THE EFFECT OF URETERAL STENTING ON THE FUNCTION AND MORPHOLOGY OF LONG-TERM RAT RENAL-ALLOGRAFTS

In the development of a reliable model for chronic rejection in rat re nal allografts, the effect of modifying the ureteric anastomosis was t ested. Rats, tolerized by pretreatment with two donor blood transfusio ns under Cyclosporin A, received renal allografts with either sewn or stented ureter. Control groups received isografts or underwent unineph rectomy with insertion of ureteric stents. For the first 6 days after transplantation, serum creatinine and urea values were lower in allogr aft recipients with stented ureters than in the group With sewn ureter s. The method of ureteric anastomosis did not affect the long-term inc idence of abnormal function. Allograft morphology was extremely variab le from minor to extensive tubular atrophy, interstitial fibrosis, glo merular hypertrophy, focal and segmental glomerulosclerosis as well as vascular changes. Glomerulosclerosis was absent in controls and incre ased with time in the allografts. Two hundred days after transplantati on all allograft recipients with sewn ureters exhibited some glomerulo sclerosis, in half of these kidneys more than 25% of glomeruli were af fected. Only 33% recipients of allografts with stented ureters exhibit ed some glomerulosclerosis and less than 20% of glomeruli were affecte d. The stented ureteric anastomosis provides a reliable method, a redu ction of the technical failure rate, a reduction of the incidence of h ydronephrosis, allows more accurate assessment of early renal function and may be of importance in reducing the occurrence and prevalence of glomerulosclerosis in the long-term allografts.