Retrospective Analysis of patients that received shockwave lithotripsy as Treatment of ureteral or kidney Stones. Condition examinated is the effect of low molecular weight Heparins and acetylsalicylic acid on the Formation of renal hematoma after shockwave lithotripsy. Primary outcome is documented hematoma in a postoperative ultrasound control. Secondary outcomes are perioperative complication, Need for erythrocyte tranfusion, interventions for bleeding control, readmission or death within 30 days.

Inclusion Criteria:

• consent
• Stones in kidney and proximal Ureter
• Treatment with shockwave lithotripsy for urolithiasis between January 2009 and September 2015 at Kantonsspital Winterthur

Exclusion Criteria:

• other Position of ureteral Stones
• missing data in Patient reports
• refused consent
• under Age limit

All patients that received shockwave lithotripsy at Kantonsspital Winterthur between January 2009 and September 2015 and were 18 years or older at the time of treatment