Keywords
coronary artery - truncus arteriosus - situs inversus
Introduction
Coronary artery anomalies are a diverse and complex group of congenital disorders
with variable manifestations and pathophysiological mechanisms.[1] In this case report, we describe an extremely rare case of a female child with a
common vascular trunk from the brachiocephalic artery giving rise to the coronaries.
The child also had situs inversus and truncus arteriosus.
Case Report
A 6-month-old female child was brought with breathing difficulty and poor weight gain.
There was cyanosis on clinical examination. Chest radiograph showed dextrocardia and
cardiomegaly. Echocardiography revealed dextrocardia and a large truncus arteriosus.
A 64-slice multidetector cardiac computed tomography (CT) was done for further evaluation
of the pulmonary arteries and the coronaries.
Sections of the upper abdomen showed the liver to the left and the spleen to the right
suggestive of situs inversus ([Fig. 1A, B]).
Fig. 1 Axial (A) and coronal reformatted (B) postcontrast CT images show the liver(L) to the left and the spleen(S) to the right-situs
inversus.
The right atrium and the right ventricle were to the left. The left atrium was to
the right. The left ventricle was hypoplastic and placed inferior to the right ventricle.
The right ventricle was apex forming and directed to the right side suggestive of
dextrocardia ([Fig. 2A, B]).
Fig. 2 (A) Axial cardiac CT image—superior section shows cardiac apex directed to the right.
The right atrium (RA) and the right ventricle (RV) are to the left. The left atrium
(LA) is to the right. The RV is apex forming and directed to the right side (dextrocardia).
The left ventricle is hypoplastic and not seen in this image. (B) Axial cardiac CT image—inferior section shows a smaller sized left ventricle (LV)
inferior to the right ventricle (RV). Right atrium (RA) left atrium (LA) are also
seen.
There was a large ventricular septal defect ([Fig. 3A]).
Fig. 3 (A) Cardiac CT reformatted RVOT view image shows truncus arteriosus (T) and a large
VSD (**) along with inferiorly placed small left ventricle (LV). The left atrium (LA),
the right atrium (RA), and the right ventricle (RV) are also seen. (B–D) Volume rendered image from the posterior aspect of the heart shows truncus arteriosus
(T) with separate origins of the right pulmonary artery (RPA) and the left pulmonary
artery (LPA) and continuation as the aortic arch (AA). The aorta has been removed
posteriorly to display the origins of the pulmonary arteries.
Truncus arteriosus was seen. Both pulmonary arteries had separate origins from the
common trunk with the right pulmonary artery arising superior to the left pulmonary
artery at the level of the arch of the aorta (type A3—Van Praagh classification system;
[Fig. 3B]).
The aortic arch showed complex variant anatomy. There was right-sided aortic arch
and an aberrant left subclavian artery. The brachiocephalic artery and the left common
carotid artery shared a common origin suggestive of a bovine variant of the aortic
arch ([Fig. 4A-C]).
Fig. 4 Axial cardiac CT image (A), posterior oblique (B), and anterior oblique (C) 3D volume rendered images shows right aortic arch (AA) with aberrant left subclavian
artery (**). The brachiocephalic artery (BA) and the left common carotid artery (I)
shares a common origin suggestive of bovine variant of aortic arch. The right common
carotid artery (II), the right subclavian artery (III), the right brachiocephalic
vein (black arrowhead) and the left brachiocephalic vein (white arrowhead) are also seen.
There was a common vascular channel arising from the brachiocephalic artery passing
inferiorly and dividing into the three coronary arteries ([Fig. 5A, B]).
Fig. 5 Anterior (A) and lateral (B) 3D volume rendered images shows a common vascular trunk (white arrow) from the brachiocephalic
artery which descends inferiorly and gives rise to the coronaries—the right sided
left circumflex artery (black arrowhead), the left anterior descending artery (white arrowhead), and the left sided right coronary artery (black arrow).
Discussion
Congenital abnormalities of the coronary arteries are uncommon.[2]
[3]
[4]
[5]
[6]
[7]
[8] Though rare, it is an important cause of sudden cardiac death in young adults.[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8] Normally, there are three main coronary arteries: the right coronary artery (RCA),
the left anterior descending (LAD), and the left circumflex artery (LCX). The LAD
and the LCA arise from the left main coronary artery.[2]
[3] The RCA arises from the anterior right coronary sinus/right sinus of Valsalva and
the left main coronary artery arises from the left posterior coronary sinus/left sinus
of Valsalva of the ascending aorta.[2]
[3]
Anomalies of the coronary arteries are of various types like anomalies of origin,
anomalies of course, and anomalies of termination.[1]
[2]
[3] Of these, anomalous origin of the coronary artery is a common type of congenital
coronary abnormality.4 The increased use of multidetector CT in cardiac and coronary imaging has improved
the detection and characterization of such anomalies.5 Very few cases of anomalous origin of the coronary artery from the brachiocephalic
artery have been reported in the literature. All these cases were also associated
with truncus arteriosus.[9]
[10]
[11]
Follow-Up
The proposed management plan to the patient's family was unifocalization of the branch
pulmonary arteries with right ventricle to pulmonary artery conduit repair and routing
of the ventricular septal defect to the aorta. The patient was lost to follow-up.
Conclusion
Anomalies of the origin of the coronary arteries are an important part of the spectrum
of congenital coronary artery disorders. The knowledge of these entities is essential
for their detection and further management if required. Advances in CT imaging techniques
like multidetector CT, multiplanar reconstructions, maximum intensity projection,
and 3D volumetric rendering have helped in improving our understanding of these anomalies.
Few cases of anomalous coronary artery origin from the brachiocephalic artery reported
in the literature were also associated with truncus arteriosus suggesting a probable
association between these two entities.
