What this Trial Is About

Background/Rationale for the study: Lithiasis pathology is increasingly common because of the change in our lifestyle and our food. Thus, we hold a prevalence for urinary lithiasis 10% in France currently including 13% of the male population and 6% of the female population. The formation of urinary lithiasis is the result of a complex mechanism involving factors anatomical and infectious metabolics. They are classified according to their size, topography and composition. The treatment of urinary lithiasis has changed dramatically in recent years. The recommendations of the French Urology Association (AFU) for the management of kidney stones and ureteral of the adult of 2004 give a certain place to the treatment by extracorporeal lithotripsy (ECL). The ELC is indicated for the first purpose for lithiasis ureteral or renal lithiasis of less than 20 mm, whether or not associated with the setting up of a JJ stent. For kidney stones of more than 20 mm or complex or Coralliformes, the ECL can be associated with treatment with percutaneous nephrolithotomy. In addition, the ECL is indicated in case of residual cholelithiasis 3 months after a first treatment whatsoever. It is found, as the main complication of the ECL, a risk of the appearance of Hematomas under capsular, peri-renal and intra-parenchymatous. Its prevalence is estimated to be between 6.2% and 13% according to studies. ACETYLSALICYLIC ACID less or equal to 250 mg is the usual dosage of aspirin (for the adult), the Marketing Autorisation recognises in secondary prevention after a first myocardial or cerebral ischemic attack related to atherosclerosis. It entrains a reduction mortality and morbidity of cardiovascular causes. Acetylsalicylic acid is currently being stopped 5 to 7 days before the ECL. The interest of maintaining the Acetylsalicylic acid is: * A simplification of the management of patients under on acetylsalicylic acid below (or equal to) 250 mg (No modification of Treatment to be implemented) * A cardiovascular risk decreased by maintaining their initial treatment without any modification. Main objective: Evaluation of the proportion of renal hematoma during the production of Lithotripsy for renal lithiasis, on a 15-day scan, in patients under on acetylsalicylic acid below (or equal to) 250 mg not stopped Secondary objectives: Evaluation of the efficacy of treatment with lithotripsy (Stone free, fragments Minimal residuals) Evaluation of the proportion of hematuria macroscopic post lithotripsy in Patients under on acethylsalicylic acid not stopped. Evaluate the rate of post-ECL complications requiring treatment, Analgesic, obstructive pyelonephritis. Evaluate post-ECL pain due to hematoma or lithiasis migration Evaluation of the evolution of renal function post session of Lithotripsy on the patients under acethylsalicylic acid not stopped. Type of Study: Interventional study, prospective, mono centric, single-arm

Maintenance of an Antiaggregation by Acetylsalicylic Acid, While a Extracorporeal Lithotripsy Session on a Kidney Stone is Perfomed: Comparative Unicentric Prospective Study