Elderly man with abnormal chest radiograph after central venous catheter insertion.

INTRODUCTION

A 78‐year‐old male presented to the emergency department with septic shock. A left‐sided internal jugular central venous catheter (CVC) was inserted using ultrasound guidance. A routine post‐procedure chest radiograph was obtained to confirm CVC placement (Figure 1).

FIGURE 1

Portable chest radiograph demonstrating the distal tip of a central venous catheter (black arrow) terminating in a left paramediastinal location.

DIAGNOSIS: LEFT‐SIDED SUPERIOR VENA CAVA (SVC) ANATOMIC VARIANT

The chest radiograph findings raised concerns for the possibility of an unanticipated carotid artery placement as the intraluminal catheter did not appear to cross the midline and terminated in an abnormal left paramediastinal location. A follow‐up computed tomography (CT) scan of the chest was performed to further evaluate line positioning (Figure 2 and 3).

FIGURE 2

Coronal view computed tomography scan demonstrating a central venous catheter coursing toward the heart through a left‐sided superior vena cava, lateral to the carotid artery (white arrows) and aortic arch.

FIGURE 3

Axial view computed tomography image demonstrating a small right‐sided superior vena cava (dashed white arrow) connected (via vessel marked with asterisk) to the dominant left‐sided superior vena cava (solid white arrow) with the intraluminal catheter evident.

The prevalence of left‐sided SVC is unknown as it is often silent and detected incidentally on imaging, though estimates range from 0.3% to 3%. Paired transient anterior cardinal veins are present during routine fetal development. The left anterior cardinal vein typically involutes and the right anterior cardinal vein enlarges to form the SVC. A left‐sided SVC is a congenital anomaly resulting from the failure of the left anterior cardinal vein to obliterate. A left‐sided SVC typically drains into the right atrium via the coronarysinus, though the precise vascular anatomy may be challenging to delineate in the absence of intravenous contrast. Infrequently, it drains into the left atrium causing a right‐to‐left shunt most frequently without significant cyanosis.

Inadvertent arterial placement is the principal consideration that should be excluded when a left‐sided CVC fails to cross the midline as anticipated. Occasional anatomic variants may exist that can be more readily delineated with the use of cross‐sectional imaging if needed.

In this case, after confirmation of the anatomical variation and adequate venous placement by CT imaging, the catheter was used without issue or complication.