Factors influencing cold ischaemia time in deceased donor kidney transplants

Abstract

Kidney transplant remains the optimal treatment for majority of patients with end stage renal failure. The major challenge facing the transplant community is the shortage of organs for donation as demand outstrips supply. This has led to a significant change in practice over the last decade with an increasing use of kidneys from deceased donors following circulatory death (DCD) and extended criteria donors (ECD) that are more susceptible to ischaemic injury. A period of cold ischemia time (CIT) is an inevitable consequence of organ retrieval and transplantation in the process of deceased organ donation. It is well established that longer CIT is associated with poorer outcomes following kidney transplantation. It is also one of the few potentially modifiable risk factors. It is, therefore, crucial to identify and address the factors that adversely affect CIT to enable optimal utilisation of available kidneys. The study investigated multiple factors affecting CIT, involving all aspects of kidney journey from retrieval to transplantation to identify areas for improvement. The aims of the study are: • To undertake comprehensive review of logistical factors in transplant centres in the United Kingdom (UK) and, their impact on CIT in deceased donor kidney transplants • To determine whether there are specific areas to focus efforts on to reduce CIT • To put forward proposals about how to reduce CIT across the UK This is a prospective, longitudinal study over 14 months examining logistical pathway of deceased donor kidney transplants in the UK that includes kidney allocation, retrieval, transport, histocompatibility testing and preparation of recipients for transplantation. Four sets of questionnaires were developed and utilised to encapsulate critical events along the kidney timeline with additional data input from the National Health Service Blood and Transplant (NHSBT). Results identified a number of factors that affected CIT, the most important of which was adoption of a virtual crossmatch (vXM) policy where appropriate. CIT was also reduced significantly if pre-transplant crossmatch (pXM) was performed with donor pre-retrieval peripheral blood rather than donor tissues. Significant reduction also resulted from use of stored recipient blood for pXM rather than a current sample. Other factors that led to increase in CIT in the vXM group were travel times, recipients requiring haemodialysis immediately before transplantation and kidney reallocation. This study identifies specific factors that can be addressed to potentially minimise CIT and improve outcomes in deceased donor kidney transplants in the UK.