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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, an altering appreciation of donor risks. In this issue, a report from the Hannover group1 is both a product of that trend and expresses a logical conclusion. In a previous era, only the best lung would do, and all the emphasis was on the “standard donor.” Gas exchange had to be good, the chest X-ray clear, and previous history unblemished. 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 progressive retrenchment of donor lung assessment. Ischemia time, geographic distance, adverse radiology, and sputum purulence have all disappeared as factors to be considered when considering the potential lung donor. Some stubbornly remain: smoking, despite previous doubts, is established as a risk factor for early and mid-term risk.3 Similarly, although the color of tracheal secretions is unimportant, organisms in the lung parenchyma and the lower airway are not good.4 But, on the other hand, lungs donors with severe asthma or pulmonary emboli have been used successfully. The current state of our knowledge is well illustrated by the seminal report from the lung transplant outcomes group in the United States looking at predictors of primary graft dysfunction.5 Oxygenation and ischemic time, the former, in particular, 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, predict acute lung injury. They add to others, such as ventilation, extracorporeal membrane oxygenation, and previous surgery, which we already knew about. There is a general realization that many donor factors imagined to be important are no longer so and that many early problems are related to aspects of the recipient. So how does this relate to allocation, ostensibly the topic of this paper from Sommer and colleagues? Within the Eurotransplant area, which includes Germany, lungs are allocated, in the first instance, to specific patients in a manner that includes an “urgent category.” The best lungs come this way, many of them going to patients in the high-urgency categories. If initially turned down for the first
patient because of functional or logistic issues, the organ is offered on to other specific patients. But if refused 3 times for specific patients, it is then offered in a general way, to centers to allocate to whom they see is best suited. This is termed “rescue” allocation. Within this system, stable, non-urgent patients might have a considerable wait for a lung. But often they are the same individuals who, by modern reckoning, represent low-risk recipients, lacking, for instance, pulmonary hypertension. The imaginative step taken by the Hannover group was to ensure that the best lungs (although we have no really good way to make that definition) went largely to the sickest patients. But then, they were prepared to give the “rescue” lungs, already turned down 3 times, to the most stable recipients. This slightly counterintuitive approach, perhaps bordering on the ethically questionable, was justified by what we now know about the influence of recipient factors on early outcome. The results of this “experiment” form the report. The patients in the “rescue” allocation group, themselves significantly older, received lungs from older donors with worse gas exchange. But they had shorter ventilation times, shorter hospital stays, and identical survival to more than 2 years. In other words, this was a triumph of intelligent use of these previously “marginal” lungs, giving excellent outcomes from lungs 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 an average oxygenation ratio of 398. Recipients had a mean age of 53 years. We are not talking about extremes of acceptance in either group. And the Hannover program is large and active: the 72 recipients of the “rescue” lungs came out of 183 transplants in only 1.5 years. The advantages of good-sized activity have been repeatedly demonstrated, and these good results might not be repeated by a smaller team. But this report shows us a way forward. As we gain a greater understanding of just what are the important donor variables and the best way to define the riskiest recipients, we can increase the overall benefit for all our patients.
1053-2498/$ - see front matter r 2013 International Society for Heart and Lung Transplantation. All rights reserved. http://dx.doi.org/10.1016/j.healun.2013.08.018
Dark
Choosing the Right Lungs for the Right Patient
Disclosure statement The author does not have a financial relationship with a commercial entity that has an interest in the subject of the presented manuscript or other conflicts of interest to disclose.
References 1. Sommer W, Kühn C, Tudorache I, et al. Extended criteria donor lungs and clinical outcome: results of an alternative allocation algorithm. J Heart Lung Transplant 2013;32:1065-72.
1055 2. Sundaresan S, Semenkovich J, Ochoa L, et al. Successful outcome of lung transplantation is not compromised by the use of marginal donor lungs. 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 the Association of Lung Transplant Physicians (UK). Effect of donor smoking on survival after lung transplantation: a cohort study of a prospective registry. Lancet 2012;380:747-55. 4. Avlonitis VS, Krause A, Luzzi L, et al. Bacterial colonization of the donor lower airways is a predictor of poor outcome in lung transplantation. Eur J Cardiothorac Surg 2003;24:601-7. 5. Diamond JM, Lee JC, Kawut SM, et al. Clinical risk factors for primary graft dysfunction after lung transplantation. Am J Respir Crit Care Med 2013;187:527-34.
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, an altering appreciation of donor risks. In this issue, a report from the Hannover group1 is both a product of that trend and expresses a logical conclusion. In a previous era, only the best lung would do, and all the emphasis was on the “standard donor.” Gas exchange had to be good, the chest X-ray clear, and previous history unblemished. 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 progressive retrenchment of donor lung assessment. Ischemia time, geographic distance, adverse radiology, and sputum purulence have all disappeared as factors to be considered when considering the potential lung donor. Some stubbornly remain: smoking, despite previous doubts, is established as a risk factor for early and mid-term risk.3 Similarly, although the color of tracheal secretions is unimportant, organisms in the lung parenchyma and the lower airway are not good.4 But, on the other hand, lungs donors with severe asthma or pulmonary emboli have been used successfully. The current state of our knowledge is well illustrated by the seminal report from the lung transplant outcomes group in the United States looking at predictors of primary graft dysfunction.5 Oxygenation and ischemic time, the former, in particular, 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, predict acute lung injury. They add to others, such as ventilation, extracorporeal membrane oxygenation, and previous surgery, which we already knew about. There is a general realization that many donor factors imagined to be important are no longer so and that many early problems are related to aspects of the recipient. So how does this relate to allocation, ostensibly the topic of this paper from Sommer and colleagues? Within the Eurotransplant area, which includes Germany, lungs are allocated, in the first instance, to specific patients in a manner that includes an “urgent category.” The best lungs come this way, many of them going to patients in the high-urgency categories. If initially turned down for the first
patient because of functional or logistic issues, the organ is offered on to other specific patients. But if refused 3 times for specific patients, it is then offered in a general way, to centers to allocate to whom they see is best suited. This is termed “rescue” allocation. Within this system, stable, non-urgent patients might have a considerable wait for a lung. But often they are the same individuals who, by modern reckoning, represent low-risk recipients, lacking, for instance, pulmonary hypertension. The imaginative step taken by the Hannover group was to ensure that the best lungs (although we have no really good way to make that definition) went largely to the sickest patients. But then, they were prepared to give the “rescue” lungs, already turned down 3 times, to the most stable recipients. This slightly counterintuitive approach, perhaps bordering on the ethically questionable, was justified by what we now know about the influence of recipient factors on early outcome. The results of this “experiment” form the report. The patients in the “rescue” allocation group, themselves significantly older, received lungs from older donors with worse gas exchange. But they had shorter ventilation times, shorter hospital stays, and identical survival to more than 2 years. In other words, this was a triumph of intelligent use of these previously “marginal” lungs, giving excellent outcomes from lungs 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 an average oxygenation ratio of 398. Recipients had a mean age of 53 years. We are not talking about extremes of acceptance in either group. And the Hannover program is large and active: the 72 recipients of the “rescue” lungs came out of 183 transplants in only 1.5 years. The advantages of good-sized activity have been repeatedly demonstrated, and these good results might not be repeated by a smaller team. But this report shows us a way forward. As we gain a greater understanding of just what are the important donor variables and the best way to define the riskiest recipients, we can increase the overall benefit for all our patients.
1053-2498/$ - see front matter r 2013 International Society for Heart and Lung Transplantation. All rights reserved. http://dx.doi.org/10.1016/j.healun.2013.08.018
Dark
Choosing the Right Lungs for the Right Patient
Disclosure statement The author does not have a financial relationship with a commercial entity that has an interest in the subject of the presented manuscript or other conflicts of interest to disclose.
References 1. Sommer W, Kühn C, Tudorache I, et al. Extended criteria donor lungs and clinical outcome: results of an alternative allocation algorithm. J Heart Lung Transplant 2013;32:1065-72.
1055 2. Sundaresan S, Semenkovich J, Ochoa L, et al. Successful outcome of lung transplantation is not compromised by the use of marginal donor lungs. 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 the Association of Lung Transplant Physicians (UK). Effect of donor smoking on survival after lung transplantation: a cohort study of a prospective registry. Lancet 2012;380:747-55. 4. Avlonitis VS, Krause A, Luzzi L, et al. Bacterial colonization of the donor lower airways is a predictor of poor outcome in lung transplantation. Eur J Cardiothorac Surg 2003;24:601-7. 5. Diamond JM, Lee JC, Kawut SM, et al. Clinical risk factors for primary graft dysfunction after lung transplantation. Am J Respir Crit Care Med 2013;187:527-34.
