Imaging of Type I Retroaortic Left Renal Vein & Nutcracker Syndrome

Retroaortic left renal veins are an often overlooked, but no so rare anatomic anomaly that might cause a few aspecific symptoms and signs, especially flank or inguinal pain, microscopic or even gross hematuria; in the vast majority of cases it is, thought, totally asymptomatic. The nutcracker syndrome that might arise in the case of RLRV is mainly due to the re- duced space between aorta and the vertebral body and the consequent compression on the venal rein; this might in turn cause upstream hypertension, hematuria, varicocele, pain. The compression of RLRV leads to hematuria because of renal venous hypertension, consequent left renal congestion. This upstream venous congestion might result, in some cases, in left-sided varicocele in men and pelvic congestion syndrome in women. From a radiologic point of view, the presence of RLRV and the precise reporting its subtypes is mandatory.