Renal transplantation using kidneys from older donors is associated with reduced long-term graft survival as compared to kidneys from younger donors. However, it has been clearly shown that even transplants from these so-called expanded criteria donors improve patient survival as compared to remaining on the waiting list. It has also been clearly shown that patient survival following renal transplantation is inversely proportional to the length of time on dialysis on the waiting list. These facts have led to an attempt to increase utilization of expanded criteria donors where they are likely to have the most benefit.
Studies have now shown that older recipients and those with the most severe comorbidities are most disadvantaged by prolonged waiting times for deceased donor kidney transplants. Accordingly, in regions with long waiting times, it seems reasonable to offer expanded criteria donors to older/sicker potential recipients with informed consent. Conceptually then a program might have two waiting lists, one which would include all potential recipients, waiting for ideal donors. The other list would consist of a subset of the first group, generally older/sicker patients, with a view that they might receive an expanded criteria donor kidney sooner thus improving their survival.
Clearly all expanded criteria donor kidneys are not created equal. Outcomes might be improved by improved selection criteria, reducing cold ischemia time and possibly the use of Pulsatile Perfusion.. A number of conflicting studies have appeared with respect to the value of glomerular sclerosis or vascular disease in selection. Retrospective data supports using donor calculated creatinine clearance suggesting that in single kidney transplants, once the clearance drops below 80ml/min, are associated with reduced two-year graft survival. Other individuals have suggested scoring systems, however their utility is suboptimal because age has such a major influence on outcome.