Trephine Health Dictionary

An operation in which a portion of the CRANIUM is removed. Originally the operation was performed with an instrument resembling a carpenter’s brace and known as the trephine or trepan, which removes a small circle of bone; but now this instrument is only used, as a rule, for making small openings, whilst, for wider operations, gouge forceps, circular saws driven by electric motor, or wire saws are used.

Trepanning is used in cases of fracture, with splintering of the skull; the operation is performed to remove fragments of bone and any foreign bodies, like a bullet, which may have entered. In compression of the brain with unconsciousness following an injury, the skull is trephined and any blood clots removed, or torn vessels ligatured. The operation may also be done for an ABSCESS within the skull and for other conditions where operative access to the brain is required.... trepanning

A procedure to obtain a sample of cells from the bone marrow (aspiration biopsy) or a small core of bone with marrow inside (trephine biopsy). The sample is usually taken, under local anaesthesia, from the sternum (breastbone) or iliac crests (upper part of the hip-bones). Microscopic examination gives information on the development of the blood components

surrounding tissues. Radionuclide scanning detects areas throughout the skeleton in which there is high bone-cell activity. This type of scanning and on the presence of cells foreign to the marrow.

It is useful in the diagnosis of many blood disorders, including leukaemia and anaemia.

It can also show whether bone marrow has been invaded by lymphoma or cells from other tumours.... bone marrow biopsy

(marrow) the tissue contained within the internal cavities of the bones. At birth, these cavities are filled entirely with blood-forming myeloid tissue (red marrow) but in later life the marrow in the limb bones is replaced by fat (yellow marrow). Samples of bone marrow may be obtained for examination by *aspiration through a stout needle or by *trephine biopsy. See also haemopoiesis.... bone marrow