Comparison of relative renal function by renal scintigraphy and lateralized creatinine clearance in children with bilateral vesicoureteral reflux.

OBJECTIVES

To evaluate the relative renal function on preoperative and postoperative renal scintigraphy with lateralized creatinine clearance. Multiple factors affect renal blood flow and glomerular filtration that alter the relative renal function calculated by renal scintigraphy. The relative renal function according to renal scintigraphy in children with bilateral vesicoureteral reflux has not been compared with lateralized creatinine clearance.

METHODS

We retrospectively reviewed the charts of 45 children treated surgically for bilateral vesicoureteral reflux. The average age at time of reimplantation was 5.3 years. Bilateral ureteral catheters were placed intraoperatively. Lateralized creatinine clearance was measured with 24-hour urine collections postoperatively from each catheter. Bladder catheterization was not performed during the renal scans.

RESULTS

Thirty-six of 45 children had preoperative 1 to 3-minute relative renal function assessed by scintigraphy, 28 had a postoperative assessment, and 24 had both. Preoperative relative renal function ranged between 51% and 94% (mean 61.3%) in the higher functioning kidney. Postoperative renal function ranged from 47% to 90% (mean 60.5%) in the higher functioning kidney. A strong correlation existed between preoperative relative renal function and lateralized creatinine clearance (P <0.0001). Similarly, a significant correlation existed between the postoperative assessment and lateralized creatinine clearance (P <0.0003). No significant difference occurred between the preoperative and postoperative 1 to 3-minute relative renal function (P = 0.3552).

CONCLUSIONS

The 1 to 3-minute relative renal function determined by renal scintigraphy accurately reflects the relative renal function determined by lateralized creatinine clearance. Bladder catheterization does not appear necessary for accurate determination of relative renal function by renal scan even in the presence of bilateral reflux.