RESUMO
Mixed connective tissue disease (MCTD) syndrome in children may lead to large aortic aneurysms, which in turn pose a difficult surgical problem. Valve-sparing root replacement is not always a viable option as the disease process invariably affects the aortic valve leaflets. Among pediatric patients, the Ross procedure is contraindicated on account of weakness of the pulmonary root, while Bentall surgery is the 'gold standard' treatment of aortic aneurysm, with reproducible and excellent long-term results. The case is presented of a three-year-old girl with a large thoracic aortic aneurysm in whom Bentall's surgery was performed, with a good result. The present patient, with MCTD syndrome, was too young to have undergone aortic root replacement with a composite mechanical valved graft.