A bone marrow transplant is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells.

Bone marrow is the soft, spongy, fatty tissue inside your bones. The bone marrow produces blood cells. Stem cells are immature cells in the bone marrow that produce all of your different blood cells.

Description
Before the transplant, chemotherapy or radiation may be given.

This may be performed in two ways:

Ablative (myeloablative) treatment. High doses of chemotherapy and radiation are given to destroy any cancer cells. This also destroys all healthy bone marrow that remains and allows new stem cells to grow in the bone marrow.

Reduced intensity treatment, also called a mini transplant. Lower doses of chemotherapy and radiation are given before a bone marrow transplant. This allows older people and those with other health issues to have a transplant.

There are 3 types of bone marrow transplants:

Autologous bone marrow transplant. The word “auto” means self. Stem cells are taken from you before you receive high-dose chemotherapy or radiation treatment. The stem cells are stored in a freezer. After high-dose chemotherapy or radiation treatments, your stem cells are returned back to your body to make normal blood cells. This is called a rescue transplant.

Allogeneic bone marrow transplant. The term “allo” means other. Stem cells are taken from another person, called a donor. Most times, the donor's genes must at least partially match your genes. Special tests are done to see if a donor is a good match for you. A brother or sister is most likely to be a good match. At times parents, children, and other relatives are good matches. Donors who are not related to you, yet still match, can be found through national bone marrow registries.

Umbilical cord blood transplant. This is a type of allogeneic transplant. Stem cells are taken from a newborn baby's umbilical cord right after birth. The stem cells are frozen and stored until they are required for a transplant. Umbilical cord blood cells are very immature so there is little or no need for perfect matching. Due to the smaller number of stem cells, blood counts take longer to recover.

A stem cell transplant is normally done after chemotherapy and radiation is complete. The stem cells are delivered into your bloodstream typically through a tube called a central venous catheter. The process is like getting a blood transfusion. The stem cells pass through the blood and into the bone marrow. Most times, no surgery is needed.

Donor stem cells can be gotten in 2 ways:

Bone marrow harvest. This minor surgery is done under general anaesthesia. This means the donor will be asleep and pain-free during the surgical procedure. The bone marrow is taken from the back of both hip bones. The amount of marrow taken out depends on the weight of the person who is receiving it.

Leukapheresis. First, the donor is given several days of shots to aid stem cells in moving from the bone marrow into the blood. During leukapheresis, blood is taken from the donor through an IV line. The part of white blood cells that has stem cells is then separated in a machine and removed to be later given to the recipient. The red blood cells are returned back to the donor.

Why the Procedure is Performed
A bone marrow transplant replaces bone marrow that is either not working well or has been destroyed by chemotherapy or radiation. Doctors believe that for many cancers, the donor's white blood cells may attack any lingering cancer cells, similar to when white blood cells attack bacteria or viruses when fighting an infection.

Your doctor may recommend a bone marrow transplant if you have:

Certain cancers, such as leukaemia, lymphoma, myelodysplasia, or multiple myeloma.
A disease that affects the production of bone marrow cells, such as aplastic anaemia, congenital neutropenia, severe immune system illnesses, sickle cell anaemia, or thalassemia.

Risks
A bone marrow transplant may cause the following symptoms:

Chest pain
Drop in blood pressure
Fever, chills, flushing
Funny taste in the mouth
Headache
Hives
Nausea
Pain
Shortness of breath

Possible complications of a bone marrow transplant depend on many things, including:

The disease you are being treated for
Whether you had chemotherapy or radiation before the bone marrow transplant and the dosages of such treatments
Your age
Your overall health
How good of a match your donor was
The type of bone marrow transplant you received (autologous, allogeneic, or umbilical cord blood)

Complications may include:

Anemia
Bleeding in the lungs, intestines, brain, and other areas of the body
Cataracts
Clotting in the small veins of the liver
Damage to the kidneys, liver, lungs, and heart
Delayed growth in children who receive a bone marrow transplant
Early menopause
Graft failure, which means that the new cells do not settle into the body and start producing stem cells
Graft-versus-host disease (GVHD), is a condition in which the donor cells attack your own body
Infections, which can be very serious
Inflammation and soreness in the mouth, throat, oesophagus, and stomach, called mucositis
Pain
Stomach problems, including diarrhoea, nausea, and vomiting

Before the Procedure
Your doctor will ask about your medical history and do a physical exam. You will have many tests before treatment begins.

Before the transplant, you will have one or two tubes known as catheters, inserted into a blood vessel in your neck or arms. This tube allows you to receive treatments, fluids, and at times nutrition. It is also used to draw blood.

Your doctor will likely discuss the emotional stress of having a bone marrow transplant. You may want to meet with a counsellor. It is necessary you talk to your family and children to help them understand what to expect.

You will need to make plans to help you prepare for the procedure and handle tasks after your transplant:

Complete an advance care directive
Arrange medical leave from work
Take care of bank or financial statements
Arrange care of pets
Arrange for someone to help with household chores
Confirm health insurance coverage
Pay bills
Arrange for care of your children
Find housing for yourself or your family near the hospital, if needed

After the Procedure
A bone marrow transplant is usually done in a hospital that specializes in such treatment. Most of the time, you stay in a special bone marrow transplant unit in the hospital. This is to reduce your chance of getting an infection.

Depending on the treatment and where it is done, all or part of an autologous or allogeneic transplant may be performed as an outpatient. This means you do not have to remain in the hospital overnight.

How long you stay in the hospital depends on:

How much chemotherapy or radiation you received
The type of transplant
Your medical centre's procedures
While you are in the hospital:

The healthcare team will closely monitor your blood count and vital signs.
You will receive medicines to prevent GVHD and prevent or treat infections, including antibiotics, antifungals, and antiviral medicine.
You will likely need many blood transfusions.
You will be fed through a vein (IV) until you can eat by mouth and stomach side effects and mouth sores have gone away.
After you leave the hospital, be sure to follow instructions on how to care for yourself at home.

Outlook (Prognosis)
How well you do after the transplant depends on:

The type of bone marrow transplant
How well do the donor's cells match yours
What type of cancer or illness do you have
Your age and overall health
The type and dosage of chemotherapy or radiation therapy you had before your transplant
Any complications you may have
A bone marrow transplant may completely or partially cure your illness. If the transplant is a success, you can return to most of your normal activities as soon as you feel well enough. Usually, it takes up to one year to recover completely, depending on what complications occur.

Complications or failure of the bone marrow transplant can result in death.