Dissecting aneurysms of the ascending aorta occurring late after aortic valve replacement.

In 4 patients who had undergone aortic valve replacement, a dissection of the ascending aorta appeared between 7 and 16 years later (mean 12 years). This is a rare complication, occurring in less than one percent of cases. Three cases of aortic regurgitation and one of aortic stenosis developed, and 3 of the cases had dilatation of the ascending aorta and hypertension. The symptoms of dissection were accompanied by signs of either the superior vena caval syndrome or compression of the pulmonary artery. The diagnosis was confirmed by echography and by CT scan. Despite the advances made in the surgery of dissection the prognosis was serious, and 2 of the 4 patients died. Avoidance of this complication depends on replacement of the ascending aorta (composite tube or supracoronary graft according to the involvement of the sinuses of Valsalva) as soon as the diameter of aorta exceeds 55 mm. In cases of moderate dilatation (45-50 mm), systemic reinforcement with Dacron mesh has been shown to have long-term effectiveness.