Outcomes After Transplantation of Lungs Subjected to Prolonged Cold Ischaemic Time Following Ex-Vivo Lung Perfusion

Abstract

<h3>Purpose</h3> Ex vivo lung perfusion (EVLP) rewarms donor lungs to normothermia following a period of cold static preservation (CIT1) and returns the lungs to a state of cold static preservation following EVLP (CIT2). We hypothesize that EVLP interrupts cold ischemic injury and allows for safe additional cold ischemic time after EVLP. <h3>Methods</h3> We performed a retrospective review of data from the Toronto Lung Transplant Program Database. Adult patients who underwent bilateral lung transplant following EVLP assessment between January 2008 and December 2020 were included. CIT1, EVLP, and CIT2 times were collected and outcomes including PGD grade 3 at 72 hours and 30-day and 12-month mortality were assessed. <h3>Results</h3> A total of 1186 bilateral lung transplants were performed over the study period of which 315 were performed following EVLP assessment. Mean[SD] CIT1 of the lungs was 4.7h[1.6]. Mean[SD] EVLP time was 4.5h[1.5]. The first lung had a mean[SD] CIT2 of 3.8h[2.1] and the second had a mean[SD] CIT2 of 6.0h[2.2]. Survival was similar when comparing CIT2<6 hours versus CIT2>6 hours of the second lung (p=0.53) (Figure). PGD3 rate was also similar between those groups (18.1% vs 17.2%, p=1). <h3>Conclusion</h3> Prolonged (>6h) ischemic time following EVLP assessment (CIT2) did not affect short- and long-term mortality in our patients. Therefore we feel that using a period of CIT after EVLP assessment is acceptable, and it provides us flexibility in terms of logistics, widening geographical reach of our program, and allows us to make lung transplantation a semi-elective procedure.