[The recommendations of the S2k guideline for the diagnosis, therapy and metaphylaxis of urolithiasis provide a safe course of action for ureterorenoscopic stone treatment - results of the BUSTER study].

BACKGROUND  Given the high incidence, prevalence and rate of recurrence, urolithiasis stone treatment at a high stone-free rate should have a low complication rate. The German S2k guideline (GS2k-GL) for the diagnostic testing, therapy and metaphylaxis of urolithiasis provides recommendations for the first and second choice for stone treatment, depending on stone location and size. Ureterorenoscopy (URS) is the treatment of first choice for most stones. URS is only the second option for renal stones > 20 mm and proximal ureteric stones ≤ 10 mm. The objective was to examine the impact of using URS as the stone treatment of first or second choice on the endpoints stone-free rate and severity of complications. PATIENTS/METHODS  The multicentric prospective observational study "Evaluation of ureteroroscopic stone treatment - results with regard to complications, quality of life and the stone-free rate" (BUSTER) standardised recorded perioperative data from 307 patients who had undergone ureterorenoscopic stone treatment from January to April 2015 at 14 German urological clinics. Treatment decisions were not affected by the study protocol. RESULTS  In the univariate analysis, the stone-free rate for ureteric stones was significantly higher when URS was the treatment of first choice (OR 2.21, 95 % CI 1.11 - 4.40, p = 0.027). After adjustment for age, BMI, ASA score, preoperative ureteral stenting, stone location and size, presence of multiple stones, experience of the surgeon, acute or elective URS and operating time, the application of URS as treatment of first choice had no significant effect on the stone-free rate (OR 2.048, 95 % CI 0.890 - 4.710, p = 0.092). After adjustment for stone location and size as well as ureteral stenting following URS, the application of URS as treatment of first choice had no significant influence on the severity of complications (OR 1.019, 95 % CI 0.347 to 2.993; p = 0.973). CONCLUSION  On the basis of our data, URS proved to be a safe and effective stone treatment procedure regardless of the degree of guideline conformity. Although the stone-free rate was higher with URS as treatment of first choice, the results of URS as treatment of second choice were not significantly worse. The recommendations of the GS2k-GL offer a safe guide for ureterorenoscopic stone treatment. The tendency for higher stone-free rates in URS as a treatment of first choice should be examined in further studies.