Urolithiasis in renal transplantation: diagnosis and management.

OBJECTIVES To report our experience of diagnosis and multimodal management of urolithiasis in renal transplantation. PATIENTS AND METHODS From January 1995 to December 2012, 953 patients underwent renal transplantation in the Kidney Transplant Unit of Treviso General Hospital. Ten (10%) of them developed urinary calculi and were referred at our institution. Their mode of presentation, investigation and treatment were recorded. RESULTS Seven had renal and 3 ureteral calculi. Urolithiasis was incidentally discovered on routine ultrasound in 6 patients, 1 presented with oliguria, 1 with anuria and acute renal failure and in 2 urolithiasis was found at removal of the ureteral stent. Nephrostomy tube was placed in 5 patients. Hypercalcemia with hyperparathyroidism (HPT) was present in 5 patients and hyperuricemia in 3. Two patients were primary treated by shock wave lithotripsy (SWL) and one of them was stone-free after two sessions. Two patients, one with multiple pielocaliceal calculi and the other with staghorn calculus in the lower calyx, were treated with percutaneous nephrolitothotomy (PCNL). Three patients were treated by ureteroscopy (URS) and in one of them two treatments were carried out. One patient had calculus impacted in the uretero-vesical anastomosis and surgical ureterolithotomy with re-do ureterocystoneostomy was performed after failure of URS. Two patients with calculi discovered at removal of the ureteral stent were treated by URS. CONCLUSIONS The incidence of urolithiasis in renal transplantation is uncommon. In the most of patients the condition occurs without pain. Metabolic anomalies and medical treatment after renal transplantation may cause stone formation. Advancements in endourology and interventional radiology have influenced the management of urolithiasis that can be actually treated with a minimal incidence of risk for the renal allograft.