Organ transplantation has transformed from experimental surgery into a cornerstone of modern medicine, saving thousands of lives each year. In just over half a century, the United States has built a robust transplant system — from the first successful kidney transplant in 1954 to the one-millionth organ transplant performed in 2022.
The history of organ transplantation in the U.S. is marked by pioneering surgical feats and cutting-edge medical developments. The first successful human organ transplant was performed in 1954 at Brigham Hospital in Boston by Dr. Joseph Murray, where a kidney was transplanted between identical twin brothers. This breakthrough proved that an organ could be permanently accepted when immunologic rejection was not a factor (as in identical twins).
Early attempts at other organs soon followed. By the 1960s, surgical teams began achieving landmark successes transplanting the first deceased-donor kidney, liver and heart. This was followed in the early 1970s by the first lung transplant. These surgical breakthroughs coincided with advances in organ preservation and immunology, including the development of tissue typing and crossmatching to improve donor-recipient compatibility, as well as the advent of powerful immunosuppressant drugs – most famously cyclosporine in 1983, which revolutionized transplant outcomes by dramatically reducing rejection rates.
During this same period, the development of national policy aimed at facilitating transplantation was critical to its growth. This began in 1968 with the “Definition of Irreversible Coma”, a landmark report that laid the foundation for the concept of brain death and enabled ethically procuring organs from heart-beating donors. At the same time, The Uniform Anatomical Gift Act of 1968 created a standardized legal basis for individuals to donate organs and for next-of-kin consent, and it introduced the first donor card system.
In 1972, Congress took the unprecedented step of extending Medicare coverage to patients with end-stage renal disease (ESRD), including dialysis and kidney transplantation, recognizing transplant as a viable therapy and ensuring financial access to it. This was soon followed by the National Organ Transplant Act of 1984, which outlawed the sale of organs and established the national Organ Procurement and Transplantation Network (OPTN) to fairly allocate organs. Since then, the U.S. transplant system has grown in scope and sophistication Ð incorporating multiple organ procurement organizations (OPOs) across regions and data-driven allocation policies.
Today, organ transplantation is a critical component of U.S. healthcare. Since 2000, the number of transplants performed per year has more than doubled, with 48,149 total transplants performed in 2024. This has been primarily driven by increases in annual transplant volume that has occurred over the last 10 years. (See Figure 1.)
Despite this, there has also been rapid growth in waitlist additions. In 2024 alone, more than 70,000 people were added to the organ transplant waitlist, and as of June 2025, more than 105,000 individuals were waiting for an organ transplant. The growth in waitlist additions outpacing the growth in number of transplants performed highlights a primary challenge facing organ transplantation today Ð a critical shortage in the number of transplantable organs.
A multifaceted approach to addressing this issue and ensuring that no transplantable organ is discarded is currently in our midst. A critical component of this rests with Organ Procurement Organizations (OPOs). In 2020, the Centers for Medicare and Medicaid Services (CMS)ÊandÊthe Health Resources and Services Administration (HRSA) introduced the OPO Final Rule. This redefined how OPOs are evaluated by using objective, transparent metrics based on actual organ donation and transplantation rates.
OPOs are now compared to the top 25% of performers, and those failing to meet benchmarks risk decertification and replacement. In response, many OPOs have adopted clinical and logistical strategies to improve donor identification, management and organ recovery. This has resulted in a significant increase in both number of donors and number of transplantable organs.
A component of this has included broadening criteria for what constitutes an acceptable donor and deliberate, evidence-based donor management protocols to increase the number of transplantable organs from each donor. Expanding criteria for acceptable organ donation is highlighted by looking at trends in donor age.
The number of organ donors ages 50-64 and age 65 and greater has rapidly increased. (See Figure 2.) At the same time, the number of donors aged 18-34 has been recently decreasing, likely in part due to progress made in reducing opioid-related deaths.
In addition to expanding criteria for acceptable organ donation, the proportion of each type of deceased donor has changed markedly. Deceased donors are classified based on how death is declared and the conditions surrounding organ recovery.
Donation after Brain Death (DBD) in many respects is thought of as a ÒtypicalÓ deceased donor and is the most common type of deceased donor. These donors have been declared dead based on irreversible loss of all brain function, including the brainstem. However, the heart continues to function and organs are kept perfused with oxygenated blood until organ procurement occurs.
A second type of deceased donor is referred to as a Donation after Circulatory Death (DCD) donor. These donors do not meet criteria for brain death but require life-sustaining treatment in the setting of a non-survivable condition.
In the event that life-sustaining treatment is planned for withdrawal, this can occur with an intent for organ donation after death has been declared. After the heart stops and a mandatory waiting period confirms death, organs may be recovered for transplant.
An important component of a DCD donor is that the transplant recovery team has no involvement in the donorÕs care prior to confirmation of death. Because organs in DCD donors are exposed to warm ischemia time (WIT), where they are both underperfused or nonperfused, they have been associated with increased risks for recipients.
As a result, DCD donors have traditionally been used with strict selection criteria that considers both donor and recipient characteristics. However, as seen in Figure 3, the number of DCD donors has increased drastically in recent years and along with expanded criteria DBD donors have been critical in expanding the donor pool.
OPO operational changes and donor management improvements have allowed for the expansion of organs offered from extended criteria DBD donors and DCD donors to transplant centers. However, the burden of ensuring these organs can be utilized safely and with good recipient outcomes lies with the countryÕs transplant centers.
To effectively utilize these organs while maintaining acceptable recipient outcomes, transplant centers have worked diligently to identify and incorporate new technologies. In fact, the field of transplant is in the midst of one of the most rapid expansions of technological innovation that it has experienced in decades.
This revolution has had a rapid impact. Indeed, many donor organs used today would not have been deemed suitable for transplant just 3 years ago. This issue of Atlanta Medicine focuses on these technological innovations, including donor management, normothermic regional perfusion, normothermic ex vivo machine perfusion and other advanced preservation techniques. These are the technologies that are reshaping the field of transplantation today, however the future may be even more transformative.
Although still in early clinical stages, recent breakthroughs in gene editing and immunosuppression suggest that xenotransplantation could one day provide a virtually limitless supply of organs, potentially ending the waitlist entirely. As the field evolves, a combined strategy of optimizing human donor utilization and advancing novel technologies like xenotransplantation holds the greatest promise for addressing the global organ shortage and saving countless more lives in the decades to come.
References
Organ Procurement and Transplantation Network. (2025).ÊNational data: Transplants by donor type. U.S. Department of Health & Human Services.Êhttps://optn.transplant.hrsa.gov/data/view-data-reports/national-data/#
Miller, R. A. et al. (2024). Impact of CMS Final Rule on OPO metrics and procedural trends.ÊPancreas, 53(2), e176Ðe179.
Organ Procurement and Transplantation Network & Scientific Registry of Transplant Recipients. (2022).Ê2022 Annual Data Report. U.S. Department of Health & Human Services.
Spencer, M. R., Curtin, S. C., & Hedegaard, H. (2024).ÊDrug overdose deaths in the United States, 2003Ð2023Ê(NCHS Data Brief No. 522). National Center for Health Statistics.Êhttps://www.cdc.gov/nchs/data/databriefs/db522.pdf
Murray, J. E., Merrill, J. P., & Harrison, J. H. (1955). Renal homotransplantation in identical twins.ÊSurgical Forum,Ê6, 432Ð436.
OPTN. (2022).ÊU.S. reaches historic milestone of 1 million organ transplants. Organ Procurement and Transplantation Network.Êhttps://optn.transplant.hrsa.gov/news/u-s-reaches-historic-milestone-of-1-million-organ-transplants/
Starzl, T. E., Marchioro, T. L., Von Kaulla, K. N., Hermann, G., Brittain, R. S., & Waddell, W. R. (1963). Homotransplantation of the liver in humans.ÊSurgery, Gynecology & Obstetrics,Ê117, 659Ð676.
Adam Gracon, MD, PharmD, FACS
Dr. Adam Gracon is a multi-organ transplant surgeon at the Piedmont Transplant Institute. Dr. Gracon completed his surgical residency at Indiana University. He went on to complete his fellowship in Abdominal Transplant Surgery at the University of Wisconsin. He is board certified by the American Board of Surgery and is a Fellow of the American College of Surgeons. Dr. Gracon has a special interest in donor organ optimization and emerging technology.
