Non-randomized study of 5 subjects that have been selected for prophylactic open surgery due to abdominal aortic aneurysm. During surgery the renal arteries are identified and subjected to about 60 seconds each of freezing by application of liquid nitrogen in dedicated catheters around the circumference of each artery. Another 5 patients that are not subjected to the freeze therapy serve as controls. Main outcome is change in ambulatory blood pressure levels.