Overview of Bone Marrow Aspiration and Biopsy
Bone marrow aspiration and biopsies are tests that doctors often do both in a hospital and in an outpatient clinic (where you go for treatment but don’t stay overnight). These tests help diagnose a broad range of blood disorders. The tests can be conducted in two ways: by feeling the area where the test is to be done (palpation-guided), or by using computed tomography, also known as a CT scan (CT-guided). Both of these methods are highly precise and carry a low risk of complications.
We’ll explain what is done in a bone marrow aspiration and biopsy, and also describe how the medical team works together to take care of patients having this procedure. Before performing these tests, it’s critical that those involved understand the steps and know what tools they’ll need, to avoid not obtaining enough sample or causing issues for the patient. Additionally, if healthcare professionals better understand when to do this, how to manage the patient during the procedure, and possible complications, they can improve both the patient’s experience and the chance of making an accurate diagnosis.
Anatomy and Physiology of Bone Marrow Aspiration and Biopsy
When we’re born, there are many places in our body where new blood cells are made. However, by the time we’re teenagers, this only happens in the middle part of our skeleton. Doctors usually take samples from a part of the pelvis called the posterior superior iliac crest because it’s typically more comfortable and safer for the patient.
Sometimes, if a person is very overweight or has a wound in this area, the doctor can also take a sample from the anterior superior iliac crest, which is another area of the pelvis. If neither of these places are suitable, for example, if there has been a previous treatment in this area or a patient is extremely overweight, doctors can also take a sample from the upper part of the breastbone. But they only do this for patients over the age of 12.
Usually, one sample is enough. However, in some cases like certain types of non-Hodgkin lymphoma (a kind of cancer), the doctors would need to take samples from two different places, as studies have shown this gives a more precise diagnosis. But if a doctor can take one good, sufficiently sized (about 2 cm long) sample, this might not be necessary.
Why do People Need Bone Marrow Aspiration and Biopsy
A bone marrow aspiration and biopsy is a medical procedure that doctors use to help diagnose certain blood-related diseases and conditions. These include various types of cancer such as leukemia, multiple myeloma, and lymphoma, as well as conditions like unexplained anemia and myelodysplastic syndrome, which affects the blood cells in the bone marrow. This procedure is also helpful for identifying other conditions such as variations in the number of chromosomes in newborns, or fevers where the cause is unknown.
Besides these, the procedure can help identify less common fungal and parasitic disorders such as histoplasmosis, leishmaniasis, cryptococcus, and Q fever. Histoplasmosis is a lung infection caused by inhaling spores of a fungus often found in bird and bat droppings. Leishmaniasis is a disease spread by the bite of the female sandfly. Cryptococcus is a fungus that people can get by inhaling the microscopic, airborne fungal spores from the environment and Q fever is a disease caused by infection with Coxiella burnetii, a bacterium that affects humans and other animals.
Most of these conditions require both parts of this procedure – aspiration and biopsy – for doctors to understand the complete picture of your health, make a diagnosis, and plan the best treatment. Aspiration involves drawing out a small amount of liquid bone marrow through a needle, and a biopsy takes a small solid sample from the marrow. Both samples will then be analyzed in a lab.
When a Person Should Avoid Bone Marrow Aspiration and Biopsy
There are certain reasons why someone may not be able to have a bone marrow biopsy or aspiration, which are procedures that involve taking a small sample of bone marrow (the spongy tissue inside your bones) for testing:
Severe bleeding disorders could make these procedures dangerous. If someone has severe hemophilia (a condition that makes bleeding difficult to control) or severe disseminated intravascular coagulopathy (a severe disorder that creates small blood clots throughout the body), they might not be able to have this procedure.
If a person has a low platelet count (platelets are tiny blood cells that help your body form clots to stop bleeding), it’s not a reason to avoid these procedures, but they might need a platelet transfusion beforehand. This is often done if platelet counts are below 20,000 cells/microliter.
Another point is that bone marrow should only be taken from the breastbone (sternum) in patients older than 12 years. Furthermore, in patients suffering from conditions leading to widespread bone breakdown (like metabolic or lytic processes seen in multiple myeloma patients), the bone marrow should be taken from the hip bone (iliac crest) instead of the sternum due to the risk of damaging the sternum and chest cavity (mediastinum). Due to the same risk, the sternum should never be used for biopsy, even in patients who otherwise have healthy bone.
Equipment used for Bone Marrow Aspiration and Biopsy
Doctors may use a machine called a computed tomography (CT) scanner for this procedure, often when a specialist known as an interventional radiologist is carrying out the process.
For this procedure, a bone marrow kit is necessary. This kit includes:
- Sterile drapes – these are clean sheets used to maintain a safe and hygienic environment during the procedure.
- Needles and Syringes – these are for withdrawing the bone marrow.
- An aspiration needle – this special needle is used to extract the bone marrow.
- A Biopsy needle – this needle may be used to remove a small piece of bone marrow for testing. If the area in question is the posterior iliac crest (the back part of the hip bone), a type of needle called a Jamshidi needle is typically used.
- 1% to 2% lidocaine with or without epinephrine – this is a local anesthetic, used to numb the area where the procedure will be carried out.
- Specimen slides – these are used to place the bone marrow sample so it can be examined under a microscope.
- Specimen containers – these are used to store the samples of bone marrow removed during the procedure. The number of specimen slides and containers required varies depending on the nature of the medical investigation, and if a biopsy (extraction of tissue for further examination) is also to be carried out in addition to the aspiration (extraction of fluid).
Who is needed to perform Bone Marrow Aspiration and Biopsy?
The health care professional doing the procedure, alongside the nursing staff, and in instances where the procedure is done with the help of a CT scan, a CT technologist, should always be there during the entire process. If the patient needs to be in a relaxed or sleep-like state for the procedure, an anesthesiologist or a similar certified professional might be needed depending on the rules of the hospital or clinic. Also, having an assistant can be useful for getting the slides ready for collecting samples of bone marrow and a container for the biopsy (tissue sample) specimen.
Preparing for Bone Marrow Aspiration and Biopsy
Before starting a medical procedure, doctors need to be sure that they have identified the correct issue to be treated. Each hospital or medical institution has specific rules on how to prepare tissue samples for examinations in the lab. Sometimes, the doctor may give the patient medication before the procedure if they think it’s needed for safety reasons or if the patient is very anxious.
The way a patient is positioned during the procedure is really important. It needs to be easy for the doctor to get to the place in the body where they need to collect a sample, but it’s also important that the patient is comfortable. Usually, patients lie on their stomach or their side to make it easier for the doctor to reach the back upper corner of their hip bone, a common site for sample collection.
Like with all procedures, doctors will talk in detail with patients or their caregivers, before starting. They will explain what they plan to do, why they think it’s the best course of action, and what other treatment options are available.
How is Bone Marrow Aspiration and Biopsy performed
If a CT scan is being used to help guide the procedure, a special grid will be placed on the patient’s skin over an area called the iliac crest, near the pelvis. This grid serves as a guide for where the needle will be placed into the body. If the CT scan isn’t being used, the doctor will use their hands to feel for the correct location for the needle.
The typical place to insert the needle is about three finger-widths away from the midline of the body and two finger-widths below the iliac crest. They will aim the needle towards a specific location on the pelvis called the anterior superior iliac spine.
Before starting, the doctor will mark the spot on the skin where the needle will be inserted. The medical staff will then put on protective equipment, such as a sterile mask, gown, and gloves. They’ll get the tools ready on a clean table and clean the area on the skin that will be worked on.
Next, they will inject a 1% to 2% lidocaine solution, to numb the area, using a 23-gauge needle – this is a very thin needle. An important part of this step is to numb the periosteum, a layer of tissue covering the bone, as it can be very sensitive. Once the area is numb, a small cut is made on the skin.
The doctor will then take a special bone marrow needle and move it towards the bone. If the CT scan is being used, the doctor will scan the area they’re going to insert the needle into, to check the needle’s path. They’ll make any necessary adjustments and scan again to ensure the needle is correctly placed.
The needle will then be pushed into the bone, with soft forward pressure. A back-and-forth, clockwise and counterclockwise, twisting motion can be used to insert the needle. After the needle is in the bone marrow cavity, a part of the needle called a stylet is removed. A small syringe is then attached to the end of the needle to collect bone marrow samples.
Once the sample has been taken, a medical assistant will prepare the sample for laboratory testing by either putting the sample on slides or putting it into a special tube. If the process wasn’t successful at first, the stylet can be reinserted and a new site can be used.
If a biopsy is also needed, the biopsy needle will be inserted at the same location in the skin but at a slightly different angle towards the bone. The biopsy needle needs a little more pressure to get into the bone. The needle is twisted in a clockwise and counterclockwise motion to secure the sample.
Then, by twisting the needle, it can be removed and the sample collected. The sample is then placed in a particular container to be sent for examination. If the sample isn’t enough, a new biopsy needle can be used to repeat the process.
Possible Complications of Bone Marrow Aspiration and Biopsy
Bleeding after a medical procedure is pretty common. This is especially true when tissue rich in blood vessels is involved. If bleeding occurs, doctors may apply physical pressure or use a special dressing until it stops. In rare cases, bleeding can occur deeper in your body, usually due to injury to particular arteries. This is less likely when the biopsy needle is used correctly. It’s important to know that severe complications like heavy bleeding, heart injury, and even death can occur if a needle is misplaced during bone marrow sampling, particularly from the breastbone. Doctors will use extreme caution when sampling from this spot.
Infections also could happen with any invasive procedure. The risk of infection can be reduced by maintaining sterile conditions and avoiding areas of the body where infections already exist when choosing where to sample tissue. Another risk that patients should be aware of is that cancer cells might spread in the case that a biopsy is performed at the site of a suspected cancerous lesion.
If medical imaging tests are scheduled before a procedure, doctors should mark where they’ve taken tissue samples. This is because these areas might show up as ‘false positives’ on certain scans, leading to potentially misleading results. Additionally, damage to nearby tissues could happen, especially with uncooperative or aggressive patients. It’s important to stress patient compliance while planning the medical procedure and to consider sedation if it’s believed to be necessary.
What Else Should I Know About Bone Marrow Aspiration and Biopsy?
Doctors commonly use a medical procedure known as bone marrow aspiration and biopsy to diagnose blood-related cancers. This method is preferred because it avoids the need for more invasive procedures, gives accurate results quickly, and is reasonably straightforward to perform.
The procedure’s speed is a big advantage, often removing the need for sedation or general anesthesia. This means it can usually be done in an outpatient setting, allowing patients to go home the same day. As a result, patients can get their diagnosis and start treatment faster, and the overall experience is less stressful for them.
