Review Question - QID 106451

Leaking of urine from the umbilical stump represents a failure of obliteration of the urachus. The urachus is the embryological remnant of the allantois that originally connected the bladder to the yolk sac.

Failure of urachal obliteration results in an abnormal connection between the bladder and outside. In severe cases, the bladder can extrude through the umbilicus (urachal diverticulum) and must be corrected surgically. During normal development the allantois provides a connection between the bladder and yolk sac. It then gives rise to the umbilical artery and vein. During normal development the urachus is obliterated and gives rise to the the median umbilical ligament which connects the bladder to the anterior abdominal wall.

Naditch et al. review their experience with the management of urachal remnants. They found that there is a subset of patients in whom spontaneous resolution can be expected. If surgery is required, complications including persistent urachus, umbilical hernia, bladder leak and wound infection are not uncommon.

Lipskar et al. review their experience with the non-operative management of urachal remnants. They found that in many cases, drainage of a urachal cyst will precipitate obliteration of the cyst over time. They found that this process would occur even in cysts that showed signs of infection.

Illustration A is a schematic diagram showing the consequences of abnormal obliteration of the urachus.

Incorrect Answers:
Answer 1: A patent ductus arteriosus would not present in this fashion.
Answer 3: There is never an anatomic connection between these structures.
Answer 4: The remnant of this structure is the ligamentum teres.
Answer 5: There is never an anatomic connection between these structures.