Bone Marrow Aspirate and Trephine Biopsy

A bone marrow aspirate and trephine biopsy is a diagnostic procedure used to examine the health of bone marrowthe spongy tissue found inside your bones where blood cells are produced. This dual procedure is often performed simultaneously to provide a comprehensive look at both the liquid and structural components of the marrow.

What is the Procedure?

The procedure generally involves two distinct parts performed during a single session:

• Bone Marrow Aspirate: A thin needle is inserted into the bone, and a syringe is used to draw out a small sample of the liquid portion of the bone marrow. This is used primarily to examine the cells under a microscope and perform genetic testing.
• Trephine Biopsy (Core Biopsy): A slightly larger, hollow needle is used to extract a small, cylindrical piece of solid bone marrow tissue. This allows pathologists to see the "architecture" of the marrow, showing how cells are arranged and whether there is any scarring (fibrosis) or abnormal cellular infiltration.

How to Prepare

Preparation is usually straightforward. You should inform your healthcare provider about any medications you are taking, especially blood thinners like aspirin, warfarin, or clopidogrel, as these may need to be paused. Fasting is generally not required, but you may be asked to arrange for someone to drive you home if you are receiving sedation.

The Experience

The procedure is typically performed in a clinic or hospital setting. The most common site for the collection is the posterior iliac crest, which is the back portion of the hip bone. You will likely be asked to lie on your side or stomach.

The skin over the area is cleaned, and a local anesthetic is injected to numb the skin and the surface of the bone. While the anesthesia significantly reduces pain, you may feel a brief sensation of pressure or a dull ache when the sample is extracted. The entire process usually takes about 15 to 30 minutes.

Aftercare and Recovery

Following the biopsy, a bandage will be placed over the site. It is important to keep this area clean and dry for at least 24 hours. Most patients can resume normal activities within a day or two, though heavy lifting or vigorous exercise should be avoided for a few days to prevent bleeding or discomfort.

Mild soreness at the site is common and can usually be managed with over-the-counter pain relief, such as acetaminophen. You should contact your medical team if you experience signs of infection, such as fever, worsening redness, or persistent bleeding that soaks through the dressing.

Understanding the Results

The samples are sent to a laboratory where a pathologist examines the cells and the tissue architecture. Results can take several days to a few weeks, depending on the complexity of the tests required, such as flow cytometry or chromosomal analysis. Your doctor will discuss these results with you to determine the best course of treatment, if necessary.