For people awaiting a transplant, expanded criteria donor (ECD) organs may bridge the gap between life and death. ECD availability can separate those on the waiting list from those who will die before receiving their needed organ.
As of the first six months of 2021, only one out of every five people actively listed for transplant received an organ. Organ Procurement and Transplantation Network (OPTN) data shows that as of December 1, 2021, 117,314 people were waiting for a transplant, mostly accounted for by kidneys, (97,948), livers (11,837), hearts (3529) and lungs (1023). As the gap between available organs and the number of people on the transplant list continues to widen, ECD organs can allow more people to receive transplants sooner.
In 2019, Summit Re published an article focused specifically on expanded criteria liver transplants and the use of Hepatitis C antiviral treatments. While livers and kidneys represent the most often transplanted ECD organs, expanded criteria donors can offer the same life-saving potential to people who need other organs, as well.
What is an Expanded Criteria Donor?
The standard donor organ has historically come from a healthy donor aged 10 to 39, who has suffered a trauma or anoxic event resulting in brain death. Expanded criteria donors, however, carry certain risk factors that would otherwise exclude them from organ donation. Although criteria vary by organ, typically ECDs are older than 60 with a significant medical history or chronic disease, including but not limited to obesity, hypertension, diabetes, Hepatitis, asthma, or a history or smoking. In addition, donation after cardiac death is also now occurring at some facilities under strict rules for organ recovery; these are also considered expanded criteria organs. Although the donor, graft survival, and function of the organ are not considered ideal or standard, use of the ECD organ can significantly shorten the waiting time to transplant.
The availability and risk of an expanded criteria organ must be disclosed to the patient. The patient must then decide whether to accept a less than perfect organ versus the possibility of dying while waiting for a more optimal organ. The decision must be made quickly, as the transplant facility has a one-hour decision window to accept or decline (this applies to any organ, not just ECD organs) before the organ is offered to the next facility with a patient that matches the organ.
In 2020, the Public Health Service (PHS) added fields to the donor form in order to track and report on ECD organs. The Organ Procurement and Transplantation Network (OPTN) also tracks and reports on these organs/transplants.
Evolving Definitions of Expanded Criteria
As more data becomes available, the criteria for expanded criteria donors continues to evolve. For example, the HOPE Act, which took effect on November 21, 2015, allows the use of HIV-positive donors into HIV-positive recipients. Initially the protocol only authorized kidney and liver transplant, but a May 2020 update based on five years of data now allows organs of any type to be transplanted under HOPE Act protocols. The five-year data shows similar outcomes as with the use of HIV-negative donor organs.
More recently, a paper from Cleveland Clinic discusses the early success of using a SARS-CoV-2 RNA-positive donor for kidney transplants in ten patients. So far, the early results show no signs of donor-derived SARS infections. (Am J Transplant 2021; 21: p.3743-3749)
Kidneys
In North America, approximately 24 percent of potential donors qualify as ECD, a rate which lags behind Europe’s 30 percent. Although accepting an ECD kidney may significantly decrease the amount of wait time for a for transplant, it does come with some risk for earlier graft loss. The exact risk is unknown, but estimates posit that 8 of 10 ECD kidneys will still be functioning at one year, compared to 9 of 10 standard criteria donor (SCD) kidneys. At five years, 50 percent of ECD kidneys will still be functioning, compared to 7 of 10 of SCD kidneys. Studies have also shown that transplant patients who receive either SCD or ECD kidneys have a superior survival when compared to remaining on dialysis.
Livers
Using ECD organs in liver and other transplants became more practical with the advent of Hepatitis C antiviral medication. It then became possible to transplant a negative Hepatitis C organ recipient with a positive Hep C organ and subsequently treat the recipient with antiviral drugs to eliminate the disease.
Researchers at the Michael E. DeBakey VA Medical Center and Baylor College of Medicine in Houston and the VA Pittsburgh Healthcare System reviewed 35 studies that examined outcomes for 852 solid organ transplants (SOT) in which the donor organs were positive for Hepatitis C and the transplant recipients did not have the virus
The review included studies that looked at 343 kidney, 233 heart, 204 liver, and 72 lung transplants. Eight to twelve weeks after treatment with drugs called direct-acting antiviral agents (DAAs), 100 percent of the transplant recipients who were measured for viral load were cured of Hepatitis C. Seven transplant recipients relapsed with Hepatitis C infection, but all were successfully retreated. No patient deaths or organ graft failures related to Hepatitis C infection were reported. They recommend that relevant scientific societies like the American Association for the Study of Liver Disease (AASLD) and the Infectious Diseases Society of American (IDSA) update their guidelines to "approve the use of Hepatitis C-positive organs as the new standard of care."
Hearts
Several groups have demonstrated that careful use of ECD hearts has acceptable outcomes in select patients. These results have further been aided by the use of OCS™ Heart System, an ex-vivo device (defined below), which has resulted in high utilization of ECD hearts with excellent short-term post-transplant outcomes, most notably a low rate of primary graft dysfunction (PGD). These results provide clinical evidence supporting its use in ECD heart preservation and assessment and may significantly increase donor utilization for transplantation.
Lungs
A 2021 retrospective study by the Society of Thoracic Surgeons looked at data from May 2005 to December 2018 using the United Network for Organ Sharing (UNOS) database. They found that of the 24,888 lung transplants, 80 percent had expanded criteria and that the use of expanded criteria had increased over the study period. Recipients of ECD organs and standard criteria organs showed no difference in one-year survival.
Donor supply limits the number of lung transplants performed. Extension of donor criteria has occurred alongside increased overall lung transplant volume. Use of ECD did not compromise 30-day, 90-day, nor one-year survival. Further studies are warranted to define long-term outcomes.
The International Study for Lung and Heart Transplantation did a retrospective study in 2019 on 57 pediatric lung transplantation cases and concluded ECD lungs can be used safely for pediatric lung transplantation without compromising short- and mid-term results. Pulmonary function testing results at discharge from initial hospital stay, after one year, and at last assessment were also similar. Freedom from chronic lung allograft dysfunction at one and five years after transplantation showed no significant differences between groups. Such data continues to make the case for ECD transplantation.
Effects of the COVID-19 Pandemic on Organ Donation Rates
With the help of ECD organs, donation has been increasing steadily year over year. Organ transplants from deceased donors totaled 33,309 in 2020, setting an annual record for the eighth consecutive year. This occurred despite significant adverse effects from the COVID-19 pandemic, where deceased donor transplantation briefly fell by approximately 50 percent in early April of that year before returning to a more consistent baseline in late May.
Much of the increase in deceased donation was made possible by donors representing less traditional medical criteria. For the second straight year, the most common age range of deceased donors was 50 to 64. The 3,726 donors in this category increased by 7.9 percent over 2019. Donation also increased significantly among individuals who died of cardiorespiratory failure as opposed to brain death; the 3,223 donors after cardiorespiratory death (DCD donors) increased by 18.6 percent over the total in 2019.
The number of living donor transplants performed was affected more significantly by the COVID-19 pandemic. Many transplant programs temporarily deferred living donor transplantation in areas particularly affected by outbreaks of the virus due to concerns of unnecessarily exposing potential living donors and living donor recipients to possible COVID-19 infection. A total of 5,725 living donor transplants were performed in 2020, a decrease of 22.6 percent over the record of 7,397 set in 2019. Living donor transplants since June of 2020 have occurred at rates more similar to pre-pandemic activity.
Technology Advancements Improve Transplantation Rates
In addition to the use of ECD organs, a number of the recent gains in organ donation and transplantation can be attributed to advancements in technology. Traditionally, donated organs are placed on ice until they are transplanted into a recipient. With ex vivo perfusion, however, a machine keeps organs warm by continuously pumping blood through them. Benefits of these devices include:
Significant reduction of “cold ischemic time.” This means the organ spends much less time on ice without blood flow, which is better for the organ.
Quality assessment: While an organ is perfused in a machine, transplant experts can better assess its quality and function before it is transplanted into a patient.
Extended operating window of time: Ex vivo perfusion may allow organs to survive longer outside the body, making immediate transplant less urgent.
Ex vivo devices such as OrganOx and TransMedix, among others, allow for greatly extended time from procurement to implant. They are most commonly used for heart, lung, and kidney transplants.
Other Considerations
Post-transplant treatment cost can be significant, and in some cases may not be covered in transplant contracts and/or may fall under the pharmacy benefit for employers. For example, in the case of Hepatitis C positive transplants, antiviral therapy varies from four to twelve weeks and averages from $30,000 to $180,000, depending upon which drug is used (determined by the genotype of the Hep C virus). A patient is considered cured when he does not have detectable Hep C RNA in his blood tests for six months or more after completing the antiviral treatment.
Treatment costs notwithstanding, the use of ECD organs shows great promise in helping to bridge the gap between demand and supply for patients in need of transplants. Most research demonstrates that with the proper precautions and follow-up treatment, the use of ECD organs as safe, with minimal issues found at one- and three-year follow-up checkpoints. Long term studies are still needed as this practice continues to evolve, but the outlook remains cautiously optimistic.
Article written by Ginny Fisher, RN, BSN, Managed Care Specialist for Summit Reinsurance Services, Inc. For more information about how this may affect your plan, please contact your Summit ReSources care specialist. The following sources were used as reference material for this article:
https://pubmed.ncbi.nlm.nih.gov/32663473/
https://pubmed.ncbi.nlm.nih.gov/30852096/
https://my.clevelandclinic.org/departments/transplant/programs/kidney/types
https://health.ucdavis.edu/transplant/nonlivingdonors/expanded-criteria-donors.html
https://www.jhltonline.org/article/S1053-2498(19)30089-0/fulltext
https://optn.transplant.hrsa.gov/
https://emergingtherapies.com/
https://www.hopkinsmedicine.org/transplant/programs/Ex-Vivo-Perfusion.html
https://unos.org/news/in-focus/hope-act-impact-continues-at-five-year-milestone/