Persistent right venous valve as a cause of fetal and neonatal pathology from prenatal to postnatal periods: a case report and review.

Background: Neonatal cyanosis is a clinical manifestation of hypoxemia and is usually pathological. Persistent right venous valve (PRVV) is a rare cause of cyanosis in newborns and can cause prenatal abnormalities, the clinical significance of which varies depending on the severity of the abnormality. There have been few reports on the intrauterine detection of these abnormalities and their follow-up during infancy. Here, we report a case of PRVV causing supravalvular tricuspid valve (TV) obstruction and secondary right ventricle (RV) hypoplasia. This case is unique in terms of its early prenatal detection, distinct cardiac anomalies, and successful surgery that reversed the symptoms, and the findings offer insights into the diagnosis and management of such rare cardiac conditions.

Case description: We report a case of a newborn diagnosed with PRVV at 31 weeks of gestation at our center. There was no underlying family history of congenital heart disease. Prenatal sonography identified an echogenic membrane in the right atrium, suggesting TV obstruction and subsequent RV hypoplasia. After birth, the neonate suffered hypoxia with decreased arterial oxygen saturation (SaO₂). Minimally invasive surgery successfully corrected the membrane. Postoperative SaO₂ improved immediately. Three months later, follow-up echocardiography revealed normalized TV and RV dimensions. The patient demonstrated steady progress without any complications. We also reviewed previous cases of PRVV before and after birth and summarized the sonographic and clinically relevant features.

Conclusions: Although PRVV is typically considered as a benign structure, it may lead to significant clinical complications, particularly in fetuses and neonates. The precise identification of its variant forms and related flow patterns is crucial to inform decisions regarding patient management.