What is the most common left renal vein anatomic variant?
Generally, renal veins have more consistent anatomy than renal arteries. Knowledge of the venous anatomy before laparoscopic surgery is important to prevent vascular injury and bleeding. The left renal vein is longer than the right renal vein, which is one reason that the left kidney is preferred for transplantation.
The most common left renal vein anatomic variant is a circumaortic left renal vein, which occurs in up to 10% of the population. With this anatomic variant, the left renal vein forms a ring around the aorta. The anterior segment of the ring connects with the inferior vena cava at the expected level of the left renal vein, and the posterior segment connects with the inferior vena cava below the insertion of the anterior segment. A retroaortic left renal vein is less common and occurs in up to 3% of the population. Multiple renal veins constitute the most common renal vein variant overall, occurring in 15% to 30% of the population.
