Minimising cold ischaemic injury in an experimental model of kidney transplantation

Cold ischaemic (CI) injury is associated with reduced renal graft function and survival. However, there is little evidence on the benefits of reducing CI injury within a 24 h period in donation after cardiac death (DCD) kidney transplantation.

Porcine kidneys subjected to 10-min warm ischaemia were retrieved and flushed with hyperosmolar citrate (HOC) preservation solution at 4 °C. They were stored on ice for periods of 2, 6, 18 or 24 h (n = 6). Renal function and injury were assessed during 3 h of ex-vivo reperfusion with oxygenated autologous blood.

Area under the curve (AUC) serum creatinine (Cr) levels were significantly higher in the 18- and 24-h groups and creatinine clearance (CrCl) lower compared to the 2-h group (P = 0·001, 0·003). Urinary biomarkers of ischaemic damage (Endothelin-1, Total nitric oxide) and renal and tubular cell function significantly correlated with the duration of CI time (r = 0·726, 0·642; P ≤ 0·001).

This study demonstrated the progressive effects of CI injury in DCD porcine kidneys over a 24 h hypothermic storage period. This highlights the need to minimise the cold storage period to improve graft function in DCD kidney transplantation.