Ex vivo lung perfusion: a potential platform for molecular diagnosis and ex vivo organ repair

Lung transplantation is a proven treatment for selected patients with end-stage lung disease. However, the number of patients on the transplant waiting list far exceeds the number of available donor lungs, resulting in waiting list morbidity and mortality. The problem is further exacerbated by the low utilisation rate of available donor lungs, for fear of selecting a damaged lung and the resultant primary graft dysfunction. In the past decade, ex vivo lung perfusion (EVLP) has become part of standard lung transplant clinical practice in Canada and Europe, and it has been shown to improve the usage of available donor lungs by allowing physiological and radiologic evaluation of explanted donor lungs that are considered marginal. This allows clinicians a second opportunity to decide whether to proceed to transplantation, instead of declining an organ that appears questionable by standard clinical criteria. However there has been much research activity looking at EVLP as a platform for (I) molecular diagnosis, thereby further improving the diagnostic accuracy regarding quality of the donor lung; (II) organ repair, thereby allowing injured donor lungs to become clinically useable. This manuscript summarises some of the preclinical and clinical research from the Toronto group focusing on these promising aspects of EVLP which may further increase the number of useable donor lungs in lung transplantation.