What disease is Nutcracker?

Nutcracker syndrome, also known as left renal vein compression syndrome or nutcracker phenomenon, refers to a long-unidentified disease that occurs when the left renal vein returns to the inferior vena cava and is squeezed at the intersection between the abdominal aorta and the superior mesenteric aorta, causing hematuria, proteinuria, left lower back pain, and spermatic varices. The disease is more common in children and adolescents. Most patients are tall and tall. The clinical symptoms are mainly asymptomatic gross hematuria or microscopic hematuria. Some may have renal varicose veins, sperm varicose veins, proteinuria, hypertension and low back pain.

The diagnostic criteria for this disease are: bleeding from one kidney； Urinary red blood cells are non-tubular in shape ； Calcium metabolism in urine is normal; cystoscopy shows blood spurting or strong urine from the left urethral orifice; abdominal color ultrasound or CT examiner can see the enlargement of the left renal vein, etc.

Ultrasound has obvious advantages in diagnosing nutcracker syndrome. Color Doppler ultrasound can clearly display the anatomy of the abdominal aorta, superior mesenteric aorta and left renal vein. The largest diameter of the left renal vein that has recently enlarged can be found in different cross-sections, and the measurement value is accurate. At the same time, the intersection angle between the superior mesenteric aorta and the abdominal aorta can be observed and measured. B-ultrasound blood velocity provides more accurate hemodynamic changes, which is beneficial to the diagnosis of this disease. Color ultrasound examination can also diagnose hematuria caused by congenital malformations, trauma, tumors, stones, infectious diseases and abnormal isosceles triangles in blood vessels.

MRA can clearly display the renal veins and their three-dimensional relationship with surrounding blood vessels. The intersection angle of the superior mesenteric aorta and the distance between it and the pulmonary artery are of great value for diagnosis, and the left and right diameter of the left renal vein are of reference significance for diagnosis.