Long-term outcome following decompressive craniectomy: an inconvenient truth?

PURPOSE OF REVIEW: There is little doubt that decompressive craniectomy can reduce mortality following malignant middle cerebral infarction or severe traumatic brain injury. However, the concern has always been that the reduction in mortality comes at the cost of an increase in the number of survivors with severe neurological disability. RECENT FINDINGS: There has been a number of large multicentre randomized trials investigating surgical efficacy of the procedure. These trials have clearly demonstrated a survival benefit in those patients randomized to surgical decompression. However, it is only possible to demonstrate an improvement in outcome if the definition of favourable is changed such that it includes patients with either a modified Rankin score of 4 or upper severe disability. Without this recategorization, the results of these trials have confirmed the 'Inconvenient truth' that surgery reduces mortality at the expense of survival with severe disability. SUMMARY: Given these results, the time may have come for a nuanced examination of the value society places on an individual life, and the acceptability or otherwise of performing a procedure that converts death into survival with severe disability.

Uncertainty, conflict and consent: revisiting the futility debate in neurotrauma.

The concept of futility has been debated for many years, and a precise definition remains elusive. This is not entirely unsurprising given the increasingly complex and evolving nature of modern medicine. Progressively more complex decisions are required when considering increasingly sophisticated diagnostic and therapeutic interventions. Allocating resources appropriately amongst a population whose expectations continue to increase raises a number of ethical issues not least of which are the difficulties encountered when consideration is being given to withholding "life-preserving" treatment. In this discussion we have used decompressive craniectomy for severe traumatic brain injury as a clinical example with which to frame an approach to the concept. We have defined those issues that initially lead us to consider futility and thereafter actually provoke a significant discussion. We contend that these issues are uncertainty, conflict and consent. We then examine recent scientific advances in outcome prediction that may address some of the uncertainty and perhaps help achieve consensus amongst stakeholders. Whilst we do not anticipate that this re-framing of the idea of futility is applicable to all medical situations, the approach to specify patient-centred benefit may assist those making such decisions when patients are incompetent to participate.

Long-term survival with unfavourable outcome: a qualitative and ethical analysis.

OBJECTIVE: To assess the issue of 'retrospective consent' among a cohort of patients who had survived with unfavourable outcome and to assess attitudes among next of kin regarding their role as surrogate decision makers. METHODS: Twenty patients who had survived for at least 3 years with an unfavourable outcome following a decompressive craniectomy for severe traumatic brain injury were assessed with their next of kin. During the course of a semistructured interview, participants were asked whether they would have provided consent if they had known their eventual outcome. They were also asked for general comments regarding all aspects of the clinical journey. Eighteen patients had next of kin who were available for interview. For two patients, there was no longer any family involvement. RESULTS: Of the 20 patients, 13 were able to provide a response and 11 felt that they would have provided consent even if they had known their eventual outcome. Of the 18 next of kin who were able to express an opinion, 10 felt that they would have provided retrospective consent. CONCLUSIONS: Many patients appeared to have adapted to a level of disability that competent individuals might deem unacceptable. This does not necessarily mean that such outcomes should be regarded as 'favourable', nor that decompressive craniectomy must be performed for patients with predicted poor outcome. Nevertheless, those burdened with the initial clinical decisions and thereafter the long-term care of these patients may draw some support from the knowledge that unfavourable may not necessarily be unacceptable.

Validation of the CRASH model in the prediction of 18-month mortality and unfavorable outcome in severe traumatic brain injury requiring decompressive craniectomy.

OBJECT: The goal in this study was to assess the validity of the corticosteroid randomization after significant head injury (CRASH) collaborators prediction model in predicting mortality and unfavorable outcome at 18 months in patients with severe traumatic brain injury (TBI) requiring decompressive craniectomy. In addition, the authors aimed to assess whether this model was well calibrated in predicting outcome across a wide spectrum of severity of TBI requiring decompressive craniectomy. METHODS: This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia between 2004 and 2012 and for whom 18-month follow-up data were available. Clinical and radiological data on initial presentation were entered into the Web-based model and the predicted outcome was compared with the observed outcome. In validating the CRASH model, the authors used area under the receiver operating characteristic curve to assess the ability of the CRASH model to differentiate between favorable and unfavorable outcomes. RESULTS: The ability of the CRASH 6-month unfavorable prediction model to differentiate between unfavorable and favorable outcomes at 18 months after decompressive craniectomy was good (area under the receiver operating characteristic curve 0.85, 95% CI 0.80-0.90). However, the model's calibration was not perfect. The slope and the intercept of the calibration curve were 1.66 (SE 0.21) and -1.11 (SE 0.14), respectively, suggesting that the predicted risks of unfavorable outcomes were not sufficiently extreme or different across different risk strata and were systematically too high (or overly pessimistic), respectively. CONCLUSIONS: The CRASH collaborators prediction model can be used as a surrogate index of injury severity to stratify patients according to injury severity. However, clinical decisions should not be based solely on the predicted risks derived from the model, because the number of patients in each predicted risk stratum was still relatively small and hence the results were relatively imprecise. Notwithstanding these limitations, the model may add to a clinician's ability to have better-informed conversations with colleagues and patients' relatives about prognosis.

Futility in neurosurgery: a patient-centered approach.

The concept of futility has been a source of discussion for many years. Even though it is tempting to propose that an action or clinical intervention should be deemed futile if it does not achieve the goals of that action, further clarification is needed in terms of the nature of the likely outcomes of an intervention and the probabilities of various outcomes being achieved. The outcome, in an age of balance between autonomy and necessity, should, at a minimum, be acceptable to the person on whom the intervention is to be performed. This is especially the case when considering outcome following decompressive craniectomy for severe traumatic brain injury, in which certain outcomes are likely to be severely impaired states that the patient would consider unacceptable. In this article, we use some key ethical concepts such as substantial benefit and the risk of unbearable badness to explore the concept of futility in severe traumatic brain injury and, by linking that to recent advances in neurosurgical science, propose a pragmatic patient-centered approach to deal with the concept of futility.

Cost-effectiveness of decompressive craniectomy as a lifesaving rescue procedure for patients with severe traumatic brain injury.

BACKGROUND: Decompressive craniectomy has been traditionally used as a lifesaving rescue procedure for patients with refractory intracranial hypertension after severe traumatic brain injury (TBI), but its cost-effectiveness remains uncertain. METHODS: Using data on length of stay in hospital, rehabilitation facility, procedural costs, and Glasgow Outcome Scale (GOS) up to 18 months after surgery, the average total hospital costs per life-year and quality-adjusted life-year (QALY) were calculated for patients who had decompressive craniectomy for TBI between 2004 and 2010 in Western Australia. The Corticosteroid Randomisation After Significant Head Injury prediction model was used to quantify the severity of TBI. RESULTS: Of the 168 patients who had 18-month follow-up data available after the procedure, 70 (42%) achieved a good outcome (GOS-5), 27 (16%) had moderate disability (GOS-4), 34 (20%) had severe disability (GOS-3), 5 (3%) were in vegetative state (GOS-2), and 32 (19%) died (GOS-1). The hospital costs increased with the severity of TBI and peaked when the predicted risk of an unfavorable outcome was about 80%. The average cost per life-year gained (US$671,000 per life-year) and QALY (US$682,000 per QALY) increased substantially and became much more than the usual acceptable cost-effective limit (US$100,000 per QALY) when the predicted risk of an unfavorable outcome was >80%. Changing different underlying assumptions of the analysis did not change the results significantly. CONCLUSIONS: Severity of TBI had an important effect on cost-effectiveness of decompressive craniectomy. As a lifesaving procedure, decompressive craniectomy was not cost-effective for patients with extremely severe TBI.

Decompressive craniectomy for diffuse cerebral swelling after trauma: long-term outcome and ethical considerations.

BACKGROUND: There is currently much interest in the use of decompressive for the management of diffuse cerebral swelling after trauma. Although the use of the procedure may improve survival, some of those survivors may be left severely disabled. The aim of this study was to see whether severe disability can be predicted and discuss the difficult ethical issue that this raises. METHODS: This was a retrospective cohort subgroup analysis of those patients with severe head injury in Western Australia between 2004 and 2008 who had had a decompressive craniectomy for intractably raised intracranial pressure despite maximal medical management. RESULTS: Among a total of 1,786 adult neurotrauma patients admitted between 2004 and 2008, 74 patients required a bifrontal decompressive craniectomy for intractably raised intracranial pressure. After the application of Corticosteroid Randomization After Significant Head Injury (CRASH) trial collaborators' prediction model, predicted and observed outcomes were compared. The mean timing and median timing of surgery were 42 hours and 30 hours after hospital admission, respectively. The timing of decompressive craniectomy was inversely correlated to the severity of the head injury (Spearman's correlation coefficient = -0.251, p = 0.031). At 18-month follow-up, 16 patients were deceased, 3 were in a persistent vegetative state, and 10 were severely disabled. In contrast to these unfavorable outcomes, 35 patients had a good outcome and 10 were moderately disabled at 18 months. The discrimination of the CRASH prediction model was excellent (area under receiver-operating characteristic curve, 0.905; 95% confidence interval, 0.829-0.982; p = 0.001). CONCLUSION: Our data provide some evidence that the CRASH prediction model may help clinicians and families to make informed decision about the benefits and risks of decompressive craniectomy for diffuse cerebral swelling.

Surgical intervention for severe head injury: ethical considerations when performing life-saving but non-restorative surgery.

BACKGROUND: The aim of this study was to compare the predicted outcome with observed outcome in those patients who have had a unilateral decompressive craniectomy following evacuation of an intracranial mass lesion and to consider some of the ethical issues that need to be addressed when performing life-saving but non-restorative surgery. METHODS: By using the web-based outcome prediction model developed by the CRASH trial collaborators predicted and observed outcomes were compared for those patients who had had a unilateral decompression after evacuation of a mass lesion in the two major neurotrauma hospitals in Western Australia between 2004 and 2008. Three cases were selected with differing outcome predictions. RESULTS: For the three selected cases the predicted risk of an unfavourable outcome at 6 months was 65.8%, 78.9% and 91.3%, respectively. For the 11 patients in this cohort with an outcome prediction between 61% and 70%, the observed outcome at 18 months (GOS) was: 5 had a good outcome, 4 were moderately disabled, and 3 were severely disabled. For the ten patients with an outcome prediction between 90-100%, observed outcome confirmed: one patient was moderately disabled, four patients were severely disabled, one patient was in a permanent vegetative state, and four patients had died. CONCLUSION: As the index of injury severity (as adjudged by the CRASH outcome prediction model) increases, clinical decision making and discussion with surrogates must reflect the evidence provided by observed outcome, prior to life-saving but potentially non-restorative decompressive surgery.

Observed versus predicted outcome for decompressive craniectomy: a population-based study.

A number of studies have shown that decompressive craniectomy can reduce intracranial pressure and may improve outcome for patients with severe head injury. This cohort study assessed the long-term outcome of neurotrauma patients who had a decompressive craniectomy for severe head injury in Western Australia between 2004 and 2008. The web-based outcome prediction model developed by the CRASH trial collaborators was applied to the cohort. Predicted outcome and observed outcome were compared. Characteristics of outcome between those who had had a unilateral and those who had had a bilateral decompressive procedure were compared. All complications were recorded. Among a total of 1,786 adult neurotrauma patients admitted during the study period, 147 patients (8.2%) had a decompressive craniectomy. A significant proportion of patients who required unilateral (37.3%) and bilateral (46.5%) craniectomy were able to return to work or study at 18 months after the injury. The patients who required bilateral craniectomy more likely to be associated with an unfavorable outcome (Glasgow Outcome Scale score >or=3) than those who had unilateral craniectomy (odds ratio 4.42; 95% confidence interval 1.16,16.81; p = 0.029), after adjusting for the timing of surgery, mechanism of injury, and the predicted risk of unfavorable outcome. The functional outcome after either unilateral or bilateral decompressive craniectomy was significantly better than that predicted by the CRASH head injury prediction model when the predicted risk was less than 80%. This study has demonstrated that in Western Australia decompressive craniectomy is a relatively common surgical procedure for the management of neurotrauma. A significant proportion of patients had a better-than-predicted long-term functional outcome.

Decompressive craniectomy for neurotrauma: the limitations of applying an outcome prediction model.

BACKGROUND: There is currently much interest in the use of decompressive craniectomy for patients with severe head injury. A number of studies have demonstrated that not only can the technique lower intracranial pressure but can also improve outcome. Whilst many patients who would otherwise have died or had a poor outcome now go on to make a good recovery, there is little doubt that complications can have a very significant impact on long term outcome. METHODS: By using the corticosteroid randomisation after significant head injury (CRASH) collaborators outcome prediction model, three patients were selected who had a similar outcome prediction. All three patients developed intracranial hypertension following trauma and had a decompressive craniectomy. RESULTS: Despite having a similar outcome prediction only one patient made an uneventful recovery. The remaining two patients suffered significant complications. CONCLUSIONS: This report illustrates the potential clinical applications and limitations of an outcome prediction model and demonstrates the impact that complications can have on eventual outcome.

The subjective brain, identity, and neuroethics.

The human brain is subjective and reflects the life of a being-in-the-world-with-others whose identity reflects that complex engaged reality. Human subjectivity is shaped and in-formed (formed by inner processes) that are adapted to the human life-world and embody meaning and the relatedness of a human being. Questions of identity relate to this complex and dynamic reality to reflect the fact that biology, human ecology, culture, and one's historic-political situation are inscribed in one's neural network and have configured its architecture so that it is a unique and irreplaceable phenomenon. So much is a human individual a relational being whose own understanding and ownership of his or her life is both situated and distinctive that neurophilosophical conceptions of identity and human activity that neglect these features of our being are quite inadequate to ground a robust neuroethics.

The retrospective application of a prediction model to patients who have had a decompressive craniectomy for trauma.

There is currently a resurgence of interest in the use of decompressive craniectomy. As the procedure is used more frequently, there may be an increasing number of patients surviving a severe traumatic brain injury with severe neurological impairment. The aim of this study was to determine if we could predict those cases that fall into this category. We used the web-based prediction model prepared by the CRASH collaborators and applied it to a cohort of patients who had a decompressive craniectomy in 2006 and 2007 at the two major trauma hospitals in Western Australia. All clinical and radiological data were reviewed and entered into the model, and predicted outcome and actual outcome were compared. Our analysis indicated that a significant cut-off point appeared at which the model predicted a 75% risk of an unfavorable outcome at 6 months; 19 of 27 patients with CRASH scores <75% returned to work, whereas none of the 14 patients with higher scores achieved this degree of rehabilitation at 18 months. Statistical analysis of the outcomes in our cohort confirmed that the CRASH model reliably predicted unfavorable outcome. This study demonstrated that our ability to predict poor outcome has improved.

Ethics, stem cells and spinal cord repair.

Attempted repair of human spinal cord injury by transplantation of stem cells depends on complex biological interactions between the host and graft. Extrapolating results from experimental therapy in animals to humans with spinal cord injury requires great caution. There is great pressure on surgeons to transplant stem cells into humans with spinal cord injury. However, as the efficacy of and exact indications for this therapy are still uncertain, and morbidity (such as rejection or late tumour development) may result, only carefully designed studies based on sound experimental work which attempts to eliminate placebo effects should proceed. Premature application of stem cell transplantation in humans with spinal cord injury should be discouraged.