Antegrade and Retrograde Endoscopic Approaches for Managing Obstructing Ureteral Calculi in Renal Transplant Patients: An Illustrative Case Series.

To demonstrate the various antegrade and retrograde endourologic approaches that may be required for effectively treating kidney transplant recipients presenting with ureteral obstruction caused by urolithiasis. We prospectively evaluated endoscopic management techniques of renal transplant recipients referred to a national kidney transplant center with obstructing transplant ureteral calculi for a 12-month period (April 2019-April 2020). Four kidney transplant recipients presented with ureteral obstruction caused by urolithiasis and the mean age was 66.6 (range: 62-71) years. The mean duration from renal transplantation was 16 (range: 6-25) years. Three patients presented with acute urosepsis and one patient presented with malaise and recurrent urinary tract infections. Two patients were definitively treated with percutaneous antegrade flexible ureteroscopic lithotripsy through a 16F minipercutaneous nephrolithotomy sheath. Two patients were definitively treated with retrograde flexible ureteroscopy (7F single-use disposable ureteroscope) and laser lithotripsy. Full stone clearance was achieved in all four patients and no perioperative complications occurred. Management of ureteral calculi in renal transplant recipients is challenging. A multimodal approach involving antegrade and retrograde endoscopic techniques may be required to achieve full stone clearance.