[Middle aortic syndrome: a report of three pediatric cases].

The middle aortic syndrome (MAS) is caused by stenosis of the abdominal aorta, often accompanied by concomitant stenosis of the renal or visceral arteries. Although MAS is uncommon (0.5-2%), it is an important cause of hypertension in children and adolescents. It is thought to originate in a failure of the two dorsal aortas to fuse during embryological development, and a high percentage of cases are idiopathic. MAS affects the segment of the aorta between the renal arteries in 54% of cases. Clinically, it courses with symptomatic or asymptomatic arterial hypertension. On physical examination, findings include an abdominal bruit, diminished or absent femoral pulses, and a difference between the arterial pressure of the upper and lower limbs. Angiography is the technique of choice, although noninvasive MR angiography and CT angiography have similar diagnostic accuracy. Ultrasonography is the primary screening technique. Medical treatment consists of a combination of different antihypertensives. Surgical treatment can be curative.