A 22-year-old man presented with a 2-year history of headaches and fatigue of his lower limbs. Physical examination revealed striking irregularities: the blood pressure in the left arm could not be measured, and the pressure in the right arm varied from 160/110 mmHg to 170/120 mmHg; there were markedly diminished left brachial pulses, with absent left upper-extremity pulses. The femoral pulses and lower-extremity pulses could be palpated bilaterally.
A computed tomographic scan confirmed severe coarctation of the aorta (CoA, 4.5 mm in diameter) (Fig. 1) between the left common carotid artery and the left subclavian artery with rich collateral circulation, and a proximal right subclavian artery aneurysm (SAA, 30 mm in diameter) (Figs. 2 and 3). Transthoracic echocardiography showed the absence of associated cardiac malformations, such as patent ductus arteriosus. Because of rich collateral circulation around the coarctation, complete excision was not performed. The patient underwent ascending aorta to abdominal aorta bypass grafting and right subclavian artery replacement. Ten days later, he was discharged with no complications.
Fig. 1 A reformatted 3-dimensional reconstruction of a computed tomographic scan shows coarctation of the aorta (arrow). The left common carotid artery (*), the left subclavian artery (**), the ascending aorta (AAo), and the descending aorta (DAo) are so marked.
Fig. 2 A reformatted 3-dimensional reconstruction of a computed tomographic scan shows the right subclavian artery aneurysm (arrow) and the descending aorta (DAo).
Fig. 3 This computed tomographic scan shows the right subclavian artery aneurysm (**) from a different perspective.
Comment
Coarctation of the aorta is found in approximately 7% of patients with congenital heart disease.1 Coarctation is associated with various abnormalities that affect the proximal and distal aorta adjacent to the coarctation; the ascending and transverse aorta; the radial, brachial, and carotid arteries; and the retinal vascular bed. These abnormalities can include collateral arteries, vascular rings, bicuspid aortic valve, dissecting aneurysms, cerebral aneurysms, and a decrease in left ventricular interpapillary distance.2 Subclavian artery aneurysm, reported herein, is a feature very rarely associated with coarctation of the aorta.
No consensus has been reached on whether SAA is congenital or acquired. Older medical literature3 speculates that the mechanism for left SAA formation (in the coarctated segment distal to the left subclavian artery) is probably the shear stress of rapid, high-pressure pulsatile flow directly into the subclavian artery. However, current evidence indicates that the defect is more likely genetic in nature.4
The most common sequelae to SAA are rupture, compression, thrombosis, and distal embolization. Early diagnosis and surgical correction of both CoA and SAA during childhood are of vital importance for survival, particularly in hypertensive patients. Therefore, adult patients with hypertension (such as ours) should be investigated for CoA and its complications such as SAA, especially when bilateral arm or arm-and-leg blood pressures are asymmetric. In addition, all patients with SAA should be evaluated for CoA.
Footnotes
Address for reprints: Zhian Li, MD, Department of Ultrasonography, Beijing Anzhen Hospital, Capital Medical University, No. 2, Anzhen Rd., Chaoyang District, Beijing 100029, PRC
E-mail: lizhian_anzhen@yahoo.com.cn
References
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