Urachal anomalies

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[edit] Discussion of Urachal anomalies

  • The urachus connects the dome of the bladder to the umbilicus duct during fetal life.
  • The urachus is located behind the abdominal wall and anterior to the peritoneum in the space of Retzius.
  • Before birth, the urachus is obliterated and becomes a vestigial structure known as the medial umbilical ligament.
  • In the absence of complete obliteration, the urachus persists as either a patent urachus, urachal cyst, urachal sinus, or urachal diverticulum.

[edit] Patent urachus

  • Patent urachus represents the failure of the entire course of the urachus to close resulting in an open channel between the bladder and the umbilicus.
  • A patent urachus is usually diagnosed in the neonate when urine is noted leaking from the umbilicus.

[edit] Urachal cyst

  • Urachal cyst forms when both the umbilical and vesical ends of the urachal lumen close while an intervening portion remains patent and fluid filled.
  • Urachal cysts usually remain obscure until complicated by infection or bleeding.

[edit] Urachal sinus

  • Urachal sinus is a noncommunicating dilatation of the urachus at the umbilical end.

[edit] Urachal diverticulum

  • Deformity that communicates with the anterosuperior aspect of the bladder as a result of failure of the urachus to close at the bladder.
  • A urachal diverticulum frequently coexists with congenital obstruction of the lower urinary tract.

[edit] Imaging Findings for Urachal anomalies

[edit] Patent urachus

  • Demonstrated by retrograde injection of contrast material into the orifice of the channel at the umbilical end or during VCUG in the lateral projection.
  • Patent urachus manifests at longitudinal US as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus.
  • Occasionally, patency of the urachus can be demonstrated at CT.

[edit] Urachal cyst

[edit] Urachal sinus

  • An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus.

[edit] Urachal diverticulum

  • This anomaly is identified as a urine-filled anterosuperior extension from the bladder dome at VCUG, US, CT, or MR imaging.


[edit] Images

Patient #1: Patent urachus

[edit] References for Urachal anomalies