Retrograde intrarenal surgery of renal stones: a critical multi-aspect evaluation of the outcomes by the Turkish Academy of Urology Prospective Study Group (ACUP Study)

Aims: To outline and evaluate the incidence, management and follow-up of the residual fragments (RFs) following retrograde intrarenal surgery (RIRS) of renal stones by the Turkish Academy of Urology Prospective Study Group (ACUP Study). Methods: Following the ethical committee approval, 15 centers providing data regarding the incidence, management, and follow-up of RFs after RIRS were included and all relevant information was recorded into the same electronic database program (https://acup.uroturk.org.tr/) created by Turkish Urology Academy for Residual Stone Study. Results: A total of 1112 cases underwent RIRS for renal calculi and RFs were observed in 276 cases (24.8%). Of all the parameters evaluated, our results demonstrated no statistically significant relation between preoperative DJ stenting and the presence of RFs (χ2 (1) = 158.418; p = 0.099). RFs were significantly higher in patients treated with UAS (82 patients, 29.3%) during the procedure compared to the cases who did not receive UAS (194 patients, 23.3%) (χ2 (1) = 3.999; p = 0.046). The mean period for a secondary intervention after RIRS was 28.39 (± 12.52) days. Regarding the procedures applied for RF removal, re-RIRS was the most commonly performed approach (56%). Conclusions: Despite the reported safe and successful outcomes, the incidence of RFs is higher, after the RIRS procedure particularly in cases with relatively larger calculi. Such cases need to be followed in a close manner and although a second flexible ureteroscopy is the treatment of choice for fragment removal in the majority of these patients, shock wave lithotripsy and percutaneous nephrolithotomy may also be preferred in selected cases.