Search This Blog

Saturday, May 1, 2010

About Kidney Transplantation

* Definition of Kidney Transplantation
* Description of Kidney Transplantation
* Treatment of Kidney Transplantation
* Questions To Ask Your Doctor About Kidney Transplantation

Definition of Kidney Transplantation
Article updated and reviewed by Nader Najafian, MD, Assistant Professor of Medicine, Harvard Medical School and Associate Physician, Renal Division--Brigham & Women's Hospital on May 17, 2005.

Kidney Transplantation is the surgical procedure of placing a fully functioning kidney into a person with severe kidney failure. This procedure is usually an elective one, performed in patients who have undergone careful preoperative assessment and preparation, since dialysis enables these patients to be maintained in relatively good condition until the time of surgery. The transplanted kidney may originate from a deceased donor (cadaver transplantation) or from a related or unrelated person (living transplantation).

Description of Kidney Transplantation
The function of the kidneys is to filter the blood in the body and to purify it by ridding it of soluble waste products and excess water (which is then eliminated in the form of urine). Total kidney failure, which may be gradual or sudden in onset, results in the accumulation of these waste products and water in the blood. These waste products can poison you unless removed. In addition, the excess water can accumulate in the lungs and prevent the patient from getting enough oxygen. Either processes or a combination of both can result in death.

The most common causes of kidney failure include:

* infection and inflammation of any part of the kidney structure

*

* damage to kidney tissue from some systemic diseases such as uncontrolled high blood pressure and untreated diabetes) or injury

* • damage to kidney tissue through some medications, including overuse of some over the counter pain killers such as Motrin and Aspirin

* polycystic kidneys (an inherited condition in which the tissues of the kidneys are gradually destroyed by cysts)

* failure of normal kidney development from before birth

There are two major treatment modalities for patients with kidney failure: dialysis or transplantation. In dialysis, the blood is artificially filtered through a machine or by diverting the bloodstream through another permeable membrane in the body itself. Despite numerous medical and technological advances over the last few years, dialysis patients feel very unwell. This is not surprising as even the most efficient hemodialysis regimens can only remove 10-12% of the small solute toxins as compared to normal functioning kidneys. Even though the kidney dialysis can keep the patients alive, these patients still suffer from poor quality of life, extreme dietary restrictions and the psychological burden of depending on a machine. Kidney transplantation is the treatment of choice in qualified patients with kidney failure as it has the greatest potential for restoring a healthy and productive life. This operation allows a patient to lead an independent existence instead of being reliant on regular kidney dialysis. It also allows a liberating return to a normal diet. The transplant procedure success rate has improved over the last years with one-year graft survivals exceeding 90% in most centers. A critical shortage of donor organs is the major limitation to expanding the use of this treatment. Many patients with end-stage renal (kidney) disease are suitable for transplantation. Fifty percent of all kidney transplants are received from cadaver donors and the others are received from living, related, or unrelated donors.

Regular kidney dialysis is a short-term solution to kidney failure: the blood is artificially filtered through a machine or by diverting the bloodstream through another permeable membrane in the body itself. The ideal treatment for total kidney failure is kidney transplantation.

One-third to one-half of all patients with end-stage renal (kidney) disease are suitable for transplantation. Two-thirds of all kidney transplants are recieved from cadaveric donors, and one-third are recieved from living, related donors.

Kidney Transplantation Surgery

The aim of the surgery is to supply a single, fully functioning kidney. One kidney provides more than enough filtration and regulating capacity for all purposes and is grafted into its own position while the existing (non-functioning) kidneys remain in place. The existing kidneys are removed only if they cause persistent infection or high blood pressure, and they will not interfere with the transplant procedure or functioning of the new organ. As soon as the transplanted kidney is connected to the blood vessels, it will begin purifying the blood of waste products.

Patients are required to take medications such as corticosteroids, cyclosporine, and/or azathioprine to suppress their immune system in order to prevent rejection of the transplanted kidney.

Post-operative Effects

More often than not, the first week after kidney transplantation is a grace period when things keep getting better. However, the clear sailing can be misleading, since many kidney recipients spend time in the hospital soon after discharge when the functioning of their new kidney diminishes. These episodes are almost always successfully treated by adjusting the medication regimen.

By far the two most common causes of diminished renal function are rejection and the toxic effects of cyclosporine. About 70 percent of all recipients will manifest some signs of organ rejection, and most will also have some evidence of cyclosporine toxicity. Both problems manifest themselves as decreasing urinary output and rising laboratory values of blood BUN (Blood Urea Nitrogen) and creatinine (a component of urine). These problems are usually treated simultaneously by adding extra doses of steroids.

Managing Rejection

Immediately after kidney transplant surgery, the mainstays of drug therapy are prednisone and cyclosporine, and sometimes azathioprine. It should be emphasized that cyclosporine is enormously beneficial for two reasons: first, in improving long-term survival of the kidney; and second, in permitting the rapid tapering off of the prednisone. Nevertheless, it is critically important that, as long as the transplanted organ is functioning, some level of maintenance immunosuppression (suppression of immunologic response, usually with reference to grafts or organ transplants) is necessary. If at any point a recipient stops taking the medications, rejection can occur - even ten or fifteen years after the transplant.

The important point to remember is that most recipients can expect to have some problems getting adjusted to their new organ, and that after the initial discharge it may be necessary to return to the hospital for one or more additional short stays. New drugs may be needed, and the doses of the anti-rejection medications will probably require adjustment. This fine-tuning is a normal part of recovering.

The vast majority of renal transplants are successful. Thus, the statement that someone is suffering rejection, which understandably sounds disturbing, is not cause for undue alarm. Most cases of rejection can be reversed, and the other causes of abnormal renal function also can be corrected. Well over 80 percent of recipients leave the hospital with a kidney functioning sufficiently to keep them off of dialysis.
Text Continues Below

Treatment of Kidney Transplantation
Kidney Transplantation Surgery

The aim of the surgery is to supply a single, fully functioning kidney. One kidney provides more than enough filtration and regulating capacity for all purposes and is grafted into its own position while the existing (non-functioning) kidneys remain in place. The existing kidneys are removed only if they cause persistent infection or high blood pressure, and they will not interfere with the transplant procedure or functioning of the new organ. As soon as the transplanted kidney is connected to the blood vessels, it will begin purifying the blood of waste products. Patients are required to take medications that suppress the immune system for the rest of their lives to avoid the rejection of the kidney grafts.

Post-operative Effects

In most cases, particularly in patients that get good quality kidneys from family and friends (living donors), the transplanted kidneys start working immediately after transplantation and no further hemodialysis is required. In 20-30% of cases, particularly patients who get cadaver kidneys with poorer organ quality, the kidney may not function immediately and further dialysis may be needed. Regardless, all the transplant patients need to be monitored very closely in the first month after the procedure, as many of the immunosuppressive drugs need to be adjusted carefully. This usually requires clinic visits up to two to three times a week in the first month. By far the two most common causes of diminished renal function are rejection and the toxic effects of cyclosporine. About 30% of all recipients will manifest some signs of organ rejection, and most will also have some evidence of cyclosporine toxicity. Both problems manifest themselves as decreasing urinary output and rising laboratory values of blood BUN (Blood Urea Nitrogen) and cretonne (a component of urine). These problems are usually treated simultaneously by adding extra doses of steroids. As too low a dose of immunosuppressant drugs can result in rejection, too much of it can result in infections or cancer over time. That is the reason why patients need close follow-up by a kidney transplant specialist.

Managing Rejection

After kidney transplant surgery, the mainstays of drug therapy are usually a combination of two to three immunosuppressive medications, such as prednisone, cyclosporine, tacrolimus, or rapamycin, and sometimes azathioprine or cellcept. Initially, higher doses of these drugs are used as the risk of rejection is highest immediately after transplantation. With time, the levels of these drugs can then be tapered down. Nevertheless, it is critically important that, as long as the transplanted organ is functioning, some level of maintenance immunosuppression (suppression of immunologic response, usually with reference to grafts or organ transplants) is necessary. If at any point a recipient stops taking the medications, rejection can occur - even ten or fifteen years after the transplant.

The vast majority of renal transplants are successful with over 90% of organs functioning after the first year. Thus, the statement that someone is suffering rejection, which understandably sounds disturbing, is not cause for undue alarm. Most cases of rejection can be reversed, and the other causes of abnormal renal function also can be corrected.

Questions To Ask Your Doctor About Kidney Transplantation
How long is the waiting time to get a cadaver kidney?

Who would be qualified to donate a kidney to me (family, spouse, and friends)?

How can potential interested donors be evaluated?

How is the surgery performed?

How long does the surgery take?

How many kidney transplantations have you performed?

What medications will you be prescribing?

What are the side effects of immunosuppressive drugs?

How long will you prescribe steroids or any other medication?

What should be expected after the surgery?

No comments:

Post a Comment