Morphology of the upper urinary tract in experimental hydronephrosis in pigs.

In the light of electrophysiologic findings in obstructions of the upper urinary tract in pigs, the morphological changes in kidneys, pelvices and ureters were evaluated. Gross anatomical and light and electron microscopical studies were undertaken. In total obstructions severe damage to the parenchyma was seen after 5 to 6 weeks independent of the way the obstruction was obtained. Pelvic musculature was rapidly destructed. After reconstruction performed as dismembered pyeloplasty no regeneration was registered neither in the parenchyma, in pelvic musculature or at the site of the anastomosis. In partial obstruction there were minimal to moderate changes both in parenchyma and in musculature and no signs of regression after reconstruction or relief of the obstruction. Also in these cases there were no muscular regeneration at the site of the anastomosis. When morphology was compared to electrophysiological findings a good correlation was found.