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).