Persistent left superior vena cava: the anatomical and surgical importance.

OBJECTIVE Persistence of the left superior vena cava (PLSVC) is a congenital anomaly resulting from failure of degeneration of the left cardinal vein. The prevalence of this anatomical variant is approximately 0.3% in the general population. The aim of this study was to determine the prevalence of the persistence of the left superior vena cava in order to avoid potential complications. SUBJECTS AND METHODS The study was conducted during a five-year period in 152 patients (64 males, 88 females) aged 1-65 years who underwent cardiac surgery for congenital heart diseases. RESULTS The persistence of the left superior vena cava was found in 5 of 152 patients (3.3%). All persistent left superior vena cavae opened into the coronary sinus. Furthermore, the coronary sinus was enlarged in all patients. The right superior vena cava was absent in one of the five cases (20%) in this study. CONCLUSION This anatomical variant must be recognized to avoid the potential complications.