Which Method Is Best for Stone Localization in Horseshoe Kidneys

Seven patients with calculi in horseshoe kidneys were treated with extracorporeal shock wave lithotripsy on a Dornier MPL 9000-X lithotripter. Ultrasound localization of stones proved more difficult than the X-ray technique because of the anatomic abnormality and the difficulties in targeting stones located in anterior renal calices. When treatment success was judged by stone fragmentation and clearance, there was no difference between treatments given under X-ray or ultrasonic imaging. However, fluoroscopic targeting was accomplished more easily. The longer focal distance of the Dornier X-155 electrode, together with shock wave entry via the anterolateral abdominal wall, were particularly advantageous. For third-generation lithotripters with fluoroscopic and ultrasound imaging modalities, we recommend fluoroscopic imaging as the best method for localization of stones in horseshoe kidneys.