A Sliding Scale AdaptiVe Expedited rescue algorithm for deceased donor kidney transplantation

The nonuse rate of deceased donor kidneys has increased significantly. The National Organ Transplantation Act requires sequential organ allocation to candidates, which is inefficient for medically complex organs because it increases cold ischemic time and contributes to organ decline. A novel Sliding Scale AdaptiVe Expedited rescue algorithm for deceased donor kidney transplantation was developed that uses the nonuse rate to determine a rescue trigger threshold. Once triggered, allocation occurs in sequential batches, sized proportionately to the nonuse rate. Using the validated organ allocation simulation program KSIM 2.0, the algorithm was evaluated across 20 simulation runs using Organ Procurement and Transplantation Network data before and after implementation of the Kidney Allocation System 250 allocation algorithm. Nonuse was reduced across all kidney donor profile index (KDPI) score strata. Overall, the nonuse of the recovered KDPI score >0.35 kidneys decreased from 38% to as low as 19%. For all kidneys, the nonuse rate reduced from 28% to 14%. Using lower thresholds and larger batch sizes resulted in progressive decreases in nonuse rates of kidneys with KDPI scores >0.65. Increasing the batch size has its largest effect at higher KDPI score deciles. The use of the Sliding Scale AdaptiVe Expedited rescue algorithm for deceased donor kidney transplantation significantly reduces the nonuse rate of deceased donor kidneys while adhering to the principle of sequential allocation.