As I was getting ready to perform a kidney transplant from a deceased donor on a recent Saturday afternoon, my phone rang. When I saw the ID for the organ allocation coordinator, I knew immediately what she would tell me: The other kidney from the same donor had been declined for transplant because the surgeon didn’t like how it flushed. At this point it had been out of the donor for 24 hours, and it was at a transplant center three hours away. If I wanted it, I could take it for anyone on my medical center’s wait list.
My first reaction was frustration. Why was I just hearing about this? By the time I got this kidney back to my center, brought a patient in, and prepared them for transplant, it would be the middle of the night and almost 30 hours after the kidney was removed from the donor. It would be so easy to just decline. Some other surgeon looked at the kidney and decided it was no good. Shouldn’t I just trust that?
But, as I reminded myself, taking a chance on that kidney might mean that someone on dialysis would have the opportunity to truly live again. Just as important, someone had bestowed this precious gift to the living. It was my job to make this legacy a reality.
I asked the allocation coordinator to get the kidney over to me so I could take a look. In the meantime, I would both perform the other transplant and select a patient who lived nearby, making sure to warn them it might not work out.
This might sound like an unusual situation. But it’s not. We throw out a lot of organs in this country: thousands of hearts, lungs, livers, and kidneys every year . In 2021, roughly 20,000 deceased donor kidneys were procured for transplant — and more than 20% were discarded.
Meanwhile the transplant wait list continues to grow, with more than 100,000 patients waiting for kidneys while millions suffer on dialysis without making it to the list. While some of these organs may have functioned poorly, evidence has been mounting that a majority of them would have performed well for years. Furthermore, studies have highlighted how much higher the discard rates are in the U.S. than in other countries.
There are many explanations for this, including concerns about donor quality, prolonged time to get the organ to a center that will accept it, recipient factors, scrutiny over transplant center outcomes that can lead to both decertification and financial penalties, and the increased resources and technical skill required to transplant and care for patients that receive high-risk organs. There is significant geographic variation in discard rates, and organs procured on weekends are more likely to be discarded than similar ones procured on weekdays.
The two groups that have faced the most blame for this situation are the Organ Procurement and Transplantation Network (OPTN), a government body, and the private nonprofit United Network for Organ Sharing (UNOS), which manages organ allocation and procurement for the OPTN.
Over the summer, Congress convened scathing hearings documenting numerous logistical and technical failures in organ procurement and allocation, including pictures of organs with tire tracks on them and coolers lost in airport baggage departments. Soon after, President Joe Biden signed into law the resulting bipartisan bill, which will break up the monopoly that UNOS has enjoyed, increasing competition for the contract to procure and distribute organs around the country. My colleagues and I hope that improvements in logistics and efficiency in organ allocation will improve the discard rate.
Lost in the congressional drama is the other side of the discard equation: the transplant centers and surgeons that are turning kidneys down. Organs are turned down for any number of reasons, many of which have negligible implications on how they will function: minor injuries to the blood vessels, ureter, or kidney capsule that could easily be repaired; a sampling error based on where in the kidney the biopsy was performed that leads to a false abnormal result; or some subjective assessment of how the kidney may have flushed. To dramatically reduce the discard rate overnight, we need to get marginal organs (those that are high risk for discard) into the hands of transplant surgeons who are comfortable using them as rapidly as possible and allow those organs to be transplanted into the patients that would most benefit from them. We also need to hold those surgeons and transplant programs responsible for those kidneys once they do accept them.
The kidney transplant system already has a method to identify a majority of the high-risk organs. Available kidneys are given a numerical score that assesses their predicted quality and performance based on donor characteristics, and those that score above a certain number are considered high-risk. These are the same kidneys that are most likely to be discarded, with a discard rate for these organs topping 60%. Some additional donor kidneys known to be high risk for discard could also be included in this group, such as those that are functioning poorly in the donor due whatever caused them to die.
In the current system, high-risk kidneys are offered to patients on the wait list who have agreed to accept them. This may sound reasonable, but the process has its the shortcomings. When a patient on my wait list is allocated a kidney, one of our allocation coordinators notifies me about the offer. I then have 30 minutes to review the donor and recipient characteristics and decide if I want to accept this kidney. I have to consider where the kidney is coming from and how long it might take to arrive at my center, how long it has been outside of the body, and how far away my recipient lives. I then review the crossmatch — our laboratory keeps a list of all antibodies that may be present in the blood of the recipient, typically generated by previous transplants, pregnancy, or blood transfusions. If my recipient has significant antibodies that cross-react to the donor proteins, I will likely turn down this offer.
We are supposed to update this list of antibodies every three months (since they can change over time), which requires a blood draw from that recipient. Sometimes they haven’t been updated, which can lead to serious delays, missing a great offer, or turning down a kidney late in the process once the patient or the organ arrives at our center. We check a crossmatch before doing any transplant, as transplanting across a positive crossmatch can lead to rapid rejection of an organ.
This process can go on for hours upon hours, very often occurring through the night. These offers are typically made after the kidney has been procured, so that accurate anatomy and biopsy data can be included. As the time the kidney sits outside the body increases, and every decline increases the chances the kidney gets discarded. Imagine being offered a particular high-risk kidney at 9 p.m. and declining it, then again at midnight for a different patient, and a third time at 3 a.m. By that third call, many surgeons simply decline the kidney for everyone on their list.
Ultimately a kidney might be accepted by the surgeon on call for a given patient. At that point the patient is called and given the offer, and if they agree then the acceptance is finalized. It may take them hours to get to the hospital, and then more hours to have labs drawn and resulted, Covid checked (patients with active virus do badly with the transplant and immunosuppression), cross matches rerun if needed, and X-rays taken. Then we have to wait for the operating room. By the time the patient is ready and the OR is available, a new surgeon with a different opinion about the kidney may be on call. They may decide not to use it and send it back to the offering organ procurement center where the process starts over. At this point it would probably be discarded.
There is currently no penalty for a surgeon declining a kidney at the last minute and no incentive to try to use a kidney that is found to have a repairable injury, a small area of discoloration, or some abnormal numbers on an organ perfusion pump, not to mention if it is now the middle of the night and the kidney may have been out of the body for an exceedingly long time. Transplant surgeons are human beings, with different experience, skill level, tolerance of risk, and judgment.
Decisions on a high-risk organ might also be affected by how busy a particular surgeon might be, how much sleep they may have gotten, how good a candidate the recipient is for the organ, and what the operating room access might be. If a surgeon evaluates a high-risk organ with an inclination to turn it down, they will always find a reason to support that decision.
So here is the fix. High-risk kidneys should immediately be offered to transplant centers that opt into a high-risk program as an open offer to their wait list rather than to a specific patient, on a rotating schedule with weight put on proximity to the donor hospital. Ideally the offer should be made prior to procurement of the organ, with final acceptance once it is removed and anatomy and biopsy results can be reviewed by the accepting surgeon.
If the biopsies show significant disease and the function of the kidney would be inadequate for a recipient, the receiving center can request both kidneys for a single patient, termed a dual transplant (which has been shown to have good outcomes). If a center accepts a kidney, it can then choose the patient who will benefit the most from the transplant and has a long predicted wait time for a low-risk transplant, with informed consent. That would entail a discussion with the patient about expectations regarding the quality of the kidney, how long and how well it might work, and how much longer they might need to wait for a lower-risk kidney. The ability to match the kidney to a recipient is important, as high-risk kidneys need to go into patients who can tolerate the slow initial function. Centers that opt into the high-risk program will need to maintain an updated list of informed patients who are predicted to benefit from these kidneys, who can be called in as soon an offer becomes available. For them, taking a chance beats remaining on dialysis.
The kidney would be transported rapidly to the accepting center, with assessment of the organ immediately upon arrival. If the original patient has some contraindication to transplant once they arrive at the hospital (like a positive Covid test or positive repeat crossmatch), the center can quickly identify another patient on their list and allocate the kidney to them. If a center decides to decline an organ at this point, it would rapidly be offered to another high-risk center by the organ procurement organization. Decline rates after initial acceptance would be tracked, as would the time from organ delivery to the decision to decline, and if a center goes above a target rate, say 10%, then that center would fall out of the rotation for high-risk organs for some period of time.
This would encourage centers to consider all of the available data prior to accepting the kidney and then hold them accountable after acceptance. There would be an appeal process for kidneys that were considered unusable for any patient upon inspection that wasn’t identified at the time of offer. In addition, discard rates for normal-risk kidneys would also be tracked and included in the target rate for each center, with penalties for falling below that target. Outcomes of high-risk kidneys (graft and patient survival) should be tracked separately from the outcomes of standard risk kidneys, and not be used to penalize programs in the way they are currently utilized, but rather influence inclusion in the high-risk program.
Many of my colleagues would argue against this proposal because it offers kidneys to a transplant center, which can decide which patient is most appropriate, instead of the next person on the list. Going by the list priority, they say, improves equity. But the hard truth is 60% of these high-risk organs are going in the trash bin. We need to get these organs to the surgeons and programs willing to use them, for whatever patient they feel will benefit from them. We also need to build accountability, including for equity, into the system.
Back to that Saturday night. When I released the clamps on that second kidney, this yellow lump of tissue turned into a beautiful, pink kidney that would eventually make urine. In that moment, my frustration and exhaustion were immediately replaced by elation. I was reminded of the very first kidney transplant I witnessed as a medical student in the middle of the night three decades ago. I remembered thinking then, how in the world can this actually work? And who was this selfless hero that just gave this gift of life to someone they would never actually meet? It was that moment when I decided to become a transplant surgeon, to be a steward of these precious organs that represent the best of humankind. They are just too precious to go to waste.
Joshua Mezrich is a professor of surgery, transplant surgeon and holds the Mark A. Fischer Chair in Transplantation at UW Health and the University of Wisconsin School of Medicine and Public Health.
