Mesoaortic compression of the left renal vein (nutcracker syndrome): case reports and review of the literature.

Compression of the left renal vein between the aorta and the superior mesenteric artery has been termed the nutcracker syndrome. Obstruction of left renal vein outflow results in venous hypertension with the formation of intra- and extrarenal collaterals and/or the development of gonadal vein reflux. To date, a variety of clinical symptoms due to mesoaortic compression of the left renal vein (nutcracker syndrome) have been described.