Double versus single renal allografts from aged donors

Background. The age limit of the cadaver kidney donors is increasing in res ponse to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its resul ts. However, if SDKT is performed when there are no clear indications, a ne gative effect could be produced on the total number of transplanted patient s as both kidneys would be used for only one recipient. Material and Methods. In December 1996 we designed a transplantation protoc ol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft rena l biopsy was always performed to analyze the glomerulosclerosis (GE) percen tage whenever the donors were 60 gears of age or older. A SDKT was performe d in a single recipient when the donor age was 75 years or older or when th e donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different r ecipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discar ded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. Results. Eased on the above mentioned protocol, from December 1996 to May 1 998, 181 patients received a kidney transplantation in our hospital, These patients were divided into three groups: group I which included the SDKT re cipients (n=21), group II or single kidney recipients from 60- to 74-year-o ld donors (n=40), and group III or recipients from <60-year-old donors (n=1 20). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group I I (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfuncti on rate was low in the three groups, there being no statistically significa nt differences (5, 5, and 4%, respectively). A significantly greater percen tage of patients from group I (76%) presented immediate renal graft functio n as compared with group II (43% P<0.01) and III (50%, P<0.05). The acute r ejections rate was very low in all three groups (9.5, 7.5, and 22%, respect ively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft s urvival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05 ), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0. 05). Conclusions. Simultaneous double kidney transplantations make it possible t o use kidneys from extremely elderly donors (>75 years) or those whose GE>1 5%, In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients wit h excellent results.