Successful ductal stent implantation for initial palliation in two patients with aortic atresia and interrupted aortic arch

Abstract

The coexistence of aortic valve atresia and interrupted aortic arch are an extremely rare condition. In this pathology, blood flow to the ascending aorta and coronary arteries should be provided through the ductus arteriosus or collaterals originating from the descending aorta. In rare cases where bilateral ductus arteriosus is present, they can provide circulation. Here, we report two cases in which coronary arteries and ascending aorta were supplied by one ductus arteriosus and distal systemic circulation is supplied by a second ductus arteriosus in one patient and a collateral artery in the other. Initial palliation was successfully performed by bilateral pulmonary artery banding and transcatheter ductal stent implantation in both cases.

Aortic atresia and interrupted aortic arch are a rare combination of complex CHDs. In this condition, blood flow to the ascending aorta and coronary arteries should be provided through the ductus arteriosus or collaterals originating from the descending aorta. In rare cases with bilateral ductus arteriosus, both the ascending and descending aorta can receive sufficient circulation. Accurately identifying the source of blood flow and performing appropriate interventions to maintain coronary perfusion and systemic circulation are crucial for survival.

Case presentations

Case 1

A term female newborn baby was admitted to the hospital at the age of three days due to low oxygen saturation. Echocardiogram revealed a complex combination of cardiac abnormalities including situs inversus, unbalanced atrioventricular septal defect, and type C interrupted aortic arch (aortic arch was interrupted between the left brachiocephalic trunk and right common carotid artery). There was a left-sided patent ductus arteriosus between the left brachiocephalic trunk and the main pulmonary artery and a right-sided patent ductus arteriosus between the descending aorta and the main pulmonary artery. The aortic valve was atretic with a hypoplastic (2 mm) ascending aorta. The left-sided arterial ductus was supplying the left carotid and the left subclavian artery, which in turn retrogradely perfusing the hypoplastic ascending aorta and the coronary arteries. She had no prenatal diagnosis. Prostaglandin was started to maintain ductal patency. CT angiogram demonstrated aortic atresia, type C interrupted aortic arch, a large right-sided ductus arteriosus between the main pulmonary artery and descending aorta, left-sided ductus arteriosus supplying the head and neck vessels, hypoplastic ascending aorta, and coronary arteries (Fig 1a). The treatment options considered for the patient included aortic arch repair with Damus–Kaye–Stansel operation or a hybrid approach involving bilateral pulmonary artery banding and ductal stenting would be performed. The hybrid approach was preferred because of the high risk associated with surgical repair.

Figure 1. (a) CT angiogram 3DVR images show interrupted aortic arch type C with right arterial ductus continues as descending aorta and a left-sided ductus arteriosus supplying the head and neck vessels, hypoplastic ascending aorta. (b) Angiogram shows right ductus arteriosus with 8x17-mm stent deployed; left ductus arteriosus with 7x19-mm stent deployed. MPA = main pulmonary artery; R-PDA = right ductus arteriosus; RSA = right subclavian artery; RCA = right common carotid artery; DAo = descending aorta; LCA = left common carotid artery; LSA = left subclavian artery; L-PDA = left ductus arteriosus; AAo = ascending aorta.

At four days old, the patient underwent a bilateral pulmonary banding procedure, and one week later, a cardiac catheterisation was performed. During the catheterisation, a 7x19-mm stent (Express TM®, Boston Scientific) was implanted in the left ductus arteriosus in an antegrade fashion, and an 8x17-mm stent (Myra®, Meril Life) was placed in the right ductus arteriosus also in an antegrade fashion (Fig 1b). Prostaglandin E1 was discontinued immediately after the procedure. Tracheostomy was performed on the 20th day of stent implantation because of extubation failure. However, the patient showed improvement and was successfully weaned off mechanical ventilation. Finally, on the 30th day after the procedure, the patient was discharged from the hospital. It was planned to proceed with single-ventricle palliation through a comprehensive stage 2 procedure.

Case 2

A 3.2 kg female newborn baby was hospitalised at two days old. Echocardiogram revealed well-developed right and left ventricles, large ventricular septal defect, aortic atresia, right-sided aorta, and type B interrupted aortic arch. Left ventricular trabeculation was increased with slight left ventricular dysfunction. Intravenous prostaglandin E1 was initially administered. CT angiogram confirmed the echocardiographic diagnosis. The aortic valve was atretic with a hypoplastic ascending aorta. Between the ascending and descending aorta, an abnormally wide collateral artery acts like a second ductus arteriosus. The ascending aorta and coronary arteries were filling retrogradely from this collateral vessel. The right and left carotid arteries originate from the collateral vessel. A large ductus arteriosus originating from the main pulmonary artery continued as descending aorta, and systemic circulation was maintained this way. The left subclavian artery originated from the distal part of the ductus arteriosus (Fig 2a). Considering the patient’s clinical condition, a hybrid procedure was deemed appropriate.

Figure 2. (a) CT angiogram 3DVR images show interrupted aortic arch type between the ascending and descending aorta, an abnormally wide collateral artery acts like a second ductus arteriosus, a large ductus arteriosus originating from the main pulmonary artery continued as descending aorta. ( b) Angiogram shows ductus arteriosus with 9x17-mm stent deployed, the ascending aorta and coronary arteries were filling retrogradely from this collateral artery. MPA = main pulmonary artery; AAo = ascending aorta; CA = collateral artery; PDA = patent ductus arteriosus; RSA = right subclavian artery; RCA = right common carotid artery; LCA = left common carotid artery; LSA = left subclavian artery.

A bilateral pulmonary banding operation was initially performed at six days old. Six days later, cardiac catheterisation was conducted, revealing no forward flow from the ventricle to the aorta, confirming aortic atresia. Blood supply to the ascending aorta and coronary arteries was provided by a collateral artery between the ascending and descending aorta. A 9x17-mm stent (Myra®, Meril Life) was implanted in the ductus arteriosus (Fig 2b). Subsequently, prostaglandin infusion was discontinued. During follow-up, no narrowing of the collateral artery was observed. The patient exhibited biventricular dysfunction. Only after the tracheostomy procedure on the 40th day following stent implantation, was she able to wean off mechanical ventilation. The patient’s ventricular function will be monitored, and if appropriate, a single-ventricle pathway will be pursued.

Discussion

Aortic valve atresia and interrupted aortic arch are a rare combination in which the survival of patients relies on sufficient cerebral and coronary perfusion. In the absence of antegrade flow through aorta, alternative sources of blood supply must exist to sustain the brain and myocardium. Several alternative blood supply routes to the immature ascending aorta have been described in the literature, such as aortopulmonary window, double aortic arch, bilateral ductus arteriosus, and aberrant right subclavian artery. ^1–4 Previously, a case similar to our first case was reported, involving type C aortic interruption with bilateral ductus arteriosus, which relied on the circle of Willis for circulation. ⁴

If there is no blood supply to the hypoplastic ascending aorta, type A aortic interruption with aortic valve atresia is a pathology incompatible with life. The left subclavian artery and left vertebral artery through the circle of Willis provide diminutive blood flow to the brain and heart in type B aortic interruption and aortic atresia patients. In type C interruption and aortic atresia, brain and coronary perfusion may be supported by both the left carotid artery and the left vertebral artery. In this way, adequate blood flow to the brain and myocardium can be ensured.

In our first case, cerebral and coronary perfusion was provided by the left ductus arteriosus. In the second case, an abnormal collateral artery, acting as a second ductus arteriosus, supplied cerebral and coronary perfusion. In both cases, maintaining the patency of the ductus arteriosus was crucial, achieved through prostaglandin infusion. Due to the high risk associated with surgical options in these cases, a hybrid procedure involving ductal stent implantation and bilateral pulmonary artery banding was considered feasible option. Although the surgical procedure is quite complex, Yang et al. ⁴ reported a successful biventricular repair in a neonatal case with aortic atresia and type C interrupted aortic arch.

The association of aortic atresia and interrupted aortic arch is an extremely rare condition, and its prompt recognition is crucial for the patient’s survival. Due to the scarcity of reported cases, the management of such cases remains controversial. Traditionally, surgical intervention has been the primary treatment option. However, in recent times, the implantation of a stent in the patent ductus arteriosus has emerged as an alternative treatment approach for neonates with aortic atresia. This approach has the potential to be utilised in different scenarios. Considering the complexity of the pathology, the hybrid approach will be less challenging for the patient. It can help prevent mortality in critically ill patients, stabilise the patient’s condition, and provide time for growth and development. ⁵ In conclusion, ductus arteriosus stenting should be considered an attractive and feasible option in neonates diagnosed with aortic atresia and interrupted aortic arch, offering potential benefits in terms of patient outcomes and management.