The renal vein is an asymmetrically paired vessel that carries the deoxygenated blood from the kidney to the inferior vena cava. Both left and right veins run anterior to their corresponding renal arteries.
The right renal vein receives tributaries exclusively from the kidney, while the left renal vein receives several tributaries from other organs, including the left gonadal (ovarian/testicular) vein, left inferior phrenic vein and left adrenal veins.
This article will discuss the anatomy and function of the renal vein.
|Drains from||Interlobar renal veins|
|Tributaries||Right renal vein: capsular veins of right kidney
Left renal vein: capsular veins of left kidney, left gonadal vein, left inferior phrenic vein, left adrenal vein
|Drains to||Vena cava inferior|
|Drainage area||Kidneys, left testicle/ovary, left suprarenal gland, left portion of the diaphragm|
Anatomy and course
In the kidney, the blood drainage starts with the peritubular plexuses that give off fine venules that form the interlobular veins. The interlobular veins anastomose with each other and drain into the arcuate veins. Further, the arcuate veins drain into the interlobar veins that merge to form a single renal vein.
The right renal vein is a short vein (about 2-3 cm long) that runs anterior to its corresponding artery. It courses retroperitoneally, passing posterior to the descending segment of the duodenum. It terminates by draining into the inferior vena cava at a right angle.
The left renal vein is more than three times longer than its right counterpart (about 7 cm). It courses posterior to the splenic vein and pancreas. Then, the vein crosses the aorta anteriorly, immediately below the origin of the superior mesenteric artery (mesoaortic angle). This is a clinically significant relation since this is a common point of renal vein compression (nutcracker syndrome). Due to its relatively long course across the abdomen, the left vein receives several tributaries from other organs including the left ovary/testicle, left suprarenal gland and left portion of the diaphragm. The tributaries of the left vein include:
- left gonadal vein
- left inferior phrenic vein
- left adrenal vein
- capsular veins of the left kidney
Similar to the right, the left vein is accompanied by its corresponding artery and empties into the inferior vena cava. Occasionally, there can be two left renal veins present. When this happens, one runs anterior and the other posterior to the aorta forming the ‘renal collar’. The vein that runs posterior to the aorta is also referred to as the circumaortic left renal vein.
The nutcracker syndrome is a serious medical condition that is characterized by the compression of the left renal vein between the aorta and the superior mesenteric artery. This compression results in renal hypertension that is associated with haematuria (presence of red blood cells in the urine) and left-sided abdominal pain. The gold standard diagnostic tool for diagnosis of this condition is renal venography combined with a measurement of the pressure gradient between the left renal vein and the inferior vena cava. Ultrasound, CT and MRI can also be used to help make the diagnosis.