Vascular Ring

A 4-year-old girl was referred to our pediatric cardiology department for investigation of tracheal and esophageal obstructive symptoms: inspiratory laryngeal stridor, frequent episodes of respiratory tract infection, and cough (all symptoms since birth) and difficulty swallowing semi-solid and solid foods (since the age of 1 year).

During the physical examination, the child was of inadequate weight and stature by coeval standards. She had inspiratory laryngeal stridor and dyspnea without cyanosis. Extrinsic compression of the airway and digestive tract by a vascular ring was suspected. Echocardiography suggested the presence of a double aortic arch. Multislice computed tomography (MSCT) confirmed that diagnosis and showed, further, a symmetrical type of double aortic arch: the right carotid and left subclavian arteries arose from the right arch and the left subclavian and carotid arteries arose from the left arch, each separately (Fig. 1). The trachea and esophagus were surrounded by this vascular ring, and the resultant stenosis was apparent (Fig. 2).

Fig. 1 Left: Multislice computed tomography (left superior anterior view) reveals double aortic arches that separate at the distal portion of the ascending aorta. The right subclavian artery and right common carotid artery originate separately from the right aortic arch, and the left subclavian artery and left common carotid artery originate from the left aortic arch. Right: Multislice computed tomography (superior posterior view) reveals double aortic arches that separate at the distal portion of the ascending aorta and join at the proximal portion of the descending aorta.

AA = ascending aorta; DA = descending aorta; LAoA = left aortic arch; LCCA = left common carotid artery; LSA = left subclavian artery; PA = pulmonary artery; RAoA = right aortic arch; RCCA = right common carotid artery; RSA = right subclavian artery

Fig. 2 Left: Axial image of enhanced multislice computed tomography reveals that the trachea and esophagus are surrounded by a vascular ring formed by the double aortic arch and that the trachea and esophagus are compressed by the vascular ring. Right: Coronal image of enhanced multislice computed tomography reveals that the arches join at the proximal portion of the descending aorta (*).

DA = descending aorta; LAoA = left aortic arch; RAoA = right aortic arch

A left posterolateral thoracotomy revealed compression of the trachea and the esophagus by a complete vascular ring. We divided the left aortic arch just distal to the origin of the left subclavian artery and also divided the ligamentum arteriosum, thus freeing the esophagus and trachea. The postoperative course was uneventful and brought relief from respiratory symptoms. One year after the surgical correction, the child was doing well.

Comment

The term “vascular ring” is used for congenital malformations of the aortic arch that encircle the esophagus and trachea. The usual cause is failure, during embryonic development, of the normal regression of the aortic arches that arise from the truncus arteriosus.¹ Vascular rings are formed by double aortic arches with equal right and left components or with a smaller or atretic right or left component; the descending thoracic aorta may be left or right sided, and there may be a left, right, or bilateral patent ductus arteriosus, or a ligamentum arteriosum.^2–4 Our patient had a symmetrical double aortic arch—the right carotid and right subclavian arteries arose from the right arch, and the left subclavian and left carotid arteries arose from the left arch, each separately.

Generally, diagnostic studies should include a barium swallow, echocardiography, computed tomography of the chest or magnetic resonance imaging of the heart and the great arteries, or conventional angiography of the great arteries.² The development of cross-sectional imaging techniques has facilitated the correct diagnosis and surgical treatment of compression caused by vascular anomalies.^5,6 Multislice computed tomography affords a highly accurate preoperative evaluation of the vascular anatomy and its relationship to the trachea and esophagus.

Thoracotomy should be carried out on the side of the smaller or atretic aortic arch and on the side of the persistent ductus arteriosus or ligamentum arteriosum.^3,7,8 In the presence of a double aortic arch, compression of the esophagus and the trachea is relieved by ligation and division of both the smaller or atretic aortic arch and the persistent ductus arteriosus or ligamentum arteriosum. We chose to perform a left thoracotomy and to divide the left aortic arch just distal to the origin of the left subclavian artery, then to divide the ligamentum arteriosum, thus freeing the esophagus and trachea. After the operation, the patient found complete relief both from stridor and dysphagia; we believe that the ligation and division of an atretic portion of the smaller left aortic arch was all that was needed.

Anomalies of the aortic arch, particularly vascular ring, cause compression of the esophagus and trachea and consequent cyanosis, respiratory difficulties, dysphagia, and stridor.^2,3 When there is clinical evidence of a vascular ring—inspiratory laryngeal stridor, frequent attacks of respiratory tract infection, cough since birth, and dysphagia—physicians should investigate for double aortic arch. We suggest the use of a cross-sectional imaging technique such as MSCT.