Left renal vein "nutcracker" syndrome

Left renal vein "nutcracker" syndrome test is an auxiliary diagnostic method used to check whether the kidney is normal. Left renal vein entrapment syndrome, also known as nutcracker phenome-non (NCP), refers to the mechanical compression of the left renal vein between the aorta and the superior mesenteric artery. The phenomenon of left renal venous hypertension and genital vein syndrome caused by venous blood flow obstruction is manifested by clinical symptoms such as hematuria and / or proteinuria and abdominal pain. Anatomically, the position of the left kidney is close to the abdominal aorta (AO) and the position of the right kidney is close to the inferior vena cava (IVC). Therefore, the left renal vein (LRV) is longer than the right renal vein (RRV), and the right renal vein is directly injected into the IVC. The left renal vein needs to pass through the angle between the abdominal aorta and its branch superior mesenteric artery (SMA) to inject IVC. Normally this angle is 45 ° ~ 60 °, which is stuffed with mesenteric fat, lymphoid tissue and peritoneum, so that it does not squeeze LRV, but when the angle decreases (<30 °), such as rapid puberty development and rapid height Clinical manifestations of LRV compression (ie, the "nutcracker phenomenon") can occur in conditions such as growth, excessive spinal extension, sharp changes in body shape or drooping kidneys, orthostatic or supine positions, enlarged lymph nodes, and tumor compression.