|INTERESTING CASE REPORT
|Year : 2018 | Volume
| Issue : 3 | Page : 167-169
Double aortic arch presenting with neonatal respiratory distress but not due to airway obstruction: Anatomic and embryologic explanation
Vinoth Duraiswamy, Rajeshkumar Ramasamy, Kothandam Sivakumar
Department of Pediatric Cardiology, Madras Medical Mission, Chennai, Tamil Nadu, India
|Date of Web Publication||10-Dec-2018|
Dr. Kothandam Sivakumar
Department of Pediatric Cardiology, Madras Medical Mission, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Double aortic arch resulting from embryonic persistence of bilateral fourth branchial arches often leads to neonatal stridor due to tracheal compression. Two neonates presented with dyspnea without evidence of tracheal compression. An aneurysmal ductal aneurysm from the left-sided arch in the first neonate led to symptoms. Spontaneous duct closure and regression of ductal aneurysm led to relief of symptoms. Second neonate had severe neonatal pulmonary hypertension due to aortic origin of left pulmonary artery (LPA) that was disconnected from main PA. Surgical reanastomosis of the LPA and division of the smaller right arch corrected the anatomy. These two associations show that airway obstruction alone is not the cause of respiratory symptoms in neonates with double aortic arch.
Keywords: Double aortic arch, ductal aneurysm, isolated left pulmonary artery
|How to cite this article:|
Duraiswamy V, Ramasamy R, Sivakumar K. Double aortic arch presenting with neonatal respiratory distress but not due to airway obstruction: Anatomic and embryologic explanation. J Indian Acad Echocardiogr Cardiovasc Imaging 2018;2:167-9
|How to cite this URL:|
Duraiswamy V, Ramasamy R, Sivakumar K. Double aortic arch presenting with neonatal respiratory distress but not due to airway obstruction: Anatomic and embryologic explanation. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2018 [cited 2019 Jun 18];2:167-9. Available from: http://www.jiaecho.org/text.asp?2018/2/3/167/247025
| Introduction|| |
Double aortic arch represents the most common form of vascular ring that encircles the trachea and esophagus and often presents with inspiratory stridor in neonates. It comes to clinical notice with respiratory symptoms due to lack of auscultatory abnormalities on cardiovascular examination. In the absence of airway compression, the diagnosis is often missed in infancy due to lack of symptoms. We describe two patients who presented with respiratory distress, but without any tracheal compression on the imaging. Anatomical details of the images, clinical presentation, and embryological explanations are presented.
| Clinical Presentation|| |
A 7-day-old male neonate presented with mild tachypnea and widened superior mediastinum on chest X-ray to neonatal intensive unit. There was no stridor. His echocardiogram and computed tomography (CT) aortogram showed right-dominant double aortic arch with a large ductal aneurysm arising from the left descending thoracic aorta. The right and left carotid and subclavian arteries originated from their respective arches. The ductal aneurysm was more than twice the size of the aortic arches, but there were no flows due to tight constriction at the pulmonary end [Figure 1]. No interventions were done due to lack of tracheal compression, evidence of closure of the arterial duct, and spontaneous relief of symptoms. At 1 year, the ductal aneurysm regressed totally [Figure 2].
|Figure 1: Computed tomographic maximum intensity projection image in axial view at the level of arch (a) and below the level of arch (b) shows right (r) and left (l) arches around the trachea without compressing it. A very large ductal aneurysm with rim of thrombus on the walls, seen under the left arch is much larger than the ascending aorta, descending aorta, and pulmonary artery. Volume-rendered images show the anatomy from above (c) and from left side (d). The large ductal aneurysm is seen under the left arch. The wide area between the two arches in C clearly indicates the lack of tracheal or esophageal (with nasogastric tube) compression|
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|Figure 2: After 1 year, the ductal aneurysm has fully regressed in the axial slice (a). The double aortic arches and their respective arch branches are shown in the volume-rendered image (b). SVC: Superior vena cava, AA: Ascending aorta, DA: Descending aorta, R: Right arch, L: Left arch, PA: Pulmonary artery, LPA: Left pulmonary artery, R subcl A: Right subclavian artery, L subcl A:Left subclavian artery, R car A: Right carotid artery, L car A: Left carotid artery|
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A 15-day-old male infant presented with dyspnea and interrupted feeds since birth. Echocardiography and CT aortogram showed left-dominant double aortic arch and origin of right and left carotid and subclavian arteries from the respective arches. A small right patent arterial duct connected right pulmonary artery (PA) to the hypoplastic right aortic arch. Main PA (MPA) supplied only the right lung leading to severe pulmonary arterial hypertension. The left PA (LPA) was isolated from the MPA and instead arose from the ascending aorta (AA) [Figure 3]. The right arch and right arterial duct were divided, and the LPA was reimplanted to the MPA surgically. The postoperative course was stormy due to recurrent pulmonary hypertensive crisis, but hemodynamics improved after 2 weeks of intensive care.
|Figure 3: Volume-rendered images of the double aortic arch viewed from front (a), above and front (b), left (c) and above and behind (d) show origin of left pulmonary artery from the ascending aorta, narrowed right arch, main pulmonary artery continuing as the right pulmonary artery. LPA: Left pulmonary artery, RPA: Right pulmonary artery|
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| Discussion|| |
Vascular rings are caused by aortic arch-derived vascular or ligamentous structures that encircle the trachea and esophagus to varying degrees. The most common and severe obstruction is caused by a double aortic arch in which both the embryonic left and right fourth aortic arches persist. In its most common type, both arches are patent, the right being larger than the left. Double arch manifests earlier than most of the other types of vascular rings often with respiratory symptoms of stridor, sometimes with dysphagia and rarely with manifestations of associated heart diseases.
The first patient presented with mild respiratory distress and an associated large ductal aneurysm. Aneurysms of the arterial duct detected by fetal or neonatal echocardiography often resolve spontaneously with ductal closure and thrombosis, without clinically apparent sequelae. Ductal aneurysms may present with dissection, rupture, infection, thromboemboli, vocal cord paralysis, or airway compression. The association of ductal aneurysm with aortic arch anomalies is reported once in a case report of right aortic arch and isolated left subclavian artery. If we had opted for surgery in neonatal period, high chances of rupture of aneurysm while looping around the vessels would have warranted cardiopulmonary bypass and circulatory arrest. Due to early detection of ductal constriction and thrombosis in the lumen, we opted for conservative approach. Persistent embryonic right fourth arch along with neonatal patency of the distal part of the left sixth arch (arterial duct) led to this abnormality.
The second patient had double aortic arch, patent right arterial duct, and isolated LPA, unreported before. Even though there was no tracheal compression, increased PA pressures associated with single lung perfusion from right ventricle led to respiratory distress. Surgery through sternotomy without extracorporeal circulation corrected the anatomical problems.,, Persistence of the entire right fourth embryonic arch and distal part of right sixth arch, discontinuity between the proximal sixth arch (LPA) and the MPA during spiral aortopulmonary septum formation, and abnormal connection between the proximal left sixth arch and the ventral aorta to maintain continuity of the LPA from the AA formed the embryological basis.
| Conclusion|| |
Clinical presentation of respiratory distress in neonate with double aortic arch is not always associated with tracheal compression. The unusual associations such as ductal aneurysms and isolated LPA may cause symptoms. Embryological variations explain the associations, and management strategy is individualized in every patient.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]