Stones in horseshoe kidneys: results of treatment by extracorporeal shock wave lithotripsy and endourology.

We report the results of 7 patients with calculi in a horseshoe kidney treated by extracorporeal shock wave lithotripsy (ESWL, 9 renal units) and percutaneous nephrolithotripsy (3 renal units) during a 3-year period. In the ESWL only group complete stone clearance was achieved in only 3 patients (50%) after an average of 3 sessions of therapy. On the other hand, complete stone clearance was achieved by percutaneous nephrolithotripsy with minimal complications. The poorer results with ESWL were due to difficulty in ultrasonographic localization of stones as well as poor drainage in these abnormal kidneys. Our experience with the Edap LT01 and the Sonolith 2000 lithotriptors suggests that while reasonable results are possible, treatment probably will require multiple sessions and the eventual outcome is less predictable than in normal kidneys. In contrast, the treatment of complicated stones in a horseshoe kidney presents no additional difficulty.