Case presentation
A 33-year-old pregnant woman (G1P0) was referred to our hospital at 24 weeks of gestation because of a suspected foetal heart anomaly on routine obstetric ultrasonography. The results of her prenatal laboratory tests were normal. Foetal echocardiography revealed a large ventricular septal defect (VSD) measuring 5 mm with a large overriding aorta (Figure 1A). We also observed multiple major aortopulmonary collateral arteries (Figure 1B). Therefore, the initial prenatal diagnosis was pulmonary atresia with VSD (PAVSD). A very atretic main pulmonary artery (MPA) can be seen in figure 1a retrospectively however; we were not able to detect this artery at that time. The subsequent foetal echocardiography which were performed at 26 weeks of gestation revealed a highly atretic MPA from the right ventricle (RV) giving rise to the right pulmonary artery (RPA), without bifurcation (Figure 2A). Instead of the bifurcation of the MPA, the left pulmonary artery (LPA) originated from the left subclavian artery (LSA; Figure 2B and C). The echogenicity of the thymus was not definitive on prenatal echocardiography. On the basis of these findings, the foetus was diagnosed as having PAVSD with left PAD and 22q 11.2 deletion syndrome. Considering the gestational age at diagnosis, we decided to postpone the genetic study after birth. A female neonate was delivered by elective caesarean section at 376/7 weeks of gestation for the timed delivery, with a body weight of 2,740 g, Apgar score of 8/9 points, heartbeat of 155 beats per minute, respiratory rate of 44 breaths per minute, blood pressure of 71/38 mmHg, and SpO2 of 88%. Multidetector computed tomography (MDCT) revealed a right-sided aortic arch, with the left-sided ductus arteriosus (DA) originating from the LSA and MAPCA. It also revealed a narrow RPA (2.7 mm) connecting with the MPA (2.7 mm), without connection with the LPA (2.7 mm size). The LPA originated from the left-sided DA originating from the LSA. Three-dimensional MDCT images showed the posterior aspect of the heart of the affected neonate (Figure 3A and 3B).
The neonate was assisted using the non-invasive continuous positive airway pressure (CPAP) mode because of chest retraction and tachycardia. For maintaining the patency of the DA, administration of prostaglandin E1 a-cyclodextrin clathrate (PGE1-CD; Eglandin) 5 ng/(kg·min) was initiated immediately after birth, and the dosage was adjusted between 3 and 5 ng/(kg·min), targeting 85% of the SpO2. Meanwhile, postnatal multiplex ligation-dependent probe amplification (MLPA) revealed that the neonate’s condition was complicated by 22q11.2 deletion syndrome.
The general condition of the neonate remained stable; therefore, we attempted to wean the neonate from CPAP to high flow nasal cannula (3 L) and tapered the PGE1-CD dosage to 1 ng/(kg·min). However, on the 15th day after birth, the SpO2fluctuated and required assist control mandatory ventilation in the intubation mode. After stabilisation of the neonatal status, right ventricular outflow tract (RVOT) reconstruction and pulmonary artery re-implantation were performed on the 25th day after birth. Postoperative echocardiography revealed a RVOT without turbulent flow and bilateral pulmonary arteries measuring 4.2 mm (left) and 3.3 mm (right). However, the SpO2 fluctuated and haemoptysis requiring full sedation occurred on the seventh day after the operation. The subsequent echocardiography revealed decreased blood flow in the right ventricle and RPA with pericardial effusion; thus, right heart failure was suspected. We started milrinone administration to augment ventricular contractility and decrease the afterload. However, the neonate expired because of right heart failure.