Kidney transplant: the pathway, and why early referral matters

What a transplant is, and what it is not

A kidney from a donor is placed, usually into your lower abdomen, and takes over the work. Your own kidneys are generally left where they are. Surgery typically takes three or four hours.

For people who are suitable, it is the best treatment available for kidney failure: better survival, better quality of life, no sessions, and far fewer restrictions on diet and fluid. That is not in serious dispute.

And yet: it is a treatment, not a cure. It trades one set of problems for another. Instead of dialysis, fluid limits and time in a chair, you have immunosuppressant medicines every day for as long as the kidney works, a raised risk of infection and of some cancers, the possibility of rejection, and the knowledge that transplants do not last forever. Saying this out loud at the beginning is not pessimism. It is what stops a graft failing years later from feeling like a personal failure.

The evidence, with its caveat attached

The landmark study is Wolfe and colleagues, published in the New England Journal of Medicine in 1999, using US registry data. Its numbers still frame the conversation.

• Annual death rate: 16.1 per 100 patient-years across all dialysis patients, 6.3 for dialysis patients who were on the transplant waiting list, and 3.8 for transplant recipients.
• Long-term mortality was 48 to 82% lower in transplant recipients than in comparable people waiting on dialysis.

The payment comes first

This is the part people are least often told, and it is the part they most deserve to know.

In the same study, the risk of death in the first two weeks after transplantation was 2.8 times that of matched people who stayed on the waiting list. It is major surgery, performed on someone whose heart and blood vessels have already been damaged by kidney failure.

The risk then falls below that of staying on dialysis. Survival became equal somewhere between 5 and 673 days after the transplant, depending on the group, and after that the advantage grows year on year.

Put plainly: a transplant is a bet that pays off, but the payment comes first. You are more likely to die in the weeks after the operation than you were on dialysis. You are then much less likely to die in every year that follows. The break-even point is measured in months, not years, and for most people it is well worth having. But you should walk into it knowing which way round the risk sits.

Living donor, or deceased donor

A living donor

• Better outcomes. The kidney usually works immediately, it lasts longer, and the operation can be scheduled rather than waited for.
• It allows a pre-emptive transplant, before dialysis is ever needed. NICE explicitly recommends offering a pre-emptive living donor transplant, or pre-emptive listing, to people found eligible after full assessment.
• The donor undergoes major surgery for no medical benefit to themselves. That is why they are worked up exhaustively, why their safety is the absolute priority, and why their assessment is kept independent of your team. A donor who changes their mind is entitled to, at any point, and their reasons are nobody else's business.
• Donors do not have to be blood relatives. Spouses, friends and altruistic donors are all possible.
• Where a willing donor is not compatible with you, many countries run paired exchange schemes: their kidney goes to another recipient, and you receive one from that recipient's incompatible donor. Availability varies by country.

A deceased donor

This means waiting on a list. NIDDK is honest that, because of the shortage of kidneys, waits can run from a few months to many years. How long depends on your country, your blood group, your tissue type and how sensitised you are, and we are not going to publish a waiting time, because a number from another country would be actively misleading.

Not all offers are equivalent. Donor kidneys are categorised, and a kidney from an older or less healthy donor carries different odds from a standard one. You may be offered a higher-risk kidney, and you are allowed to ask what that means for you, and to decline.

Who is eligible

Every programme has its own criteria, and eligibility is decided by a transplant centre after assessment, not by a website, not by your own guess, and not by a passing remark from someone who has not examined you. The concepts they are weighing:

• Will you survive the surgery and the immunosuppression? Cardiac fitness, lung reserve and frailty matter far more than your age.
• Is there an active cancer or an untreated infection? These usually need to be resolved first, or a cancer-free interval observed.
• Is there something that would destroy the new kidney immediately? Some recurrent kidney diseases and some severe urinary tract problems need specific planning first.
• Sensitisation. Previous transplants, pregnancies and blood transfusions can leave you with antibodies that make finding a compatible kidney much harder. This is precisely why guidelines urge a restrictive approach to blood transfusion in people who might be transplant candidates. If you are ever offered a transfusion, it is worth asking whether it is truly necessary and whether your transplant status has been considered.
• Substance misuse or an inability to take the medicines will need to be addressed, with support, rather than being an automatic exclusion.
• Obesity is a relative barrier in many programmes because of surgical risk, and the thresholds vary widely between centres.

The work-up

It is thorough, and NIDDK notes that the testing may take several visits over weeks to months. Typically it includes: blood group and tissue typing, screening for antibodies, a crossmatch against the donor, virology and infection screening, a cardiac assessment (an ECG, an echocardiogram, often a stress test), chest imaging, age-appropriate cancer screening, assessment of the bladder and urinary tract where relevant, a dental review (teeth hide infection), and a psychological and social assessment, including what support you have at home.

That last one is not a hurdle to be resented. Taking immunosuppressants every day, for years, while attending clinics, is a demanding job, and the assessment exists to make sure you are set up to succeed at it.

Afterwards

• The medicines are not optional, ever. NIDDK does not soften it: without them, your immune system may treat the donor kidney as foreign and attack it. Stopping them, even briefly, risks rejection.
• Immunosuppression has a price: a higher risk of infection, a higher risk of some cancers (skin cancer above all), and drug-specific effects on blood pressure, blood sugar, cholesterol and even the transplanted kidney itself.
• Skin cancer risk is dramatically raised in transplant recipients on immunosuppression: around 100 times for squamous cell carcinoma, 6 times for basal cell carcinoma and 4 times for melanoma. In an equatorial climate this is not a footnote. It means high-factor sunscreen year-round, covering up, a hat, no sunbathing, and regular skin checks. Note carefully: this figure applies to transplant recipients on immunosuppression, and not to people on dialysis generally.
• Transplants do not last forever. Grafts fail over years, and some people return to dialysis or are transplanted again. Knowing that in advance does not make it less painful, but it does stop it being experienced as something you did wrong.

Why early referral matters, and this is the point of the page

• A pre-emptive transplant, before dialysis ever starts, gives the best outcomes, and for some people it avoids dialysis entirely. It only happens with early referral, because the work-up takes months.
• Time on dialysis before a transplant is itself an adverse factor for both graft and patient survival. Every month of delay is a month of accruing cardiovascular damage.
• The thresholds are risk-based. KDIGO suggests considering a pre-emptive transplant work-up when the eGFR is below 15 to 20, or when the two-year risk of needing dialysis or a transplant exceeds 40%. NIDDK notes that US centres can list people when kidney function is around 20 or below.
• Finding a living donor takes time. Conversations, screening, sometimes a paired exchange. None of that is quick, and none of it can be started once you are already unwell on dialysis.

So here is the sentence worth taking to your next appointment: "Should I be referred for a transplant assessment?"Ask it long before dialysis is on the table. The worst answer you can get is "not yet", and even that answer tells you somebody is thinking about it.