The purpose of this study is to assess whether treatment with melatonin can reduce cell damage and inflammatory stress response and thereby occurrence of myocardial injury after abdominal aortic surgery.

Abdominal aortic surgery is associated with a significant increase of oxidative and inflammatory stress response. Aortic surgery is also associated with elevated troponin which is a sensitive and specific marker for myocardial injury. The severity of oxidative stress is correlated with elevated troponin. Melatonin, which is a hormone produced in brain, seems to modify cell damage and inflammation. On the other hand we know, that melatonin production first night after surgery is disturbed. The purpose of this study is therefore to determine whether treatment with melatonin can reduce cell damage and inflammation, and thereby occurrence of myocardial injury associated with abdominal aortic surgery.

Inclusion Criteria:

• Indication for elective abdominal aortic aneurism surgery or periphery atheroscleroses with indicated protheses operation
• Patients between 18 and 80 years old

Exclusion Criteria:

• Patients with ASA class > 3
• Anticoagulation therapy (marevan and marcoumar)
• Preoperative therapy with opioid, anxiolytic and hypnotic medication
• Renal insufficient (preoperative creatinin > 200 mmol/l)
• Well-known liver insufficient
• Alcohol consumption (more than 5 drinks)
• Compliance (language difficulty, mental problems etc.)
• Pregnancy and breast-feeding
• Lack of written consent