Cervical Origin of the Subclavian Artery
Imaging of a Rare but Clinically Relevant Anomaly
A 4-year-old boy was referred to our hospital for further treatment of pulmonary atresia (Fallot type), multiple systemic to pulmonary collateral arteries, and hypoplastic central pulmonary arteries. Echocardiography revealed cervical origin of the right subclavian artery, which originated close to the bifurcation of the internal and external carotid arteries (Figure 1, Movie I, and Movie II). The anomaly of the subclavian artery was confirmed with cardiac catheterization (Figure 2A, Movie III). In addition, the boy had dysmorphic features of conotruncal anomaly facies syndrome, and monosomy 22q11 was confirmed by cytogenetic testing. To improve antegrade perfusion of the hypoplastic central pulmonary arteries, the patient underwent creation of a central aortopulmonary shunt followed by interventional coil occlusion of a large collateral artery from the descending aorta. The postoperative course was complicated by formation of a seroma of the polytetrafluoroethylene shunt, diagnosed by computed tomography (CT) of the thorax. Using a 16 detector CT scanner (Sensation 16, Siemens AG), a complete 3-dimensional data set of the neck, thorax, and upper abdomen was acquired in 10 seconds with nearly isotropic voxels (0.5×0.5×0.6 mm) using a single injection of 17 mL of contrast agent (Imeron 400) in a peripheral vein. The CT scan revealed the seroma, and 3-dimensional reconstruction demonstrated clearly the anomaly of the right subclavian artery (Figure 2B, Movie IV). After surgical revision of the seroma and balloon dilatation of a right pulmonary artery stenosis, the patient made an uneventful recovery. According to the literature, cervical origin of the subclavian artery is highly specific for 22q11 syndromes as demonstrated in this patient.
The multidetector-row CT is partly supported by Siemens Medical Systems.
Movies I through IV are available in the online-only Data Supplement at http://www.circulationaha.org.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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