http://www.jhltonline.org

1053-2498/$ - see fronhttp://dx.doi.org/10.10

Choosing the right lungs for the right patient

John Dark, FRCS

From the Institute of Cellular Medicine, Newcastle University, Newcastle-Upon-Tyne, United Kingdom.

There is an historical trend in lung transplantation, analtering appreciation of donor risks. In this issue, a reportfrom the Hannover group1 is both a product of that trend andexpresses a logical conclusion.

In a previous era, only the best lung would do, and all theemphasis was on the “standard donor.” Gas exchange had tobe good, the chest X-ray clear, and previous historyunblemished. The whole process is risky, went the thinking,let’s not add to that with a bad lung.

But from as early as 1995,2 we have seen a progressiveretrenchment of donor lung assessment. Ischemia time, geo-graphic distance, adverse radiology, and sputum purulencehave all disappeared as factors to be considered when con-sidering the potential lung donor. Some stubbornly remain:smoking, despite previous doubts, is established as a riskfactor for early and mid-term risk.3 Similarly, although thecolor of tracheal secretions is unimportant, organisms in thelung parenchyma and the lower airway are not good.4 But,on the other hand, lungs donors with severe asthma orpulmonary emboli have been used successfully.

The current state of our knowledge is well illustrated bythe seminal report from the lung transplant outcomes groupin the United States looking at predictors of primary graftdysfunction.5 Oxygenation and ischemic time, the former, inparticular, a sacred cow, do not even figure in the list.Instead, and here is the trend: there are recipient factors.Obesity and pulmonary hypertension in particular, predictacute lung injury. They add to others, such as ventilation,extracorporeal membrane oxygenation, and previous sur-gery, which we already knew about. There is a generalrealization that many donor factors imagined to be importantare no longer so and that many early problems are related toaspects of the recipient.

So how does this relate to allocation, ostensibly the topicof this paper from Sommer and colleagues?

Within the Eurotransplant area, which includes Germany,lungs are allocated, in the first instance, to specific patientsin a manner that includes an “urgent category.” The bestlungs come this way, many of them going to patients in thehigh-urgency categories. If initially turned down for the first

t matter r 2013 International Society for Heart and Lung16/j.healun.2013.08.018

patient because of functional or logistic issues, the organ isoffered on to other specific patients. But if refused 3 timesfor specific patients, it is then offered in a general way, tocenters to allocate to whom they see is best suited. This istermed “rescue” allocation.

Within this system, stable, non-urgent patients might havea considerable wait for a lung. But often they are the sameindividuals who, by modern reckoning, represent low-riskrecipients, lacking, for instance, pulmonary hypertension.

The imaginative step taken by the Hannover group wasto ensure that the best lungs (although we have no reallygood way to make that definition) went largely to the sickestpatients. But then, they were prepared to give the “rescue”lungs, already turned down 3 times, to the most stablerecipients. This slightly counterintuitive approach, perhapsbordering on the ethically questionable, was justified bywhat we now know about the influence of recipient factorson early outcome.

The results of this “experiment” form the report. Thepatients in the “rescue” allocation group, themselves sig-nificantly older, received lungs from older donors with worsegas exchange. But they had shorter ventilation times, shorterhospital stays, and identical survival to more than 2 years. Inother words, this was a triumph of intelligent use of thesepreviously “marginal” lungs, giving excellent outcomes fromlungs that under some systems might never have been used!

There are, of course, some provisos: the donors of the“rescue” lungs still had an median age of 46 years and anaverage oxygenation ratio of 398. Recipients had a meanage of 53 years. We are not talking about extremes ofacceptance in either group.

And the Hannover program is large and active: the 72recipients of the “rescue” lungs came out of 183 transplantsin only 1.5 years. The advantages of good-sized activityhave been repeatedly demonstrated, and these good resultsmight not be repeated by a smaller team.

But this report shows us a way forward. As we gain agreater understanding of just what are the important donorvariables and the best way to define the riskiest recipients,we can increase the overall benefit for all our patients.

Transplantation. All rights reserved.

Dark Choosing the Right Lungs for the Right Patient 1055

Disclosure statement

The author does not have a financial relationship with a commercialentity that has an interest in the subject of the presented manuscriptor other conflicts of interest to disclose.

References

1. Sommer W, Kühn C, Tudorache I, et al. Extended criteria donor lungsand clinical outcome: results of an alternative allocation algorithm.J Heart Lung Transplant 2013;32:1065-72.

2. Sundaresan S, Semenkovich J, Ochoa L, et al. Successful outcome oflung transplantation is not compromised by the use of marginal donorlungs. J Thorac Cardiovasc Surg 1995;109:1075-9.

3. Bonser RS, Taylor R, Collett D, Thomas HL, Dark JH, Neuberger J.Cardiothoracic Advisory Group to NHS Blood and Transplant and theAssociation of Lung Transplant Physicians (UK). Effect of donorsmoking on survival after lung transplantation: a cohort study of aprospective registry. Lancet 2012;380:747-55.

4. Avlonitis VS, Krause A, Luzzi L, et al. Bacterial colonization of thedonor lower airways is a predictor of poor outcome in lungtransplantation. Eur J Cardiothorac Surg 2003;24:601-7.

5. Diamond JM, Lee JC, Kawut SM, et al. Clinical risk factors for primarygraft dysfunction after lung transplantation. Am J Respir Crit Care Med2013;187:527-34.