Nutcracker Syndrome (NCS) is a clinical condition that occurs as a result of compression of the left renal vein. The syndrome was first reported in 1937. It was described by Grantin in . The most common is compression of the left renal vein between the aorta and superior mesenteric artery. As a result, this type is defined as the "anterior type". Less commonly, retroaortic left renal vein connects with the aorta. "Posterior NCS" may occur as a result of compression between the vertebrae. Pressure on the left renal vein obstructs blood flow The resulting increase in pressure within the vein causes congestion in the left kidney.