Damaged human lungs that have been rejected for organ transplantation could be reconditioned through the use of cross-circulation from a pig, research suggests. Despite advances in the field, lung transplantation remains limited by the low availability of healthy donor organs. Additionally, most donor lungs cannot be used due to severe, but potentially reversible, injuries. Currently, a method known as ex vivo lung perfusion (EVLP) is used to provide lung support outside the body and recover marginal quality donor lungs before transplantation. However, this only provides a limited duration of six to eight hours of support – a time that is too short to recover the majority of severely damaged donor lungs.