Bone marrow harvest
What to expect the day before the bone marrow harvest
The day before the bone marrow harvest, the related donor will have a physical exam in the SCT clinic. During this clinic visit blood will be drawn to assess blood counts, clotting factors and blood type. These tests are needed to make sure the donor is healthy enough to donate. The child life specialist can take the donor to the operating room for a tour and age appropriate explanation of what will happen during the procedure, if the donor wishes. The consent for the bone marrow harvest is signed by the parent(s) or legal guardian(s) with the attending transplant doctor. A blood transfusion may be needed in the operating room on the day of the bone marrow harvest. The attending transplant doctor will also obtain blood transfusion consent, in case this is needed. The consent for anesthesia will be signed with the anesthesiologist on the day of bone marrow harvest.
What to expect the day of the bone marrow harvest
On the day of the bone marrow harvest, the donor will be taken to the operating room and given general anesthesia so he/she sleeps through the harvest without feeling any pain. The donor should not eat or drink for at least 6 hours before the harvest to prevent vomiting when the general anesthesia is given. Other instructions will be given by the SCT staff during the clinic visit.
An intravenous (IV) line will be inserted into the donor's arm or hand so medicines and blood, if needed, can be given during the harvest.
A needle will be inserted into the hip bone or "iliac crest" where a large amount of stem cells are located. The stem cells will be withdrawn through the needle with a syringe. One or two punctures into the skin on each hip and multiple punctures into the hip bone are required to harvest the needed amount of stem cells. The stem cells are placed in a plastic blood bag after it passes through a series of filters to remove fat and bone particles. If the donor and the patient have different blood types, the red blood cells or the plasma will be removed in a laboratory prior to infusion.
After the harvest, the donor will be monitored in the recovery room. Vital signs and the harvest site will be checked frequently. When the donor is fully awake he/she will be given something to drink. If the donor feels well and can drink without vomiting, he/she can go home. The donor will have a dressing at each bone marrow harvest site and these dressings should be kept dry and intact overnight. The following day, the donor will return to the SCT clinic to have the harvest site dressing removed. If the donor lives out of town, he/she will usually be allowed to return home after the dressing is removed. The donor will be allowed to return back to his/her normal routine as tolerated.
The donor will feel some pain at the harvest site which may last a few days. This pain can usually be treated with Tylenol or Tylenol with codeine. The donor may also have nausea from the anesthesia given in the operating room. The donor will receive medicine to prevent nausea in the recovery room or may be sent home with anti-nausea medicine. The donor may be placed on iron for four weeks after stem cells harvest to replace the iron in the removed marrow; if he/she receives a blood transfusion in the operating room the iron replacement is not necessary.
Other risks of the harvest are very low. They include the following:
Infection. This can occur any time needle is placed into someone, so the harvest is performed in a sterile environment in the operating room.
Bleeding. Tiny blood vessels run through the area and may be cut by the needles. The pressure dressing applied at the end of the harvest minimizes bleeding.
Numbness. Tiny nerves also run through the harvest area and may be cut by the needles. There may be a small area of skin numbness at the site which will go away over time.
Nausea. Most patients will have some nausea for the first few hours after they wake up from anesthesia.
General anesthesia. Side effects of anesthesia are a risk of low blood pressure, low oxygen levels and, very rarely, extremely high fever. Your child will be monitored very closely for these rare complications.
Peripheral blood stem cell collection
The peripheral blood stem cell (PBSC) collection is done as an outpatient. Prior to collection the donor will receive a drug called granulocyte colony stimulating factor (GCSF), for several days before the stem cell pheresis. The growth factor will increase the number of stem cells in the child’s blood allowing greater ease in collecting the stem cells. The collection process may take one or more days depending on the number of stem cells that are collected each day. The procedure is not painful but does require the donor lay in a bed for several hours during the collection.
The donor’s CD34 count will be checked daily after receiving several days of GCSF. CD34+ cells is a marker for the stem cells. Once the CD34 count is adequate the donor will be taken to Interventional Radiology for a temporary pheresis catheter placement. After the catheter is placed, the donor will go to the renal dialysis unit where the stem cell collection procedure will take place. During this procedure the donor’s blood is passed through a machine that collects the portion of white cells containing stem cells. The remaining white cells, red cells and platelets are given back to the donor. Each stem cell collection may take four to five hours during which the donor can sleep, read, or watch television. Once an adequate number of stem cells are collected, the catheter is removed and the donor is able to go home. Sometimes after the collection, a blood transfusion may be needed because along with the stem cells some red blood cells are also removed in the process. The stem cells are then frozen in liquid nitrogen in the cell processing laboratory.