Ann Thorac Surg 2011;91:624-626. doi:10.1016/j.athoracsur.2010.05.056
© 2011 The Society of Thoracic Surgeons
How To Do It
Circumflex Right Aortic Arch With Associated Hypoplasia and Coarctation: Repair by Aortic Arch Advancement and End-to-Side Anastomosis
Craig A. Bleakney, BSa,
Farhan Zafar, MDa,b,
Charles D. Fraser, Jr, MDa,b,*
a Congenital Heart Surgery, Texas Children’s Hospital, Houston, Texas
b Michael E. DeBakey Department of Surgery, Division of Congenital Heart Surgery, Baylor College of Medicine, Houston, Texas
Accepted for publication May 21, 2010.
* Address correspondence to Dr Fraser, Congenital Heart Surgery, Texas Children's Hospital, 6621 Fannin St, MC-WT 19345H, Houston, TX 77030 (Email: cdfraser{at}texaschildrenshospital.org).
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Abstract
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Right aortic arch with associated arch hypoplasia, coarctation, and an aberrant isolated left subclavian artery is a very uncommon variant of vascular rings, which itself accounts for fewer than 1% of all congenital cardiac defects. Several cases have been reported, and most commonly, extraanatomic grafts have been used for repair. We present a unique technique that involves the resection of the circumflex arch, aortic arch advancement, and end-to-side anastomosis to repair this rare aortic arch malformation.
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Introduction
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Vascular rings encompass about 1% of all surgically operated-on cardiovascular malformations, and a rightward aortic arch with a retroesophageal course to a hypoplastic distal circumflex aorta is an extremely rare presentation of a vascular ring, existing in less than 0.1% of the vascular rings [1–4]. The ligamentum arteriosum fixes the aortic arch to compress the esophagus and trachea, and most patients present with respiratory insufficiency. Most circumflex aortic arches with coarctation are repaired through a thoracotomy with extraanatomic grafts connecting the ascending to the descending aorta [3].
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Technique
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A 4-year-old boy who was found to have a heart murmur on evaluation of flu-like symptoms was referred for further attention. The patient was also noted to have a significant blood pressure difference between his right and left upper extremities, and also between right upper and lower extremities. Right and left arm pressures were 121/62 mm Hg and 85/62 mm Hg, respectively, whereas pressures from his right and left legs were 103/63 mm Hg and 98/67, respectively, as recorded on a conventional digital monitor.
An initial computed tomography scan demonstrated an unusual variant of a vascular ring. Progressive development of dysphagia and respiratory compromise were documented. Further imaging with cardiac magnetic resonance imaging revealed a circumflex aortic arch with rightward proximal segment that was more cephalic, then coursed retroesophageally and continued as a leftward descending aorta. Also noted were occlusion of the proximal left subclavian artery and distal aortic arch hypoplasia and coarctation (Fig 1). The coarctation segment appeared to involve the left subclavian artery, which had a retrograde flow through the vertebral artery. A left-sided ligamentum arteriosum completed the vascular ring.
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Fig 1. Magnetic resonance scans show (A and B) circumflex course of the arch in coronal sections. (C) A three-dimensional reconstruction of the posterior view of the defect is shown. (D) Relation of the arch to the airway and esophagus is shown.
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Surgical repair was initiated through a complete median sternotomy, and the entire ascending aorta, all the brachiocephalic vessels, and the arch on both sides of the trachea and esophagus, as well as down onto the descending aorta, were mobilized. The ligamentum arteriosus was ligated and divided, and this gave good visualization of the distal arch, which was very hypoplastic. Both vagus and recurrent laryngeal nerves were identified and protected. After this lengthy mobilization, pursestring sutures were placed in the ascending aorta and superior and inferior vena cava, and cardiopulmonary bypass was initiated. A vent was placed in main pulmonary artery, and then the ascending aorta was cross-clamped and the heart was arrested with potassium cardioplegic solution.
The distal aortic arch dissection was facilitated with the transesophageal echocardiography probe and was visualized as severely hypoplastic, measuring at most 6 to 7 mm in diameter compared with the 15 mm of the ascending aorta and the 11 mm of the proximal transverse arch. Atraumatic snuggers were placed on the right vertebral and subclavian arteries, and then a clamp was placed on the distal ascending aorta proximal to the head vessels to establish antegrade cerebral perfusion (ACP) to both carotid arteries. ACP was maintained by using near-infrared spectroscopy and arterial monitoring to adjust bypass flow.
The coarctation segment was resected and the entire circumflex arch removed. An incision was made on the left posterolateral aspect of the distal ascending aorta, and then an arch advancement type of repair was constructed by anastomosing the descending aorta to the distal ascending aorta in an end-to-side fashion. At the level of the bifurcation into the left subclavian and vertebral arteries, the subclavian artery was patent and was anastomosed to the left common carotid artery to minimize the potential for subclavian steal (Figs 2, 3).
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Fig 2. (A) Illustration of the defect demonstrating the flow of blood (arrows) and branching of the arch in this patient. (B) Closure of the site of resection of the posterior arch segment. (C) Left subclavian artery connection to the left common carotid. (D) End to side anastomosis to establish the continuity of aorta. (E) View of the surgical field at the time of final anastomosis.
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Total cross-clamp time was 60 minutes, total bypass time was 156 minutes, and the lowest temperature was 15°C. ACP was maintained for 26 minutes, with a target near-infrared spectroscopy reading within 10% of the baseline (preclamp). The baseline near-infrared spectroscopy readings in this patient were 81% on the right and 84% on the left. The ACP flow averaged about 44 mL/kg/min.
After removal from bypass, no upper-to-lower extremity blood pressure gradient was noted. A postoperative computed tomography angiogram revealed a widely patent reconstructed aortic arch and widely patent reimplanted subclavian artery, without a blood pressure gradient (Fig 4). The patient had an uneventful hospital course and was discharged 5 days after the operation without any neurologic deficits.
A follow-up echocardiogram at 9 months after the operation demonstrated no arch obstruction, with a peak velocity of around 1.7 m/s.
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Comment
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Although most repairs of a circumflex aortic arch with coarctation use extraanatomic grafts, we elected to use native tissue through an arch advancement type of repair [3, 5]. Robotin and colleagues [6], from Paris described a similar end-to-side anastomosis in patients with a circumflex aortic arch without associated coarctation. Benefits of using native tissue include the ability of tissue to grow and accommodate changes in the morphology of a growing child and, potentially, a reduced risk of infection. Depending on the size of a child at the time of operation, using prosthetic material may require future intervention due to graft size constraints. By avoiding use of a heterogeneous graft, we have eliminated issues of restenosis as well as other problems associated with graft implantation and have significantly reduced the risk of reoperation.
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References
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- Moes CA, Freedom RM. Rare types of aortic arch anomalies Pediatr Cardiol 1993;14:93-101.[Medline]
- Ahluwalia GS, Rashid AG, Griselli M, et al. Hypoplastic circumflex retroesophageal right-sided cervical aortic arch with unusual vascular arrangement and severe coarctation Ann Thorac Surg 2007;84:1014-1016.[Abstract/Free Full Text]
- Gil-Jaurena JM, Murtra M, Goncalves A, Miro L. Aortic coarctation, vascular ring, and right aortic arch with aberrant subclavian artery Ann Thorac Surg 2002;73:1640-1642.[Abstract/Free Full Text]
- Song J, Kim WH, Kim H, et al. Repair of coarctation in right circumflex retroesophageal arch Ann Thorac Surg 2009;87:307-309.[Abstract/Free Full Text]
- Konstantinov IE, Puga FJ. Surgical treatment of persistent esophageal compression by an unusual form of right aortic arch Ann Thorac Surg 2001;72:2121-2123.[Abstract/Free Full Text]
- Robotin MC, Bruniaux J, Serraf A, et al. Unusual forms of tracheobronchial compression in infants with congenital heart disease J Thorac Cardiovasc Surg 1996;112:415-423.[Abstract/Free Full Text]
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Abstract
Introduction
