LAUSR

BACKGROUND Urolithiasis has been reported in up to 1.8% of patients after renal transplantation. Limited data are available regarding the treatment of such patients owing to this low prevalence. OBJECTIVE To analyse a consecutive series of 2115 renal transplantations to elucidate the prevalence of renal graft stones (RGS) and their treatment. DESIGN, SETTING, AND PARTICIPANTS A retrospective review was performed of a consecutive series of renal transplants from 1983 to 2017. Demographic and specific data regarding symptomatology, diagnosis, and treatment of RGS were recorded. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Quantitative and qualitative variables were described. Differences in clinical variables were evaluated using unpaired t test. Statistical significance was set at p<0.05. RESULTS AND LIMITATIONS In total, 51 patients (2.4%) were diagnosed with de novo RGS. Mean stone size was 9±6.5mm, 31.4% being multiple stones. The distal ureter was the most common location (49%). Treatment modalities were extracorporeal shock wave lithotripsy (ESWL; 43.1%), active surveillance (25.4%), retrograde ureteroscopy (URS; 17.6%), antegrade URS (3.9%), percutaneous nephrolithotomy (3.9%), open approach (3.9%), and urine alkalisation (2%). Seven (13.7%) patients developed complications: two haematuria, three urinary tract infection, one steinstrasse, and one sepsis. Median follow-up was 72 mo. Overall stone-free rate was 52.9%. No significant differences were observed between mean glomerular filtration rate before and after treatment (p=0.642). There were no cases of graft loss. Limitations include the retrospective nature of the study and limited number of patients. CONCLUSIONS RGS is an uncommon complication. ESWL, endoscopic surgery, and surveillance have been used to treat or follow up such patients. In well-selected patients, endourological surgery appears to achieve better outcomes. RGS does not have a long-term impact on graft function or graft survival. PATIENT SUMMARY It is uncommon to develop stones in the transplant kidney. If such stones are properly diagnosed, several minimally invasive treatment options can yield good results while maintaining good renal function.