Images in Clinical Medicine

Patent Urachus

Tatsuo Morita, M.D., and Akihiko Tokue, M.D.

N Engl J Med 2000; 343:36July 6, 2000

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Article

Figure 1 The urachus is an epithelial tube that connects the apex of the urinary bladder with the allantois in the fetus and is involved in forming the umbilical structures. The lumen of the urachus usually becomes obliterated during embryonic development. Congenital defects, however, may occur. An 83-year-old woman who had undergone a simple ligation of a patent urachus as a neonate but who had had intermittent urine leakage through the umbilicus thereafter had a patent urachus on T₁-weighted magnetic resonance imaging. The striated structure was present between the bladder and the umbilicus and had a low signal intensity on a sagittal section (Panel A, arrow). Cystography showed that the bladder was triangular (Panel B). The urachus and the attached bladder wall were excised. Over the subsequent three years, the patient did not have urine leakage.

Tatsuo Morita, M.D.
Akihiko Tokue, M.D.
Jichi Medical School, Tochigi, Japan