Prenatal Diagnosis of Persistent Left Superior Vena Cava and its Clinical Significance

Background: Persistent left superior vena cava (PLSVC) is a variant of systemic venous return which is observed in 0.3% of autopsies in the general population and in 4-8% of patients with congenital heart disease. Aims: To evaluate associated cardiac, extracardiac and chromosomal anomalies in prenatally diagnosed cases of PLSVC and to review their outcome. Study Design: Retrospective comparative study. Methods: The data of patients with a prenatal diagnosis of PLSVC between May 2008 and January 2013 were reviewed retrospectively. Results: Data of 31 cases were reviewed. Fifteen (48.4%) cases were associated with cardiac defects and 17 (54.8%) cases had associated extracardiac sonographic or postpartum findings. Two fetuses had karyotype anomalies. Outcome was significantly more favorable in cases not associated with cardiac defects in comparison to those associated with cardiac anomalies (84.6% vs. 33.3%, p=0.009). All cases with isolated PLSVC survived, while among the cases associated with extracardiac anomalies, with cardiac anomalies and with both extracardiac and cardiac anomalies, the survival rate was 75%, 50% and 22.2%, respectively. The most frequent group of cardiac anomalies associated with PLSVC was septal defects and VSD was the most common heart defect individually, being observed in nine fetuses. Conclusion: Prenatally diagnosed PLSVC is associated with cardiac and extracardiac anomalies in the majority of cases. Outcome is significantly worse if PLSVC is associated with a cardiac defect, and the prognosis is excellent in isolated cases.