Medical Transplantation
Medical Transplantation, transfer of a living tissue or organ to an injured or ill person to restore health or reduce disability. Over the past 45 years, surgeons have made great strides in their ability to implant organs in people who are seriously ill. At least 21 different organs—such as hearts, livers, and kidneys—and tissues—such as corneas and bone marrow—can now be successfully transplanted into patients who can then expect to survive for years or even decades. Improved surgical techniques are partly responsible for the success of organ transplants, but a more important factor is the development of drugs that can suppress the body’s rejection of the implanted organ without also leaving the patient highly susceptible to infections.
Kidneys are the most common organs to be transplanted. Kidneys remove waste products from the blood stream. If they fail, often as a result of diabetes mellitus or cancer, a person can die from the buildup of these toxic materials. The waste products can be removed artificially through a process called kidney dialysis, but the patient must be hooked up to the dialysis machine two to three times each week for as long as 12 hours at a time. Kidney transplants free the recipient from dependence on dialysis. If the kidney is rejected, the patient must go back on dialysis or receive another transplant.
Heart transplants are perhaps the most dramatic of all organ transplants because without a functioning heart, a patient cannot survive more than a few minutes. The heart is also more sensitive to a lack of blood than other organs, and can be preserved for only a few hours without damage.
Liver failure caused by cirrhosis, cancer, or hepatitis can be fatal. The liver is the only internal organ with the capacity to regenerate. This capacity provides the surgeon additional flexibility in treating liver damage. For instance, if the damage is not very severe, a temporary transplant can take over the liver’s function while the patient’s own liver recovers. It is also possible to remove part of a liver from a living donor and transplant it. After the surgery both the donor’s liver and the transplanted portion will grow to full size.
Lung transplants are used to replace a single diseased lung, and sometimes both lungs. In some cases lung disease has damaged the heart, and these cases may benefit from a combined heart-lung transplantation. Successful lung transplants are hampered by the difficulty in preserving a lung from a person who has recently died so that it is still viable by the time a proper recipient is found.
The most common tissue transplant is blood transfusion, commonly used to replace blood lost by a person in an accident or during surgery. Other tissues commonly transplanted include bone marrow, corneas, skin, bone, cartilage, tendons, and blood vessels.
Kidneys are the most common organs to be transplanted. Kidneys remove waste products from the blood stream. If they fail, often as a result of diabetes mellitus or cancer, a person can die from the buildup of these toxic materials. The waste products can be removed artificially through a process called kidney dialysis, but the patient must be hooked up to the dialysis machine two to three times each week for as long as 12 hours at a time. Kidney transplants free the recipient from dependence on dialysis. If the kidney is rejected, the patient must go back on dialysis or receive another transplant.
Heart transplants are perhaps the most dramatic of all organ transplants because without a functioning heart, a patient cannot survive more than a few minutes. The heart is also more sensitive to a lack of blood than other organs, and can be preserved for only a few hours without damage.
Liver failure caused by cirrhosis, cancer, or hepatitis can be fatal. The liver is the only internal organ with the capacity to regenerate. This capacity provides the surgeon additional flexibility in treating liver damage. For instance, if the damage is not very severe, a temporary transplant can take over the liver’s function while the patient’s own liver recovers. It is also possible to remove part of a liver from a living donor and transplant it. After the surgery both the donor’s liver and the transplanted portion will grow to full size.
Lung transplants are used to replace a single diseased lung, and sometimes both lungs. In some cases lung disease has damaged the heart, and these cases may benefit from a combined heart-lung transplantation. Successful lung transplants are hampered by the difficulty in preserving a lung from a person who has recently died so that it is still viable by the time a proper recipient is found.
The most common tissue transplant is blood transfusion, commonly used to replace blood lost by a person in an accident or during surgery. Other tissues commonly transplanted include bone marrow, corneas, skin, bone, cartilage, tendons, and blood vessels.
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