Rest assured, we know how we'll crack open your skull now.
Image Credit Rama, via Creative Commons Attribution-ShareAlike 3.0 France
The New England Journal of Medicine has reported the results from a multicenter study involving 11 countries on the outcome of the two primary approaches to acute subdural hematoma.
An acute subdural hematoma occurs when blood seeps into the space between the brain and the skull; a site only filtered cerebral spinal fluid should flow. To treat, doctors open up the skull to remove the clot, relieving pressure on the brain. But then, what do you do with that chunk of the removed skull?
This was the question of their clinical trial, explained Peter Hutchinson, Professor of Neurosurgery at Cambridge and the trial's Chief Investigator, "which technique is optimal for removing an acute subdural hematoma – a craniotomy (putting the bone back) or a decompressive craniectomy (leaving the bone out)?"
At the end of the large trial, patient recovery, complication, and mortality rates were compared between the two approaches. Though results were similar, consultant neurosurgeon and Cambridge Professor Angelos Kolias explained that "based on the trial findings, we recommend that after removing the blood clot, if the bone flap can be replaced without compression of the brain, surgeons should do so, rather than performing a pre-emptive decompressive craniectomy." One clear benefit to a craniotomy is that these patients don't need skull reconstruction later.
Surgeons have been opening human skulls since 3000 BCE. A surgical procedure called trepanation was performed prehistorically. Hippocrates described trepanation in text, and it remained a practice of Western medicine until the Middle Ages. Trepanation involves cutting the scalp and drilling an opening into the cranium to relieve the swelling associated with traumatic head injuries.
Anthropologists and doctors from today have examined the still open trepanation holes of ancient Peruvians. Evidence of bone healing around the drill sites suggests up to 91% survival rates once techniques were refined in 1000-1400 ACE. This exceeded rates during the American Civil War (46%-56%). But to be fair, wartime surgery is a more chaotic operating environment.
In the present day, and after this definitive study, medical doctors will likely replace any surgically removed skull with a craniotomy technique. However, in various spaces where brain surgeries are performed, pre-emptive decompressive craniectomy might be used in cases of limited resources or front-line settings.
Sources: Hutchinson, PJ et al. Decompressive Craniectomy versus Craniotomy for Acute Subdural Hematoma. NEJM; 23 Apr 2023, World Neurosurgery, Science