Objective Donor Scoring System for Lung Transplantation

There is no objective method to estimate post-lung transplant survival solely on the basis of cumulative donor risk factors.

The United Network Organ Sharing thoracic transplant database was queried to identify patients who underwent lung transplantation between 2005 and 2015. A Cox proportional hazard model was generated using a training set to identify donor risk factors significantly associated with posttransplant survival. Significant donor risk factors were assigned a score on the basis of their hazard ratio. Donor risk score was calculated for each patient by adding the individual donor risk factor scores. Donors in the validation set were then categorized into low-risk (score = 0), intermediate-risk (score = 1), and high-risk (score >1) categories on the basis of the cumulative risk score. The Lung Allocation Score was used as a surrogate for recipient risk. Survival for each risk group was calculated using Kaplan-Meier curves.

The donor risk groups' respective survival at 1 year was 85%, 81%, and 77%, and at 5 years it was 53%, 50%, and 42% (p < 0.001). The combination of low-risk recipients and low-risk donors had 1- and 5-year survival of 89% and 59%, respectively. The combination of high-risk recipients and high-risk donors had 1- and 5-year survival of 70% and 30%, respectively.

The proposed lung donor scoring system is a simple, easy to use method that can aid transplant surgeons in the selection of a potential lung transplant donor. Using the lung donor score in conjunction with the Lung Allocation Score can allow for matching of recipients and donors, to optimize posttransplant outcomes.