Morphological study of a horseshoe kidney with special reference to the vascular system.

This is a morphological study on an autopsy case of horseshoe kidney found in a 79-year-old-female cadaver. This kidney consisted of two distinct renal masses that were connected at their lower poles by a parenchymal isthmus that was located in the front of the abdominal aorta at the level of the fourth lumbar vertebra. The kidney was supplied by four arteries arising from the abdominal aorta. The distribution of intrarenal arteries showed that the nature of segmental arteries in the present case was basically the same as in the normal kidney, except that the isthmus had its own blood supply from the artery directly arising from the aorta approximately 28 mm below the origin of the inferior mesenteric artery. Venous drainage from the kidney, including the isthmus, was taken by three veins that opened independently into the inferior vena cava. No congenital malformations were found in other organs. We discuss the anatomical and embryological significance of this anomaly and its associated vascular system.