Accidental Detection of Persistent Left Superior Vena Cava During Central Venous Port Placement.

Persistent left superior vena cava (PLSVC) is a rare abnormality of the thoracic vein that is often detected incidentally during central venous catheter insertion. We present the case of an 85-year-old female with PLSVC that was accidentally detected during central venous port placement. The left subclavian vein was punctured using the supraclavicular approach. Intraoperative fluoroscopy showed that the guidewire had descended through the left chest, suggesting PLSVC. Intraoperative computed tomography and venography confirmed that the PLSVC drained into the coronary sinus. In this case, the PLSVC and right superior vena cava (RSVC) coexisted, with no bridging veins. The diameter of the PLSVC was extremely small compared to that of the RSVC; therefore, catheter placement in the PLSVC was avoided considering the risk of venous thromboembolism, and a catheter was placed in the RSVC. When clinicians encounter cases where the PLSVC and RSVC coexist during central venous catheter insertion, the diameter of the PLSVC should be considered when deciding whether to place the catheter in the PLSVC. If the diameter of the PLSVC is narrow, it may be safer to avoid catheter placement in the PLSVC and instead place the catheter in the RSVC, considering the risk of venous thromboembolism after catheterization.