[Aneurysm of the abdominal aorta. Diagnosis and indications for therapy].

Atherosclerotic abdominal aortic aneurysms are found in about 4% of all men aged over 65 years. The most severe complication of the abdominal aortic aneurysm is rupture. The probability of rupture depends upon the diameter of the aneurysm. The chance of rupture is 30% within 2 years in aneurysms with a maximum diameter of more than 5 cm. Preoperative evaluation includes clinical examination and abdominal ultrasonography. Depending on the results, aortography and/or computed tomography are required. When the diameter is less than 5 cm in an asymptomatic patient, conservative management is indicated provided that clinical tests and ultrasonography are performed on a regular basis. The mean increase of diameter varies between 0.2 and 0.4 cm/year. All aneurysms with a diameter of more than 5 cm should be treated by implantation of a dacron graft. Symptomatic aneurysms should, independently of the diameter, be considered an emergency situation and resected immediately. Patients with ruptured aneurysms have a poor prognosis; only 40-60% of these patients reach the hospital and approximately 50% of them die despite immediate surgery. A special subgroup is the so called inflammatory abdominal aortic aneurysm. Characteristic findings of this entity are increased wall thickness and retroperitoneal fibrosis. The indications for resection are the same as for the atherosclerotic aneurysm. If management is conservative, treatment with corticosteroids is useful.