Congenital urachal anomalies are a spectrum of potential anomalies that can occur due to incomplete involution of the urachus.
A urachal remnant occurs in approximately 1 in 5000 patients.
By birth, the urachus is obliterated and becomes a vestigial structure known as the median umbilical ligament (not to be confused with the medial umbilical ligament, which is a separate structure that lies laterally to the median umbilical ligament).
In the absence of complete obliteration, the urachus persists in a number of configurations depending on the location and degree of obliteration.
There are four types of congenital urachal remnant anomalies. They are:
- communication between the bladder and umbilicus through a urachus that has not involuted
- commonest (~50%)
- a fluid-filled dilatation of the mid urachus
- next commonest (~30%)
- blind focal dilatation of the umbilical end of the urachus
- blind focal dilatation of the bladder end of the urachus
Treatment and prognosis
Congenital urachal remnants predispose to infection from urinary stasis and over a long period the remnant may develop malignancy (e.g. adenocarcinoma).
Treatment is not standardised. Some recommend surgical excision of the urachus if a remnant anomaly is present.
- 1. Parada Villavicencio C, Adam SZ, Nikolaidis P, Yaghmai V, Miller FH. Imaging of the Urachus: Anomalies, Complications, and Mimics. Radiographics : a review publication of the Radiological Society of North America, Inc. 36 (7): 2049-2063. doi:10.1148/rg.2016160062 - Pubmed
- 2. Yu JS, Kim KW, Lee HJ et-al. Urachal remnant diseases: spectrum of CT and US findings. Radiographics. 21 (2): 451-61. Radiographics (full text) - Pubmed citation
- 3. Donnelly LF, Frush DP. Cross-sectional imaging of abnormalities of the abdominal wall in pediatric patients. AJR Am J Roentgenol. 2001;176 (5): 1233-9. AJR Am J Roentgenol (full text) - Pubmed citation
- 4. Disantis DJ, Siegel MJ, Katz ME. Simplified approach to umbilical remnant abnormalities. Radiographics. 1991;11 (1): 59-66. Radiographics (abstract) - Pubmed citation