METHODS:
This was a retrospective study conducted in a single tertiary fetal medicine center. The cases diagnosed with PAVSD between January 2017 and December 2022 were identified on the electronic database of our fetal echocardiography clinic. All prenatal echocardiographies were performed using Voluson E6 (GE Healthcare Ultrasound, Milwaukee, Wisconsin) equipped with a curved transabdominal probe by the same expert fetal medicine consultant (OD) in a systematic manner, usually twice a month for each pregnancy. The cases with additional complex cardiac defects were not included. Long and short-axis views were used to assess pulmonary vasculature and comprehensive cardiac anatomy. Axial, sagittal, and coronal views of the aorta were used to detect MAPCAs. The vessels which supply blood to the pulmonary parenchyma were also identified, beginning from the parenchymal tissue and following towards the systemic origin on color Doppler. Vascular blood flow was evaluated using high-definition (HD) Doppler, applying a pulse repetition frequency of 0.3–0.6 kHz. As a routine clinical protocol, an informed consent was taken from each patient approving the publication of the ultrasound images and clinical data in case of a clinical research, provided that their identities and personal information were kept confidential. The study protocol was approved by the institutional ethical committee (22.03.2023, No. 46), and it was carried out following the principles of the Declaration of Helsinki.
Details of ultrasonographic findings such as the presence or absence of DA, pulmonary arteries, and the confluence of the pulmonary arteries, the diameters of the right pulmonary artery (RPA) and left pulmonary artery (LPA), the source of blood supply to the lungs (DA, MAPCAs or double supply), the origin of the MAPCAs were obtained from the fetal echocardiography reports and archived sonographic images. The pulmonary blood supply was assumed as ’ductus arteriosus” if retrograde flow was displayed in DA adjacent to the aortic isthmus in 3VT plane or from the undersurface of the aortic arch, distal to the left subclavian artery towards the pulmonary artery without any intervening branches in sagittal plane. The vascular supply was assumed as MAPCAs when collaterals that fed the pulmonary parenchyma were detected to originate from the main branches of the aortic arch, coronary arteries, or descending aorta. Confirmation of the fetal echocardiographies was sought from neonatal echocardiography and angiography with cardiac catheterization performed in collaborated pediatric cardiology clinic for all live-born neonates. Postnatal confirmation of the fetal echocardiographies of the babies who had undergone surgery was made by operation reports. TOP cases could not be confirmed due to the families’ refusal of an autopsy. Measures of association for categorical variables were analyzed with Pearson Chi-square test. All analyses were performed using SPSS version 22 (IBM Corp., Armonk, NY, USA). The Mann-Whitney U test was used for comparing the surgical intervention time between groups. A p-value of <0.05 was considered statistically significant.