Inclusion Criteria:  Patients scheduled for Video-assisted thoracoscopic surgery (VATS) mediastinal mass excision Patient age from 20 to 80 American Society of Anaesthesiologists (ASA) physical status classification II~III  Exclusion Criteria:  Chronic obstructive pulmonary disease (COPD) with Forced expiratory volume in 1 second (FEV1) to Forced vital capacity (FVC) ratio < 0.7 and percentage of predicted FEV1 ≤ 80% Diffusing capacity of carbon monoxide (DLCO) < 80% Aspartate transaminase (AST) level ≥100 IU/mL or alanine transaminase (ALT) ≥ level 50 IU/L Creatinine clearance ≤ 30mL/min Congestive heart failure, arrhythmia Unstable angina, coronary artery occlusive disease (CAOD), history of myocardial infarction within 6 months Pulmonary edema, pulmonary arterial hypertension Allergic to prostaglandin or prostacyclin analogue Patients with peptic ulcer bleeding, trauma, intracranial hemorrhage History of cerebrovascular disease (e.g. transient ischemic attack, stroke) within 3 months Valvular heart disease Pregnant women