Cost-effectiveness of craniotomy versus decompressive craniectomy for UK patients with traumatic acute subdural haematoma.

OBJECTIVE: To estimate the cost-effectiveness of craniotomy, compared with decompressive craniectomy (DC) in UK patients undergoing evacuation of acute subdural haematoma (ASDH). DESIGN: Economic evaluation undertaken using health resource use and outcome data from the 12-month multicentre, pragmatic, parallel-group, randomised, Randomised Evaluation of Surgery with Craniectomy for Patients Undergoing Evacuation-ASDH trial. SETTING: UK secondary care. PARTICIPANTS: 248 UK patients undergoing surgery for traumatic ASDH were randomised to craniotomy (N=126) or DC (N=122). INTERVENTIONS: Surgical evacuation via craniotomy (bone flap replaced) or DC (bone flap left out with a view to replace later: cranioplasty surgery). MAIN OUTCOME MEASURES: In the base-case analysis, costs were estimated from a National Health Service and Personal Social Services perspective. Outcomes were assessed via the quality-adjusted life-years (QALY) derived from the EuroQoL 5-Dimension 5-Level questionnaire (cost-utility analysis) and the Extended Glasgow Outcome Scale (GOSE) (cost-effectiveness analysis). Multiple imputation and regression analyses were conducted to estimate the mean incremental cost and effect of craniotomy compared with DC. The most cost-effective option was selected, irrespective of the level of statistical significance as is argued by economists. RESULTS: In the cost-utility analysis, the mean incremental cost of craniotomy compared with DC was estimated to be -£5520 (95% CI -£18 060 to £7020) with a mean QALY gain of 0.093 (95% CI 0.029 to 0.156). In the cost-effectiveness analysis, the mean incremental cost was estimated to be -£4536 (95% CI -£17 374 to £8301) with an OR of 1.682 (95% CI 0.995 to 2.842) for a favourable outcome on the GOSE. CONCLUSIONS: In a UK population with traumatic ASDH, craniotomy was estimated to be cost-effective compared with DC: craniotomy was estimated to have a lower mean cost, higher mean QALY gain and higher probability of a more favourable outcome on the GOSE (though not all estimated differences between the two approaches were statistically significant). ETHICS: Ethical approval for the trial was obtained from the North West-Haydock Research Ethics Committee in the UK on 17 July 2014 (14/NW/1076). TRIAL REGISTRATION NUMBER: ISRCTN87370545.

Decompressive Craniectomy versus Craniotomy for Acute Subdural Hematoma.

BACKGROUND: Traumatic acute subdural hematomas frequently warrant surgical evacuation by means of a craniotomy (bone flap replaced) or decompressive craniectomy (bone flap not replaced). Craniectomy may prevent intracranial hypertension, but whether it is associated with better outcomes is unclear. METHODS: We conducted a trial in which patients undergoing surgery for traumatic acute subdural hematoma were randomly assigned to undergo craniotomy or decompressive craniectomy. An inclusion criterion was a bone flap with an anteroposterior diameter of 11 cm or more. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOSE) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 12 months. Secondary outcomes included the GOSE rating at 6 months and quality of life as assessed by the EuroQol Group 5-Dimension 5-Level questionnaire (EQ-5D-5L). RESULTS: A total of 228 patients were assigned to the craniotomy group and 222 to the decompressive craniectomy group. The median diameter of the bone flap was 13 cm (interquartile range, 12 to 14) in both groups. The common odds ratio for the differences across GOSE ratings at 12 months was 0.85 (95% confidence interval, 0.60 to 1.18; P = 0.32). Results were similar at 6 months. At 12 months, death had occurred in 30.2% of the patients in the craniotomy group and in 32.2% of those in the craniectomy group; a vegetative state occurred in 2.3% and 2.8%, respectively, and a lower or upper good recovery occurred in 25.6% and 19.9%. EQ-5D-5L scores were similar in the two groups at 12 months. Additional cranial surgery within 2 weeks after randomization was performed in 14.6% of the craniotomy group and in 6.9% of the craniectomy group. Wound complications occurred in 3.9% of the craniotomy group and in 12.2% of the craniectomy group. CONCLUSIONS: Among patients with traumatic acute subdural hematoma who underwent craniotomy or decompressive craniectomy, disability and quality-of-life outcomes were similar with the two approaches. Additional surgery was performed in a higher proportion of the craniotomy group, but more wound complications occurred in the craniectomy group. (Funded by the National Institute for Health and Care Research; RESCUE-ASDH ISRCTN Registry number, ISRCTN87370545.).

Evaluation of Outcomes Among Patients With Traumatic Intracranial Hypertension Treated With Decompressive Craniectomy vs Standard Medical Care at 24 Months: A Secondary Analysis of the RESCUEicp Randomized Clinical Trial.

Importance: Trials often assess primary outcomes of traumatic brain injury at 6 months. Longer-term data are needed to assess outcomes for patients receiving surgical vs medical treatment for traumatic intracranial hypertension. Objective: To evaluate 24-month outcomes for patients with traumatic intracranial hypertension treated with decompressive craniectomy or standard medical care. Design, Setting, and Participants: Prespecified secondary analysis of the Randomized Evaluation of Surgery With Craniectomy for Uncontrollable Elevation of Intracranial Pressure (RESCUEicp) randomized clinical trial data was performed for patients with traumatic intracranial hypertension (>25 mm Hg) from 52 centers in 20 countries. Enrollment occurred between January 2004 and March 2014. Data were analyzed between 2018 and 2021. Eligibility criteria were age 10 to 65 years, traumatic brain injury (confirmed via computed tomography), intracranial pressure monitoring, and sustained and refractory elevated intracranial pressure for 1 to 12 hours despite pressure-controlling measures. Exclusion criteria were bilateral fixed and dilated pupils, bleeding diathesis, or unsurvivable injury. Interventions: Patients were randomly assigned 1:1 to receive a decompressive craniectomy with standard care (surgical group) or to ongoing medical treatment with the option to add barbiturate infusion (medical group). Main Outcomes and Measures: The primary outcome was measured with the 8-point Extended Glasgow Outcome Scale (1 indicates death and 8 denotes upper good recovery), and the 6- to 24-month outcome trajectory was examined. Results: This study enrolled 408 patients: 206 in the surgical group and 202 in the medical group. The mean (SD) age was 32.3 (13.2) and 34.8 (13.7) years, respectively, and the study population was predominantly male (165 [81.7%] and 156 [80.0%], respectively). At 24 months, patients in the surgical group had reduced mortality (61 [33.5%] vs 94 [54.0%]; absolute difference, -20.5 [95% CI, -30.8 to -10.2]) and higher rates of vegetative state (absolute difference, 4.3 [95% CI, 0.0 to 8.6]), lower or upper moderate disability (4.7 [-0.9 to 10.3] vs 2.8 [-4.2 to 9.8]), and lower or upper severe disability (2.2 [-5.4 to 9.8] vs 6.5 [1.8 to 11.2]; χ27 = 24.20, P = .001). For every 100 individuals treated surgically, 21 additional patients survived at 24 months; 4 were in a vegetative state, 2 had lower and 7 had upper severe disability, and 5 had lower and 3 had upper moderate disability, respectively. Rates of lower and upper good recovery were similar for the surgical and medical groups (20 [11.0%] vs 19 [10.9%]), and significant differences in net improvement (≥1 grade) were observed between 6 and 24 months (55 [30.0%] vs 25 [14.0%]; χ22 = 13.27, P = .001). Conclusions and Relevance: At 24 months, patients with surgically treated posttraumatic refractory intracranial hypertension had a sustained reduction in mortality and higher rates of vegetative state, severe disability, and moderate disability. Patients in the surgical group were more likely to improve over time vs patients in the medical group. Trial Registration: ISRCTN Identifier: 66202560.

Shunt performance in 349 patients with hydrocephalus after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH) is a common sequelae leading to poorer neurological outcomes and predisposing to various complications. METHODS: A total of 2191 consecutive patients with aSAH were acutely admitted to the Neurointensive Care at the Kuopio University Hospital between 1990 and 2018 from a defined population. A total of 349 (16%) aSAH patients received a ventriculoperitoneal shunt, 101 with an adjustable valve (2012-2018), 232 with a fixed pressure valve (1990-2011), and 16 a valveless shunt (2010-2013). Clinical timelines were reconstructed from the hospital records and nationwide registries until death (n = 120) or June 2019. RESULTS: Comparing the adjustable valves vs. the fixed pressure valves vs. the valveless shunts, intraventricular hemorrhage was present in 61%, 44% and 100%, respectively. The median times to the shunt were 7 days vs. 38 days vs. 10 days. The rates of the first revision were 25% vs. 32% vs. 69%. The causes included infection in 11% vs. 7% vs. 25% and overdrainage in 1% vs. 4% vs. 31%. The valveless shunt was the only independent risk factor (HR 2.9) for revision. After the first revision, more revisions were required in 48% vs. 52% vs. 45%. CONCLUSIONS: The protocol to shunt evolved over time to favor earlier shunt. In post-aSAH hydrocephalus, adjustable valve shunts, without anti-siphon device, can be installed at an early phase after aSAH, in spite of intraventricular blood, with a modest risk (25%) of revision. Valveless shunts are not recommendable due to high risk of revisions.

Integration of paper microfluidic sensors into contact lenses for tear fluid analysis.

In this article, using the integration of paper microfluidics within laser-inscribed commercial contact lenses, we demonstrate the multiplexed detection of clinically relevant analytes including hydrogen ions, proteins, glucose, nitrites and l-ascorbic acid, all sampled directly from model tears. In vitro measurements involved the optimization of colorimetric assays, with readouts collected, stored and analyzed using a bespoke Tears Diagnostics smartphone application prototype. We demonstrate the potential of the device to perform discrete measurements either for medical diagnosis or disease screening in the clinic or at the point-of-care (PoC), with future applications including monitoring of ocular infections, uveitis, diabetes, keratopathies and assessing oxidative stress.

Observations on the Cerebral Effects of Refractory Intracranial Hypertension After Severe Traumatic Brain Injury.

BACKGROUND: Raised intracranial pressure (ICP) is a prominent cause of morbidity and mortality after severe traumatic brain injury (TBI). However, in the clinical setting, little is known about the cerebral physiological response to severe and prolonged increases in ICP. METHODS: Thirty-three severe TBI patients from a single center who developed severe refractory intracranial hypertension (ICP > 40 mm Hg for longer than 1 h) with ICP, arterial blood pressure, and brain tissue oxygenation (PBTO2) monitoring (subcohort, n = 9) were selected for retrospective review. Secondary parameters reflecting autoregulation (including pressure reactivity index-PRx, which was available in 24 cases), cerebrospinal compensatory reserve (RAP), and ICP pulse amplitude were calculated. RESULTS: PRx deteriorated from 0.06 ± 0.26 a.u. at baseline levels of ICP to 0.57 ± 0.24 a.u. (p < 0.0001) at high levels of ICP (> 50 mm Hg). In 4 cases, PRx was impaired (> 0.25 a.u.) before ICP was raised above 25 mm Hg. Concurrently, PBTO2 decreased from 27.3 ± 7.32 mm Hg at baseline ICP to 12.68 ± 7.09 mm Hg at high levels of ICP (p < 0.001). The pulse amplitude of the ICP waveform increased with increasing ICP but showed an 'upper breakpoint'-whereby further increases in ICP lead to decreases in pulse amplitude-in 6 out of the 33 patients. DISCUSSION: Severe intracranial hypertension after TBI leads to decreased brain oxygenation, impaired pressure reactivity, and changes in the pulse amplitude of ICP. Impaired pressure reactivity may denote increased risk of developing refractory intracranial hypertension in some patients.

Feasibility of Hidden Markov Models for the Description of Time-Varying Physiologic State After Severe Traumatic Brain Injury.

OBJECTIVES: Continuous assessment of physiology after traumatic brain injury is essential to prevent secondary brain insults. The present work aims at the development of a method for detecting physiologic states associated with the outcome from time-series physiologic measurements using a hidden Markov model. DESIGN: Unsupervised clustering of hourly values of intracranial pressure/cerebral perfusion pressure, the compensatory reserve index, and autoregulation status was attempted using a hidden Markov model. A ternary state variable was learned to classify the patient's physiologic state at any point in time into three categories ("good," "intermediate," or "poor") and determined the physiologic parameters associated with each state. SETTING: The proposed hidden Markov model was trained and applied on a large dataset (28,939 hr of data) using a stratified 20-fold cross-validation. PATIENTS: The data were collected from 379 traumatic brain injury patients admitted to Addenbrooke's Hospital, Cambridge between 2002 and 2016. INTERVENTIONS: Retrospective observational analysis. MEASUREMENTS AND MAIN RESULTS: Unsupervised training of the hidden Markov model yielded states characterized by intracranial pressure, cerebral perfusion pressure, compensatory reserve index, and autoregulation status that were physiologically plausible. The resulting classifier retained a dose-dependent prognostic ability. Dynamic analysis suggested that the hidden Markov model was stable over short periods of time consistent with typical timescales for traumatic brain injury pathogenesis. CONCLUSIONS: To our knowledge, this is the first application of unsupervised learning to multidimensional time-series traumatic brain injury physiology. We demonstrated that clustering using a hidden Markov model can reduce a complex set of physiologic variables to a simple sequence of clinically plausible time-sensitive physiologic states while retaining prognostic information in a dose-dependent manner. Such states may provide a more natural and parsimonious basis for triggering intervention decisions.

The Evolution of the Role of External Ventricular Drainage in Traumatic Brain Injury.

External ventricular drains (EVDs) are commonly used in neurosurgery in different conditions but frequently in the management of traumatic brain injury (TBI) to monitor and/or control intracranial pressure (ICP) by diverting cerebrospinal fluid (CSF). Their clinical effectiveness, when used as a therapeutic ICP-lowering procedure in contemporary practice, remains unclear. No consensus has been reached regarding the drainage strategy and optimal timing of insertion. We review the literature on EVDs in the setting of TBI, discussing its clinical indications, surgical technique, complications, clinical outcomes, and economic considerations.

Twenty-Five Years of Intracranial Pressure Monitoring After Severe Traumatic Brain Injury: A Retrospective, Single-Center Analysis.

BACKGROUND: Intracranial pressure (ICP) is a clinically important variable after severe traumatic brain injury (TBI) and has been monitored, along with clinical outcome, for over 25 yr in Addenbrooke's hospital, Cambridge, United Kingdom. This time period has also seen changes in management strategies with the implementation of protocolled specialist neurocritical care, expansion of neuromonitoring techniques, and adjustments of clinical treatment targets. OBJECTIVE: To describe the changes in intracranial monitoring variables over the past 25 yr. METHODS: Data from 1146 TBI patients requiring ICP monitoring were analyzed. Monitored variables included ICP, cerebral perfusion pressure (CPP), and the cerebral pressure reactivity index (PRx). Data were stratified into 5-yr epochs spanning the 25 yr from 1992 to 2017. RESULTS: CPP increased sharply with specialist neurocritical care management (P < 0.0001) (introduction of a specific TBI management algorithm) before stabilizing from 2000 onwards. ICP decreased significantly over the 25 yr of monitoring from an average of 19 to 12 mmHg (P < 0.0001) but PRx remained unchanged. The mean number of ICP plateau waves and the number of patients developing refractory intracranial hypertension both decreased significantly. Mortality did not significantly change in the cohort (22%). CONCLUSION: We demonstrate the evolving trends in neurophysiological monitoring over the past 25 yr from a single, academic neurocritical care unit. ICP and CPP were responsive to the introduction of an ICP/CPP protocol while PRx has remained unchanged.

The current status of decompressive craniectomy in traumatic brain injury.

PURPOSE: This review describes the evidence base that has helped define the role of decompressive craniectomy (DC) in the management of patients with traumatic brain injury (TBI). RECENT FINDINGS: The publication of two randomized trials (DECRA and RESCUEicp) has strengthened the evidence base. The DECRA trial showed that neuroprotective bifrontal DC for moderate intracranial hypertension is not helpful, whereas the RESCUEicp trial found that last-tier DC for severe and refractory intracranial hypertension can significantly reduce the mortality rate but is associated with a higher rate of disability. These findings have reopened the debate about 1) the indications for DC in various TBI subtypes, 2) alternative techniques (e.g. hinge craniotomy), 3) optimal time and material for cranial reconstruction, and 4) the role of shared decision-making in TBI care. Additionally, the role of primary DC when evacuating an acute subdural hematoma is currently undergoing evaluation in the context of the RESCUE-ASDH randomized trial. SUMMARY: This review provides an overview of the current evidence base, discusses its limitations and presents a global perspective on the role of DC, as there is growing recognition that attention should also focus on low- and middle-income countries due to their much greater TBI burden.

A closed system irrigation & drainage technique for surgical evacuation of chronic subdural haematomas.

Background: Chronic subdural haematoma (CSDH), is a common neurosurgical disorder that is associated with morbidity and mortality affecting the ageing population. The aim is to present the treatment experience of CSDH patients treated with a technique that combines the classical single burr-hole irrigation and the continuous closed system drainage: The closed system irrigation & drainage (CSID) technique. Methods: The cases undergoing CSDH evacuation with the CSID method were captured over a 4-year period at a tertiary neurosurgical centre. The authors describe the performance of this methods with respect to post-operative clinical and radiological features, including recurrence rates, complications, and length of stay. Results: A total of 36 cases undergoing 42 CSID procedures (30 unilateral and 6 bilateral CSDHs) were performed, in cases ranging between 55-95 years old (median age 79 years). The rate of recurrence or significant ruminant blood in the subdural space on post-operative imaging was 11% (n=4). No cases of pneumocephalus were observed in this series (n=0). The mean (SD) skin-to-skin time for this procedure was 13.4 (4.4) minutes, with a mean (SD) length of stay of 4 (1.9) days. Conclusion: We conclude that the one burr-hole closed system irrigation and drainage technique with a sub-periosteal drain seems to be a simple, effective and safe procedure for treatment of CSDH. It's well tolerated under local anaesthesia for patients with high co-morbidities and these preliminary results indicated it may potentially be a better option for treatment of CSDH with a lower rate of post-operative complications.

Corrigendum: Glycemia Is Related to Impaired Cerebrovascular Autoregulation after Severe Pediatric Traumatic Brain Injury: A Retrospective Observational Study.

[This corrects the article on p. 205 in vol. 5, PMID: 28993802.].

Glycemia Is Related to Impaired Cerebrovascular Autoregulation after Severe Pediatric Traumatic Brain Injury: A Retrospective Observational Study.

INTRODUCTION: A strong association exists between hyperglycemia and outcome in pediatric traumatic brain injury (TBI). Herein, we describe observations of serum markers of glucose metabolism in a cohort of pediatric TBI patients and how these variables are related to parameters of intracranial pathophysiology. METHODS: A retrospective analysis was performed on pediatric severe TBI patients admitted to Addenbrookes Hospital Paediatric Intensive Care Unit (PICU) between January 2001 and December 2013. Demographic, outcome, systemic physiological, and cerebral autoregulatory data were extracted for patients who had received continuous invasive monitoring (ICM+, Cambridge Enterprise, Cambridge, UK). Data were analyzed using a mixed linear model. RESULTS: Forty-four patients with an average age of 12.2 years were admitted to the PICU with a TBI requiring invasive neurosurgical monitoring. Thirty-two patients (73%) survived, with favorable outcomes in 62%. The mean (SD) intracranial pressure (ICP) was 17.6 + 9.0 mmHg, MAP was 89.7 + 9.0 mmHg, and pressure-reactivity index (PRx) was -0.01 + 0.23 a.u. The mean (SD) serum lactate was 2.2 (3.3) mmol/L. and the mean (SD) serum glucose was 6.1 (1.6) mmol/L. Early hyperglycemia was strongly associated with both PRx (Pearson correlation 0.351, p < 0.001) and ICP (Pearson correlation 0.240, p = 0.002) death (p = 0.021) and impaired cerebral autoregulation (p = 0.02). There was a strong association between ICP and serum lactate (p = 0.001). CONCLUSION: Increases in systemic glucose are associated with impaired cerebrovasular autoregulation after severe pediatric TBI. Moreover, deranged blood glucose is a marker of poor prognosis. Further studies are required to delineate putative mechanisms of hyperglycemia induced cerebral harm.

Individualizing Thresholds of Cerebral Perfusion Pressure Using Estimated Limits of Autoregulation.

OBJECTIVES: In severe traumatic brain injury, cerebral perfusion pressure management based on cerebrovascular pressure reactivity index has the potential to provide a personalized treatment target to improve patient outcomes. So far, the methods have focused on identifying "one" autoregulation-guided cerebral perfusion pressure target-called "cerebral perfusion pressure optimal". We investigated whether a cerebral perfusion pressure autoregulation range-which uses a continuous estimation of the "lower" and "upper" cerebral perfusion pressure limits of cerebrovascular pressure autoregulation (assessed with pressure reactivity index)-has prognostic value. DESIGN: Single-center retrospective analysis of prospectively collected data. SETTING: The neurocritical care unit at a tertiary academic medical center. PATIENTS: Data from 729 severe traumatic brain injury patients admitted between 1996 and 2016 were used. Treatment was guided by controlling intracranial pressure and cerebral perfusion pressure according to a local protocol. INTERVENTIONS: None. METHODS AND MAIN RESULTS: Cerebral perfusion pressure-pressure reactivity index curves were fitted automatically using a previously published curve-fitting heuristic from the relationship between pressure reactivity index and cerebral perfusion pressure. The cerebral perfusion pressure values at which this "U-shaped curve" crossed the fixed threshold from intact to impaired pressure reactivity (pressure reactivity index = 0.3) were denoted automatically the "lower" and "upper" cerebral perfusion pressure limits of reactivity, respectively. The percentage of time with cerebral perfusion pressure below (%cerebral perfusion pressure < lower limit of reactivity), above (%cerebral perfusion pressure > upper limit of reactivity), or within these reactivity limits (%cerebral perfusion pressure within limits of reactivity) was calculated for each patient and compared across dichotomized Glasgow Outcome Scores. After adjusting for age, initial Glasgow Coma Scale, and mean intracranial pressure, percentage of time with cerebral perfusion pressure less than lower limit of reactivity was associated with unfavorable outcome (odds ratio %cerebral perfusion pressure < lower limit of reactivity, 1.04; 95% CI, 1.02-1.06; p < 0.001) and mortality (odds ratio, 1.06; 95% CI, 1.04-1.08; p < 0.001). CONCLUSIONS: Individualized autoregulation-guided cerebral perfusion pressure management may be a plausible alternative to fixed cerebral perfusion pressure threshold management in severe traumatic brain injury patients. Prospective randomized research will help define which autoregulation-guided method is beneficial, safe, and most practical.

Temporal profile of intracranial pressure and cerebrovascular reactivity in severe traumatic brain injury and association with fatal outcome: An observational study.

BACKGROUND: Both intracranial pressure (ICP) and the cerebrovascular pressure reactivity represent the dysregulation of pathways directly involved in traumatic brain injury (TBI) pathogenesis and have been used to inform clinical management. However, how these parameters evolve over time following injury and whether this evolution has any prognostic importance have not been studied. METHODS AND FINDINGS: We analysed the temporal profile of ICP and pressure reactivity index (PRx), examined their relation to TBI-specific mortality, and determined if the prognostic relevance of these parameters was affected by their temporal profile using mixed models for repeated measures of ICP and PRx for the first 240 hours from the time of injury. A total of 601 adults with TBI, admitted between September 2002 to January 2016, and with high-resolution continuous monitoring from a single centre, were studied. At 6 months postinjury, 133 (19%) patients had a fatal outcome; of those, 88 (78%) died from nonsurvivable TBI or brain death. The difference in mean ICP between those with a fatal outcome and functional survivors was only significant for the first 168 hours after injury (all p < 0.05). For PRx, those patients with a fatal outcome also had a higher (more impaired) PRx throughout the first 120 hours after injury (all p < 0.05). The separation of ICP and PRx was greatest in the first 72 hours after injury. Mixed models demonstrated that the explanatory power of the PRx decreases over time; therefore, the prognostic weight assigned to PRx should similarly decrease. However, the ability of ICP to predict a fatal outcome remained relatively stable over time. As control of ICP is the central purpose of TBI management, it is likely that some of the information that is reflected in the natural history of ICP changes is no longer apparent because of therapeutic intervention. CONCLUSIONS: We demonstrated the temporal evolution of ICP and PRx and their relationship with fatal outcome, indicating a potential early prognostic and therapeutic window. The combination of dynamic monitoring variables and their time profile improved prediction of outcome. Therefore, time-driven dynamic modelling of outcome in patients with severe TBI may allow for more accurate and clinically useful prediction models. Further research is needed to confirm and expand on these findings.

Survival Trends After Surgery for Acute Subdural Hematoma in Adults Over a 20-year Period.

OBJECTIVE: We sought to determine 30-day survival trends and prognostic factors following surgery for acute subdural hematomas (ASDHs) in England and Wales over a 20-year period. SUMMARY OF BACKGROUND DATA: ASDHs are still considered the most lethal type of traumatic brain injury. It remains unclear whether the adjusted odds of survival have improved significantly over time. METHODS: Using the Trauma Audit and Research Network (TARN) database, we analyzed ASDH cases in the adult population (>16 yrs) treated surgically between 1994 and 2013. Two thousand four hundred ninety-eight eligible cases were identified. Univariable and multiple logistic regression analyses were performed, using multiple imputation for missing data. RESULTS: The cohort was 74% male with a median age of 48.9 years. Over half of patients were comatose at presentation (53%). Mechanism of injury was due to a fall (<2 m 34%, >2 m 24%), road traffic collision (25%), and other (17%). Thirty-six per cent of patients presented with polytrauma. Gross survival increased from 59% in 1994 to 1998 to 73% in 2009 to 2013. Under multivariable analysis, variables independently associated with survival were year of injury, Glasgow Coma Scale, Injury Severity Score, age, and pupil reactivity. The time interval from injury to craniotomy and direct admission to a neurosurgical unit were not found to be significant prognostic factors. CONCLUSIONS: A significant improvement in survival over the last 20 years was observed after controlling for multiple prognostic factors. Prospective trials and cohort studies are expected to elucidate the distribution of functional outcome in survivors.

Risk of Shunting After Aneurysmal Subarachnoid Hemorrhage: A Collaborative Study and Initiation of a Consortium.

BACKGROUND AND PURPOSE: Shunt dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH) is a common sequela that may lead to poor neurological outcome and predisposes to various interventions, admissions, and complications. We reviewed post-aSAH shunt dependency in a population-based sample and tested the feasibility of a clinical risk score to identify subgroups of aSAH patients with increasing risk of shunting for hydrocephalus. METHODS: A total of 1533 aSAH patients from the population-based Eastern Finland Saccular Intracranial Aneurysm Database (Kuopio, Finland) were used in a recursive partitioning analysis to identify risk factors for shunting after aSAH. The risk model was built and internally validated in random split cohorts. External validation was conducted on 946 aSAH patients from the Southwestern Tertiary Aneurysm Registry (Dallas, TX) and tested using receiver-operating characteristic curves. RESULTS: Of all patients alive ≥14 days, 17.7% required permanent cerebrospinal fluid diversion. The recursive partitioning analysis defined 6 groups with successively increased risk for shunting. These groups also successively risk stratified functional outcome at 12 months, shunt complications, and time-to-shunt rates. The area under the curve-receiver-operating characteristic curve for the exploratory sample and internal validation sample was 0.82 and 0.78, respectively, with an external validation of 0.68. CONCLUSIONS: Shunt dependency after aSAH is associated with higher morbidity and mortality, and prediction modeling of shunt dependency is feasible with clinically useful yields. It is important to identify and understand the factors that increase risk for shunting and to eliminate or mitigate the reversible factors. The aSAH-PARAS Consortium (Aneurysmal Subarachnoid Hemorrhage Patients' Risk Assessment for Shunting) has been initiated to pool the collective insights and resources to address key questions in post-aSAH shunt dependency to inform future aSAH treatment guidelines.

The Role of Surgical Intervention in Traumatic Brain Injury.

The general consensus to optimize the care for severe TBI patients is management at specialized neurotrauma centers with neurosurgical and neurocritical care support and the use of guidelines-based standardized protocols. Over the last decade, significant efforts have been made to define neurotrauma treatment guidelines. However, it is important to recognize the heterogeneity of TBI and that the "one-size-fits-all approach" may not always be appropriate for these patients. Knowledge synthesis activities in neurotrauma are important to define future research agendas. Clinical and research advances have influenced neurotrauma as it continues to mature into a distinct subspecialty of neurosurgery.

Modelling of Brain Deformation After Decompressive Craniectomy.

Hyperelastic finite element models, with either an idealized cylindrical geometry or with realistic craniectomy geometries, were used to explore clinical issues relating to decompressive craniectomy. The potential damage in the brain tissue was estimated by calculating the volume of material exceeding a critical shear strain. Results from the idealized model showed how the potentially damaged volume of brain tissue increased with an increasing volume of brain tissue herniating from the skull cavity and with a reduction in craniectomy area. For a given herniated volume, there was a critical craniectomy diameter where the volume exceeding a critical shear strain fell to zero. The effects of details at the craniectomy edge, specifically a fillet radius and a chamfer on the bone margin, were found to be relatively slight, assuming that the dura is retained to provide effective protection. The location in the brain associated with volume expansion and details of the material modeling were found to have a relatively modest effect on the predicted damage volume. The volume of highly sheared material in the realistic models of the craniectomy varied roughly in line with differences in the craniectomy area.