[Venous catheterization and congenital abnormalities of the superior vena cava]

Persistent left superior vena cava is encountered in about 0.3 to 0.4% of human beings. It derives from remnants of the left cardinal vein system. This results in either a duplication of the superior vena cava or in a single left vena cava. The diagnosis is easy in case of associated cardiovascular anomalies. Two cases of single left vena cava and one case of duplication of the superior vena cava are described. All were identified owing to repeatedly aberrant courses of central venous catheters. Diagnosis was easily provided by angiography. Clinical course was uneventful. Despite its usual good tolerance, the persistence of a left vena cava, as an isolated anomaly, must not be neglected as it carries many practical implications which are reviewed.