A Single Center Analysis of Increased Risk Donors Utilized in Lung Transplantation

Abstract

<h3>Purpose</h3> In 2013, the US Public Health Service (PHS) established new guidelines for high risk donor organs and renamed the category "increased risk" (IR). We compared survival outcomes of lung transplant (LTx) patients that received either IR or non-IR donor lungs to determine if IR donor lungs are an underutilized resource. <h3>Methods</h3> This study retrospectively analyzed and compared survival and utilization rates of IR and non-IR donor lung recipients at a single center from Feb-2012 to Mar-2020. LTx recipients were stratified by PHS IR status of the donor lung(s) received. Survival of IR and non-IR donor lung recipients was assessed using Kaplan-Meier (KM) survival analysis and compared by log-rank test. Cox proportional hazards modeling was used to control for variables significantly associated with IR/non-IR status, including recipient race, average warm ischemic time, transplant type, and donor age. <h3>Results</h3> Of 742 LTx patients at the center (Feb-2012 to Mar-2020), there were 193 (26%) recipients of IR organs. In 2012 and 2013, 7% and 0% respectively of the lungs transplanted at the institution were IR labeled. After the PHS guidelines were nationally implemented in Feb-2014, the proportion of IR labeled lung transplants rose to 8% (2014), 26% (2015), 40% (2016), 53% (2017), 38% (2018), and 37% (2019). Median survival times were 1.8 years for IR and 2.0 years for non-IR LTx recipients. KM survival analysis and log-rank test comparison showed no statistically significant difference in survival between IR and non-IR donor lung recipients (p = 0.606) over the 8-year period. Cox regression controlling for significant variables suggested none of the covariates significantly affected survival. <h3>Conclusion</h3> While the 2013 guidelines caused a sharp increase in lungs labeled IR, our survival analysis suggests the criteria may be misleading and of little help when assessing risks and estimating probability of survival. IR designations risk underutilization of viable lungs, a serious concern considering the waitlist demand for donors.