Making every liver count - advances in ex vivo liver perfusion research in the CNTRP
Across the country, there are hundreds of people on waiting lists hoping that today is the day they’ll get the call that a matching liver is available. Despite this overwhelming demand however, each year, an estimated 20 percent of available donor livers must be refused for transplant because they are damaged in some way. To those on the waiting list, those livers could be the difference between life and death. Thanks to research by the Canadian National Transplant Research Program (CNTRP) supported by the Canadian Liver Foundation, it may soon be possible for these livers that would have been discarded to be made viable for transplant. Using a machine called the OrganOx metra®, donor livers can be maintained at body temperature with blood pumping through them allowing doctors the opportunity to test and repair them as needed. This technology has already been effective in prolonging the time a liver can be kept functioning outside the body before transplantation. “When you keep a liver on ice, we have no way of knowing how it will work,” says Dr. Shapiro, senior-scientist at the University of Alberta and leader of CNTRP’s research into ex vivo organ protection and repair. “You’re rolling the dice and hoping that once the blood flow is restored that it will function as it should. A liver can survive in cold storage for six to ten hours before it starts falling apart but in the OrganOx metra®, we can keep it viable for up to 24 hours before transplantation.” Dr. James Shapiro is now working with teams in both Edmonton and Toronto to test the OrganOx metra® on ‘high risk’ livers to determine how well they function and whether they can be repaired. Livers may be considered to be ‘high risk’ if they are very fatty, have been on ice too long, are infected with hepatitis B or C viruses, or have been deprived of oxygen for an extended period so that liver cells are beginning to die. “Whatever is making a liver ineligible for transplant, we may have the prescription,” says Dr. Shapiro. “The OrganOx metra® gives us the time and the opportunity to treat the liver --- whether that means purging fat cells, eliminating a virus or stopping liver cell death. It is our hope that one day we may be able to use almost any liver no matter what its condition so we could save more lives.”
Currently, there are only two OrganOx metra® machines in Canada but one day this technology may be in place in every transplant centre. “This technology will change the future,” says Dr. Shapiro. “If we can rehabilitate livers and keep them functioning for longer outside the body, we could potentially use every available organ and even share organs around the world.” The OrganOx metra® represents just one area of CNTRP research. Teams are also investigating how to: protect patients from viral infections post-transplant; encourage the body to accept a new organ without anti-rejection drugs; increase the numbers of organ donors; prevent early rejection of transplanted organs; and improve outcomes for pediatric transplants. To donate to support transplant research, click here.
Top right -- Dr James Shapiro (left) and Dr Lori West, head of the CNTRP Program, celebrate first clinical use of the OrganOx metra® in Canada. Bottom left -- Sewing in the new liver preserved with the OrganOx metra® ex vivo normothermic storage system