Cold ischemia time in kidney transplantation: From reduction to personalization

Cold ischemia time is a modifiable determinant of kidney transplant outcomes. Minimizing its duration remains a major goal, although allocation, transportation, and organizational constraints make some of this time unavoidable.

We reviewed the literature published in PubMed over the past five years, supplemented by relevant landmark studies and institutional recommendations.

Prolonged cold ischemia is primarily associated with delayed graft function and, to a lesser extent, impaired long-term graft survival. Its impact varies according to donor and recipient characteristics. Prediction models can now estimate graft failure risk across different cold ischemia times for a given donor-recipient pair. Recent data on hypothermic machine perfusion further suggest that preservation strategies may mitigate the consequences of prolonged cold ischemia.

Personalizing cold ischemia could help identify situations in which its reduction should be prioritized and provide additional information for organ allocation and clinical decision-making. However, the moderate performance of currently available models and the lack of prospective validation preclude their use as standalone decision-making tools. Cold ischemia should therefore remain as short as possible, while its expected consequences could increasingly be assessed based on the characteristics of the donor-recipient pair and the graft preservation strategy used.