Long-term effects of ureteroscopic laser lithotripsy on glomerular filtration rate in the face of mild to moderate renal insufficiency

Background and Purpose: Ureteroscopic laser treatment of calculi in the upper urinary tract was examined in regard to its effect on renal function in the setting of mild renal insufficiency. Percutaneous nephrolithotomy (PCNL) and SWL have been previously shown not to adversely affect the glomerular filtration rate (GFR) in renal insufficiency, but to our knowledge, the effect of ureteroscopic laser lithotripsy on GFR has not been previously reported. Patients and Methods: A retrospective review of all cases of ureteroscopic laser lithotripsy at our institution was performed. A total of 18 patients with a baseline serum creatinine of greater than or equal to1.5 mg/dL were found. The mean follow-up after treatment was 18.0 months (range 4-39 months). The change in the reciprocal of serum creatinine was used as an indicator of change in the GFR. Deterioration of 20% was considered significant. Results: The overall mean change in treated patients was a 5.9% improvement. Patients with a preoperative creatinine of <2.0 mg/dL improved 7.6% and those with creatinine of greater than or equal to2.0 mg/dL increased 3.9%. Other factors such as the size of the stone, location of the stone, and total joules used during treatment were not significant. Conclusion: This examination suggests that ureteroscopic laser lithotripsy has no ill effects on renal function in the face of mild to moderate renal insufficiency.