The life expectancy of patients with aortic aneurysm is significantly prolonged by graft replacement therapy. Regardless, a significant predictor of late death is complications of either residual aortic aneurysmal disease or the development of additional aortic aneurysm. This paper reviews a personal experience in the treatment of 4170 patients with aneurysmal disease of either dissection or medial degenerative origin, indicating that multiple segment involvement was or became present in 1262 (30%) patients, 463 (67%) of 694 patients with dissection, and 799 (23%) of 3476 patients without dissection. Regardless of etiology, multiple involvement varied with the location of the presenting involved segment, i.e., ascending aorta (38%), ascending and arch (70%), descending thoracic aorta (73%), and abdominal aorta (26%). This study was limited in detail to 811 patients who had ascending and ascending and aortic arch replacement for aneurysm. These patients were divided into 3 subgroups: (1) 524 patients with no distal disease; (2) 135 patients with distal disease treated by subtotal replacement in 82 and total replacement in 53; and (3) 152 patients with distal disease not treated. The 5-year survival rate from the time of first operation, including early death from operation was 75% in group 1, 65% in group 2, and 39% in group 3. The causes of death in group 3 patients were aneurysmal rupture and/or associated disease. It is concluded that initial total aortic study and regular postoperative monitoring with computed tomographic scanning is indicated to detect extensive disease or recurrence of disease and that aggressive replacement is indicated except in patients with associated disease that does not permit operation.