RESULTS:
We diagnosed 28 cases of PAVSD during five years in our fetal diagnosis
and therapy center. Four were excluded due to lacking postnatal data or
being lost to follow-ups. The mean maternal age was 30 ±5 years (range:
23-49 y). The mean gestational age at diagnosis was 22.4 ± 4.3 weeks
(range: 13-31 w). 45.8% of the cases were isolated. On prenatal
ultrasound, 37.5% of the cases (9 cases) were found to have
extracardiac anomalies other than thymus hypoplasia/ aplasia (Table 1).
Genetic studies could be employed for 17 cases. Chromosomal
abnormalities were detected in 41.1% of these cases. 22q11.2
microdeletion syndrome constituted 71.4% (5 cases) of the chromosomal
abnormalities (Table 1). All those cases with thymus hypoplasia were
found to have chromosomal abnormalities.
On prenatal ultrasound examinations, the four-chamber view was normal
except for left axis deviation in all patients. Overriding aorta,
hypoplastic or atretic pulmonary arteries, and absent antegrade flow
through the right ventricle outflow tract (RVOT) were the shared
characteristics of the cases. Right aortic arch (RAA) was detected in
five fetuses (20.8%). Confluent pulmonary arteries were identified in
15 (62.5%) fetuses when the pulmonary vasculature was assessed. The
Z-score of the dimensions of LPA and RPA were below -2 in all of the
fetuses4. The antegrade ductal flow was seen in none,
and retrograde ductal flow was displayed in 18 (75%) cases. Six of the
fetuses had MAPCA-dependent pulmonary vascular supply. Seven (30.4%)
cases had pulmonary vascular supply originating both from the ductus
arteriosus and MAPCAs (double supply), according to the fetal
echocardiographies. (Table 1)
TOP was performed in 29.1% of the pregnancies (7 cases). Additional
chromosomal or structural anomalies corroborated the decision of TOP in
all of the terminated cases. The remaining 17 fetuses were born alive.
Overall survival was 52.9% for the live-born fetuses. Two infants were
demised after the early first-stage shunt procedures. Four cases
(including three with mortal extracardiac anomalies) were demised
without surgical interventions. Nine infants survived after the cardiac
operations. Among those, seven had complete cardiac repair, and two have
been scheduled for complete repairment surgery after the palliative
Blalock Taussig (BT) shunt (Figure 2). Follow-up time since the
completion of total repairment is 1-4 years. Two infants were demised
after the cardiac surgeries. 62.5% of the babies who died before or
after surgery had major extracardiac anomalies.
There was no significant difference between the groups when we evaluated
the postoperative outcomes of our cases within the different pulmonary
blood supply groups based on postnatal diagnoses. However, the median
surgical intervention time was earlier in the DA group than in MAPCA
dependent group (Table 2). The DA-dependent group included eight
live-born babies. Four of these cases had serious extracardiac anomalies
leading to mortality (Table 1). Four cases in this group could undergo
surgery. Postoperative survival was 66.6% for this group. MAPCA
dependent group had seven live-born babies. Two cases were demised
before surgery, and five infants in this group could undergo total
cardiac repair surgery. Postoperative survival was 60%. The double
supply group had two cases, both surviving after surgeries. One of them
had a coronary artery-originated collateral, feeding the RPA. She
underwent surgery, which included the closure of the DA and collateral,
unifocalization of central PAs, and a modified BT shunt. She is
currently scheduled for total repair.
All of the live-born fetuses were confirmed to have PAVSD on postnatal
echocardiography. Pulmonary vascular supply type was defined precisely
on fetal echocardiography in 88.2% of the cases, according to postnatal
echocardiography, angiography, or surgery. The existence or absence of
MAPCA was accurately detected in 100% of the cases. There were only two
misdiagnosed cases who were considered to have a double supply on fetal
echocardiography, but were found to have only MAPCA-dependent pulmonary
flow in the catheter angiography (Table 3). The sources of MAPCAs were
mainly descending aorta except for one case with the prenatal diagnosis
of coronary artery-originated MAPCA (Figure 3) and two cases with MAPCAs
from both descending aorta and aortic arch (Figure 4). Fetal
echocardiography was 94.1%, 82.3%, and 88.2% accurate in defining the
confluence of the PAs, RPA/LPA, and main pulmonary trunk, respectively
(Table 3).