[Variability in occurrence, course and division into branches of renal arteries in human fetuses]

The existence and position of kidneys and suprarenal glands as well as the occurrence of the renal arteries were examined in 347 human fetuses between 3 and 9 months of age. The studies on the course and division variability of the right and left renal arteries were performed in 220 fetuses. The investigations consisted in filling arteries with resin, X-raying and preparing. No absence of a kidney, suprarenal body and renal artery was disclosed. In 2 cases an abnormal position of the right kidney was stated. The renal arteries, both right and left, were most frequently running off from the aorta as single branches, the right one in 190 (86.4%) cases, the left in 152 (69%) cases. Two branches on the right side were recorded in 24 (10.9%) fetuses, and on the left side in 56 (25.5%) fetuses. Three renal branches were stated in 6 (2.7%) on the right side and in 12 (5.5%) fetuses on the left side. In 50.9% of cases the renal arteries were leaving the aorta symmetrically on the same level. In 32.7% the right renal artery was higher and in 2.7%, it was lower than the left one. The horizontal course from the aorta to the kidney hilus of the right renal artery was observed in 83 (37.7%) and of the left one in 99 (45%) of fetuses. In others the renal arteries were running less or more obliquely and downwards. The way, in which the right and left renal arteries are divided into branches, and also the departure places of renal suprarenal ramifications were so different that it is not possible to work out their classifications.