Christopher Wigfield, MD, Surgical Director of the lung transplant program at the University of Chicago Medicine, demonstrates the ex vivo lung perfusion system during a trial run at the Center for Care and Discovery.
Lungs are the most difficult organs to transplant. They’re highly susceptible to injuries and infections in the late stages of the donor’s life, and physicians racing against the clock to get them to a waiting recipient don’t have much time to address these problems before procurement.
To overcome these challenges, the University of Chicago Medicine has become the first hospital in Illinois to use an new system called ex vivo lung perfusion (EVLP) to prepare donor lungs for transplant. The procedure allows physicians to assess the viability of donor lungs that don’t meet the typical criteria for transplant–lungs that doctors may not have considered using in the past. More than 50 percent of lungs evaluated with the system are ultimately deemed suitable for transplant, which has increased the number of available donor lungs significantly.
“This really heralds a new era in lung transplantation, as we will eventually have additional lungs for transplant candidates, and have the opportunity to rule out truly unsuitable grafts and reduce the risk of life threatening complications from marginal quality donor lungs,” said Christopher Wigfield, MD, Surgical Director of the lung transplant program at the University of Chicago Medicine.
During the EVLP process, physicians connect donor lungs to a circulation system that runs a solution through the blood vessels. This gently warms up the lungs after transport and establishes normal tissue flow. Physicians can then re-ventilate the lungs in a gradual, controlled manner, expanding them more deliberately compared to when they’re transplanted directly in the recipient. This decreases the risk of damaging the lungs and allows detailed assessment to ensure more successful transplants.
The University of Chicago joins 15 other sites in the United States currently using the XVIVO Perfusion System (XPS™), manufactured by XVIVO Perfusion AB, based in Göteborg, Sweden. A trial in Canada and subsequent FDA approval has paved the way for use in the US.
Currently, only one out of five donors who give organs of any kind provide suitable lungs, placing an even greater demand on the organ donation system. Nearly 1,700 people in the United States are already on the waiting list for lung transplants.
“Despite this scarcity of acceptable donor lungs, more lung transplants are performed every year, aggravating the situation further,” said Jamie Bucio, Thoracic Organ Procurement Coordinator at the University of Chicago Medicine.
Limiting damage to donor lungs before transplant
Lungs can sustain damage during the process to transfer them from the donor and prepare them for the recipient. They can collapse, and, as surgeons begin to ventilate them after transplant, they may not re-expand properly. Fluid can build up within lungs and affect the function of the lung tissue. Brain death of the donor can trigger an inflammatory effect in the lung tissue that can jeopardize the transplanted lung as well.
In addition to these more obvious factors, a number of more mysterious processes happen in the lungs after a donor’s death that can decrease the odds of a successful transplant. Lungs may be dysfunctional in the recipient despite adequate appearance in the donor. Two to three out of 10 lungs show signs of such limitations within 72 hours after being transplanted.
“This technology has the potential to reduce that occurrence and allow for better recovery planning of transplant recipients,” Wigfield said.
“Losing patients while they are waiting for lungs is unacceptable, but a harsh reality at times due to continued donor limitations,” he said. “That’s where we would like to see the impact. Reducing that to a minimum would be a huge success.”