Isolation of the left subclavian artery in an infant with tetralogy of Fallot, right aortic arch and DiGeorge syndrome. Echocardiographic diagnostic case study

Abstract

We present a case of a 6-month-old infant with an isolated left subclavian artery coexistent with right-sided aortic arch, tetralogy of Fallot and DiGeorge syndrome, with an emphasis on echocardiographic detection of this extremely rare anomaly. Specific difficulties related to echocardiographic visualization of abnormally coursing artery were a result of significantly limited ultrasonographic access due to the absence of thymus and a very close proximity of the left subclavian artery and left common carotid artery, mimicking a normal brachiocephalic trunk, which is usually present in patients with right-sided aortic arch. Precise analysis of the course of carotid and vertebral arteries as well as the nature and direction of flow in these vessels (particularly in the left vertebral and subclavian artery) suggested ductal rather than aortic origin of the left subclavian artery. Precise delineation of anatomical relationships between major arteries prior to surgical closure of the arterial duct was necessary to prevent potential postoperative ischemia of the left upper extremity; therefore the diagnosis was completed with CT angiography.

Clinical and imaging characteristics of isolated subclavian artery in pediatric patients

“…To the best of our knowledge, only two studies have reported each reported one ISA patient with a chromosome 22q11 deletion. 15,16 Both patients presented with a left-sided ISA in a right-sided aortic arch; one patient had a tetralogy of Fallot, while the other had no intracardiac defects. Our findings demonstrate that an ISA can occur in a normal or mirrorimage aortic arch with a 22q11 deletion.…”

Isolated left subclavian with a compensatory ductus in a child with Tetralogy of Fallot

“…2,3 Amongst cyanotic heart diseases, it is seen more frequently in TOF with a right aortic arch. [4][5][6] The embryological origin of an isolated subclavian artery as put forth by Edward 1948, 1 is explained by the involution of tissue between the left carotid and left subclavian artery and regression of dorsal aortic root tissue distal to the left ductus. Persistence of the right ductus arteriosus may sometimes result in a dual patent ductus arteriosus (PDA) in these cases.…”

“…The clinical implications of an isolated subclavian artery with a patent ductus arteriosus in a TOF indicate a natural palliation in the form of a systemic to pulmonary shunt as seen in our case. 5,6 But with a decreased pulmonary blood flow situation, these children may present with episodes of vertebrobasilar insufficiency with a pulmonary run off or even stunted growth of the affected arm 7 in the long run. Fortunately, we did not encounter any of these features in our patient.…”