mg/dL or receiving renal replacement therapy), severe hepatic disease (Child-Pugh classification=C), diabetes (fasting blood glucose not in the range of 3.9-13.8 mmol/L ), or acute infectious diseases (WBC\>10000/μL) before surgery. 9. BMI \> 35. 10. All contraindications to epidural block. 11. Chronic opiate medication/drug abuse. 12. Complicated with severe mental illness, cognitive disorder or unable to collaborate during the study. 13. Refuse to sign an informed consent form.