Safety of Single Lung Transplantation Post Donation Service Area-Specific Organ Distribution

Abstract

<h3>Purpose</h3> The organ allocation change in 2017 removed donation service area (DSA) and was aimed at prioritizing donor lungs for patients with a higher lung allocation score (LAS). Given that patients who are listed for singe lung transplantation alone have, on average, a lower LAS, we hypothesized that this allocation change would negatively impact those listed for a single lung transplant. <h3>Methods</h3> A UNOS database analysis was performed for patients listed for an isolated single lung transplant. Data was queried 2.5 years prior to and after the allocation change with recipients from 1/2015-6/2017 deemed as pre-allocation and recipients from 1/2018-6/2020 as post-allocation. The primary outcome was waitlist time and post-transplant survival. <h3>Results</h3> 1,435 patients were identified: 753 pre-allocation patients and 682 post-allocation patients. In the post-allocation era, patients were less likely to be listed for single lung transplant alone (15% vs 12%, P<0.001). Post-allocation recipients were older (P<0.001), more likely to be hospitalized (P=0.033), and had a nominally higher LAS score at transplant (P=0.002). While donor distance was greater (P<0.001) in the post-allocation era, demographics were similar and PaO2/FiO2 was higher in post-allocation era donors (P<0.001). The change in allocation did not impact waitlist times (42 (16-114) vs 45 (13-122), P=0.898). Survival (87% vs 87%, P=0.889) and freedom from graft failure (P=0.964) at 1 year was similar in both groups. Patients in the post-allocation group were less likely to have severe primary graft dysfunction at 72h (24% vs 31%, P=0.043). <h3>Conclusion</h3> After removal of the DSA, there was a lower prevalence of listing for only single lung transplantation. However, waitlist times, available donor lungs, and post-transplant outcomes were similar, or potentially improved, after the allocation change. Given this, single lung transplantation appears to be a reasonable strategy for appropriate patients requiring lung transplantation.