Minimally invasive treatment of renal transplant nephrolithiasis.

PURPOSE: Urolithiasis is a rare complication of renal transplantation, and there is limited evidence to guide treatment. Management of stones in the transplanted kidney can be challenging. We present our experience in treating upper urinary tract (UUT) allograft lithiasis using minimally invasive procedures, with the aim of demonstrating their efficacy and safety in renal transplant recipients.

METHODS: The records of 1615 patients undergoing kidney transplantation and follow-up in our center between August 2000 and July 2014 were reviewed. The mode of presentation, donor type, onset time, immunosuppression protocol, stone character, therapeutic intervention and outcomes of those with UUT allograft lithiasis were recorded. Extracorporeal shock wave lithotripsy (SWL), flexible ureteroscopy (F-URS) and percutaneous nephrolithotomy (PCNL) were used in the management of these calculi. Stone composition was analyzed after the procedure.

RESULTS: Nineteen renal transplant recipients (1.2 %, nine males and ten females) were found to have UUT allograft calculi. Of these, five underwent SWL (26.3 %), four had F-URS combined with lithotomy forceps extraction or holmium laser disruption (21.1 %), six had PNCL (31.6 %), one submitted to F-URS after two failed sessions of SWL (5.3 %), one combined PCNL and F-URS (5.3 %), and two spontaneously of stones (10.5 %). All patients were rendered stone-free with a combination of treatments, and none required a blood transfusion.

CONCLUSIONS: The incidence of calculi in the transplanted kidney is low. Minimally invasive procedures are safe and effective means of removing allograft calculi.