The prevalence of persistent vesicoureteral reflux after 1 negative nuclear medicine cystogram

Radionuclide cystography is a widely used test for the diagnosis or indication of resolution of vesicoureteral reflux. The recurrence or persistence of reflux after 1 negative radionuclide cystogram has been previously reported. We examined the value of a second radionuclide cystogram in patients who were believed to be cured on 1 previous study and tried to identify variables that could explain the false-negative result on the initial cystogram.

The study included 85 patients with primary vesicoureteral reflux, treated conservatively between 1991 and 1996 who had 1 negative radionuclide cystogram. A repeat radionuclide cystogram was done 12 to 18 months after the negative study. Patients were divided into those with and without reflux recurrence identified, and compared in regard to sex distribution, age at presentation and reflux resolution, time between presentation and first negative radionuclide cystogram, change in reflux grade between presentation and just before resolution, side of reflux at presentation and grade before resolution. The differences between both groups were statistically analyzed.

Of the 85 patients 25 (29%) had reflux recurrence, including 18 (72%) with grade 2 or greater recurrent reflux and 15 (60%) with persistent reflux 12 months after the second positive radionuclide cystogram. There was no observed association between the 2 groups in any of the variables (p >0.05).

This study emphasizes the importance of a second negative radionuclide cystogram to indicate the absence or resolution of reflux as 1 negative cystogram alone would have missed persistent reflux in 25 of 85 patients at 1 year and 15 of 85 patients at 2. Whether absence or resolution of reflux is a variable of the disease or an unknown factor inherent in the test is unknown as there was no statistical difference in the parameters studied between our 2 groups.