Persistent Left-Sided Superior Vena Cava: A Case Report.

A persistent left-sided superior vena cava (PLSVC) is the most common thoracic venous anomaly. However, it is still quite rare in the general population. PLSVC occurs during the embryological stages and is seen mostly in patients with congenital heart disease. Normally during development, the left anterior cardinal vein will regress and obliterate to form the ligament of Marshall. In cases of PLSVC, the left anterior cardinal vein persists and can become a persistent left superior vena cava (SVC). There are different anatomical variants of a left-sided SVC, most commonly presenting with both a right and a left SVC. In some PLSVC cases, there is an isolated left SVC. Though rare, this anomaly is not without clinical significance. This case report describes a 48-year-old male with incidental findings of isolated PLSVC seen on chest X-ray after the placement of a temporary dialysis catheter. This report will also describe the incidence/prevalence, embryological origin including anatomical variants, and clinical implications of PLSVC.