Background
The ideal solution for recovery of donor lungs remains unknown. Low potassium dextran (LPD) solution is most common, but University of Wisconsin (UW) solution is also used. The United Network for Organ Sharing (UNOS) database allows assessment of preservation solutions in a large cohort of lung transplant (LTx) patients.
Methods
We retrospectively reviewed the UNOS dataset for adult primary LTx patients (2005–2008) whose donor lungs were recovered with UW or LPD solution. Patients were stratified by UW vs. LPD, and secondarily grouped by quartiles of the lung allocation score (LAS) to examine high risk recipients. Kaplan-Meier (KM) short term mortality (30d, 90d, 1 yr), and rejection in the 1st yr, were examined for intervals with adequate follow-up. Cox proportional hazard regression using 11 variables examined all cause 1-yr mortality.
Results
Of 4455 patients, 4161 (93.4%) received LPD lungs and 294 (6.6%) received UW lungs. 1105 (24.8%) patients died during the study. There was no mortality difference based on flush solution with all patients examined together. However, patients in the upper two LAS quartiles (Q3:37.8-45.4, Q4:>45.4) receiving LPD lungs had greater 1 yr survival (81.5% vs.73.5%, p=0.02). On multivariable analysis, flush with UW solution resulted in an increased risk of 1 yr mortality (Hz ratio 1.77[1.21–2.58], p=0.003) compared to LPD. Preservation solution did not affect rejection rates in the year after LTx. KM modeling demonstrated the impact of flush solution on survival (p=0.02).
Conclusions
This study is the largest modern cohort to evaluate the effect of donor lung flush solutions on survival in adult LTx. UW solution increases the risk of 1 yr mortality in high risk LTx recipients.