Sternal Puncture
Definition
It is a diagnostic procedure done to take a biopsy of the bone marrow or aspirate bone marrow.
Indications
Leukemia, multiple myeloma, anemia, and pancytopenia.
To examine the source of the blood cells
To examine hematopoiesis
The aspirate yields semi-liquid bone marrow
Trephine biopsy yields a narrow, cylindrically shaped solid piece of bone marrow
Examination done
Light microscopy
Flow cytometry
Chromosome analysis, or polymerase chain reaction
Examined microscopically (sometimes with the aid of immunohistochemistry) for cellularity and infiltrative processes.
Procedure
Informed consent for the procedure required.
May be pretreated with analgesics , anti-anxiety medications
Site : posterior iliac crest or sternum
A trephine biopsy should never be performed on the sternum : risk of injury to blood vessels, lungs or the heart.
A needle used for bone marrow aspiration, with removable stylet.
At O.P
Prone position or lateral decubitus position
Skin is cleansed
Local anesthetic injected
Aspiration is performed first.
An aspirate needle is inserted through the skin until it abuts the bone. Then, with a twisting motion, the needle is advanced through the bony cortex (the hard outer layer of the bone) and into the marrow cavity. Once the needle is in the marrow cavity, a syringe is attached and used to aspirate ("suck out") liquid bone marrow. A twisting motion is performed during the aspiration to avoid a too high content of blood in the sample, which might be the case if a too large sample from one single point is taken.
Then biopsy is performed if indicated. A different, larger trephine needle is inserted and anchored in the bony cortex. The needle is then advanced with a twisting motion and rotated to obtain a solid piece of bone marrow. This piece is then removed along with the needle.
Takes 10-15 minutes.
If several samples are taken, the needle is removed between the samples to avoid blood coagulation.
Pt lies flat for 5-10 minutes to provide pressure over the procedure site.
After that can get up and go about their normal activities.
Simple analgesics - for 2-3 days after the procedure.
Contraindications
Severe bleeding disorder
Infection - select different site
Safe even in extreme thrombocytopenia
