This set of frequently asked questions and answers refer to kidney transplantation.
Another set elsewhere on this website answer questions about organ donation.
Each renal dialysis unit will be able to provide patients with information on kidney transplantation. Following discussion about its advantages and disadvantages with each patient, a decision is then made about their suitability for transplantation
There is no upper age limit for renal transplantation although it is important that whenever a kidney transplant is considered, the potential benefits outweigh the disadvantages. The transplant operation and the subsequent treatment are both relatively arduous and therefore a patient needs to be fit enough to withstand the entire process. Where patients are very frail, or have significant medical problems, the risks of undergoing a transplant may be too great and it is less likely that transplantation will be considered an option for them. The decision on the appropriateness of renal transplantation is made by the individual concerned in consultation with their doctors.
The number of people with severe kidney disease that require dialysis and transplantation is increasing in all western societies and this has led to an increase in the demand for kidney transplantation. The number of deceased donor kidneys available in the UK has not really changed in the last 10 years and therefore the waiting list has grown. Intensive efforts are being made to increase both living and deceased donor renal transplantation to address the demand for kidneys.
This question is always difficult to answer as waiting time is influenced by several factors, including among others blood group, age and rareness of genetic type. On average, patients who are listed for a deceased donor transplant wait approximately three years, but there is a great deal of variability in this. Patients who receive live donor kidney transplants usually have much shorter waiting times than those who receive kidneys from deceased donors. Your kidney unit will know the details of your case and should be able to give you an indication of how easy it will be to find a kidney. Any prediction however will always be an approximation.
Kidneys are allocated based on, among other considerations, the match between the donor and recipient blood groups and genetic type (called the tissue type or HLA type). The length of time that a patient waits for a transplant will be influenced by how often donors with kidneys that are well matched to the patient become available. For example, for a patient with a rare tissue type, there will be fewer donors with a tissue type that matches that of the patient well, compared to patients with more common tissue types.
Furthermore some patients have antibodies directed against certain tissue types, which means that some, or even most, donor kidneys are not suitable for these patients. Pregnancy, blood transfusions or previous failed transplants can induce these antibodies.
With the introduction of a new allocation scheme in April 2006, the unit in which an individual dialyses will not affect whether he / she is offered a kidney. The allocation is based purely on tissue match and the number of points they have, determined by factors such as the length of time they have been on the waiting list and age. The exceptions to this are live donor kidneys (all transplant units in the UK perform live donor kidney transplants) and non-heartbeating donor kidneys, which are used by the local unit / group of units and not allocated through the national scheme. Non-heartbeating donor kidneys make up a small but increasing percentage of all transplants.
The current scheme is based very strongly on getting the best tissue match for the recipient, as the information at the time (1986 - 1993) showed that this was very important. More recent information shows that this is less necessary now, as other factors have been increasingly recognised as important. The national allocation scheme has evolved progressively over the past 20 years to improve outcomes, ensure equity of access to transplantation and also to maximise the number of transplants performed. Previous schemes were designed to do this but the data available have shown that these schemes needed to be adapted to make access to transplantation fairer.
The decision about which patients should receive priority is very difficult. The previous scheme gave an advantage to paediatric patients with a sharp cut-off at the age of 18. This was in part because dialysis in children can be very difficult and in part because as children are likely to need more than one transplant in their lifetime, receiving a first well-matched kidney increases the chance of getting further kidneys for subsequent transplants. It was felt that a sharp cut-off severely disadvantaged young adults aged 19 and above. So, while the new scheme still prioritises well-matched children, it is designed to give an additional advantage to young adults. Unfortunately, whenever one group of patients is given an advantage, another is inevitably disadvantaged. The new scheme slightly reduces the chances of receiving a kidney for patients over the age of 60.
All UK transplant units carry out living donor kidney transplants, although the number performed varies from unit to unit. The suitability of an individual for living kidney donation depends upon their willingness to donate, their overall health, the presence of any other significant medical problems that might affect renal function and whether both of their kidneys function normally. Each unit will be happy to discuss living donor transplantation in greater detail with any patient and will meet any parties interested in kidney donation for further discussion. Appropriate verbal and printed information will be provided.
Although living kidney donation is associated with a very small risk of death (probably less than 1 in 2,500), a very large majority of live donors will quickly recover from the operation. Patients can expect to be in hospital for five to eight days and will normally not work or undertake work-like activities for between four to six weeks. Evidence is available that long-term health is not affected by kidney donation and this is one reason why the UK renal community is keen to increase the number of living donors.
Heartbeating donors are patients who have suffered permanent and irreversible brain injury such that their heart will stop beating in the next week or so. Once the patient’s relatives have given permission for donation and tests demonstrate irreversible brain injury and the patient has been certified dead, the donor is taken to the operating theatre for retrieval of the kidneys and other organs whilst the heart is still beating. In a patient who suffers a cardiac arrest and cannot be resuscitated, it is occasionally possible to flush the kidneys and liver with a cold preserving solution and then remove these organs quickly before irreversible damage occurs. In this situation, the heart is no longer beating, hence the term non-heartbeating. It used to be felt that non-heartbeating donor kidneys were less viable and that their use gave rise to lower transplant success rates. The most recent survey of UK data by UK Transplant indicates that success rates for non-heartbeating donor transplants are very similar to those achieved for heartbeating donor transplants. It is likely that the percentage of kidney transplants from non-heartbeating donors will increase as units continue to work to increase the number of kidneys available for transplantation. A recipient will always be informed if they are being considered for a non-heartbeating donor kidney transplant.
The national allocation scheme uses a computerised protocol to allocate a particular kidney to an individual patient primarily based on blood group, degree of tissue matching and time spent on the waiting list. Under this scheme, all patients across the country are treated as fairly as possible, although children are given some priority. The local schemes in operation across the country vary slightly from area to area but tend to use very similar protocols to allocate the kidney to a local recipient. Whenever a pair of kidneys is retrieved from a donor, the allocation process usually results in one kidney being used locally and one nationally. The exception to this is if there are two very well matched recipients elsewhere in the country and none locally, in which case both kidneys are used at national level. UK Transplant is reviewing the current national allocation scheme and the protocol may change within the next year.
The success of transplantation is influenced by a number of different factors, some of which are within the control of the patient. A table of risk factors published within the statistics section of this website lists those that are important in predicting the length of time for which a transplant is likely to survive.
Living donor kidney transplants are on average more successful than transplants from deceased donors. Transplants done relatively soon after starting dialysis are on average more successful than transplants performed two or more years after a patient starts dialysis. The degree of matching between the donor and the recipient is also important, but is less so for living donor transplantation. For this reason, most units are happy to perform a living donor transplant even if the tissue match is relatively poor. The age of the donor is another factor that affects the success of a transplant. Transplants of kidneys from younger donors tend to survive longer than transplants from older donors.
Most kidneys that fail in the first year after transplant do so because of rejection. After one year, there are a number of reasons for graft failure and these include death of the patient with a functioning transplant and graft loss due to the patient's poor compliance with the medication prescribed to them. The risk of death is influenced, not surprisingly, by patient age but smoking, obesity, the presence of other significant diseases such as diabetes and heart disease, and the overall level of fitness are also important. Patients who do not smoke or give up smoking, maintain a good body weight and exercise regularly are more likely to have many years of good quality life with a well functioning kidney.
Predicting transplant function for an individual is difficult as this depends on a number of factors. Survival rates for organ transplants in the UK are given in the Transplant Activity report published elsewhere on this website.
UK Transplant continually monitors how successful each unit is compared with other units across the country. The centre-specific reports indicate that, on the whole, units in the UK have similar results.
There is some variation in the CIT between units and there will also be a difference between transplants in the same unit. There is evidence that a CIT of over 20 hours affects outcomes and if the CIT is very long for a particular kidney, the transplant team will discuss this with the patient.