Embryological Origin

Embryological origin
Embryological origin has been considered the most acceptable theory to explain the prevalence of variants in renal vasculature. The theory proposed by W.Felix is the most quoted and widely accepted explanation of the embryological origin of the variants in renal vasculature. The mesonephros, in a 5th week human embryo, is supplied by a group or arteries arising from the lateral surface of the abdominal aorta. As given in Fig 1a.

Figure 1
Their primary distribution is noted within the mesonephric area, but later they also supply the reproductive glands, suprarenal bodies, metanephros and diaphragm. The number of mesonephric arteries is variable, and it follows the degeneration of the mesonephros with the progressive

Each renal artery is divided into anterior and posterior branches (presegmental arteries) at the hilium of the kidney. The further division of the arteries is into following branches apical, upper, middle, inferior and posterior.

ARTERIAL VARIATIONS
It has been established that each of the segments is supplied by their own segmental artery without any collateral connection therefore the importance of each and every branch is equal and needs proper evaluation(33).
The variations that we observe are probably the result of anomalous degeneration of the rete arteriosum urogenitale and the rest of the mesonephric arteries. This may explain why there is some variation in the point of origin of those arteries that persist to form the final segmental arteries of the adult kidney.
The diversity in renal arterial anatomy can be classified according to the number, division pattern as well as distribution/origin of the arteries. Accessory renal arteries can arise from the abdominal aorta above the main branch or as low (inferiorly) as the internal iliac artery. Varied origins such as the iliac, superior and inferior mesenteric, celiac, middle colic, lumbar, middle sacral and contralateral renal arteries have been reported