Urachal remnant causing umbilical in-drawing during micturition.

The urachus is a vestigial remnant of the allantois, which is normally obliterated during fetal life to become the median umbilical ligament, which runs between the urinary bladder and umbilicus in adults. Failure of obliteration leaves a tubular urachal remnant, which may present with disease. We report a unique case of a urachal remnant causing umbilical pain and in-drawing on micturition in a nine-year-old boy. There was no urine discharge from the umbilicus and in-drawing did not occur on defecation. His urinary stream was normal. High frequency ultrasonography revealed a thick band with a narrow, anechoic, fluid filled central channel. Exploration via an infraumbilical curvilinear incision identified a thick urachal band that could be traced to the dome of the bladder. This was excised flush with the bladder. The patient remains well at nine months following surgery with complete cessation of symptoms.