Title:
Extended criteria donor lungs and clinical outcome: results of an alternative allocation algorithm.

Abstract:
Despite the scarcity of donor lungs, most potential donor organs are not offered by organ procurement organizations or are turned down by transplant centers because no suitable recipient is found according to regular allocation. Although extended criteria donors (ECDs) have recently been considered by many programs, the lung utilization rate remains < 30% in most countries. The allocation policy of Eurotransplant for donor lungs that have been turned down for donor-related medical reasons by 3 centers is to attempt a rescue offer, for which centers choose the recipients themselves. At Hannover Medical School we systematically divert these organs to more stable recipients to avoid adverse transplant outcomes. We follow up on these transplants and compare them with those following regular allocation.
This study is an analysis of all organ offers and corresponding recipients at our center during the period from January 2010 to August 2011.
A total of 183 lung transplantations were performed, 111 regular donor lung offers were accepted for their intended recipient, whereas a total of 72 rescue lung offers, including all extended criteria donors, were accepted for recipients selected by our center. Donor characteristics differed between the 2 groups accordingly. Median age of ECD organ donors was significantly higher than that of regular donors (46.0 [IQR 21] vs 40.0 [IQR 22] years, p = 0.02). Donor mechanical ventilation time did not differ (3.5 ± 4.8 vs 3.0 ± 4.0 days, p = 0.33, not statistically significant [NS]). Donor oxygenation ratio (PaO2:FIO2) at time of organ offer was significantly lower (398.3 ± 110.3 vs 423.0 ± 97.6 mm Hg, p = 0.02). Recipients of rescue allocation organs were older than regularly selected recipients (53.7 ± 11.7 vs 46.7 ± 15.4 years, p = 0.0003), needed a shorter time for mechanical ventilation post-operatively (19.5 ± 306.6 vs 68.5 ± 718.8 hours, p = 0.02), and had shorter hospital stays (24.0 ± 23.4 vs 47.0 ± 43.4 days, p > 0.0001). Intensive care stay length did not differ significantly (2.0 ± 14.5 vs 5.0 ± 23.7 days, p = 0.21 [NS]). Post-operative survival up to 27 months after transplantation was not worse in recipients receiving rescue allocation when compared with standard allocation lung offers (81.62% vs 80.76%, p = 0.89 [NS]). The pre-operative status of the 2 recipient cohorts differed considerably, as indicated by the standard allocation group consisting of 65.8% "high-urgency" (HU)-listed patients, whereas the rescue offers were used for only 11.1% of HU-listed recipients, reflecting our center's policy.
Rescue allocation donor lungs can be used safely for transplantation and therefore salvaged for the donor pool. The data support our policy of accepting marginal donor lungs for stable recipients. This practice leads to very good overall survival.