Removing some of the skull is a neat way of cheating the Monro-Kellie doctrine. Pity it does you no favours. LITFL have an excellent page devoted to this practice. Additionally, an article directed at neurosurgeons is available and it highlights all the important features.
Decompressive craniectomy (not specifically in TBI) has appeared several times in the CICM Part II past papers. The most detailed SAQ had been Question 25 from the second paper of 2018, which had asked the candidates to critically evaluate the use of decompressive craniectomy in traumatic brain injury. It was also the subject of in Question 9 from the first paper of 2009, where the focus was more on indications complications and outcomes. Its use in malignant MCA infarction appeared in Question 2 from the second paper of 2014. To the latter, an entire chapter is dedicated ("Decompressive craniectomy for malignant MCA infarction").
As most indications for decompression are neurological and nuerosurgical, the best article to read about this topic would probably be the 2016 paper by Crudele et al, provided one can get a hold of a free copy. It goes through TBI, SAH, malignant MCA infarction and parenchymal intracerebral haemorrhage. The other good articles for this topic are locked up behind paywalls. However, if one were ever going to throw money into that bottomless hole that is Springer-Verlag, one could do worse than this article by S.Y Chu, from Current Treatment Options in Neurology (2015). Its major attraction is a nice big table discussing indications for decompressive craniectomy. Owing to his poverty, the author of this manuscript could not throw money into that particular hole, and was forced to compile his own list of indications.
In brief:
Indications: |
Outcomes: |
Complications:
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Traumatic brain injury |
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Malignant MCA infarction syndrome |
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Subarachnoid haemorrhage |
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Intraparenchymal intracranial haemorrhage |
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Dural sinus thrombosis |
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Encephalitis |
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Subdural haematoma |
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In greater detail:
To put simply, borrowing words from the abstract to an article by Quinn et al (2011),
"the rationale for this procedure is based on the Monro-Kellie Doctrine; expanding the physical space confining edematous brain tissue after traumatic brain injury will reduce intracranial pressure".
If one were forced to spell things out in a viva or a CICM SAQ, it would benefit from a platform approach, as if explaining the concept to a toddler - as this would be much easier to mark than prose. Thus:
There are many pages written on this topic, and not being a surgeon, I will refrain from meaninglessly gibbering about it. A few features, however, are worth knowing:
There are several indications for decompressive cranienctomy, of which some are vigorously debated, and others well accepted. Frequently, the debate is not about the intracranial pressure benefits of removing the bit of skull, but more about the enhancement of survival for the severely disabled patients who would otherwise have died.
This is the only agreed-upon firm indication for decompressive craniectomy. It is supported by the findings of three European trials, and enjoys a thorough discussion elsewhere.
In brief:
It is worth pointing out that in the DESTINY trial, the numbers were small because statistical significance was achieved with only 32 patients. Conversely, the research board terminated the DECIMAL trial because they had trouble recruiting. Anyway. The bottom line is a decrease in mortality. Additionally, it seems in the craniectomised survivors the hemiplegia is less severe; this may be viewed as a positive step, even though the therapy still generates a stream of disabled hemiplegic people.
This was the subject of Question 25 from the second paper of 2018 and Question 25 from the first paper of 2021. In summary, the evidence for decompressive craniectomy was explored in several trials which need to be well known to the ICU trainee:
The new (2016) BTF Guidelines are careful to make clear that improving outcome is not what this technique is for. A large bifrontal decompression (no less than 12 × 15 cm) is recommended if you are going to go down that road.
Advantages of decompression in TBI include
Disadvantages include:
Case series report good outcomes. However, even people who publish these case series tend to mention that there is a lack of definitive evidence to support this practice. In general, the studies which report good outcomes also report that one is better off performing a craniectomy within 48 hours of the haemorrhage. Patients with progressive brain oedema but no radiological signs of infarction
and those with obvious hematoma will benefit the most. Overall, though large matched group analysis failed to identify any real survival benefit (or improvement in disability), a small subset of patients (about 25%) achieved a good long-term outcome, suggesting that careful patient selection is the key to success.
Again, this practice is built on shaky foundations. Small case series report good outcomes and refer to decompression as a "life saving" measure. A more recent (2015) local case series of ICH in patients with arteriovenous malformations produced outcomes which the authors described as "good", even though of their twelve patients seven ended up with severe disability and one was described as "vegetative". The same author, writing about hypertensive ICH in 2013, noted a 71% incidence of a poor outcome in a case series of 21 patients, with a mortality rate of 10% overall.
A literature review from 2008 identified papers with a total of 13 cases. In the majority of these case reports, the authors waited until there were features of brainstem herneation before they went ahead with the procedure. The reviewers were forced to conclude that if you are about to cone, decompressive craniectomy begins to look very attractive.
Small scale retrospective studies have found that in the patients with the most severe cereral venous thrombosis, decompression leads to more favourable outcomes. Most importantly, it seems that full systemic anticoagulation within 24 hours of surgery seems to be safe. A 2009 review from Stroke courageously asserted that the therapy is "lifesaving" and that the outcome can be "excellent", on the basis of three cases. A larger and more recent case series from Pakistan also reported excellent outcomes from a series of seven patients, although worryingly "1 of 7 left against medical advice (in a comatose state) and was lost to follow-up."
Decompressive craniectomy is an option for this condition, even though surveys indicate that the majority of neurosurgeons use it in less than 25% of cases. A 2012 retrospective review found that the patients who were decompressed were likely to have a more severe pathology and be more comatose, which likely influenced the somewhat discouraging mortality data for that group.
The complications of decompressive craniectomy are well summarised in an article by Margules and Jallo. I will present them as a list:
Cooper, D. James, et al. "Decompressive craniectomy in diffuse traumatic brain injury." New England Journal of Medicine 364.16 (2011): 1493-1502.
Hutchinson, Peter J., et al. "Trial of decompressive craniectomy for traumatic intracranial hypertension." New England Journal of Medicine 375.12 (2016): 1119-1130.
Vahedi, Katayoun, et al. "Sequential-design, multicenter, randomized, controlled trial of early decompressive craniectomy in malignant middle cerebral artery infarction (DECIMAL Trial)." Stroke 38.9 (2007): 2506-2517.
Hofmeijer, Jeannette, et al. "Surgical decompression for space-occupying cerebral infarction (the Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial [HAMLET]): a multicentre, open, randomised trial." The Lancet Neurology 8.4 (2009): 326-333.
Jüttler, Eric, et al. "Decompressive surgery for the treatment of malignant infarction of the middle cerebral artery (DESTINY) a randomized, controlled trial." Stroke 38.9 (2007): 2518-2525.
Lee, Kyeong Woo, et al. "Functional Outcomes of Patients with Severe MCA Infarction after Decompressive Craniectomy." Brain & Neurorehabilitation 7.1 (2014): 48-53.
Tuzgen, Saffet, et al. "Decompressive craniectomy in patients with cerebral
infarction due to malignant vasospasm after aneurysmal subarachnoid hemorrhage." Journal of neurosciences in rural practice 3.3 (2012): 251.
Murthy, J. M. K., et al. "Decompressive craniectomy with clot evacuation in large hemispheric hypertensive intracerebral hemorrhage." Neurocritical care 2.3 (2005): 258-262.
Güresir, Erdem, et al. "Decompressive craniectomy in subarachnoid hemorrhage." Neurosurgical focus 26.6 (2009): E4.
Keller, E., et al. "Decompressive craniectomy in severe cerebral venous and dural sinus thrombosis." New Trends of Surgery for Stroke and its Perioperative Management. Springer Vienna, 2005. 177-183.
Schirmer, Clemens M., Daniel A. Hoit, and Adel M. Malek. "Decompressive hemicraniectomy for the treatment of intractable intracranial hypertension after aneurysmal subarachnoid hemorrhage." Stroke 38.3 (2007): 987-992.
Adamo, Matthew A., and Eric M. Deshaies. "Emergency decompressive craniectomy for fulminating infectious encephalitis." (2008). Journal of Neurosurgery January 2008 / Vol. 108 / No. 1 / Pages 174-176
Hutchinson, Peter, Ivan Timofeev, and Peter Kirkpatrick. "Surgery for brain edema." Neurosurgical focus 22.5 (2007): 1-9.
Margules, Andrew, and Jack Jallo. "Complications of decompressive craniectomy." JHN Journal 5.1 (2010): 4.
Chu, Stacy Y., and Kevin N. Sheth. "Decompressive Craniectomy in Neurocritical Care." Current treatment options in neurology 17.2 (2015): 1-11.
Kolias, Angelos G., et al. "Primary decompressive craniectomy for acute subdural haematomas: results of an international survey." Acta neurochirurgica154.9 (2012): 1563-1565.
Li, Lucia M., et al. "Outcome following evacuation of acute subdural haematomas: a comparison of craniotomy with decompressive craniectomy."Acta neurochirurgica 154.9 (2012): 1555-1561.
Uozumi, Yoichi, et al. "Decompressive craniectomy in patients with aneurysmal subarachnoid hemorrhage: a single-center matched-pair analysis" Cerebrovasc Dis 37 (2014): 109-115.
Takeuchi, Satoru, et al. "Decompressive craniectomy for arteriovenous malformation-related intracerebral hemorrhage." Journal of clinical neuroscience: official journal of the Neurosurgical Society of Australasia (2015).
Takeuchi, Satoru, et al. "Decompressive craniectomy with hematoma evacuation for large hemispheric hypertensive intracerebral hemorrhage." Brain Edema XV. Springer Vienna, 2013. 277-279.
Coutinho, Jonathan M., et al. "Decompressive hemicraniectomy in cerebral sinus thrombosis consecutive case series and review of the literature." Stroke40.6 (2009): 2233-2235.
Raza, Emmon, et al. "Decompressive Surgery for Malignant Cerebral Venous Sinus Thrombosis: A Retrospective Case Series from Pakistan and Comparative Literature Review." Journal of Stroke and Cerebrovascular Diseases 23.1 (2014): e13-e22.
Sonuca, Dekompresif Kraniektominin. "Effect of early bilateral decompressive craniectomy on outcome for severe traumatic brain injury." Turkish neurosurgery 20.3 (2010): 382-389.
Crudele et al. "Decompressive Hemicraniectomy in Acute Neurological Diseases." Journal of Intensive Care Medicine 2016;31(9):587–596
Quinn, T. M., et al. "Decompressive craniectomy." Acta Neurologica Scandinavica 123.4 (2011): 239-244.
Torres, Roland. "DECRA… Where do we go from here?." Surgical neurology international 3 (2012).
Muñoz, Javier, et al. "Primary decompressive craniectomy in neurocritical patients. a meta-analysis of randomized controlled trials, cohort and case-control studies." Journal of Emergency and Critical Care Medicine 2.9 (2018).