Horseshoe kidney ascent is prevented by:
Ascent of horseshoe kidney remains incomplete due to Inferior Mesentric Aery prevents fuher migration of kidney . Isthmus usually located adjacent to L3-L4 veebrae , just below the origin of IMA from abdominal aoa .
Superior mesenteric aery
Superior mesenteric vein
Inferior mesenteric aery
Inferior mesenteric vein
Kidney and ureter