Persistent Left Superior Vena Cava: Implications for Long-Term Arteriovenous Fistula Patency and Potential Cardiac Complications

A persistent left superior vena cava (PLSVC) is a rare congenital thoracic venous anomaly where the left SVC exists as a separate vessel and drains into the right atrium (RA), most commonly, through the coronary sinus (CS) in about 80-90% or directly into the left atrium (LA). This vascular abnormality can present challenges during central dialysis catheter placement and for the maintenance of arteriovenous fistulas (AVF). In addition, dilation of the coronary sinus from increased blood flow secondary to a PLSVC can cause cardiac complications, especially arrhythmias. We present a case of PLSVE incidentally detected after a dysfunctional arteriovenous fistula.