Trepanobiopsy is a method of in vivo extraction of bone tissue (mainly spongy) for the study of bone marrow. Trepanobiopsy has a definite advantage over sternal puncture (see), which makes it possible to study only scattered bone marrow cells mixed with blood cells. When trepanobiopsy extract a piece of bone marrow with preservation of its structure, which allows to properly assess the ratio of active and fatty bone marrow, to identify focal and diffuse changes in it. Trepanobiopsy is produced by a special needle-trocar of the design of prof. M. G. Abramova (Fig.). The needle-trocar consists of a needle with a length of 4 cm and an internal diameter of 2 mm, a shield that allows you to set the required puncture depth, mandrel and arm. The end of the needle is sharpened in such a way that the needle cuts a column of bone and bone marrow tissue during rotation.
Needle - Abramov's trocar (on the left - assembled)
The puncture is made in the iliac crest 2-3 cm posterior to the anterior superior spine after anesthesia of the soft tissues and the periosteum with a 2% novocaine solution. When the needle penetrates into the bone tissue, which is recognized by the sensation of fixing the needle, they remove the handle, take out the mandrin, put the handle back on and move the needle inwards with a rotating movement. With the same rotational movement, the needle is removed and a mandrel is pushed out of it onto a glass of a piece of bone tissue 6-10 mm long, which is then transferred to the solution for fixation. In the future, the resulting sample is processed according to the rules of histological technology. From the material remaining on the glass, mandrin and in the needle, smears are made, which are painted and studied as sternal punctate.
The study of histological preparations allows us to distinguish hyperplastic, hypoplastic or aplastic bone marrow from normal. Trepanobiopsy also provides valuable information for the diagnosis of such hematopoietic tissue lesions as reticulosis , myeloma, erythremia, chronic myeloid leukemia, etc.
Trepanobiopsy produces a doctor. The role of the nursing staff is to help the doctor, to sterilize the needle of the trocar with dry heat or boiling, followed by drying with alcohol and ether , preparing the puncture site and applying a sterile sticker on it after the biopsy.