Left renal artery

The left renal artery is a major paired branch of the abdominal aorta that supplies arterial blood to the left kidney. It typically arises from the lateral or posterolateral aspect of the abdominal aorta, most commonly at the level between the lower border of the first lumbar vertebra (L1) and the upper border of the second lumbar vertebra (L2). The left renal artery generally originates slightly inferior to the right renal artery and courses almost horizontally or with a slight downward angulation toward the renal hilum.[1][3]

In the transverse plane, the left renal artery most often arises from a posterolateral or lateral position on the aorta, in contrast to the right renal artery, which is more commonly anterolateral. The left renal artery passes posterior to the left renal vein, the body of the pancreas, and the splenic vein, and anterior to the psoas major muscle before reaching the renal hilum.[4-6] Its initial course is generally shorter and more direct than the right renal artery, as the aorta lies closer to the left kidney.[7]

Upon reaching the renal hilum, the left renal artery typically divides into anterior and posterior segmental branches, which further subdivide to supply the renal parenchyma. Variations are common, including early branching, accessory renal arteries, and differences in the number and pattern of segmental branches.[8-9] The left renal artery has a mean diameter of approximately 5.4 mm and a mean length of about 35 mm, though these values can vary with patient anatomy and renal function.[7]