Intrathecal Morphine Injection Versus Continuous Wound Infiltration After Pancreaticoduodenectomy

Inclusion Criteria: * Adults 19 years of age or older * Scheduled for elective open pancreaticoduodenectomy or pylorus preseriving pancreaticoduodenectomy * Disease of periampullary lesions * Perfromance status assessed with ECOG score is 0 or 1 at the time of enrollment * Able to provide written informed consent to participate in the study, understand the procedures of this study, and complete patient-reported questionnaires * American Society of Anesthesiologists physical status I to III Exclusion Criteria: * Hypersensitivity to medications used for pain control (fentanyl, ropivacaine, morphine, acetaminophen, NSAIDs) * Cognitive impairment that affects using patient-controlled analgesia device or answering patient-reported questionnaires * Infection or anatomical abnormalities of the abdominal wall and skin that preclude catheterization for continuous wound infiltration * Contraindicated for intrathecal injection due to any coagulation disorder or continued use of anticoagulants * Have a major medical or psychiatric illness that would affect response to treatment * History of chronic pain, or chronic use of analgesics or psychiatric medications * Have severe liver or kidney disease * Anyone who are not appropriate for the study in the opinion of the investigators