Middle aortic syndrome: Surgical treatment in a child with neurofibromatosis

Abstract

A 9-year-old boy was referred to our institution for management of severe renovascular hypertension (controlled with 6 antihypertensive medications), postprandial abdominal pain, and bilateral lower-limb claudication. He was diagnosed with neurofibromatosis at age 6, manifested by multiple cafe-au-lait macules ( 5cm), axillary and inguinal freckling, and brain lesions on magnetic resonance imaging consistent with neurofibromas. Physical findings included a midepigastric bruit and attenuated lower limb arterial pulses (ankle-brachial index (ABI), 0.67[Rt]/0.7[Lt]). Digital subtraction angiography revealed segmental narrowing of the abdominal aorta frombelowtheceliac to the inferiormesenteric artery (meanpressuregradient 30mmHg)andorificial stenoses ( 75%)of the right renal (A)andsuperiormesenteric arteries (A, insert). Investigation excluded a pheochromocytoma. Surgery, through a midline incision, entailed an aortoaortic bypass (14-mm gelatin-coated polyester) from the supraceliac to distal infrarenal aorta, tunneled posterior to the left kidney, and a retrograde bypass to the superior mesenteric (end-to-side) and right renal (end-to-end) arteries, using 6-mm collagen-coated polyester grafts from the infrarenal aorta (B [Cover]). The patient was discharged on the fifth post-operative day on a single antihypertensive medication, with normal pulses and pressure indexes (ABI, 1.07[Rt]/1.09[Lt]), and a serum creatinine of 0.86. Four months postoperatively the child was normotensive on no drug treatment, free of abdominal pain and claudication, with all of his grafts patent and stenosis-free, as depicted in 3-dimensional contrast computed tomography imaging of the reconstructed aortovisceral circulation (C). Segmental narrowing of the abdominal aorta, designated middle aortic syndrome (MAS), represents an uncommon variety (0.5%-2%) of aortic coarctations attributable to acquired or congenital etiologies. Acquired etiologies include non-specific (Takayasu’s) and giant cell arteritis and neurofibromatosis, whereas congenital aortic hypoplasia is ascribed to a developmental anomaly in the fusion and maturation of the paired embryonic dorsal aortas. 1-4