Double aortic arch: the break of silence

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1 case report Double aortic arch: the break of silence Duplo arco aórtico: a quebra do silêncio Ana Rita Abrão 1, Vanessa Queiroz de Souza 1, Eduardo de Oliveira Campos 2, Rosangeles Konrad Brito 3, Alexandre Dias Mançano 4 Abstract Vascular rings represent 1 to 2% of cases of congenital heart disease. We report a rare case of double aortic arch. A 60-year-old woman was admitted to the hospital presenting a one-year history of dysphagia, six months of dyspnea and two months of sporadic chest pain. Radiograph of the chest revealed diffuse pulmonary hyper inflation, widening of the mediastinum, heart of normal size and shape, a right-sized aortic arch, and degenerative changes of the thoracic spine. Computed tomography of the chest showed a double aortic arch encircling and compressing the trachea and the esophagus. The right aortic arch had a larger caliber, with brachiocephalic trunk arising from it. The left common carotid artery and the left subclavian artery arose from the left aortic arch. Diagnosis: tracheoesophageal vascular ring due to double aortic arch, with dominant right arch. In this case, we chose to follow the patient medically, taking into consideration the mildness of the symptoms. Keywords: Vascular malformations; congenital abnormalities; heart defects, congenital; aorta, thoracic. Resumo Anéis vasculares representam 1-2% dos casos das cardiopatias congênitas. Relatamos um caso raro de duplo arco aórtico. Mulher, 60 anos, procurou atendimento na clínica médica apresentando 1 ano de história de disfagia, 6 meses de dispneia e 2 meses de dor torácica esporádica. Raio X de tórax revelou: hiperinsuflação pulmonar difusa, alargamento mediastinal, coração com volume e configurações normais, arco aórtico à direita e alterações degenerativas vertebrais. Tomografia computadorizada do tórax: arco aórtico duplo circundando e comprimindo a traqueia e o esôfago. Arco direito mais calibroso, emergindo dele o tronco braquiocefálico. Do arco esquerdo emergem a artéria carótida comum e a subclávia esquerda. Diagnóstico: anel vascular traqueoesofagiano decorrente do duplo arco aórtico, sendo o arco direito dominante. No presente caso, optou-se por seguimento clínico da paciente, levando-se em conta a intensidade dos sintomas apresentados. Descritores: Malformações vasculares; anormalidades congênitas; cardiopatias congênitas; aorta torácica. Introduction Vascular rings are abnormalities of the aortic arch that partially or completely encircle the esophagus and/or trachea and may cause dysphagia and/or respiratory symptoms 1-5. They are more frequently found in children due to the early appearance of symptoms; this disease is rare in adults. However, it can be silent and discovered by chance or it can present with exuberant symptoms. Vascular rings are an important cause of tracheal obstruction, and were classified by the International Congenital Heart Surgery Nomenclature and Database Committee (Table 1) 6,7. We describe a case of double aortic arch with dominant right arch in a 60-year-old woman, whose symptoms have arisen a year ago. Vascular rings represent 1 to 2% of congenital heart diseases 2. The objective of this paper is to report a rare case of double aortic arch. Case report A 60-year-old woman was seen at the Internal Medicine Clinic in January 2009, with a one-year history of dysphagia, six-month history of dyspnea at moderate efforts, and twomonth history of sporadic sharp retrosternal pain, of mild intensity, with irradiation to the back. Physical examination did not disclose any abnormalities Electrocardiogram did not present alterations. Investigation with imaging methods proceeded as follows. Chest radiography showed signs of diffuse and 1 Resident Physician at the Radiology and Diagnostic Imaging Department of the Hospital Regional de Taguatinga; Secretaria de Estado de Saúde do Distrito Federal, Brasília (DF), Brazil. 2 Resident Physician at the Department of Internal Medicine of the Hospital Regional de Taguatinga; Secretaria de Estado de Saúde do Distrito Federal, Brasília (DF), Brazil. 3 Cardiologist at the Cardiology Department of Hospital Regional de Taguatinga; Secretaria de Estado de Saúde do Distrito Federal, Brasília (DF), Brazil. 4 Residency Program Director, Department of Radiology and Diagnostic Imaging of the Hospital Regional de Taguatinga; Secretaria de Estado de Saúde do Distrito Federal, Brasília (DF), Brazil. No conflict of interest was declared associated with publication of this article. Received on: Accepted on: J Vasc Bras. 2011;10(1):59-63.

2 60 J Vasc Bras 2011, Vol. 10, Nº 1 Double aortic arch - Abrão AR et al. Table 1 Classification of the vascular rings, defined by the International Congenital Heart Surgery Nomenclature and Database Committee 6,7 Double aortic arch Dominant right aortic arch Dominant left aortic arch Balanced arches Right aortic arch left ligament Image in mirror of the arterial branches Retroesophageal left subclavian artery Circumflex aorta Innominate artery compression Pulmonary artery compression bilateral pulmonary hyperinflation, widening of the mediastinum, heart of normal size and shape, right aortic arch and degenerative spinal disorders (Figure 1). Chest computed tomography (CT) showed double aortic arch encircling the trachea and esophagus, with compression and displacement of those structures (Figure 2). The right aortic arch was dominant and had the largest caliber (Figures 3 and 4), from which the common carotid artery and ipsilateral subclavian artery arose. The common carotid artery and the left subclavian artery arose from the left aortic arch (Figure 5). The descending aorta was to the right of the midline. The diagnosis was tracheoesophageal vascular ring deriv- Figure 1 X-ray of the posteroanterior thorax. Signs of diffuse and bilateral pulmonary hyperinsufflation. Mediastinal enlargement. Heart with normal volume and configurations. Aortic arch on the right (white arrow). Figure 3 - Computed tomography of axial thorax with endovenous contrast, mediastinal window. Right aortic arch (black arrow) involving the trachea (white arrow). E: esophagus. Figure 2 Thorax computed tomography. Coronal re-image with endovenous contrast. Aorta emerging from the left ventricle (arrow), by issuing an arch on the right, more calibrated, and another one on the left. Figure 4 - Computed tomography of axial thorax with endovenous contrast, mediastinal window. Left aortic arch (black arrow) involving the trachea (x) and comprising the esophagus (white arrow).

3 Double aortic arch - Abrão AR et al. J Vasc Bras 2011, Vol. 10, Nº 1 61 ing from double aortic arch with dominant right arch (Figure 6). Cardiac catheterization showed no obstructive lesions of the coronary circulation and confirmed the CT findings of a double aortic arch (Figure 7). The patient has been in good general condition up to this moment, despite being symptomatic. She was evaluated at the heart surgery unit and, because of the exams and mildness of her symptoms, medical management and outpatient follow-up were chosen. Discussion Vascular embryologic development results from modifications in the six pairs of aortic arches, which are connected to two primitive aortas: ventral and dorsal (Figure 8) 8. The largest portion of the first, second, and fifth arches regress. The third arch forms the carotid arteries. The branch from the ventral bud of the sixth arch meets the pulmonary bud in order to form the pulmonary artery. On the right side, the dorsal contribution to the sixth arch disappears; on the left, it persists as the ductus arteriosus. The seven intersegment arteries arise from the branch of the dorsal aorta and form the subclavian arteries 3,8,9. Usually, the right portion of the fourth arch regresses, and leaves the known left aortic arch. If the right and left Figure 5 - Computed tomography of thorax with coronal re-image and endovenous treatment. Right aortic arch, more calibrated, dominant, from which a brachiocephalic trunk arises. Left aortic arch with its branches: common carotid artery and left subclavian artery. Figure 7 Coronary Angiography: vascular ring due to double aortic arch. Figure 6 Thorax computed tomography with coronal re-image and endovenous contrast. Vascular ring comprising the esophagus (E) and trachea (T). Source: Mafeei FHA, Lastoria S, Yoshida WB, et al. 8 Figure 8 - Diagram of aortic arches. Six pairs of arches are developed between the dorsal and ventral aortas.

4 62 J Vasc Bras 2011, Vol. 10, Nº 1 Double aortic arch - Abrão AR et al. branches of the fourth arch persist, a double aortic arch is formed 3,8. The vascular ring formed by the double aortic arch was first described by Hommell, in However, the term vascular ring was only popularized in 1945, when Robert Gross successfully divided the ring of a double aortic arch 1. The annual incidence of vascular ring is less than 0.2%, being primarily diagnosed in children, in whom respiratory and gastrointestinal symptoms represent, respectively, 93 and 41% 1. We report the case of an 60 year-old patient who presented a one-year history of dysphagia and dyspnea. Dysphagia is the most common symptom of vascular ring in adults 1. The mechanisms that keep patients asymptomatic for decades still remain obscure. The vascular ring formed by the classic double aortic arch occurs as follows: the ascending aorta runs anterior to the trachea and gets divided into two arches. The arches branch in the carotid and ipsilateral subclavian arteries, passing over the respective bronchi and meet on the opposite side, behind the esophagus, forming the descending aorta (Figure 9). Source: Hardin, Brevetti, Sanusi, et al. 1 Figure 9 Left lateral view. Double aortic arch illustration. RC: right carotid artery; RSA: right subclavian artery; R Arch: right arch; L Arch: left arch; LC: left carotid artery; LSA: left subclavian artery; PA: pulmonary artery. The double aortic arch is a classical example of vascular ring the arch is formed by the aorta itself. The fact that the arterial duct passes between the aorta and the pulmonary arterial system is an aggravating factor of the compression of the anterior trachea wall. Esophageal compression occurs through the descending aorta segment 4,8-10. Among double aortic arch cases, the right arch is dominant 75% of the time, but the left arch is usually patent. Atresia of the left arch is generally distal to the left subclavian. When the left aortic arch is dominant, the right one is usually patent. Generally, atresia occurs in only 30% of the arches that are not dominant 4,8. In the present case, the arches are wide enough to perfuse all aortic branches and the right aortic arch has a larger caliber. Tracheal compression is caused by the right aortic arch and the esophageal compression by the descending aorta. Respiratory symptoms result from tracheal compression by dilatation of the aorta, which can occur by static or dynamic mechanisms. The administration of fluids and exercises may cause dynamic dilatation, and exercise is known to exacerbate preexistent vagal symptoms. During exercise, the diameter of the ascending aorta increases about 1 mm or more for every 15 mmhg increase in the systolic or diastolic pressure, which can cause 3 to 6 mm circumferential compression of the respiratory system 1. The ageing process results on dilatation of the aorta, about 0.1 cm per decade. Hypertension and arteriosclerosis can dilate and increase the tortuosity of the aorta, causing tracheal compression. These two mechanisms can contribute with the onset of symptoms in adults. Finally, the thoracic and spinal ageing process can limit the mediastinal dimensions, aggravating the compression 1. The reported patient does not present, at this moment, arterial hypertension; however, she presented with degenerative changes in the thoracic spine. The evaluation of the patient with suspected double aortic arch starts with the chest routine: conventional radiography in posteroanterior and lateral position; it is also possible to include esophagogram as a complementary evaluation 1,9,11. Signs suggestive of vascular ring are: mediastinal widening, presence of an aortic knob on the right, and evidence of tracheal and/or esophageal compression. Echocardiogram is useful to evaluate the aortic arch and heart anatomy; however, CT and magnetic resonance (MR) have showed more accuracy for the evaluation of mediastinal structures 1,9,11. In this case, CT was useful to diagnose and define the anatomy of the arches, showing which one was dominant.

5 Double aortic arch - Abrão AR et al. J Vasc Bras 2011, Vol. 10, Nº 1 63 Radiology has greatly contributed to define the causes of airway obstruction due to vascular compression since 1940, with the use of conventional and contrast radiography: from 1960 to 1970, with the advent of angiography; and from 1980 to 1990, with CT and MR. These imaging methods facilitate the accurate diagnosis, and allow an appropriate treatment of the disease 11. In conclusion, extrinsic compression due to vascular ring is extremely rare and, at times, silent. It may present vague or exuberant symptoms, both in childhood and adult life. Complementary diagnostic methods are essential to detect congenital heart disease. References 1. Hardin RE, Brevetti GR, Sanusi M, et al. Treatment of symptomatic vascular rings in the elderly. Tex Heart Inst J. 2005;32: Muto A, Nishibe T, Kondo Y, Sato M, Ando M. Detection and treatment of complete vascular ring in an elderly woman with dysphagia. J Thorac Cardiovasc Surg. 2005;130: Lowe GM, Donaldson JS, Backer CL. Vascular rings: 10-year review of imaging. Radiographics. 1991;11: Yedururi S, Guillerman RP, Chung T, et al. Multimodality imaging of tracheobronchial disorders in children. Radiographics. 2008;28:e Longo-Santos LR, Maksoud-Filho JG, Tannuri U, et al. Vascular rings in childhood: diagnosis and treatment. J Pediatr (Rio J). 2002;78: Backer CL, Mavroudis C, Rigsby CK, Holinger LD. Trends in vascular ring surgery. J Thorac Cardiovasc Surg. 2005;129: Backer CL, Mavroudis C. Congenital Heart Surgery Nomenclature and Database Project: vascular rings, tracheal stenosis, pectus excavatum. Ann Thorac Surg. 2000;69(4 Suppl):S Mafeei FHA, Lastoria S, Yoshida WB, et al. Doenças Vasculares Periféricas: o desenvolvimento do sistema vascular. 3ª ed. Rio de Janeiro: MEDSI; p Harty MP, Kramer SS, Fellows KE. Current concepts on imaging of thoracic vascular abnormalities. Curr Opin Pediatr. 2000;12: Knight L, Edwards JE. Right aortic arch. Types and associated cardiac anomalies. Circulation. 1974;50: Berdon WE. Rings, slings, and other things: vascular compression of the infant trachea updated from the midcentury to the millennium--the legacy of Robert E. Gross, MD, and Edward B. D. Neuhauser, MD. Radiology. 2000;216: Correspondence: Ana Rita Abrão Avenida T-30, 1492, 2 nd floor Setor Bueno Zip Code Goiânia (GO), Brazil [email protected] Authors contributions: Study conception and design: ARA, EOC Data analysis and interpretation: ARA, VQS, EOC Data collection: EOC Writing: ARA, EOC Critical analysis: ARA, EOC, RKB, ADM Final text approval*: ARA, VQS, EOC, RKB, ADM Statistical analysis: N/A Overall responsibility: ARA, EOC, RKB, ADM *All authors have read and approved the final version submitted to J Vasc Bras.