Coarctation of Right Aortic Arch with Left Descending Aorta in an Adult
Masanori Hirota, MD,
Kozo Ishino, MD,
Masaaki Kawada, MD,
Shunji Sano, MD
Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry & Pharmaceutical Sciences Okayama, Japan
Masanori Hirota, MD Tel: +81 86 235 7359 Fax: +81 86 235 7431 Email: mhirota{at}md.okayama-u.ac.jp, Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan.
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ABSTRACT
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We report an adult case of right aortic arch coarctation with a left descending aorta. Associated anomalies included dextrocardia, situs inversus, polysplenia, bilateral superior vena cava, and absent inferior vena cava with azygos connection. Extensive mobilization of the azygos vein was needed to obtain a good surgical field, including the left descending aorta via a right thoracotomy, and the lesion was anatomically repaired by resection and end-to-end anastomosis.
Key Words: Aortic Coarctation • Cardiovascular Abnormalities • Dextrocardia
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INTRODUCTION
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In neonates or infants, coarctation of the aorta associated with various complex anomalies requires surgical treatment.1 However, in adolescents or adults, isolated coarctation is usually repaired using several techniques such as aortoplasty, end-to-end anastomosis, and anatomic or extraanatomic bypass grafting.2,3 In many cases, the length and location of the isolated coarctation determine the surgical strategy, but it is very important to understand the morphological relationships of the coarctation, especially in a patient with an anomalous aortic course.
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CASE REPORT
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A 51-year-old man presented with a blood pressure gradient between the upper (160 mm Hg) and lower extremities (90 mm Hg) without cyanosis. A grade 4/6 systolic murmur was heard over the right interscapular area. On chest radiography, dextrocardia, a right-sided stomach bubble, left-sided liver, and rib notching were seen. The electrocardiogram was compatible with typical dextrocardia. On echocardiography, situs inversus with no intracardiac anomalies was noted. Computed tomography demonstrated coarctation of the right aortic arch with a contralateral (left) descending aorta, dextrocardia with situs inversus, polysplenia, bilateral superior vena cava (SVC), and absent inferior vena cava with an azygos connection (Figure 1
). The descending aorta gradually shifted to the left, then ran caudally. Magnetic resonance angiography revealed a short coarctation (1 cm) located just distal to the right subclavian artery (SCA), a mirror-image type branch of the cervical arteries (type IIIA according to Stewart and colleagues4), no persistent ductus arteriosus, and dilated bilateral internal thoracic arteries (Figure 2A). On cardiac catheterization, no coronary artery stenosis was seen, and the right SVC was found to connect to the coronary sinus, while the left SVC connected to the left-sided morphological right atrium. Under general anesthesia, the patient was placed in the left poster-olateral position. The chest was opened via the right 4th intercostal space. The coarctation of the right aortic arch was identified just distal to the root of the right SCA. The large azygos vein lay on the coarctation, and the distal descending aorta gradually shifted from the right towards the left. To obtain a good surgical field, the dilated azygos vein was extensively dissected and mobilized after being cannulated for drainage (Figure 3). Partial cardiopulmonary bypass was started with drainage from the azygos vein and return to an artificial graft (6 mm) sewn to the hypoplastic right femoral artery. After the distal right aortic arch and descending aorta were clamped, the ductal ligament was divided, and the coarctation was repaired by end-to-end anastomosis using a 4/0 polypropylene running suture. The patient’s postoperative course was uneventful, and he was discharged on the 12th postoperative day. Postoperative magnetic resonance angiography showed a good reconstruction with no stenosis (Figure 2B).
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Figure 1. On serial computed tomography scans, coarctation (CoA) of the right aortic arch with a contralateral (left) descending aorta (DesAo), bilateral superior vena cava (RSVC, LSVC), and an absent inferior vena cava with an azygos connection are shown. The coarctation, which showed some calcification, was located between the azygos vein (AZV) and the descending aorta.
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Figure 2. (A) Preoperative magnetic resonance angiography showed a mirror-image type branch of the cervical arteries and a short coarctation (1 cm) just distal to the right subclavian artery. (B) Postoperative magnetic resonance angiography showed no stenosis after end-to-end anastomosis.
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Figure 3. The coarctation (CoA) was located just distal to the right subclavian artery (RSCA). The large azygos vein (AZV) lay on the coarctation and the distal descending aorta (DesAo), which gradually shifted from the right towards the left. To obtain a good surgical field, the dilated azygos vein was extensively dissected and mobilized after being cannulated for drainage.
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DISCUSSION
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Coarctation of the right aortic arch with a contralateral (left) descending aorta is a rare anomaly. Although it was anatomically repaired using end-to-end anastomosis in this adult case, the surgical strategy for this anomaly has not been extensively discussed. To the best of our knowledge, only 4 surgical cases (2 adults and 2 infants) have been described previously.5–8 In one of the adults, Sakamoto and colleagues4 documented a long coarctation (5.2 cm) repaired by extraanatomic bypass (ascending-to-descending aorta) via a median and left thoracotomy. In the other adult, Wallace and Levin5 urgently performed total arch replacement via a median sternotomy, due to reversed acute aortic dissection. End-to-end anastomosis is reported to be associated with a long event-free survival, and continues to be an excellent method of repair3; however, there are no reports of its use in an adult. In the infant cases, Honey and colleagues7 carried out repair using a subclavian flap with an aberrant left subclavian artery via a left thoracotomy, and Ad and Vidne8 conducted end-to-end anastomosis via a left thoracotomy due to the short length of the coarctation (1.8 cm) which was located between the right SCA and an aberrant left SCA. In patients with this type of branching pattern (type IIIB according to Stewart and colleagues4), distal and proximal clamping of the coarctation is technically feasible via a left thoracotomy. Although extensive dissection via a left thoracotomy facilitates good exposure to perform end-to-end anastomosis, it was found to be associated with increased risk of chylothorax.8
Based on these surgical reports, the length and location of the coarctation are the most important factors determining surgical technique. A broad surgical field for segmental clamping of the coarctation is also crucial in selecting the surgical approach for this anomaly. Thus, in our case, the lesion was repaired by end-to-end anastomosis due to the short length of the coarctation which was located just distal to the right SCA. The right thoracotomy allowed proximal clamping of the distal right aortic arch and distal clamping of the contralateral (left) descending aorta after extensive dissection and mobilization of the azygos vein.
Understanding of the embryological development of the vascular system is important in this complex anomaly. A right aortic arch with a mirror-image type branch of the cervical arteries is classified as type IIIA.4 Embryologically, the anterior part of right aortic arch is developed principally from the ventral aortic root between the 4th and 6th embryonic aortic arch (the 5th arch does not contribute to the definitive aortic arch). In the venous system, bilateral SVCs and absent inferior vena cava with an azygos connection are the characteristic features of polysplenia. This case is considered as a variant of polysplenia syndrome. Diligent preoperative imaging may facilitate successful anatomical repair of such a rare anomaly.
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REFERENCES
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- Hopkins RA, Kostic I, Klages U, Armiru U, de Leval M, Sullivan I, et al. Correction of coarctation of the aorta in neonates and young infants. An individualized surgical approach. Eur J Cardiothorac Surg 1988;2:296–304.[Abstract]
- Bouchart F, Dubar A, Tabley A, Litzler PY, Haas-Hubscher C, Redonnet M, et al. Coarctation of the aorta in adults: surgical results and long-term follow-up. Ann Thorac Surg 2000; 70:1483–8.[Abstract/Free Full Text]
- McGrath LB, Gonzalez-Lavin L, Amini SB, Graf D. Late events following repair of aortic coarctation with resection and end-to-end anastomosis: a twenty-five-year experience. Heart Vessels 1990;5:93–7.[Medline]
- Stewart JR, Kincaid OW, Edwards JE. An atlas of vascular rings and related malformations of the aortic arch system. Springfield, IL: Charles C Thomas, 1969:97–104.
- Sakamoto Y, Miyazawa S, Suzuki K, Mochizuki Y, Arai T, Kurosawa H. Right aortic arch with mirror-image branching and coarctation of the aorta—a case report. Nippon Kyobu Geka Gakkai Zasshi 1992;40:1001–5.[Medline]
- Wallace TM, Levin HS. Mixed gonadal dysgenesis. A review of 15 patients reporting single cases of malignant intratubular germ cell neoplasia of the testis, endometrial adenocarcinoma, and a complex vascular anomaly. Arch Pathol Lab Med 1990; 114:679–88.[Medline]
- Honey M, Lincoln JC, Osborne MP, de Bono DP. Coarctation of aorta with right aortic arch. Report of surgical correction in 2 cases: one with associated anomalous origin of left circumflex coronary artery from the pulmonary artery. Br Heart J 1975; 37:937–45.[Abstract/Free Full Text]
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Asian Cardiovasc Thorac Ann 2009;
17:76-78
© 2009 by SAGE Publications
DOI: 10.1177/0218492309102523
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ABSTRACT
INTRODUCTION
