Double renal arteries originating from the aorta.

From a study of renal vascularization, we present 54 cases of double renal arteries supplying one kidney and originating from the aorta. Of the 54 cases, 42 were unilateral, showing a left predominance (25 cases), three of them with triple renal arteries on the opposite side. In six cases we encountered bilateral double renal arteries. Most often, the supplementary renal artery originated from the lateral side of the aorta (58%). Examination of the renal approach showed that in 28 cases the supplementary renal artery entered the kidney through the hilum (proper supplementary renal artery), in 16 cases it was inferior polar, in five cases it was superior polar and in five cases the supplementary renal artery terminated in two branches, equal in caliber, one polar and the other hilar, thus showing a combined character, identical with the manner of termination of the main renal artery. In most of the samples the supplementary renal artery ended with a bifurcation inside the kidney, either into the renal sinus (proper supplementary renal artery) or inside the renal parenchyma (polar supplementary renal artery). The course of the double renal arteries showed multiple variations: retroureteral passage of the supplementary renal artery (6 cases), right supplementary renal artery passing anterior to the inferior vena cava (5 cases), crossed course of the double renal arteries (5 cases). Double renal arteries may coexist with other uro-vascular variations, such as: double renal veins on the same side (4 cases) or on the opposite side (3 cases), double ureter on the same side (2 cases) or on the opposite side (1 case), persistence of the fetal renal lobulation on the adult kidney (3 cases) and genital artery originating from the supplementary renal artery (3 cases).