An unusual case of therapy-resistant hypertension

Abstract

A 37-year-old male patient received a kidney transplant from his brother as treatment for end-stage renal failure due to immunoglobulin-A nephropathy. The procedure was uncomplicated, and his serum creatinine stabilized at 1.7 mg/dl (150 μmol/l). However, 18 months after transplantation, his serum creatinine increased to 2.5 mg/dl (220 μmol/l). He developed hypertension, which could not be adequately controlled by four antihypertensive drugs prescribed in high doses. In addition, he complained of headaches and pain in the lower limbs during physical exercise. Physical examination revealed bilateral absence of femoral arterial pulsations. These findings raised the suspicion of diminished perfusion of the lower body. Magnetic resonance arteriography revealed a severe aortic stenosis just below the origin of the native renal arteries, causing hypoperfusion of the lower limbs and the allograft (Figure 1). Hypertrophied collaterals had developed via the arc of Riolan. The inferior mesenteric artery was hypertrophic, resulting from retrograde flow from the arc of Riolan into the distal aorta (Figure 2). Abdominal aortic stenosis, middle aortic syndrome, or coarctatio aortae abdominalis is characterized by segmental narrowing of the abdominal aorta. This rare entity affects mostly children and adolescents. It often presents as treatment-resistant hypertension, reduced or absent femoral arterial pulsations, intermittent claudication, and/or abdominal angina. A diagnostic delay is common. Middle aortic syndrome can be congenital or result from vasculitis. We successfully performed a vascular bypass from the suprarenal to the infrarenal abdominal aorta. The role for endovascular therapy for aortic stenoses close to the origin of major side branches is limited, as peri-procedural side-branch occlusion and peripheral embolization may occur. The perfusion of the graft and the iliac arteries, as well as the blood pressure, normalized postoperatively. In our patient, we postulate that the stenosis was of congenital origin.