Placement of a pulmonary artery catheter via a previously unrecognized persistent left superior vena cava

This case report describes a patient with persistent left superior vena cava (LSVC) as discovered by difficult placement of a pulmonary artery catheter via the left subclavian vein. After positioning in wedge position, chest x-ray showed a catheter route suggestive of persistent LSVC. Since this abnormality may yield potential clinical complications, this possibility should be considered in every difficult central venous access.