Lung allocation.

Shortage of donor lungs in most western countries and broadening of indications for lung transplantation (LTx) has led increased waiting list mortality in the past. Usually donor lungs and recipients are matched by size as measured by total lung capacity and blood type in first order. In some countries regional allocation comes first, in other countries a national wait list exists and some nations are organized in supranational allocation systems. Organ distribution should respect the ethical principles of equity, justice, beneficence and utility. Generally, top priority on the list should be given to patients with the least amount of time to live but outcome is an important factor to consider to avoid futile transplantations. Installation of an urgency status will decrease mortality of the sickest candidates on the waitlist unless the proportion of patients on urgency status will be too high. Urgency can be determined by clinical judgment (so called center decision), an audit process or objectively by a score system. Among the 3,500 transplants performed worldwide annually, approximately 60% are allocated by lung allocation score (LAS) (US, Germany, the Netherlands). With the LAS a model for survival prediction after lung transplantation and wait list survival probability was created. Clinical experience in the US since 2005 and in Germany since 2011 favourable reports regarding effects on waiting list outflow, transplant activity and outcomes have been published. Future perspectives will focus on broader geographic sharing, updating and further development of the LAS.