Midaortic Syndrome in Neurofibromatosis Type 1 Resulting in Bilateral Renal Artery Stenosis

We describe the case of a 23-year-old white woman with a long history of hypertension. She was referred to us 7 years after her initial diagnosis of hypertension when her blood pressure control worsened during pregnancy. Clinical examination showed an abdominal bruit and weak femoral pulses. Imaging showed midaortic syndrome with bilateral renal artery stenosis as the cause of her hypertension, and further investigations showed neurofibromatosis type 1 as the underlying disorder. Midaortic syndrome, a rare disorder of the abdominal aorta that is different from classic coarctation, typically is associated with neurofibromatosis. Renal artery stenosis is common, as are weak femoral pulses and impaired development of the lower limbs. Because of the rarity of this syndrome, only anectodal evidence exists with regard to treatment. Surgery and interventional treatment with stent placement in the abdominal aorta have been reported, as well as good outcomes with long-term medical management. Our patient continues to be healthy without intervention, with reasonable blood pressure control and normal kidney function on a 4-drug antihypertensive regimen. We discuss midaortic syndrome with a focus on diagnosis, differential diagnosis, associated conditions, and management. Nephrologists, radiologists, and ultrasonographers should be aware of this rare cause of renovascular hypertension.

Index Words: Midaortic syndrome, renal artery stenosis, neurofibromatosis, hypertension