Effectiveness of Different Kidney Exchange Mechanisms to Improve Living Donor Transplantation in Chile

Introduction. Chile has a low cadaveric organ donation rate; at the same time, living donor transplantation activity is also low. The purpose of this study was to analyze the impact on the number and quality of transplants using various mechanisms for kidney exchange from living donors to patients on Chile's waiting list. Methods. A computerized model was developed to simulate five options for living kidney donation: (1) direct donation; (2) direct donation plus pairwise and three-way exchanges; (3) pairwise exchange; (4) three-way exchange; and (5) allocation of donors based on the top trading cycles (TTC) mechanism. We calculated the projected number of transplantations, adjusting for the risk of a positive crossmatch, as well as the average quality in terms of the human leukocyte antigen (HLA) match. Results. If all patients on the waiting list have a willing direct donor, 47.7% of patients will receive a transplant. Allowing for incompatible pairs or pairs with a positive crossmatch an exchange of kidneys, can increase the number to 51.8%. This figure rises to 60% or 61% for pairwise or three-way exchanges, respectively. Although TTC ensures that 55% of the patients could be transplanted, the graft quality is better with an average HLA match of 3.5 versus 1.25. Conclusions. These results showed that kidney exchange mechanisms can increase the number of living donor transplantations by 4% and 13%.