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Persistent left superior vena cava is a venous anomaly of the thorax and it is often detected incidentally. It typically occurs simultaneously with the right superior vena cava, but in rare cases there is only an isolated persistent left superior vena cava (IPLSVC). Knowing this condition is important during central venous procedures, as it can lead to decisions regarding catheter placing, definition of puncture site, and prevent complications. We believe all nephrologists who insert catheters should know this anatomical variation, even when considering the rarity of it.
We described the case of a patient with IPLSVC diagnosed during the insertion of an elective transjugular hemodialysis catheter, with a later image exam confirming the anatomical variation.
A 46 year-old woman with a history of polycystic kidney disease was admitted electively for hemodialysis catheter insertion to start renal replacement therapy. Ultrasonographic guidance was used to insert the catheter into the right internal jugular vein. Fluoroscopy demonstrated the catheter’s guidewire crossing the midline towards the left at the level of the second intercostal space. Injection of iodinated contrast revealed passage through the brachiocephalic vein to the left of the superior vena cava as shown in image (a). At this point, we decided to cannulate the left internal jugular vein and a fluoroscopy image revealed the catheter going straight to the right atrium, as shown in image (b). Thoracic CT scans confirmed the presence of an isolated persistent left superior vena cava (image c), a fact that was unknown to the patient and to the medical staff.
Conclusions
IPLSVC is a rare condition, occurring in only 0.09%–0.13% of patients presenting with congenital heart abnormalities. Embryologically, it occurs due to regression of the right anterior cardinal vein with preservation of the left one. Although often asymptomatic, it can cause complications during central venous access and cardiothoracic surgery. Due to the possible complications, knowing this anatomical variation is very important to all nephrologists who insert venous catheters.