ABSTRACTS 13th International Symposium on Urolithiasis LECTURE L-01 Extracorporeal shock wave lithotripsy (ESWL) Christian G. Chaussy 1 , Hans-Go ¨ran Tiselius 2 1 University of Regensburg, Germany; 2 Department of Clinical Science, Karolinska Institutet, Stockholm, Sweden Despite the successful achievements with SWL there is presently a trend towards the preferred use of invasive endoscopic procedures rather than a non-invasive approach by means of SWL. This development is an effect of a considerable discrepancy in SWL results. Literature data name stone-free rates for renal and ureteral stones in the range of 32–90 % and 43–98 %, respectively, and a similar variation in terms of successful stone disintegration. Proper use of the lithotripsy system and correct application of shock waves are crucial aspects for the SWL outcome regarding efficacy and safety. Before asking for technical improvement it needs to be pointed out that a significant fraction of patients with inferior SWL results could have been better treated if the SWL technique had been used in an appropriate way. Lack of interest in SWL and the false assumption that it is the lithotripter rather than the operator that is responsible for the treatment result are a bad prerequisite for success. All users should be aware, that SWL is a complex technology with potential risks and that they must have basic knowledge of the under- lying physics as well as of characteristics and features of the used lithotripsy system. Sufficient analgesia, fixation of the patient, proper coupling of the shock wave system and a slow shock wave adminis- tration rate are important measures to ensure a good stone disintegration. Patient adapted selection of shock wave parameters, pretreatment with low shock wave energy and renoprotective drugs like calcium channel blockers or antioxidants seem to be beneficial for a reduction of tissue traumatization. Stonefree rate after SWL can be improved with supporting measures like physical therapy (percussion, diuresis, inversion) and short term medical therapy (medical expulsive therapy) with a1-receptor blockers or calcium channel blockers. In spite of all newly arisen discussion SWL still remains the only non-invasive treatment modality for urolithiasis besides conservative stone management and it plays a major role in stone therapy due to its efficacy, low rate side effects and comfortable application, without the need of general anaesthesia and—last but not least— patients’ acceptance. COI: No. L-02 Residual fragments: definition, evaluation and management Kemal Sarica Department of Urology, Dr. Lutfi KIRDAR Research and Training Hospital, Turkey The number of patients undergoing active minimal invasive stone removal procedures is steadily increasing. Depending on this fact again, concern of the residual stone material is being encountered in a significant proportion of the patients treated im this manner. Although the residual fragments (RF) are commonly seen after ESWL, but they may also remain in the renal collecting system following PNL and RIRS. Currently, a consensus that symptomatic residuals need to be eliminated has been established while studies did show that in up to 42 % of the of these patients additional stones may form at a follow- up of 5 years. Again, long-term studies did show that recurrent stone formation may be seen in as many as 70–80 % of the patients after 10–20 years. Regarding the definition of RF; asymptomatic, non obstructive as well as non-infection related stone particles sizing less than 4 mm after certain types of treatment are being accepted as RF. The risks involved with RF are new stone formation, recurrent UTI and obstruction-pain due to positional change. Some types of calculi including infection, uric acid and cystine stones have the most like- lihood of growth over time. On the other hand, for calcium containing stones the presence or absence of metabolic risk-factors are highly important for re-growth and new stone formation. Available data showed that secondary procedures are needed in symptomatic patients with urinary obstruction and UTI as well as in special cases as pilots and kidney recipients. Although stone type, size and location seem to be important for future changes in residual fragments; extensive invasive methods, do not seem to be necessary in a majority of these patients, where SWL will be the first choice. However removal of all remaining fragments is paramount importance in patients with non- calcium contain in stones. Last but not least, while calcium stone residual fragments usually do not require aggressive re-treatment with the aim of removing every little fragment from the kidney; they require a meticulous metabolic evaluation and recurrence preventive measures. COI: No. L-03 Urinary risk factors for urolithiasis William G. Robertson Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, UK Objectives: Three systems are compared for assessing the biochem- ical risk of forming urinary stones based on the composition of 24-h urine. Methods: The relative supersaturation of urine (RSS), the Tiselius Indices (TI) and the Robertson Risk Factor Algorithms (P sf ) are compared in the 24-h urine samples from 460 consecutive calcium and/or uric acid stone-formers in terms of the numbers of variables required to be measured, the ease of use of the system and the relative cost of the analyses concerned. Results: The calculation of RSS (SUPERSAT) requires 12 analyses in every urine sample but provides RSS data on calcium oxalate 123 Urolithiasis (2016) 44 (Suppl 1):S1–S66 DOI 10.1007/s00240-016-0883-8