Early pyeloplasty for idiopathic hydronephrosis.

Evaluation has been made of a total of 272 patients who underwent surgery for hydronephrosis at the Department of Urology, Faculty Hospital in Olomouc, from 1979 to 1983. On the whole 221 (81%) pyeloplasties and 51 (19%) nephrectomies were performed. Five grades of hydronephrotic nephropathy were distinguished according to their significance. The clinical evaluation was based mainly on the results of excretory urography. The five grades of hydronephrosis were also characterized on the basis of the histological and electron-microscopical patterns and perioperational bioptic findings. Besides the dystrophic changes, seen on the tubular system of the kidney were morphological signs of regeneration, viz. the incidence of differentiated, pale "regeneration cells". However, in advanced stages of hydronephrosis, also these cells are subject to dystrophy making the hydronephrotic changes in the kidney irreversible. On the basis of the histological and clinical findings in correlation with the results of pyeloplasty the authors recommend to operate upon patients with Grades I-II hydronephrosis.