The role of interventional radiology in detecting abnormalities of the superior vena cava anatomy

Dear Editor,

We read with great interest the article published in your Journal by Rossi et al entitled “Congenital anomalies of superior vena cava and their implications in central venous catheterization” (1). Authors give a clear overview on how to approach a central venous cannulation in cases of persistent left superior vena cava (PLSVC). Usually, this kind of anomaly remains silent as it is mainly asymptomatic, but it can become a clinical problem when the patient undergoes central venous catheterization (1).

We know that, at present, a certain number of central venous catheters (CVCs) are still placed without ultrasound (US) or fluoroscopy guidance in daily practice, but several complications can occur in these cases, such as misplacement, lesion of the vessels or of the surrounding structures, pneumothorax and others (2, 3).

We would like to stress the importance of imaging (US and fluoroscopy) when placing a CVC, because with the US guidance we can check the patency of the vein we are planning to cannulate and, under fluoroscopy, we can check the correct placement of the tip of the catheter as well as the course of the thoracic tract of the vein (4). In case of PLSVC, a fluoroscopy guidance is mandatory to suddenly recognize the anomaly and to check if any communication between the venous and arterial system is present, in order to avoid any further complications (such as tromboembolization of the cerebral arteries) (1, 5).

Once a PLSVC is detected, different approaches can be proposed: first, a venography has to be performed to recognize if there is any possibility to leave the catheter safely in the SVC. Second, if the catheter cannot be left in place, different veins can be cannulated: an evaluation of the subclavian vein should be performed and, in addition, a CT scan should be proposed to evaluate the status of inferior vena cava (IVC) (1) as a femoral access can be safely used when the SVC catheterization is not possible (6).

In conclusion, a precise evaluation of the venous system is important when performing a CVC placement in order to give the best options of care to patients, even in cases of rare congenital vascular anomalies and in elderly dialysis patients with possible unknown previous venous thrombosis and/or occlusion.