What is duplicity?

Congenital condition where the kidneys have two separate drainage systems instead of one, two ureters and two renal pelvises. The first ureter inserts laterally to the lower moiety of the kidney and drain in the normal location into the trigone of the bladder and commonly leads to reflux. The second ureter inserts medially into the upper moiety of the kidney and will drain in an ectopic location away from the bladder which commonly leads to obstruction.