Once you have been evaluated as a donor and have passed the screening, you are ready to donate. If donation is imminent, such as to an ill friend or relative, the process beings immediately. If you are a volunteer and your name is in a registry, you will be notified when a patient with matching blood and tissue types has been identified.
The National Marrow Donor Program estimates that donation takes up to 30 – 40 hours, including travel time, to attend appointments and complete donation. The time is spread out over a four- to six-week period.
There are two donation procedures, the surgical extraction of bone marrow and the use of apheresis to extract peripheral blood stem cells.
Donation of Bone Marrow
The surgical process of marrow collection is often performed in a single day on an outpatient basis. Some collection centers may require an overnight stay, depending on the type of anesthesia used.
You arrive at the hospital in the morning, change into a hospital gown, and receive an IV. You enter the operating room when the surgeon is ready. You receive general anesthesia through the IV, meaning you are unconscious throughout the surgical procedure. Some centers use a local anesthesia to numb only the area where donation will occur, and you remain conscious. Be sure to ask the center personnel how they use anesthesia.
The surgeon typically removes marrow from the iliac crest, which is the back part of the pelvis (your hip bone). Several incisions—from four to eight—are made in your skin, and a large needle is inserted several times through these incisions into the bone to extract the marrow. The incisions are small enough to heal without requiring stitches.
About one or two pints (500-1,000 milliliters) of marrow are taken, representing only 2%-5% of your body’s entire marrow. The procedure lasts 60 to 90 minutes. The bone marrow is cleaned to remove bone fragments and unwanted blood components. The marrow may also be specially treated and frozen for transportation. Frozen marrow can last as long as three years.
You will be moved to a recovery room following the surgery until you wake up from the anesthesia, then you will be moved to a hospital room. When you go home depends on how quickly you recover from the anesthesia.
Following surgery you will have pain in your hip area. You may also feel tired. Donors typically return to their usual routine within a week or less. Your donated marrow will be replaced within four to six weeks.
The risks associated with this procedure are similar to those of other surgeries involving anesthesia but not as severe as whole organ donation:
- Pain. This is a certainty. The pain is described as similar to having taken a hard fall. The pain is treated with analgesics and goes away after 14 days on average.
- Infection. The wound(s) from the incisions could become infected, delaying the healing process and possibly causing scarring. Antibiotics are used to treat any infections.
- Allergic reaction to anesthesia. Part of the screening process includes identifying allergies you may have. In the event of an allergic reaction to anesthesia, the anesthetist will take immediate corrective action.
Donation of Peripheral Blood Stem Cells
A less invasive, nonsurgical procedure collects peripheral blood stem cells (PBSC) from your blood. A stem cell is an early form of blood cell that matures into different types of cells, such as white blood cells, red blood cells, and platelets. These cells are formed in bone marrow, and some are released into the bloodstream. The stem cells can be collected by filtering them out of your blood. PBSC donation is now the most common form of donation.
The number of stem cells normally occurring in your blood stream is insufficient for a transplant. Also, the amount of blood needed to filter out a useful amount of PBSCs is too large to do by drawing a blood sample. Therefore, there are two steps in this form of donation:
1. Stimulating production of PBSCs. For four or five days prior to the donation date, you are given a daily shot of filgrastim. This medicine, a growth factor medication, stimulates the production of stem cells, increasing the number appearing in your bloodstream. You receive the injections of filgrastim from a visiting nurse or at a donation center. It is common to experience bone pain and headaches as a result of taking the medicine. It may feel like you have the flu. This pain goes away within a day or two of stopping the injections.
2. Collecting the PBSCs. The PBSCs are collected from your blood using a process called apheresis. The process involves inserting a tube into a vein in one arm, passing your blood through a special machine that collects the stem cells, and returning the blood through a vein in your other arm.
On donation day, you arrive at the collection center or hospital at your appointed time. The attendants prepare you for apheresis by inserting a needle connected to a tube into each arm. The tubes are connected to the apheresis machine. You receive an anticoagulant to keep your blood cells from clotting during the procedure. A small percentage (5%-10%) of donors may find they do not have suitable veins in their arms. In such a case, the donor will be asked to consider use of other large veins such as those in the groin, neck, or below the collarbone. This alternative procedure may require the use of a local anesthetic.
The machine is started while you lie comfortably. Once a sufficient number of stem cells has been collected, usually after three to four hours, the machine is shut down and the tubes are removed.
You are allowed to go home that day. You will be contacted weekly by the donor center to check on your status until you are feeling fully recovered. Side effects from donating typically are gone within 24 hours of donating.
The risks associated with this procedure, like bone marrow donation, are relatively small:
- Pain. Studies of PBSC donors show they experience pain as a consequence of taking filgrastim prior to donation. One German study of 40 donors showed almost all donors experienced side effects–bone pain (80%), headaches (50%), chest pain (5%), and night sweats (3%). Pain can be managed with analgesics. The pain subsided within two to four days after the filgrastim injections ceased. The apheresis experience also had effects (not necessarily pain) on some donors—abnormal skin sensations (45%), nausea (5%), and dizziness (3%).
- Lower platelet count. PBSC donors experience a reduction in the number of platelets in their bloodstream as a result of the apheresis. The reduction is especially pronounced if the donor undergoes a second apheresis. In theory, a lower platelet count could make it more difficult for a donor’s blood to coagulate (to stop bleeding). However, there have been no reports of problems among donors, and the platelets naturally return to normal levels after a week or two. For some donors, the collection center may collect platelets from your blood prior to the PBSC donation and return them to you after the PBSC donation (a process called autologous platelet transfusion).
- Infection. A PBSC donor could experience infection where the needles are inserted into the veins. Any infection would be treated with antibiotics.
In all, the risks associated with bone marrow or peripheral blood stem cell donation are small. A report by the National Institutes of Health notes “life-threatening complications for all marrow donors have been rare; there were 13 reported in 4,800 [0.27%, or one in 370] analyzed marrow donations.”