[Music] i want to see whether we can optimize the outcome of these patients you can see here there's a patient with a significant i'm going to now that you've seen my face i'm just going to take my video off so that it doesn't provide a distraction so as you can see here we have a very large subdural hematoma and this is a very severely interpaciant because there's also intraparenchymal spot hemorrhages here and that indicates a very severe injury lots of underlying brain damage as well as the compressive lesion that's causing a tremendous amount of shift so my goal over the course of the last 20 odd years is to try to help people get better so that they recover it would be wonderful everybody was able to get back to work and become productive members of society again as they were previous to the injury but alas i don't think we've gotten there for severe uh traumatic brain injury while the mortality rates are generally about 25 and we have made a lot of strides in severe tbi uh we still have a long way to go in trying to make the outcomes optimal so that we can return patients to something of a semblance of their previous level of functioning most of these patients unfortunately are coming back to some sort of new type normal that the families have to deal with but many families are very grateful if they do survive and are functional able grateful for having them come back to them decompressive craniectomy has been method of treatment for severe intracranial hypertension and now it's been going on for many many years it was actually first described in 1901 by dr coker and it became more popular in the 1960s so that's why i say there's sort of a biphasic use so in the 1960s and 70s it was pretty popular and then it fell out of favor because we realized they realized then that the outcomes were pretty dismal in these patients regardless of whether you took off phone and then there was a resurgence of interest in this procedure from the 1990s to the 2000s plus and the era of doubt occurred when we had the decker trial which was april 2011. and that's a very it's a very significant trial set because it was the first large-scale randomized controlled trial this picture is a picture of a subdural hematoma and part of the dura has sort of been torn through during the process of the craniotomy here's the temporalis muscle is in front and then the scalp is flapped over and that big uh purplish thing is this big subdural hematoma so the purpose of decompressive craniectomy is to really open the cranial vaults so that you can give more room for an expanding brain and expanding swelling there are three components as we know there's the brain which we can get rid of mass lesions we can do low bar resections we can reduce infarct size uh by taking out pieces of brain in order to reduce that component there's blood and by vasoconstricting through various means we can reduce the amount of blood that's in the brain and we have csf which also occupies that space in this rigid closed cavity which we call the skull cavity and ventricular drainage can help reduce that particular element here so because this is a closed cavity there's really no place for this brain to go once there's an increase in pressure and this is the monroe kelly doctrine and this is the famous pressure volume curve where we actually see that over time there's a there's a point in time where the brain can tolerate some added volume within the skull cavity but as we get further and further with uh crowding the structures of the brain the brain is deformable to some degree and so are the blood vessels and the csl there comes a critical point where for any further change of volume you get an asymptotic rise in the pressure so that is really uh what we call the pressure volume curve and traditionally you know there's this inflection point but the goal of decompressive craniectomy is to remove that rigid outer covering of the skull cavity so that the brain and the elements within can now expand further if there's more swelling and hopefully we can shift that pressure volume curve over to the right and we can flatten this more so that it would take even more swelling more volume expansion of either added blood or contusions that occur in the brain before we get terrible rises in icp and decompressive craniectomy has a significant benefit actually reducing intracranial pressure it's reduced infarct volume it's increasing brain perfusion and very importantly it actually reduces the need for intensive therapy we have we can use uh pressers and hyperoz molar therapy and getting a lot of cat scans but once you take the head off in a large proportion of these patients the icp will become better controlled and therefore you can relax a little bit more you don't have to have all of this therapeutic intensity in order to get the intracranial pressure under control there is a technique to a decompressive craniectomy and this diagram shows a hemispheric craniactomy or what we call the the hemicraniectomy and this could be done on the right or the left depending on what the pathology is but what's important is that you really need to have uh 12 to 15 centimeters of uh anterior posterior diameter of this bone flap and it has to be about 12 centimeters in the superior inferior dimension as well and so this is an example of how if you're going to do a hemi craniectomy you have to go large because what can happen is if you don't go large you can get pinching of veins against the dura and the skull that can cause venous infarcts and contusions and and dead brain so it's important to have very large craniactomies the by frontal craniectomy is um described first by kelberg and prieto in 1971 and this is when we use bifrontal it's actually by frontotemporal where we licate the sinus and they cut the faults and they found that uh there was an 18 survival among the 73 cases that went there underwent this procedure however um they did have five excellent and four patients with some deficits so regardless of the fact that these patients were very severely injured and a very poor survival rate the ones who did survive actually did pretty well [Music] hey everyone ryan rad here from neurosurgery training.org if you like that video subscribe and donate to keep our content available for medical students across the world