Urachal remnants: from embryology to clinical practice

Abstract

The urachus is a tubular structure that is apparent on the third week and connects the ventral cloaca to the yolk sac, as a progression from the allantois. Following the normal regression procedure, the urachus remains as the median umbilical ligament. Urachal remnants are present in 1.03% of paediatric patients while in 92.5% of cases represent incidental findings. Urachal anomalies are classified in four types as patent urachus (50-52%), urachal sinus (15%), urachal cyst (30%) and urachal diverticulum (3-5%). Ultrasound scan is the most commonly performed diagnostic imaging study. In case of symptomatic urachal remnants, surgical excision is indicated. Asymptomatic urachal remnants that are diagnosed at the neonatal period or early infancy should be watched up to 6 months of age, as they are likely to resolve. In persistent or symptomatic urachal remnants there is a risk of inflammation or even malignancy development, therefore we believe that there is indication for preventive surgical excision that may be performed either open or laparoscopically or by robot-assisted laparoscopy.