Extracorporeal shock wave lithotripsy in horseshoe kidneys
Horseshoe kidneys are prone to stone formation because of their special anatomy. Extracorporeal shock wave lithotripsy (E.S.W.L.) treatment of these stones is associated with some problems. In this study factors influencing the outcome of E.S.W.L. as a monotherapy for horseshoe kidney calculi are assessed. During a 3 year period 28 horseshoe kidneys were treated for urinary calculi using Siemens Lithostar. Of these 19 stones were located in pelvis and 10 in the calyces ( one case of bilateral stones).Stones diameters ranged from 9 mm to 32 mm. Patients were followed between 4 and 36 months (average 24 months). Stone fragmentation rate was 82.7% (24/29) but stone free rate was 55.2% (16/29). This discrepancy is largely due to retained fragments in calyces specially the lower ones. Some factors such as the degree of calyceal dilation and the initial size of the stone are related to the failure of stone clearance. We analysed these data & suggest that E.S.W.L. is not a convenient monotherapy for stones located in the horseshoe kidneys,when the stone size is large (greater than 2 cm ) and the kidney is hydronephrotic.(0.05p).