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.