Donor sequence number is not associated with worse lung transplant outcomes regardless of transplant center case volume.

Abstract

Background: Potential lung transplantation (LTx) recipients are assigned a donor sequence number (DSN) based on their position on the match list. Since a higher DSN offer has already been declined for other recipients, some providers may assume that a high DSN connotates poorer allograft quality. This study evaluated the association between DSN and outcomes, the correlation between transplant program case volume and the utilization of higher DSN lungs, and whether LTx outcomes differ between lower- and higher-volume programs.

Methods: Using the Scientific Registry of Transplant Recipients database, LTx cases from 2015-2021 were retrospectively reviewed. Recipients were categorized into low (<20), medium (21-50), high (51-100), and very high (>100) DSN groups. The primary outcome was LTx survival. For cases involving high or very high DSN donors, a subgroup analysis compared survival among programs with annual transplant volumes in the bottom, middle 2, and top quartiles.

Results: Median survival was similar among the low (6.9 years), medium (6.1), high (5.9), and very high DSN (6.5) groups (log-rank p = 0.09). Higher DSN donors were more commonly accepted by higher-volume LTx centers. However, the annual case volume of the transplanting institution did not impact survival when high (log-rank p = 0.16) or very high DSN (log-rank p = 0.36) donors were used.

Conclusions: Higher DSN should not be considered an independent marker of low allograft quality. Additionally, lower-volume centers achieved similar post-transplant outcomes as higher-volume centers for recipients receiving higher DSN lungs. These findings underscore that surgeons must judge each donor offer independent of other programs' assessments.