Harvesting stem cells from the blood stream is accomplished by a process called apheresis . The patient is connected to a cell separation machine via a needle in each arm. Blood is taken from one arm, circulated through the machine to remove the stem cells, and the remaining blood cells are returned to the patient through the other arm. Several sessions of up to six hours are required to harvest, through apheresis, enough stem cells for transplantation. The patient undergoes all other activities, complications or side effects, and recovery period that are involved in traditional bone marrow transplantation.
Bone marrow is the soft, spongy tissue found inside bones.
It is the medium for development and storage of about 95 percent of the body's blood cells. The blood cells that produce other blood cells are called stem cells . It is the stem cells that are needed in bone marrow transplantation. When a patient's stem cells are defective, immature, or low in number because of life-threatening disease, his or her bone marrow is destroyed by chemotherapy or radiation. Healthy marrow is then transplanted or transfused into the patient's blood stream where it migrates to the bone cavities to begin producing normal blood cells.