Dị tật ống niệu rốn The urachus is an embryological canal connecting the urinary bladder of the fetus with the allantois, a structure that contributes to the formation of the umbilical cord. The lumen (inside) of the urachus is normally obliterated during embryonic development, transforming the urachus into a solid cord, a functionless remnant. The urachus lies in the space of Retzius, between the transversalis fascia anteriorly and the peritoneum posteriorly. Formation The vesico-urethral portion of the urogenital sinus absorbs the ends of the Wolffian ducts and the associated ends of the renal diverticula, and these give rise to the trigone of the bladder and part of the prostatic urethra. The remainder of the vesico-urethral portion forms the body of the bladder and part of the prostatic urethra; its apex is prolonged to the umbilicus as a narrow canal, which later is obliterated and becomes the median umbilical ligament (urachus). Note: The two medial umbilical ligaments are the obliterated umbilical arteries. Pathology Failure for the lumen of the urachus to be filled in leaves a patent (open) urachus. The telltale sign is leakage of urine through the umbilicus. A patent urachus needs to be surgically removed. There are four anatomical cases 1. Urachal cyst: there is no connection between the bladder and the umbilicus 2. Urachal fistula: there is free communication between the bladder and umbilicus 3. Urachal diverticulum: the pouch opens toward the bladder 4. Urachal sinus: the pouch opens toward the umbilicus . Dị tật ống niệu rốn The urachus is an embryological canal connecting the urinary bladder of the fetus