The nutcracker syndrome. Morphology and clinical aspects of the important vascular variations: a systematic study of 112 cases.

Nutcracker syndrome (NCS) is the name given to entrapment of the left renal vein (LRV) between the aorta and superior mesenteric artery (SMA). The aim of the study was to review current research and clarify the most common clinical image of the syndrome. A systematic review of PubMed and EBSCO databases was performed. Articles included in the study had to meet the following criteria: publication between 1980 and 2014, a detailed report on patient symptoms and laboratory test results, medical imaging confirmation of LRV entrapment diagnosis. Fifty-five publications which met the inclusion criteria provided the final database containing 112 cases. The male-female distribution was equal, the mean age on diagnosis for the whole group was 26.47±13.77years. Diagnosis was made earlier in males (23.59±13.09) than females (29.34±13.93). The following frequency of symptoms was noted: 78.57% for haematuria, 38.39% for left flank pain, 35.71% for varicocele in males, 30.36% for proteinuria and 13.39% for anaemia. NCS diagnosis was made earlier if proteinuria occurred as one of the symptoms (P<0.001). Anemia occurred more often in older patients (P=0.0128). NCS was diagnosed in younger age in patients with varicocele (P=0.037). Although NCS is not a common diagnosis, it should be taken into consideration, particularly in hematuria of unknown origin and varicocele.