Electroureterogram in the obstructed ureter and vesicoureteral reflux

An electroureterogram (EUG) was identified for the normal ureter (A. Shafik, 1996). It was postulated that the EUG might change under pathologic ureteric conditions. This communication studies the EUG pattern in the obstructed ureter and in the ureter with vesicoureteral reflux.

11 patients with stricture of the lower end of ureter (all men; mean age 36.6 +/- 6.2 years) were studied. Urography showed a hugely dilated ureter. Nineteen patients with vesicoureteral reflux (13 women and 6 men; mean age 32.8 +/- 5.6 years) had moderately dilated ureters. All patients were scheduled for operative correction in the course of which the current study was done. A monopolar silver-silver chloride electrode was applied to each of the upper, middle, and lower third of the ureter. The EUG activity and intraureteric pressure were recorded before and immediately after ureteric reconstruction.

The obstructed ureter showed a "silent" EUG. The refluxing ureter revealed three EUG patterns: silent, bradyureter (diminished frequency and amplitude of slow waves or pacesetter potentials, PPs), and ureteroarrhythmia (irregular PP frequency and amplitude). These patterns were reproducible when the tests were performed before or immediately after ureteric reconstruction. The intraureteric pressure in the strictured ureters was high and dropped after ureteric stricture resection. It recorded normal values in the refluxing ureter.

It appears that ureteric dilatation interferes with the electric ureteric activity. The most dilated ureters showed a silent EUG while the least dilated exhibited bradyureter. The results have shown that the dilated ureter may display an abnormal EUG and that with the development of a noninvasive technique in the future, the EUG may be of diagnostic significance in ureteric disorders.