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The role of ureteral stent placement in the prevention of Steinstrasse.

BACKGROUND AND OBJECTIVE
Steinstrasse constitutes a potentially serious complication of extracorporeal shock-wave lithotripsy (SWL). Ureteral stent placement has been used to prevent Steinstrasse after fragmentation of larger stones. However, particularly more recently, its preventive efficacy has been questioned. The aim of this study therefore was to analyze the role of ureteral stent placement in the prevention of Steinstrasse.


METHODS
We analyzed data of 1087 patients who had been treated with a Wolf Piezolith 2300 in the General Infirmary in Leeds/UK for stones ranging from 10 to 95 mm in diameter.


RESULTS
The incidence of Steinstrasse was 6.3%. The likelihood was significantly correlated with the stone size and was significantly less in patients with stones >20 mm if a stent had been inserted prior to SWL. Moreover, in these patients, the risk of acute clinical symptoms in the event of Steinstrasse was greatly reduced, and the treatment could be continued safely in the majority of cases (86%). Treatments of the Steinstrasse itself with SWL resulted in its clearance in most of the cases (78%). It was always possible to clear even extended persistent Steinstrasse by laser lithotripsy.


CONCLUSION
These results provide a clear indication for the pre-SWL insertion of a ureteral stent in patients with stones >20 mm in diameter. In the event of Steinstrasse, SWL of the collection should be tried before more invasive endourologic procedures are considered.