Between 1975 and 1986, 100 consecutive patients with aneurysms of the descending thoracic (84 cases) or the thoracoabdominal aorta (16 cases) underwent surgical repair. Intraluminal graft inclusion procedure was employed in principle under routine circulatory support with partial cardiopulmonary bypass. In this study, overall surgical results were reviewed, and multiple factors discriminately contributing to early results were assessed using multivariate analysis (quantification theory type II) to determine if this therapeutic modality is pertinent. Fifty-five patients had non-dissecting, 42 had dissecting aneurysms and 3 had pseudoaneurysms. Seventeen patients were treated in the emergency setting. Perioperative or early deaths occurred in 14 patients. Mortality increased with advanced age (greater than 70 years) and with atherosclerotic aneurysms, especially when they involved the entire thoracic or thoracoabdominal aorta. Operative mortality during the last 5 years of the study was 9.3%: significantly lower than the figure in the first 5 years of 28% (p = 0.0198). The incidence of renal dysfunction (7.4%) or paraplegia (2.1%) was not related to aortic cross-clamp time, and both were markedly decreased to 3.8% and 0.0%, respectively, when the cases of thoracoabdominal aneurysms were excluded. There were 8 cases of exploration for postoperative hemorrhage and 6 cases of pulmonary insufficiency requiring more than 3 days of mechanical ventilation. Prolonged bypass time was a discriminative risk factor for these two complications. Cerebral vascular accidents developed in 5 patients, three of them terminated in death. In spite of partial bypass, the factors of advanced age, atherosclerosis, and cross-clamp on the aortic arch were defined responsible for brain stroke.(ABSTRACT TRUNCATED AT 250 WORDS)