Analysis of Kidney Transplant System 147 Figure 4. Kidney paired exchange system. s Donot Figure 5. n-way kidney exchange. that the rate of candidates entering the waitlist is reduced. However, for those in the waitlist, the same procedure is still being used Kidney paired exchanges have higher priority than larger cycles, for logisti- cal reasons Recipients must receive a transplant in the region in which they are on the waitlist(this reduces travel time) Exchanges withno mismatch are prioritized over exchanges with mismatch. Waiting time for an exchange is assumed to be 0, as was live donor matches in Task 1. After an exchange, all individuals involved are removed from the pools of donors and recipients We use Region 9 as a sample region to test our model. Region 9 has a waitlist(6058 )similar to the average waitlist per region, and 909 candidates (15%) have willing but incompatible donors. We ran our simulation 100 times and computed averages. Table 5 shows extrapolationof the Analysis In 2006, there were 26,689 kidney transplants nationwide, including only a few kidney paired exchanges. The approximately 9, 656 additional transplants yearly indicated in Table 5 would have been a 36% increase and would have reduce the waitlist correspondingly by 14%, from 69, 983 to 60, 327Analysis of Kidney Transplant System incompab compatIblenepabe Figure 4. Kidney paired exchange system. DanorlI Doncr2 Patient N tsi re PaPatinn IA Patilent 2 Paint ,Patient 3' Donor A Figure 5. n-way kidney exchiange. that the rate of candidates entering the waitlist is reduced. However, -for those in the waitlist, the same procedure is still being used. "* Kidney paired exchanges have higher priority than larger cycles, for logisti￾cal reasons. "* Recipients must receive a transplant in the region in which they are on the waitlist (this reduces travel time). "* Exchanges with no mismatch are prioritized over exchanges with mismatch. Waiting time for an exchange is assumed to be 0, as was live donor matches in Task 1. After an exchange, all,individuals involved are removed from the pools of donors and recipients. We use Region 9 as a sample region to test our model. Region 9 has a waitlist (6058) similar to the average waitlist per region, and 909 candidates (15%) have willing but incompatible donors. We ran our simulation 100 times and computed averages. Table 5 shows extrapolation of the results nationwide. Analysis In 2006, there were 26,689 kidney transplants nationwide, including only a few kidney paired exchanges. The approximately 9,656 additional transplants yearly indicated in Table 5 would have been a 36% increase and would have reduce the waitlist correspondingly by 14%, from 69,983 to 60,327. 147