What Is a Bone Marrow Needle?

Bone marrow aspiration is an indispensable method for the diagnosis of most leukemias, but many patients and their families still have doubts about bone marrow aspiration. The main concern is the risk of this operation.

Basic Information

Visiting department

Hematology

Multiple groups

Leukemia patients

Common locations

Superior iliac spine or posterior superior iliac spine

Bone marrow aspiration

Bone marrow aspiration is usually selected from the posterior superior iliac spine or anterior superior iliac spine of the pelvis. The bone mark at this part is clear, and there are no large blood vessels and nerve trunks around it, so it has good safety. If multiple punctures are not satisfactory, sternum puncture is optional in a few cases. As long as the oblique advancement of the needle (30 ° ~ 45 ° with the sternum), it is safer to not penetrate the sternum. Before the puncture, local anesthesia must be performed at the puncture point. The anesthetic is from the skin and subcutaneous to the periosteum on the surface of the bone, so the patient will not cause pain during the puncture. A skilled operator can usually complete it in more than 10 minutes, so there is no need to worry. The puncture site should not be washed (including bathing) for 2 to 3 days after local application of a sterile dressing to avoid local infection.

Bone marrow aspiration indication

An essential tool for the diagnosis of most leukemias.

Misunderstanding of bone marrow aspiration

Some people mistake the bone marrow puncture as "pumping the spinal cord", that is, lumbar puncture, and cerebrospinal fluid, which is thought to cause paraplegia. In fact, the two are not the same thing, and the puncture site is completely different. The lumbar puncture site is the waist of the spine (large spine), that is, the needle is inserted from the space of the lumbar spine. In fact, as long as you master the essentials and standardize the operation, it is also very safe in most cases.

The most common problem encountered in bone marrow aspiration is "unsatisfactory material selection". The most common reason is that the needle does not actually enter the bone marrow cavity. The extracted content is blood in the blood vessels of nearby tissues, or although it has entered the bone marrow cavity, the contents are extracted Too much, that is, the blood vessels in the bone marrow cavity will be damaged, and the peripheral blood in the blood vessels will be mixed with the bone marrow fluid, causing the "dilution" of the bone marrow fluid, commonly known as "mixed blood". The above two conditions cause the smear to look like a blood smear when viewed under a microscope. As long as the puncture operator masters the essentials, including correct positioning, ensuring that the puncture needle is in the bone marrow cavity, and extracting the contents so as not to be mixed, at the same time the patient overcomes the state of fear under good anesthesia and cooperates with the operation. It can be completed smoothly and is very safe. Complications such as accidental anesthesia (allergy), local bleeding, and infection are rare.

Bone marrow aspiration

Due to the special condition of a small number of patients, bone marrow aspiration may fail, for the following reasons:

Bone marrow necrosis

Sometimes when leukemia cells proliferate in the bone marrow, they are also accompanied by a large number of lysis and necrosis, which is called bone marrow necrosis. At this time, the bone marrow fluid was very thin, and almost no complete cells were found on the smear. Only the remaining broken cells were left, which could not be identified and diagnosed. Fortunately, this situation is very rare, with hundreds of punctures, which can only occur once.

2. Dry pumping

(1) Cell hyperplasia Leukemia cells are hyperproliferated in the bone marrow, the cells are very crowded, and they are drawn to each other and difficult to extract by negative pressure, which is called "dry extraction".

(2) The number of nucleated cells in the bone marrow of a few acute leukemia patients with hypoproliferative or fibrous tissue proliferation is significantly reduced, and the absolute number of leukemia cells is also significantly reduced. Low proliferative acute leukemia can also occur "dry pumping."

The latter two cases can be replaced with bone marrow biopsy to solve the problem. A slightly thicker bone marrow puncture needle is used, and the front end is provided with a device capable of hooking bone marrow tissue. The specific operation steps are generally the same as those of bone marrow puncture, which will not increase the patient. s pain. The bone marrow tissue can be smeared at the same time, and pathological sections can be made after fixation, which can make a diagnosis.