The renal veins in the

renal circulation The renal circulation supplies the blood to the kidneys via the renal artery, renal arteries, left and right, which branch directly from the abdominal aorta. Despite their relatively small size, the kidneys receive approximately 20% of the cardiac ...

, are large-calibre

vein Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and feta ...

s that drain blood filtered by the

kidneys In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and right in the retro ...

into the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the ...

. There is one renal vein draining each kidney. Each renal vein is formed by the convergence of the interlobar veins of one kidney. Because the inferior vena cava is on the right half of the body, the left renal vein is longer than the right one.

Structure

One renal vein drains each

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

. A renal vein is situated anterior to its corresponding accompanying renal artery. The renal veins empty into the

, entering it at nearly a 90° angle. Due to the right-ward displacement of the inferior vena cava from the midline, the left renal vein is some 3 times longer than the right one (~7.5 cm and ~2.5 cm, respectively). The renal vein divides into 4 divisions upon entering the kidney: * the anterior branch which receives blood from the anterior portion of the kidney and, * the posterior branch which receives blood from the posterior portion.

Tributaries

Because the tributaries of the

are not bilaterally symmetrical, the left renal vein often receives the ipsilateral inferior phrenic vein, suprarenal vein, gonadal vein ( left testicular vein in males, left ovarian vein in females), and 2nd lumbar vein.Dissector Answers - Kidney & Retroperitoneum
This is in contrast to the right side of the body, where these veins drain directly into the IVC.

Relations

The anatomical relations of the two renal veins are bilaterally asymmetrical. Left renal vein The left renal vein is situated posterior to the

splenic vein In human anatomy, the splenic vein (formerly the lienal vein) is a blood vessel that drains blood from the spleen, the stomach fundus and part of the pancreas. It is part of the hepatic portal system. Structure The splenic vein is formed from ...

, and the body of the pancreas. It passes through the angle formed by the abdominal aorta (situated posteriorly), and superior mesenteric artery (situated anteriorly) (increased acuteness of this angle may lead to the left renal vein being "pinched" between the two arteries, with the resulting compression impairng blood flow through the vein, a condition known as

nutcracker syndrome The nutcracker syndrome (NCS) results most commonly from the compression of the left renal vein (LRV) between the abdominal aorta (AA) and superior mesenteric artery (SMA), although other variants exist. The name derives from the fact that, in ...

). Occasionally, the left renal vein (or accessory left renal vein) passes posterior to the aorta. Right renal vein The right renal vein is situated posterior to the descending part of the

duodenum The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest p ...

Variation

There is typically a single renal vein drainin each kidney, but accessory renal veins are commonly encountered; renal vasculature anomalies are more frequent with ectopic kidneys, and almost always present with horseshoe kidney). In some individuals, the left renal vein passes posterior to the abdominal aorta instead of in anterior to it; this is termed a retro-aortic left renal vein (also known as "The Vein of Schnitker"). If there is both a vein passing in front of and one behind the aorta this is called a circumaortic renal vein. In the case of a left sided IVC and the right renal vein passes behind the abdominal aorta, this is termed a retroaortic right renal vein, which is also known as “The Reverse Vein of Schnitker”.

Clinical significance

Diseases associated with the renal vein include renal vein thrombosis (RVT) and

(renal vein entrapment syndrome).

Additional images

File:3D rendered CT of abdominal aortic branches and kidneys.svg, 3D-rendered

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

, showing one renal vein (in red color) for each kidney File:Illu kidney2.jpg, Frontal section through the kidney File:Gray480.png, Diagram showing completion of development of the parietal veins. File:Gray577.png, The venæ cavæ and azygos veins, with their tributaries. File:Slide11iii.JPG, Renal vein File:Gray1120.png, Human kidneys viewed from behind with spine removed. File:Njuren.gif, Kidney File:Slide4nn.JPG, Renal vein File:Slide14iii.JPG, Renal vein File:Slide1kkk.JPG, Renal vein

References

External links

* - "Retroperitoneal structures on the posterior abdominal wall." {{Authority control Veins of the torso