Preoperative contrast ultrasonographic diagnosis of patent urachal sinus.

A patent urachal sinus, as well as other congenital urachal anomalies, may be at risk of injury during laparoscopy. Leakage of fluid at the midline site of trocar entry is the usual postoperative sign of injury to a patent urachal sinus. Pre-operative diagnosis of this anomaly can prevent injury during laparoscopy. We describe a contrast ultrasound technique for diagnosis of patent urachal sinus.