Survival in recipients of marginal cadaveric donor kidneys compared with other recipients and wait-listed transplant candidates

An increasing number of cadaveric kidney transplants are now performed with organs from donors who would have been deemed unsuitable in earlier times. Although good allograft outcomes have been obtained with these marginal donor transplants, it is unclear whether recipients of marginal kidney transplants achieve a reduction in long-term mortality as do recipients of "ideal" kidneys. Patients with end-stage renal disease registered on the cadaveric renal transplant waiting list between January 1, 1992, and June 30, 1997, were studied for mortality risks according to three outcomes: wait-listed on dialysis treatment with no transplant (WLD); transplantation with marginal donor kidney (MDK); and "ideal" or optimal donor kidney transplantation (IDK). Thirty-four percent of wait-list registrants had received a cadaveric kidney transplant by June 30, 1998. Of these, 18% received a marginal kidney that had one or more of the following pretransplant factors: donor age >55 yr, non-heartbeating donor, cold ischemia time >36 h, and donor hypertension or diabetes mellitus of >10 yr duration. Five-year graft and patient survival was 53% and 74% for MDK recipients compared with 67% (P < 0.001) and 80% (P < 0.001) for IDK recipients. Adjusted annual death rate and estimated remaining life time was 6.3%, 4.7%, and 3.3% and 15.3 yr, 20.4 yr, and 28.7 yr for WLD, MDK, and IDK groups, respectively. The average increase in life expectancy for MDK recipients compared with the WLD cohort was 5 yr, although this benefit varied from 3 to 10 yr depending on the recipient's characteristics. It is concluded that transplantation of a marginal kidney is associated with a significant survival benefit when compared with maintenance dialysis.