Tissue

Home

Tissue
Tissue transplants are used to improve the lives of burn victims, the blind, people born with birth defects and cancer patients.

A single tissue donor provides an average of 20 pieces of tissue that potentially can help as many as 70 different people, says Mary Freeman, a donor development coordinator with the Northern California Transplant Bank.

Types of tissue that can be donated include:

Corneas

The cornea is a colorless covering over the lens of the eye that acts as a filter to refract light. Many disorders can affect the cornea and diminish its clarity and health. For example, corneal blindness affects more than 10 million people worldwide, according to the Northern California Transplant Bank. In 2002, more than 33,000 people in the United States received corneal transplant surgery. During the surgery, the damaged tissue is replaced with a clear cornea, which may restore sight.

Heart Valves:
Children born with heart problems or adults with heart disease or damaged valves may benefit from this type of transplant. Heart valves may be recovered from hearts that are not used in transplantation.

Bone

Bones support the body and protect the vital organs. Bones recovered from deceased donors may be used to repair or replace bone damaged by injury, cancer or other disease. About 700,000 bone grafts are done yearly, according to LifeLink, an organ procurement organization that serves Florida, Georgia and Puerto Rico.

Bones that may be recovered include:

Iliac crest (hip bones). Parts of this porous bone are ground into a paste, which can be used to hold other bone together.
Femur (thigh bones)
Humerus (arm bones)

Tendons
Tendons are like rubber bands that attach muscle to bone.

Tendons recovered from deceased donors may be used to replace or strengthen damaged tissue in the knee or other joints.

Skin
Transplanted skin is mostly used to treat burn patients. Skin is removed from deceased donors in thin layers, usually from the back, buttocks and thighs, according to LifeLink. "It's like a sunburn peeling, that's about the thickness," says Mary Freeman of the Northern California Transplant Bank. If the recovered skin is too small to treat burns, it can be used for cosmetic purposes or other treatments, she says.

Veins
Femoral veins from the thighs are removed from deceased donors and used for heart bypass surgery, according to Freeman, or as shunts to help blood passage in patients on dialysis machines, which can cause veins to collapse.

Stem cells/bone marrow
These cells, used mostly to treat blood disorders, leukemia and other cancers must be taken from a live donor.

First, the patient undergoes radiation and/or chemotherapy. These treatments basically destroy the patient's immune system and bone marrow. Then, donor stem cells are injected through a vein. The transplanted donor stem cells begin to grow inside the recipient, building healthy red blood cells, white blood cells and blood platelets necessary to sustain life, according to the National Marrow Donor Program.

At any given time, the National Marrow Donor Program works with at least 3,000 people worldwide who cannot find suitable donors within their family and thus must find other donors who are stem cell matches.

There are three ways stem cells may be extracted, according to the National Marrow Donor Program.

The first is from bone marrow using a needle inserted into the pelvic region. Stem cells are retrieved from the marrow. The donor's marrow replenishes itself within a month. Donors often feel a bit tired after the procedure and ache in the buttocks area. These donors must be tissue matched to the recipient, just like other organ donors.
The second is from blood, using an injection of the drug filgrastim for four to five days to increase the number of stem cells in the blood. Filgrastim causes flu-like symptoms and achy bones. After four or five days, the donor is hooked up to a machine. Blood is drawn from one arm, the stem cells are removed and then the blood is returned through the other arm. This method is usually performed on people whose stem cells will be re-injected into their own bodies. Thus no tissue matching is necessary.
The third is from the umbilical cord, which is rich in stem cells. Women who give birth can donate their umbilical cord, which otherwise would be disposed of. Blood and stem cells are taken from the cord and cryopreserved.