Persistence of Left Superior Vena Cava Anomalies: From Shrewd Suspicion to Accurate Diagnosis

Introduction: Persistent left superior vena cava (PLSVC) is an important anatomical variation that challenges hemodialysis (HD) vascular access placement and may lead to adverse outcomes. We present three cases of PLSVC, including one leading to an inaccurate thoracotomy. Case Description: Case 1: A 17-year-old kidney recipient with graft failure returning to HD had a non-tunneled catheter (NTC) inserted in his left internal jugular vein (LIJV). Computed tomography (CT) revealed unusual left mediastinum anatomy, suggesting a perforation of the catheter through the left atrium, which led to urgent thoracotomy. The procedure revealed a PLSVC with a lateral course to the aorta, without atrial perforation. The anomalous vein encircled the left atrium and drained into the inferior cavoatrial junction, where the catheter tip resided. Case 2: A 46-year-old woman admitted for HD underwent a catheter insertion through the right internal jugular vein. Fluoroscopy revealed guidewire path through the brachiocephalic vein to the LSVC. It was then opted to cannulate the LIJV, with the catheter going through the LSVC to the right atrium. CT confirmed an isolated persistent left superior vena cava (IPLSVC). Case 3: A 60-year-old woman with a corrected atrial septal defect was admitted to the intensive care unit due to sepsis-associated kidney injury requiring dialysis. After a NTC was inserted via the LIJV, CT demonstrated a PLSVC with the catheter tip in the right atrium. The catheter functioned properly. Discussion: PLSVC occurs in 0.3-0.5% of healthy individuals and 1.3-11% of those with congenital heart diseases (CHD). Embryologically, it arises due to persistence of the left common cardinal vein. IPLSVC is rarer, manifesting in 0.09%-0.13% of patients with CHD. Often asymptomatic, PLSVC can lead to complications during HD vascular access placement or misinterpretation of exams. These cases highlight the importance of awareness of this anatomical variation.