What is Trepanning?
Trepanning refers to a specialized form of surgery involving drilling or scraping a hole into the skull. The goal of trepanning is to expose the tough and inflexible dura mater, or pachymeninx, which is the outermost layer of the meninges surrounding the brain and spinal cord. Trepanning has taken place for hundreds of years all over the world for a variety of reasons. There is even evidence in the form of cave paintings that trepanation occurred during the Neolithic times as a cure for migraines, epileptic seizures, and mental disorders. Hippocrates also provided directions for the procedure during the Greek age. Trepanning remained a common practice through the 19th century and has recently started making a comeback for both mystical and medical reasons. To complete a trepanation, the surgeon first drills a hole into the skull. A small piece of bone is then removed in order to relieve pressure from the brain. Over time, the bone grows back but the new bone is shallower than the rest
Trepanning uses what is in effect a tubular boring head and produces a plug or “core” which can be reused. The core can be turned and either re-entered into stock, or directly transferred to other components. This method is also very useful for producing larger bores in one pass, as the amount of material that is actually being cut is far less than conventional boring techniques.
The word comes from the Latin trepanum which in turn comes from the Greek word trupanon meaning an auger or borer. It was a rock boring tool used in the sinking of mineshafts and it was a tool for making circular holes or grooves. When applied in the context of healing it generally involved cutting holes in the skull. In prehistoric times, the evidence of such techniques being employed has been found in skulls dating back to the Mesolithic or early Neolithic Periods. There is a pre-historic skull which resides in Norwich Castle museum which has according to my recollection 3 or 4 trepanned holes cut in it, one of which has shown a re-growth of bone over the hole, thereby indicating that the patient fully recovered after the procedure. Another hole showed a partial re-growth of bone, indicating that the patient had recovered from that particular operation. Another hole however showed no re-growth which meant that the patient did not survive for very long after the subsequent operation.
