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

Purpose: 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. Materials and Methods: 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). Results: 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. Conclusion: 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.