Venous ischemia as a cause of ureteral necrosis in transplanted ureters

Background: Urologic complications after pediatric renal transplantation ca n adversely effect the outcome and may result in decreased graft survival. Efforts to prevent these complications are worthwhile. This study investiga tes the incidence of these complications in a clinical transplant program a nd reports on an animal model used to investigate one possible cause. Methods: In the clinical study, the results of a pediatric renal transplant program at a large children's hospital for a 5 1/2-year period were review ed with special attention paid to patients suffering ureteral necrosis. In the experimental study, 9 swine underwent laparotomy, bilateral complete in frahilar ureteric dissection, and extravesical ureteroneocystostomy. On the left side only, the renal and adrenal veins were ligated. The arterial sup ply remained intact. The right side did not undergo vessel ligation and ser ved as the control. Three pigs each were killed at 3, 8, and 15 days. Kidne ys, ureters and a cuff of bladder were examined histologically. Results: In the clinical study 75 renal transplants were performed with a t otal of 5 cases of early ureteral necrosis. Two of these 5 displayed venous congestion and ischemia, and 2 were associated with kidneys displaying pri mary nonfunction of the graft. Seventy-one of 75 grafts are continuing to f unction. One of the 4 early graft losses also had an ischemic ureter. In th e experimental study all right kidneys and ureters were normal. All left ki dneys had complete hemorrhagic necrosis. Necrosis also was found in 5 of 9 proximal left ureters and in 7 of 9 distal left ureters, Viable left ureter s displayed moderate to severe submucosal and periureteric hemorrhage. Four of 9 ureters displayed more damage distally than proximally. The extent of necrosis was similar at 3, 8, and 15 days. Conclusion: In both clinical and experimental studies, venous congestion an d subsequent ischemia have been shown to be important causes of ureteral ne crosis after renal transplantation. Copyright (C) 1999 by W.B. Saunders Com pany.