Renal artery aneurysm secondary to fibromuscular dysplasia in a young patient.

An 8-year-old male was found on routine physical examination to have a blood pressure of 220/110. Renal angiography demonstrated bilateral renal artery stenosis and an aneurysm of the distal left renal artery with branch involvement. At operation, the left renal artery stenosis and aneurysm was repaired by ex vivo arterial reconstruction and autotransplantation of the kidney. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis in children over 1 year of age and can in rare cases be associated with the development of renal artery aneurysms. In complex cases of renal artery stenosis with involvement of renal artery branches, ex vivo repair and orthotopic autotransplantation is an excellent approach for surgical management.