The urachus, a fibrous cord connecting the umbilicus to the anterosuperior aspect of the bladder dome, usually obliterates at birth and becomes the median umbilical ligament
Urachal pathology results from failure of involution of the embryonic structures, resulting in the formation of a urachal cyst, umbilical urachal sinus, vesicourachal diverticulum or patent urachus - completely patent, tubular remnant communicating the developing bladder and the umbilical cord