A Case Study of Malrotated Kidneys with Asymmetric Multiple Renal Arteries, Variant Venous Drainage, and Unilateral Ureteral Duplication

Figure 5

Simplified schematic representation of renal development. Around 5 weeks of fetal life, kidneys are formed from the metanephros. They are situated at the level of the pelvis and pelvic branches of the common iliac artery provide initial arterial blood supply. During the following 3 weeks, the kidneys ascend in the abdominal cavity (a) to their adult retroperitoneal location. As they move cranially and the metanephros coalesces, the lower arteries degenerate to, most often, leave a single renal artery as the main arterial supply. Occasionally, the temporary arteries (dotted lines (a)) do not degenerate leading to anatomical variations in the adult (). The cardinal systems contribute to the developing venous network of the kidney as it ascends (b). Persistence of some aspects of the developing venous network may lead to anatomical variations in the adult (dotted lines (b), ()). More than one ureteric bud may penetrate the metanephric mesoderm during ureteral development (c) that results in duplex kidney (left ()).