The prognostic value of renal resistance during hypothermic machine perfusion of deceased donor kidneys

Vascular renal resistance (RR) during hypothermic machine
perfusion (HMP) is frequently used in kidney
graft quality assessment. However, the association between
RR and outcome has never been prospectively
validated. Prospectively collected RR values of 302
machine-perfused deceased donor kidneys of all types
(standard and extended criteria donor kidneys and kidneys
donated after cardiac death), transplanted without
prior knowledge of these RR values, were studied.
In this cohort, we determined the association between
RR and delayed graft function (DGF) and 1-year graft
survival. The RR (mmHg/mL/min) at the end of HMP
was an independent risk factor for DGF (odds ratio
21.12 [1.03–435.0]; p = 0.048) but the predictive value
of RR was low, reflected by a c-statistic of the receiver
operator characteristic curve of 0.58. The RR was also
found to be an independent risk factor for 1-year graft
failure (hazard ratio 12.33 [1.11–136.85]; p = 0.004). Determinants
of transplant outcome are multifactorial in
nature and this study identifies RR as an additional
parameter to take into account when evaluating graft
quality and estimating the likelihood of successful outcome.
However, RR as a stand-alone quality assessment
tool cannot be used to predict outcome with
sufficient precision.