Recipient outcomes for expanded criteria living kidney donors: the disconnect between current evidence and practice

Older individuals or those with medical complexities are undergoing living donor nephrectomy more than ever before. Transplant outcomes for recipients of kidneys from these living expanded criteria donors are largely uncertain. We systematically reviewed studies from 1980 to June 2008 that described transplant outcomes for recipients of kidneys from expanded criteria living donors. Results were organized by the following criteria: older age, obesity, hypertension, reduced glomerular filtration rate (GFR), proteinuria and hematuria. Pairs of reviewers independently evaluated each citation and abstracted data on study and donor characteristics, recipient survival, graft survival, serum creatinine and GFR. Transplant outcomes for recipients of kidneys from older donors (> or =60 years) were described in 31 studies. Recipients of kidneys from older donors had poorer 5-year patient and graft survival than recipients of kidneys from younger donors [meta-analysis of 12 studies, 72% vs. 80%, unadjusted relative risk (RR) of survival 0.89, 95% confidence interval (CI) 0.83-0.95]. In meta-regression, this association diminished over time (1980s RR 0.79, 95% CI 0.65-0.96 vs. 1990s RR 0.91, 95% CI 0.85-0.99). Few transplant outcomes were described for other expanded criteria. This disconnect between donor selection and a lack of knowledge of recipient outcomes should give transplant decision-makers pause and sets an agenda for future research.