Intraoperative identification of persistent left superior vena cava with intracavitary electrocardiogram during venous port insertion: A report of eight cases

Persistent left superior vena cava is a rare congenital anomaly, occurring in 0.3% to 0.5% of general population and up to 10% in patients with congenital heart disease. This anomaly is usually discovered incidentally during central venous catheterization from left side. Since 2015, we have identified eight cases of persistent left superior vena cava out of a total of 2637 patients who had left sided venous port insertion in our department. The persistent left superior vena cavae were identified with the aid of intracavitary electrocardiogram. The characteristic finding was an initial negative P-wave (in lead II), followed by a biphasic P-wave pattern during catheter insertion. All the ports worked properly, with a total catheter dwelling time of 2586 days (range: 96–756 days, mean: 323.25 days), and no catheter-related complication was observed. However, because of the paucity of clinical evidence, we should still be prudent in the long-term use of venous ports in persistent left superior vena cava.