Management of ureteral strictures by different modalities and effect of stents on upper tract drainage.

Ureteral strictures were induced experimentally by unilateral partial ligation of the upper ureter on the left side in 56 female rabbits. Six weeks later, stricture stability was documented by intravenous urography. In all cases, there was fibrosis of the muscular wall of the ureter. The lumen, although narrowed to various degrees, was preserved in most animals, and moderate to marked hydronephrosis resulted. Control animals were not treated in order to study the natural progress of the stricture. The other strictures were treated either by dilation (catheter or balloon) with or without ureteral stenting, by intubated external ureterotomy, or by excision of the strictured segment and stented end-to-end anastomosis. Follow-up studies consisted of intravenous urography, renography, and histologic examination for 24 weeks. Ureteral dilation without and with 2 weeks of stenting could be an adequate treatment of strictures associated with a moderate degree of hydronephrosis. Intubated external ureterotomy did not give satisfactory results in any animal. Excision of the strictured segment with a stented anastomosis produced satisfactory results and has a great role in the treatment of the strictured ureter in comparison with the variable outcome of endourologic treatment. Stenting of the unobstructed ureter, tested in six rabbits, showed a positive correlation between renal obstruction and long-term ureteral stenting.