Predictors of intervention in Steinstrasse following shock wave lithotripsy (SWL)

Introduction Steinstrasse (SS) is a well known complication of shock wave lithotripsy (SWL)and occurs in 2-10 of cases. The majority of SS clears spontaneously whereas about 6 require intervention. This study was carried out to see whether the need for intervention in SS could be predicted.Material and method This was a retrospective study spanning 6 years. It included all patients who had steinstrasse following SWL at our center. They were divided into two groups A) Those who cleared steinstrasse spontaneously and B) Those required interventions. The two groups were compared with regard to demographic profile, stone factors and steinstrasse factors. Steinstrasse was classified according to Coptcoat classification.Results Out of 2436 only 89 (3) formed steinstrasse. The majority of the patients (35) who formed steinstrasse and who required intervention were in the group 10-14mm. Coptcoat type III steinstrasse required significantly more interventions for clearance (p0.001). The site and the size of the SS was not a predictor of intervention of SS.Conclusions Early intervention is warranted in patients with steinstrasse where the lead fragment is 5mm (Coptcoat type III).