Ann Thorac Surg 2006;82:e11-e13
© 2006 The Society of Thoracic Surgeons
Case report
Interrupted Aortic Arch and Aortic Atresia With Circle of Willis-Dependent Coronary Perfusion
Henry J. Tannous, MD*,
Achintya N. Moulick, MD,
Richard A. Jonas, MD
Children's National Medical Center, Washington, District of Columbia
Accepted for publication May 11, 2006.
* Address correspondence to Dr Tannous, 7050 Ducketts Ln, Apt 304, Elkridge, MD 21075. (Email: henrytannous{at}hotmail.com).
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Abstract
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We present a case of type B interrupted aortic arch and aortic atresia. This combination is usually incompatible with life. However, the presence of an aberrant right subclavian artery and enough blood flow through the circle of Willis allowed perfusion of the coronary arteries through retrograde carotid and aortic blood flow. A two-ventricular repair was successfully undertaken.
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Introduction
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Interrupted aortic arch (IAA) is the discontinuation of a segment of the aortic arch, and it can be one of three types, A, B, or C, depending on the site of interruption. This defect is thought to be a result of a faulty development of the aortic arch structure during the fifth to seventh week of gestation. Aortic atresia is a very rare association with IAA due to a consequential severe compromise in coronary perfusion.
A 2-day-old, 3.6-kg boy was transferred to our institution from Tennessee. He was the product of a full-term, uncomplicated pregnancy to a 17-year-old G1 P1 mother. The patient was diagnosed with ventricular septal defect (VSD) and IAA, with two normal ventricles. He was started on prostaglandin E1 and electively intubated before the transfer.
Echocardiography at our institution demonstrated aortic atresia in addition to type B IAA with a large conoventricular VSD and posterior malalignment. Flow in the ascending aorta, which was 2.5 mm in diameter, was retrograde. Supply was from the right and left carotids, both of which were very small (Figs 1 and 2).
Magnetic resonance angiography of the brain confirmed retrograde flow in the patient's carotids bilaterally, vertebral arteries supplying the basilar artery (mostly left), and an aberrant right subclavian artery emerging from the descending aortic arch (Fig 3). Other magnetic resonance imaging findings were normal brain structures with bilateral very small hemorrhages. The child remained stable preoperatively with normal acid/base balance and normal renal and neurologic function.
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Fig 1. Carotid ultrasound reveals parallel blood flow in the common carotid artery (CCA) and internal jugular (IJ) vein. The vertebral artery (VA) flow is reversed.
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Fig 3. Magnetic resonance angiography of the head and neck vessels shows the basilar artery supplied by both vertebral arteries with more prominent flow from the left side. The aberrant right subclavian, arising from the descending aortic arch is also evident.
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On day 7 of life, the patient was taken to the operating room for a two-ventricular repair (Figs 4 and 5).
Surgical findings included thymic aplasia. The operation involved the creation of an autologous pericardial baffle to direct left ventricular outflow through the VSD to the main pulmonary artery. A nonvalved 11-mm aortic homograft was anastomosed between the native transverse aortic arch and the pulmonary artery/neoaorta. The left common carotid artery was ligated and divided with the proximal stump anastomosed together with the ascending aorta and its right common carotid artery extension to the neoaorta in an end-to-side fashion, thereby correcting the interrupted arch. A right ventriculotomy was performed and an 11-mm valved aortic homograft was placed between the infundibulum of the right ventricle and the distal divided main pulmonary artery.
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Fig 4. Preoperative diagram. Arrows indicate direction of blood flow. (VSD = ventricular septal defect.)
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The procedure was undertaken at deep hypothermia with 25 minutes of hypothermic circulatory arrest and clamp time of 77 minutes. The patient tolerated the procedure well and weaned from bypass with dopamine support at 5 µg/(kg · min). The chest was left open electively.
The patient did well postoperatively and was extubated on postoperative day 13 after chest closure on day 6. He was fed exclusively by mouth by day 25 and was discharged home on day 32.
Before discharge, a fluorescence in situ hybridization test result was positive for chromosome 22q11 deletion.
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Comment
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IAA is a relatively rare defect, comprising 1% of congenital cardiac anomalies. The incidence is 2/100,000 live births. Approximately two thirds of the patients have a type B interruption, between the left common carotid and the left subclavian artery. More than half of those patients are usually affected by chromosome 22q11 deletion [1], a verified abnormality in most patients with DiGeorge syndrome [2]. The embryologic basis of type B IAA is involution or failure of development of the fourth aortic arch [3].
Other cardiac defects may also be concomitant with IAA, such as ventricular septal defects in 73% [4], or an aberrant origin of the right subclavian artery from the descending aorta. This latter finding increases the risk of subaortic stenosis and underdevelopment of left heart structures [3].
Aortic atresia is usually associated with left ventricular hypoplasia as part of hypoplastic left heart syndrome; however 2% of patients with hypoplastic left heart syndrome have a VSD and two normal ventricles. Such patients can be corrected to a normal in-series circulation in one stage, as first described by Austin and colleagues [5].
The Yasui procedure was described originally for patients with IAA and severe subaortic stenosis [6]. The procedure involves baffling left ventricular output to the divided proximal pulmonary artery, which is anastomosed distally to the aortic arch.
The particularly unusual feature of our patient was aortic atresia in addition to IAA, which would usually be incompatible with life because of inadequate coronary blood flow. However, the presence of an aberrant right subclavian artery presumably supplied sufficient flow to the basilar artery that retrograde flow to the coronary arteries through the circle of Willis allowed survival.
Our patient was offered a definite two-ventricular repair. We anticipate, however, future replacement of the homografts because of their inherent lack of growth potential
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References
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- Goldmuntz E, Clark BJ, Mitchell LE, et al. Frequency of 22q11 deletions in patients with conotruncal defects J Am Coll Cardiol 1998;32:492-498.[Abstract/Free Full Text]
- Momma K, Kondo C, Matsuoka R, Takao A. Cardiac anomalies associated with a chromosome 22q11 deletion in patients with conotruncal anomaly face syndrome Am J Cardiol 1996;78:591-594.[Medline]
- Jonas RA. Comprehensive surgical management of congenital heart disease. London: Arnold; 2004. pp. 470-471.
- Jonas RA, Quaegebeur JM, Kirklin JW, Blackstone EH, Daicoff G. Outcomes in patients interrupted aortic arch and ventricular septal defect J Thorac Cardiovasc Surg 1994;107:1099-1109.[Abstract/Free Full Text]
- Austin EH, Jonas RA, Mayer JE, Castaneda AR. Aortic atresia with normal left ventricle. Single-stage repair in the neonate J Thorac Cardiovasc Surg 1989;97:392-395.[Abstract]
- Yasui H, Kado H, Nakano E, et al. Primary repair of interrupted aortic arch and severe aortic stenosis in neonates J Thorac Cardiovasc Surg 1987;93:539-545.[Abstract]
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Abstract
Introduction
