Corpus: Renal vein

The renal veins are responsible for collecting venous blood from the kidneys and draining it into the inferior vena cava.

There are two main renal veins:

• Right renal vein
• Left renal vein

2.1. Course

Both veins pass in front of their corresponding renal arteries. After a short course, they empty into the inferior vena cava. Because the vena cava is situated slightly to the right of the midline, the left renal vein is longer than the right. The left renal vein runs between the abdominal aorta and the superior mesenteric artery, whereas the right renal vein takes a more direct path.

The left renal vein passes behind the pancreas and in front of the abdominal aorta, while the right renal vein runs behind the descending part of the duodenum and in front of the pancreatic head.

2.2. Inflows

The left renal vein may receive several tributary veins, including:

• Left inferior phrenic vein
• Left suprarenal vein
• Left testicular vein (or left ovarian vein in females)
• Left second lumbar vein

On the right side, these veins usually drain directly into the inferior vena cava.

Compression of the left renal vein between the superior mesenteric artery and the abdominal aorta is referred to as the nutcracker phenomenon. This condition may lead to symptoms such as hematuria (blood in the urine) and proteinuria (protein in the urine).