Box 2.

Marginal donors

About 30% of kidneys are retrieved from suboptimal, or marginal, donors. These kidneys may function suboptimally, which means that higher numbers of transplants must be balanced against the possibility of poorer transplant outcomes. For renal transplantation, marginal donors include cadavers from one or more of the following categories:

• Extremes of age (usually <14 years or >65 years)
• Prolonged cold or warm ischaemia
• Technical problems with organ retrieval (such as vascular injury)
• Diabetic donors
• Hypertensive donors (especially if subarachnoid haemorrhage)
• Donors with impaired renal function
• Donors with primary brain tumour
• Donors with prolonged hypotension or poor physiology before brain stem death
• Donors with primary renal disease
• Unfavourable results from pretransplant biopsy of the donor kidney