Ex Vivo Lung Perfusion: A Historical Review to Modern Day Applications
Ever week in the United States, 130 patients awaiting a lung transplant either die or are removed from the waitlist after becoming too sick for transplantation. Three thousand patients were added to the waitlist in 2020 alone, on top of 4,000 people waiting for lungs already. The need for donor lungs is staggeringly high, but despite this need, 75 percent of donor lungs are discarded—the lowest recovery rate among all solid organ transplants. This is an unacceptable state for lung transplantation, and major efforts are under way to rectify it.
One of the strategies cardiothoracic surgeons have developed to address this shortage is ex vivo lung perfusion, or EVLP. At its core, EVLP is a way to perfuse explanted lungs with warm blood via cannulation of the pulmonary artery, while ventilating the lungs via the tracheobronchial tree.
This allows surgeons to evaluate or even provide therapy to the lungs for twelve to twenty-four hours, far extending the previous limitations of cold ischemia. This is especially relevant as surgeons begin to use more donors who are deceased from circulatory death (DCD), as the standard evaluation time for the allograft in typical brain-dead donation is curtailed.
The video above discusses the history of ex vivo lung perfusion, and the three main contemporary methods of performing EVLP: the Lund Protocol, the Toronto Protocol, and the Organ Care System (OCS) Protocol.
EVLP is currently expanding the donor pool by as much as 50 percent at certain centers, and this video discusses some of the major trials that demonstrate its efficacy. Despite these successes, there are still major limitations to its use, and exciting research is under way to further expand the utilization of EVLP.
Possoz J, Neyrinck A, Van Raemdonck D. Ex vivo lung perfusion prior to transplantation: an overview of current clinical practice worldwide. J Thorac Dis 2019;11(4):1635-1650. doi: 10.21037/jtd.2019.04.33
Steen S., Sjoberg T., Pierre L., Liao Q. Eriksson L., Algotsson L. Transplantation of lungs from a non-heart-beating donor. Lancet. 2001; 357: 825-829