A consecutive series of 28 patients operated on at the Oulu University Hospital during the years 1974-1994 for aneurysms of the descending thoracic aorta is presented. Twenty-five cases were elective and three were operated on as emergencies. Their mean age was 58 years. During the aortic cross-clamp, circulatory support of the lower body, was used in 27 cases as follows: a direct aorto-femoral shunt without a pump (12/28), left-heart bypass (11/28) or femoro-femoral perfusion (4/28). Hospital mortality was 14% (4/28). One patient with a ruptured aneurysm died of renal failure, but there were no other renal complications. None had paraplegia postoperatively. Three had symptoms of paraparesis, but only one of them had a slight permanent discomfort while walking. The mean follow-up time was 100 months, range 2-242 months. Late actuarial survival including hospital mortality, was 65% at 5 years and 41% at 10 years, reflecting the generalized aortic disease with a high risk of very late rupture (4) and other manifestations of atherosclerosis with myocardial infarction (6) or cerebral atherosclerosis (1), the remaining late deaths being unrelated. The efficacy of lower body circulatory support in avoiding peroperative renal and spinal cord ischaemic complications is demonstrated.