Increasing the number of lungs available for transplant

When patients are put on the transplant list, they have hope at a better life through a new organ, whatever it may be. However, organs are difficult to transplant. For one, there is a high risk of rejection, but in the case of lungs, the desperately needed lung can also be damaged through the surgery needed to obtain it or through the donor's lifestyle choices (ongoing ECMO, decreased oxygen perfusion, et cetera) (Wallinder et al. 2013). Currently, up to 85% of donated lungs are excluded from selection for transplantation (Ware et al. 2002). Many lungs that are donated are actually suitable for transplantation, but they unfortunately are not transplanted. An analysis of lungs that were not transplanted was conducted in order to determine if they would have been suitable for transplantation. Ultimately, 41% of all lungs that were not transplanted could have been suitable for transplantation (Ware et al. 2002). Luckily for potential lung recipients, there is a new method in the field of lung transplantation that could increase the viability of potential lungs for transplant. This new method is called ex-vivo lung perfusion (EVLP). In ex-vivo lung perfusion, the potential transplant lung is put into a sterile chamber. The lung is attached to a circuit and filtered with leukocyte-filtered blood that is deoxygenated with carbon dioxide and nitrogen (Egan et al. 2006). The lungs were also ventilated with fractionated oxygen when it is brought above freezing (Egan et al. 2006). This kind of treatment can prove useful in the problems with getting adequate lungs for transplant due to the process of obtaining the lung itself. In obtaining lungs, the lung must be obtained from a dead donor. When the donor dies, the lungs cease oxygenating the body, and so the cells undergo damage and the lungs become less oxygen-rich. The longer the donor is dead, the less suitable the lungs become for transplant. Ideally, the lung would be most viable for transplant if it was taken out of a living donor, but due to the essential nature of the lungs in human function, this is not possible. The lungs that are deemed unsuitable can be resuscitated using this technique (Egan et al. 2006). Ultimately, the technique has shown success in patients in limited clinical trials. Lungs that were originally rejected for transplant underwent EVLP and were transplanted into patients. The lungs that underwent EVLP showed an average improvement in oxygen content of 28.4 kPa, but the EVLP patients had a longer time to extubation (removing the artifical airway) and a longer ICU stay associated with the procedure than their traditional transplant counterparts (Wallinder et al. 2013). However, three of the patients who underwent traditional transplant died before leaving the hospital, while all of the patients who received EVLP lungs were discharged from the hospital alive (Wallinder et al. 2013). This method could prove very useful in increasing the viability of lungs that are on the borderline for transplant and making lungs used in transplant more viable. Since lung transplants are the main method of treatment, increasing the amount of available donor lungs would greatly increase the potential of survival for people afflicted with terminal lung diseases. It would make the transplant list less of a hope for survival and more of a guaranteed treatment. References: Egan TM, Haithcock JA, Nicotra WA, Koukoulis G, Inokawa H, Sevala M, Molina PL, Funkhouser WK, Mattice BJ. 2006 Apr. Ex vivo evaluation of human lungs for transplant suitability. The Annals of Thoracic Surgery. 81(4): 1205-1213. Wallinder A, Ricksten SE, Silverborn M, Hansson C, Riise GC, Liden H, Jeppsson A, Dellgren G. 2013 May. Early results in transplantation of initially rejected donor lungs after ex vivo perfusion: a case-control study. European Journal of Cardiothoracic Surgery. doi: 10.1093/ejcts/ezt250 Ware LB, Wang Y, Fang X, Wamock M, Sakuma T, Hall TS, Matthay MA, Warnock M. 2002 Aug. Assessment of lungs rejected for transplantation and implications for donor selection. The Lancet. 360(9333): 619-620.