Dynamics of the urinary tract in longterm vesico-ureteric reflux in pigs. III.

The dynamic function of the pyelo-ureter was studied in 5 pigs 10 and 20 weeks after induction of reflux on the left side. In the baseline period the pelvic pressure and the ureteric activity of refluxing ureters were both indistinguishable from those of the patent ureter. During bladder filling the median ureteric activity in the non-refluxing ureters increased 43%. In the refluxing ureters the median increases after 10 and 20 weeks were 65% and 106%. This was consistent with findings previously obtained during acute bypassing of the vesico-ureteric junction (median increase 88%). The ureteric resistance to pressure equilibration was unaltered. Almost all peristalsis was antegrade and no peristalsis stopped in ureter. Thus reflux into a non-dilated upper urinary tract of growing pigs with normal bladder and bladder outlet function did not produce any changes in the dynamic function of the urinary tract.