Due to the introduction of newer, more effective immunosuppressant medications during the 1980s, rates of serious complications that arise after a kidney transplant have fallen sharply.
However, kidney transplants, like any other type of surgery, are not risk free. The risks of a kidney transplant can arise from a number of factors:
- risks related to the procedure itself
- risks related to the use of immunosuppressant medications
- risks related to something going wrong with the transplanted kidney
In turn, complications can occur in the first few months after a transplant or, alternatively, not for many years, and in some cases, decades.
Both short-term and long-term complications of a kidney transplant are discussed below.
After a transplant, minor infections are common. They affect an estimated one in two people. These infections usually take the form of:
More serious infections, such as pneumonia (a lung infection) and cytomegalovirus (a viral infection that can be severe in people with weakened immune systems) can occur and may require aggressive treatment and admission to hospital.
Blood clots can develop in the arteries that have been connected to the donated kidney. They are estimated to develop in around one in 30 kidney transplant cases.
In some cases, it may be possible to dissolve the blood clots using medication. In more serious cases, where clotting does not respond to treatment, it is usually necessary to remove the donated kidney.
Narrowing of an artery
In an estimated one in 20 cases, the arteries connected to the donated kidney become narrowed. This is known as arterial stenosis.
Arterial stenosis can develop months or even years after the transplant. It can cause a sudden rise in blood pressure, which is potentially dangerous. Surgery is usually required to widen the artery, often using a small metal tube called a stent.
Ureteral obstruction and urinary leakage
Ureteral obstruction is a common complication after a kidney transplant. It develops when the ureter (the tube that carries urine from the kidney to the bladder) becomes blocked from clots of tissue or fluid that form during or after the operation.
The symptoms of a ureteral obstruction include:
- a high temperature (fever) of 38C (100.4F) or above if infection is also present
- pain in the side of your abdomen (stomach)
- feeling sick
- being sick
- blood in your urine
It may be possible to unblock the ureter by draining it with a small tube called a catheter. The catheter is inserted into your urethra (the opening in the penis or vagina that urine flows out of), before being guided into your ureter. If this treatment does not work, surgery may be required to unblock the ureter.
Urine may leak from any part of the urinary system (the kidney, bladder, ureter and urethra) as a result of damage or disruption caused during surgery. Urine leakage usually occurs during the first month after surgery.
Symptoms of urine leakage include:
- fluid leaking from the site of your surgical incision
- abdominal (stomach) pain
- swelling of your perineum (the area of skin between your genitals and anus)
Small leaks can be treated using a catheter to drain away the excess urine.
However, larger leaks may require surgery to correct them. Ureteral obstruction and urinary leakage occur in an estimated 3-5% of kidney transplant cases.
Acute rejection is where the immune system suddenly begins to attack the donated kidney because it mistakes it for a foreign object.
Despite the use of immunosuppressants, acute rejection is a common complication in the first year after a transplant, affecting an estimated one in five people.
In many cases, acute rejection does not cause noticeable symptoms, and is only detected during a blood test.
Acute rejection can usually be successfully treated using a short course of more powerful immunosuppressants.
Side effects of immunosuppressants
Immunosuppressants prevent your body's immune system from attacking the new kidney, which would cause the transplanted kidney to be rejected.
Widely used immunosuppressants are:
The downside of taking immunosuppressants are that they can cause a wide range of side effects, including:
- loss of appetite
- feeling sick
- being sick
- stomach pain
- swollen gums
- bruising or bleeding more easily
- extra hair growth
- weight gain
The doctor in charge of your care will be trying to find the right dose that is high enough to 'dampen' the immune system sufficiently to stop rejection, but low enough that you experience very few, or no, side effects.
Finding the optimal dose to achieve both goals is often a difficult balancing act. It may take several months to find the most effective dose that causes the least amount of side effects.
Side effects should improve once the right dosage is identified. Even if your side effects become troublesome, never suddenly stop taking your medication because your kidney could be rejected.
Contact the doctor in charge of your care for advice.
Diabetes is a common complication of having a kidney transplant. Diabetes is a long-term condition that causes high blood glucose levels and can be triggered by a number of (not always negative) factors, such as:
- people tend to eat more and put on weight after a transplant as they no longer feel ill all the time
- some types of immunosuppressants can make you more likely to develop diabetes
Symptoms of diabetes include:
- feeling very thirsty
- going to the toilet a lot, especially at night
- extreme tiredness
Diabetes can often be controlled using a combination of lifestyle changes – such as getting more exercise – and medication. Read more about the treatment of diabetes.
High blood pressure
High blood pressure is another common complication of a kidney transplant.
Many people who require a kidney transplant already have an increased risk of developing high blood pressure and taking immunosuppressants can make the condition worse.
High blood pressure usually causes no noticeable symptoms but can increase your risk of developing other serious, and in some cases fatal, health conditions, such as:
Because of the risk of high blood pressure you should be given a blood pressure test every time you attend one of your follow-up appointments. In addition to this you can check your own blood pressure at home with a simple device available from most chemists.
Read more about treating high blood pressure.
The long-term use of immunosuppressants does increase your risk of developing some types of cancer.
Often these are types of cancer known to be caused by viruses (as you will be more vulnerable to the effects of infection.)
If you are taking immunosuppressants, you also have a much higher risk of developing skin and lip cancers.
Avoid going out in the sun during the hottest part of the day and apply complete sun block to your lips and all exposed areas of your skin every day, regardless of whether or not it is sunny.
Your care team will be able to provide more advice on your individual risks, whether you require regular check-ups and any early signs to watch out for.