The First Reported Case
Samantha Gilg, MD; Gabe Linke; James Hammel, MD; Scott Fletcher, MD
Three-dimensional (3D) printing has become a valuable imaging modality for Complex Congenital Heart Disease. 3D modeling of the heart has been described in the literature and its importance in the diagnosis and treatment of Congenital Heart Disease is rapidly expanding.
Interrupted Aortic Arch (IAA) is a rare congenital defect, accounting for about 1% of all Congenital Heart Disease.[2,3] The most common type of interruption is Type B, which occurs between the left common carotid and the left subclavian artery. Type A is less common and occurs beyond the left subclavian artery origin. Type C is the most rare, accounting for only 3% of cases of IAA, and occurs between the innominate artery and the left carotid artery.
Isolation of the right subclavian artery from the pulmonary artery is another rare congenital cardiac anomaly. It is, however, frequently associated with other aortic arch or intracardiac anomalies, which are reported in up to 68% of patients with isolated right subclavian.
FIGURE 1 Edward’s Diagram. ARSA – Aberrant Right Subclavian Artery. DAo – Descending Aorta. LSA – Left Subclavian Artery. LCA – Left Carotid Artery. AAo – Ascending Aorta. RCA – Right Carotid Artery. RPDA – Right Patent Ductus Arteriosus. LPDA – Left Patent Ductus Arteriosus. RPA – Right Pulmonary Artery. LPA – Left Pulmonary Artery. PA – Pulmonary Artery.
Our patient was diagnosed prenatally with suspicion of Interrupted Aortic Arch and Ventricular Septal Defect (VSD). The patient was born via C-section at 38 weeks and an echocardiogram showed large outlet malalignment VSD and IAA of uncertain type due to inability to accurately visualize the aortic arch branching pattern and the continuity between ascending and descending aorta.
A cardiac CT scan was performed to clarify anatomy; the scan demonstrated prior known intracardiac anatomy and bilateral Patent Ductus Arteriosus (PDA). The right-sided PDA provided blood flow to an isolated right subclavian artery and the left-sided PDA provided flow to the descending aorta, distal to the right carotid artery, with Type C-IAA.
A classic Edward’s diagram, which represents the abnormal embryologic development of our patient, is shown (Figure 1). The patient had normal ascension of the 7th intersegmental artery on the right followed by distal involution, but also abnormal involution of the proximal right 4th arch early on in development, which led to formation of the isolated right subclavian artery receiving blood flow from the right-sided PDA (persistent ductal portion of the right 6th arch). The patient also had abnormal regression of the ventral portion of the left 3rd and 4th arches leading to the Type C-IAA and required the left-sided PDA to provide blood flow to the descending aorta.
On Day of Life 4 the patient was taken for complete repair which included re-implantation of the anomalous right subclavian artery from the right pulmonary artery to the right carotid artery, Yasui arch repair, and Rastelli right ventricle-to-pulmonary artery homograft. The patient has had a very good result clinically and based on echocardiograms.
To read the full article, please go to the June 2019 Issue of CCT.