lunes, 4 de marzo de 2019

When is a kidney transplant needed?

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By Ananya Mandal, MDReviewed by April Cashin-Garbutt, MA (Cantab)

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.