Sixty-seven operations were performed in 59 patients for aneurysmal disease occurring after previous operations involving the ascending aorta and transverse aortic arch. The initial aortic pathological condition included the following: fusiform aneurysm due to medial degenerative disease in 34 patients, 12 of whom had Marfan's syndrome; aortic dissection in a previously undilated aorta in 23; and aneurysm persisting or occurring after brachiocephalic bypass in 2. One of the latter had an aneurysm because of aortitis. Various operations initially performed did not completely treat the disease, and certain complications occurred spontaneously, including infection and dissection. The residual pathological condition led to the development of aortic insufficiency, aortic dissection, coronary artery insufficiency, and progressive aneurysmal dilatation. These complications were treated by composite valve graft replacement of the aortic valve and ascending aorta or the transverse aortic arch or both, simple aortic valve replacement, graft replacement of the ascending aorta or arch or both, and suture of false aneurysm with viable tissue wrap. Twenty patients (34%) had an aneurysm of the distal aorta. The entire aorta was replaced in 3, thoracoabdominal segments in 9, and the abdominal aorta in 1. Of the 59 patients, 49 (83%) were early survivors and 40 (68%) were alive on January 1, 1985. Principles of therapy that may have prevented the complications leading to reoperation include aneurysm replacement at the time of aortic valve replacement and coronary artery bypass; total replacement of the ascending aorta and aortic valve in patients with Marfan's syndrome; the same procedure or aortic valve replacement and separate graft replacement in patients with non-Marfan's medial degenerative disease; ascending aortic replacement in all patients with dissection combined with valve resuspension, aortic valve replacement, or composite valve graft depending on the involvement of the aortic sinuses and the presence of aortic insufficiency.