Extracorporeal shockwave lithotripsy in anomalous kidneys.

Traditionally, stones in anomalous kidneys have been removed by open or percutaneous surgery. Extracorporeal shockwave lithotripsy (SWL) with the Dornier MPL 9000 lithotripter was performed in seven patients with horseshoe kidneys, four with pelvic ectopic kidneys, and six with malrotated kidneys. Twelve patients (71%) needed repeated treatments. A total of 11 patients (65%) in all the groups were stone free, and four patients had asymptomatic residual fragments no more than 5 mm in diameter. In the remaining two patients, no sign of stone disintegration was observed, and they underwent open surgery. Extracorporeal lithotripsy is the treatment of choice for stones in horseshoe or malrotated kidneys but is not useful for stones in most pelvic kidneys.