Renal artery variations: a 20.782 kidneys review.

Introduction: vascular anatomy variations are important in academic, clinical and surgical areas as well as nephrology, urology, oncological and vascular surgery, among others. The main objective of this review is to know the real prevalence of multiple renal arteries in a wide, multiethnic population. Secondary objectives are to establish the prevalence of early branching of the renal artery and the prevalence of these variations in left and right kidneys. Methods: this study analyzes the renal arterial anatomy of 20.782 kidneys from 64 anatomical and radiological studies. Results: Multiple renal arteries (MRA) were present in 19,95% of the total kidneys, in number of 2 to 6 arteries arriving to the hilum. The most frequent number of MRA was 2 renal arteries (89,48%), followed by 3 (9,31%), 4 (1,06%), 5 (0,02%) and 6 (0,005%). This last one being found in only one kidney. Reported data on the lateralization of the MRA are rather poor, and among these no side’s predilection was found: MRA were found in 49,83% on the right side and 50,17% of left kidneys. Early branching patterns were described in only one third of the published data, being present in 11,4% of the total kidneys from those data (corresponding in 4,23% of right kidney cases and in 4,52% of left kidney cases; 2,66% had no right/left information). Discussion: the most difficult part was to merge the results from the different studies due to the heterogeneity of their descriptions. A universally accepted medical nomenclature is needed in order to allow a more precise lecture and transmission of results in clinical practice. Renal anatomical variations have clinical and surgical implications in renal transplantation, correctable hydronephrosis, ablation treatment for refractory hypertension or endovascular reconstructions and should be taken into account by every physician.