Kidney Transplant

Kidney transplant – What is a kidney transplant?

A kidney transplant is an operation where a healthy kidney from one person (the donor) is transferred to a person who has little or no kidney function (the recipient).

Normal kidneys and their function

The kidneys are two bean-shaped organs located on each side of the body, just below the ribcage. These organs work continuously to filter waste products from the blood and convert the waste into urine.

When is a kidney transplant needed?

Loss of kidney function means these waste products can build up in the body leading to life threatening complications. Normally a kidney can function with small amount of damage. With progressive damage it may reach a point of no return called “End Stage Renal Disease” or ESRD. This is also called chronic renal failure. This is the most common condition that may require a kidney transplant.

At initial phases before a donor kidney is available the functions of the kidney are replicated by an artificial blood filtering procedure called dialysis. But dialysis can be inconvenient, expensive and time-consuming and the treatment of choice for end stage chronic kidney disease remains kidney transplant.

Types of kidney transplant

There are two kidneys in the body and a person only needs one kidney to survive. Thus, unlike other organ donations like heart and liver, living donors may donate a kidney. This ideally should be a close relative so that the blood group and tissue types match. This type of donation is known as a living donation. A similar blood and tissue type ensures that there is less risk of the body rejecting the kidney.

Kidney donations are also possible from donors who have recently died. These may not match the recipient in tissue and blood group type and face the risk of being rejected by the body. The body perceives the new kidney as foreign object and mounts an immune attack against it. This can be suppressed by using long term immunity suppressing drugs.

Kidney transplant procedure

The surgery is commonly performed under general anesthesia. The abdomen is opened and the surgeon places the new kidney inside the lower abdomen and connects the artery and vein of the new kidney to the existing renal artery and vein after removing the diseased kidney. The blood flows through the new kidney, which makes urine like the original kidney.

Risks of kidney transplant

A kidney transplant is a major surgical procedure and common risks include risk of pain, bleeding, infections and formation of blood clots. Long term risks are associated to the donor organ rejection by the recipient’s body. The immunity suppressing medications also have side effects which may be cumbersome on long term use.

Life after kidney transplant

Lifestyle after kidney transplant should be healthy with no smoking, eating a healthy diet, losing weight and exercise regularly. These measures prevent the onset of kidney disease in the donated organ as well for as long as possible in most cases.

The outlook is generally good for those who have had a living donation, or one from a close relative or someone with the same tissue type, the age and general state of health of the recipient etc.

Over 90% of transplants should be working 1 year after surgery. Around 8 out of 10 of people who receive a live donation will live for at least five years after receiving the donation.

Young people and children live much longer. The success rate (at least five year survival) of recipients of kidneys from dead donors is 7 in 10. In general, a transplant from a deceased donor has a mean survival rate of 15 years, and a living transplant about 18-20 years.

When is a kidney transplant needed?

The most common reason for a kidney transplant is end stage kidney disease or kidney failure.

Normal kidney function

The kidneys are two bean shaped organs on each side of the lower abdomen near the back. These organs get a regular blood flow from the large renal blood vessels that bring in the blood from the body.

There are millions of tiny filters, known as nephrons within the kidney. These help to filter out the harmful waste products and chemicals in blood and filter out excess fluid as well to form the urine. The urine then flows out of the kidneys via the ureters into the urinary bladder from where it is passed out of the body via the urethra.

Kidney disease

With disease these nephrons become damaged, the kidneys can lose their filtering abilities. This means high and life threatening levels of waste products and chemicals in the body. When the kidneys have lost around 90% of their filtering ability, the person is said to have end stage kidney disease.

Causes of end stage kidney disease

Common causes of end stage kidney disease include:-

  • Diabetes – These patients have a continuously high blood sugar. This high blood sugar can damage the filters in the kidneys, leading to long-term kidney damage and finally kidney failure. This is called diabetic nephropathy.

  • High blood pressure or hypertension – This is another common cause of kidney disease and failure. High blood pressure in the tiny blood vessels to the kidney leads to damage and prevents the filtering process from working properly.

  • Blockages in the arteries that bring blood to the kidneys over time called renal artery stenosis is another cause of end stage renal disease

  • Another condition is called polycystic kidney disease which is an inherited condition. There are several large cysts or hollow spaces formed within the kidney that make its normal functioning difficult.

  • There may be congenital problems in development of kidneys. This occurs since before birth and manifests when over 90% of the kidney function is compromised.

  • Disease of the immunity such as systemic lupus erythematosus (SLE) in which the immune system of the body fails to recognise the kidney as its own and attacks it thinking it to be a foreign object.

Treatment for end stage kidney disease

End stage kidney disease needs treatment to prevent life threatening consequences of the waste product build up leading to coma and death. In these situations dialysis is an option.

A device is used to filter the blood as it flows through it and the filtered blood is then injected back into the body. This is a time consuming, expensive procedure and is associated with a myriad of side effects and risks of infection etc.

Kidney transplant, if possible, is usually the preferred option because it is much less inconvenient than having dialysis.

When can a kidney transplant take place?

A kidney transplant may be performed regardless of age of the recipient (patient who requires the kidney) provided they have a general health status that can withstand the major operation, there is a good chance of transplant success and the person is aware and willing to comply with taking immunosuppressant medications after the transplant to prevent rejection of the new organ by the body’s immune system.

Who cannot use a kidney transplant?

Patients in whom kidney transplant cannot be performed include:

  • those with a widespread cancer,

  • those with an active infection,

  • those with liver or heart disease,

  • those with AIDS.

Waiting for a kidney

Patients requiring a kidney transplant may need to wait on the waiting list for an average of around two years. Those with rarer blood groups tend to wait longer than those with a common blood group.

Those on the list must be prepared for the operation at a very short notice. While on the list the patient may be maintained on dialysis and must attempt to remain as healthy as possible by adopting healthy diet and exercise regimen.

How is a kidney transplant performed?

A kidney transplant is needed in persons who have end stage renal disease with 90% of their kidneys not functioning adequately to remove the waste products from the body.

The patients are put on a waiting list for a donor kidney. As soon as a suitable donor kidney is found, the transplant centre will contact the patient who is maintained on dialysis till the kidney is available.

Those who have the availability of a living donor from a family member or close relative need not wait on the list.

Two main types of kidney transplant

Kidney transplant is of two main types – living donation and deceased donation.

Living donation

There are two kidneys in the body and a person only needs one kidney to survive. Thus, unlike other organ donations like heart and liver, living donors may donate a kidney. This ideally should be a close relative so that the blood group and tissue types match. Tissue types are determined by a test called HLA matching. This type of donation is known as a living donation.

A similar blood and tissue type ensures that there is less risk of the body rejecting the kidney. HLA stands for human leukocyte antigen and is a genetic marker located on the surface of the white blood cells. All persons inherit a set of three antigens from their mother and three from their father. A higher number of matching antigens increases the chance that the newly donated kidney will last for a long time.

Deceased donation or Cadaveric donation

Kidney donations are also possible from donors who have recently died. These may not match the recipient in tissue and blood group type and face the risk of being rejected by the body. The body perceives the new kidney as foreign object and mounts an immune attack against it. This can be suppressed by using long term immunity suppressing drugs.

When contacted the patient is checked again for new medical problems and is advised not to eat or drink anything to prepare for a surgery as early as possible. For kidney transplant surgery anesthesia at least 6 to 8 hours of complete fasting is required. Patient is asked to take all report and prescriptions along with their bag of necessities for hospital stay.

Before surgery a medical team examines the donor kidney if the kidney was taken from a recently deceased donor. If the kidney is in good condition and suitable, the operation needs to be performed immediately, to ensure chances of success.

The patient is wheeled into the operation theatre and a general anesthetic is given to render him or her unconscious.

Kidney transplant surgery

The most widely used operative technique is the Gibson incision. First a cut is made over the lower abdomen through which the donated kidney is put into place. Unless there is an indication like an infection or cancer the recipient’s own kidney is left in its position.

As a next step the blood vessels from the lower abdomen are attached to the donated kidney much like the original kidney. This ensures that the donated kidney has the blood supply that it needs to function properly. Finally the ureters that take the urine from the kidneys into the urinary bladder for stage are attached to the donated kidney.

This surgery is a complex one and may take around three to four hours to complete. After the procedure the skin is tied up with sutures or stables leaving a tube behind to drain blood and fluids collecting in the operative area. Patient is wheeled back to a recovering room.

Pain medications are provided for pain relief. Antibiotics are given intravenously for prevention of infections. Immunity suppressing medications including ciclosporin, azathioprine, mycophenolate mofetil, tacrolimus, sirolimus or prednisolone are begun as soon as possible to prevent the body rejecting the new donated kidney.

Most patients can leave the hospital in five to seven days. In around 7 out of 10 people who have a kidney transplant, their new kidney begins working immediately after surgery. In some it may take around 4 to 6 weeks to function normally. If this is the case, the patient requires dialysis during this time. Patients need to be followed up for life.