Intracranial Pressure Rescued by Decompressive Surgery after Traumatic Brain Injury

Super resolution imaging reconstruction reveals that gold standard methods may not correctly conclude neural/brain functional recovery

The status of cerebral perfusion and its restoration level play a vital role in the prognosis and clinical decision making of many neurosurgical diseases. As such, gold standard methods including CT, MR and ICP monitoring, which can indicate and measure cerebral perfusion and restoration, have been widely adopted to evaluate whether or not a patient has recovered from neurofunctional disabilities. This robust combination of methods, however, is confronted with a growing number of contradictions in recent years due to its inability to measure the status of cerebral reperfusion in microvasculature level, even though this has been shown to determine neurofunctional restoration as well or even better. To this date, nevertheless, we have very limited imaging methods that could evaluate human cerebral microperfusion both safely and accurately under most neurosurgical conditions. We herein report a new method of acquiring a patient's cerebral microperfusion status noninvasively which could display the precise distribution of microvasculature in deep cerebral regions with a resolution of ∼30 µm, using everyday bed-side ultrasonography combined with a computerized super-resolution reconstruction algorithm. Using this imaging modality, we found that a patient's cerebral microperfusion might not be improved by some routine administrations even though the gold standard method had yielded the opposite conclusions. Our imaging modality retains the safe, portable feature of ordinary ultrasonography while possesses the extraordinary super-resolution nature, which enables an efficient, precise diagnosis of cerebral perfusion. Most importantly, the super resolution nature of this method may also facilitate early-stage evaluation of a patient's neurofunctional restoration level and avoid overoptimistic conclusions from conventional angiography or ICP monitoring.

Absorbable Artificial Dura Versus Nonabsorbable Artificial Dura in Decompressive Craniectomy for Severe Traumatic Brain Injury: A Retrospective Cohort Study in Two Centers

Background

Severe traumatic brain injury (TBI) patients usually need decompressive craniectomy (DC) to decrease intracranial pressure. Duraplasty is an important step in DC with various dura substitute choices. This study aims to compare absorbable dura with nonabsorbable dura in duraplasty for severe TBI patients.

Methods

One hundred and three severe TBI patients who underwent DC and dura repair were included in this study. Thirty-nine cases used absorbable artificial dura (DuraMax) and 64 cases used nonabsorbable artificial dura (NormalGEN). Postoperative complications, mortality and Karnofsky Performance Scale (KPS) score in one year were compared in both groups.

Results

Absorbable dura group had higher complication rates in transcalvarial cerebral herniation (TCH) (43.59% in absorbable dura group vs. 17.19% in nonabsorbable dura group, P = 0.003) and CSF leakage (15.38% in absorbable dura group vs. 1.56% in nonabsorbable dura group, P = 0.021). But severity of TCH described with hernial distance and herniation volume demonstrated no difference in both groups. There was no statistically significant difference in rates of postoperative intracranial infection, hematoma progression, secondary operation, hydrocephalus, subdural hygroma and seizure in both groups. KPS score in absorbable dura group (37.95 ± 28.58) was statistically higher than nonabsorbable dura group (49.05 ± 24.85) in one year after operation (P = 0.040), while no difference was found in the rate of functional independence (KPS ≥ 70). Besides, among all patients in this study, TCH patients had a higher mortality rate (P = 0.008), lower KPS scores (P < 0.001) and lower functionally independent rate (P = 0.049) in one year after surgery than patients without TCH.

Conclusions

In terms of artificial biological dura, nonabsorbable dura is superior to absorbable dura in treatment of severe TBI patients with DC. Suturable nonabsorbable dura has fewer complications of TCH and CFS leakage, and manifest lower mortality and better prognosis. Postoperative TCH is an important complication in severe TBI which usually leads to a poor prognosis.

Emerging therapeutic targets for cerebral edema

INTRODUCTION

Cerebral edema is a key contributor to death and disability in several forms of brain injury. Current treatment options are limited, reactive, and associated with significant morbidity. Targeted therapies are emerging based on a growing understanding of the molecular underpinnings of cerebral edema.

AREAS COVERED

We review the pathophysiology and relationships between different cerebral edema subtypes to provide a foundation for emerging therapies. Mechanisms for promising molecular targets are discussed, with an emphasis on those advancing in clinical trials, including ion and water channels (AQP4, SUR1-TRPM4) and other proteins/lipids involved in edema signaling pathways (AVP, COX2, VEGF, and S1P). Research on novel treatment modalities for cerebral edema [including recombinant proteins and gene therapies] is presented and finally, insights on reducing secondary injury and improving clinical outcome are offered.

EXPERT OPINION

Targeted molecular strategies to minimize or prevent cerebral edema are promising. Inhibition of SUR1-TRPM4 (glyburide/glibenclamide) and VEGF (bevacizumab) are currently closest to translation based on advances in clinical trials. However, the latter, tested in glioblastoma multiforme, has not demonstrated survival benefit. Research on recombinant proteins and gene therapies for cerebral edema is in its infancy, but early results are encouraging. These newer modalities may facilitate our understanding of the pathobiology underlying cerebral edema.

Deciding Under Uncertainty: The Case of Refractory Intracranial Hypertension

A challenging clinical conundrum arises in severe traumatic brain injury patients who develop intractable intracranial hypertension. For these patients, high morbidity interventions such as surgical decompression and barbiturate coma have to be considered against a backdrop of uncertain outcomes including prolonged states of disordered consciousness and severe disability. The clinical evidence available to guide shared decision-making is mainly limited to one randomized controlled trial, the RESCUEicp. However, since the publication of this trial significant controversy has been ongoing over the interpretation of the results. Is the mortality benefit from surgery merely a trade off for unacceptable long-term disability? How should treatment options, possible outcomes, and results from the trial be communicated to surrogates? How do we incorporate patient values into forming plans of care? The aim of this article is to sketch an approach based on insights from Decision Theory, and specifically deciding under uncertainty. The mainstream normative decision theory, Expected Utility (EU) theory, essentially says that, in situations of uncertainty, one should prefer the option with greatest expected desirability or value. The steps required to compute expected utilities include listing the possible outcomes of available interventions, assigning each outcome a utility ranking representing an individual patient's preferences, and a conditional probability given each intervention. This is a conceptual framework meant to supplement, and enhance shared decision making by assuring that patient values are elicited and incorporated, the possible range and nature of outcomes is discussed, and finally by attempting to connect best available means to patient-individualized ends.

Downregulation of Thbs4 caused by neurogenic niche changes promotes neuronal regeneration after traumatic brain injury

OBJECTIVE

Following brain injury, the neurogenic niche provides a permissive cue for iatrogenesis rather than neurogenesis; reactive astrocytes play essential roles in orchestrating this process, markedly forming a glial scar around the area of damaged brain tissue. The objective of this study was to alter the neurogenic niche at the injured cortex and study its impact on neurogenesis.

METHODS

We constructed a stromal cell-derived factor 1 (SDF-1) gradient matrix to attract reactive astrocytes to the glial scar core.

RESULTS

SDF-1 reacted with the astrocytes in the injured site. By changing the neurogenic niche of the injured part of the brain after traumatic brain injury (TBI), SDF-1 downregulated thrombospondin 4 (Thbs4) promoting neuronal cell regeneration and playing a beneficial role in nerve function recovery after brain injury.

DISCUSSION

The matrix we created in this study could attract and interact with reactive glial cells and, thus, we called it a glial pump. Using the glial pump, we identified a new mechanism of brain injury repair and neuronal regeneration after TBI, which relied on Thbs4 downregulation after the altered neurogenic niche promoted neuronal regeneration and functional recovery.

Role of Sulfonylurea Receptor 1 and Glibenclamide in Traumatic Brain Injury: A Review of the Evidence

Cerebral edema and contusion expansion are major determinants of morbidity and mortality after TBI. Current treatment options are reactive, suboptimal and associated with significant side effects. First discovered in models of focal cerebral ischemia, there is increasing evidence that the sulfonylurea receptor 1 (SUR1)-Transient receptor potential melastatin 4 (TRPM4) channel plays a key role in these critical secondary injury processes after TBI. Targeted SUR1-TRPM4 channel inhibition with glibenclamide has been shown to reduce edema and progression of hemorrhage, particularly in preclinical models of contusional TBI. Results from small clinical trials evaluating glibenclamide in TBI have been encouraging. A Phase-2 study evaluating the safety and efficacy of intravenous glibenclamide (BIIB093) in brain contusion is actively enrolling subjects. In this comprehensive narrative review, we summarize the molecular basis of SUR1-TRPM4 related pathology and discuss TBI-specific expression patterns, biomarker potential, genetic variation, preclinical experiments, and clinical studies evaluating the utility of treatment with glibenclamide in this disease.

The Role of Decompressive Craniectomy in the Context of Severe Traumatic Brain Injury: Summary of Results and Analysis of the Confidence Level of Conclusions From Systematic Reviews and Meta-Analyses

Introduction: Traumatic brain injury (TBI) is a global epidemic. The incidence of TBI in low and middle-income countries (LMICs) is three times greater than in high-income countries (HICs). Decompressive craniectomy (DC) is a surgical procedure to reduce intracranial pressure (ICP) and prevent secondary injury. Multiple comparative studies, and several randomized controlled trials (RCTs) have been conducted to investigate the influence of DC for patients with severe TBI on outcomes such as mortality, ICP, neurological outcomes, and intensive care unit (ICU) and hospital length of stay. The results of these studies are inconsistent. Systematic reviews and meta-analyses have been conducted in an effort to aggregate the data from the individual studies, and perhaps derive reliable conclusions. The purpose of this project was to conduct a review of the reviews about the effectiveness of DC to improve outcomes.

Methods: We conducted a systematic search of the literature to identify reviews and meta-analyses that met our pre-determined criteria. We used the AMSTAR 2 instrument to assess the quality of each of the included reviews, and determine the level of confidence.

Results: Of 973 citations from the original search, five publications were included in our review. Four of them included meta-analyses. For mortality, three reviews found a positive effect of DC compared to medical management and two found no significant difference between groups. The four reviews that measured neurological outcome found no benefit of DC. The two reviews that assessed ICP both found DC to be beneficial in reducing ICP. DC demonstrated a significant reduction in ICU length of stay in the one study that measured it, and a significant reduction in hospital length of stay in the two studies that measured it. According to the AMSTAR 2 criteria, the five reviews ranged in levels of confidence from low to critically low.

Conclusion: Systematic reviews and meta-analyses are important approaches for aggregating information from multiple studies. Clinicians rely of these methods for concise interpretation of scientific literature. Standards for quality of systematic reviews and meta-analyses have been established to support the quality of the reviews being produced. In the case of DC, more attention must be paid to quality standards, in the generation of both individual studies and reviews.

International prospective observational study on intracranial pressure in intensive care (ICU): the SYNAPSE-ICU study protocol

INTRODUCTION

Intracranial pressure (ICP) monitoring is commonly used in neurocritical care patients with acute brain injury (ABI). Practice about indications and use of ICP monitoring in patients with ABI remains, however, highly variable in high-income countries, while data on ICP monitoring in low and middle-income countries are scarce or inconsistent. The aim of the SYNAPSE-ICU study is to describe current practices of ICP monitoring using a worldwide sample and to quantify practice variations in ICP monitoring and management in neurocritical care ABI patients.

METHODS AND ANALYSIS

The SYNAPSE-ICU study is a large international, prospective, observational cohort study. From March 2018 to March 2019, all patients fulfilling the following inclusion criteria will be recruited: age >18 years; diagnosis of ABI due to primary haemorrhagic stroke (subarachnoid haemorrhage or intracranial haemorrhage) or traumatic brain injury; Glasgow Coma Score (GCS) with no eye opening (Eyes response=1) and Motor score ≤5 (not following commands) at ICU admission, or neuro-worsening within the first 48 hours with no eye opening and a Motor score decreased to ≤5. Data related to clinical examination (GCS, pupil size and reactivity, Richmond Agitation-Sedation Scale score, neuroimaging) and to ICP interventions (Therapy Intensity Levels) will be recorded on admission, and at day 1, 3 and 7. The Glasgow Outcome Scale Extended (GOSE) will be collected at discharge from ICU and from hospital and at 6-month follow-up. The impact of ICP monitoring and ICP-driven therapy on GOSE will be analysed at both patient and ICU level.

ETHICS AND DISSEMINATION

The study has been approved by the Ethics Committee 'Brianza' at the Azienda Socio Sanitaria Territoriale (ASST)-Monza (approval date: 21 November 2017). Each National Coordinator will notify the relevant ethics committee, in compliance with the local legislation and rules. Data will be made available to the scientific community by means of abstracts submitted to the European Society of Intensive Care Medicine annual conference and by scientific reports and original articles submitted to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03257904.

Use of Hematocrit for Short-Term Prognosis of Patients with Traumatic Brain Injury After Decompressive Craniectomy

OBJECTIVE

To discuss the effects of the hematocrit (Hct) in patients with traumatic brain injury after decompressive craniectomy (DC).

METHODS

Demographic data, inspection and treatment procedures, and 30-day prognosis were obtained for 158 patients with head injury who underwent unilateral DC in our hospital between January 2013 and June 2018. Uni- and multivariate logistic regression was applied to analyze independent risk factors for 30-day outcome. The quantitative analysis of postoperative Hct, ΔHct (postoperative Hct minus initial Hct), and their combination for the prognosis of patients with TBI was displayed graphically using receiver operating characteristic (ROC) curves. Multiple linear regression was used to explore factors influencing postoperative Hct and ΔHct.

RESULTS

Short-term mortality was 29.7%. Uni- and multivariate logistic regression analysis showed that age (odds ratio [OR], 1.064; P = 0.024), Glasgow Coma Scale score (OR, 0.711; P = 0.027), Injury Severity Score (ISS) (OR, 1.156; P = 0.047), midline shift in millimeters (OR, 1.809; P <0.001), postoperative Hct (OR, 0.743; P = 0.001), and ΔHct (OR, 1.242; P =0.048) were independent risk factors for short-term death. In ROC curves, a combination of postoperative Hct and ΔHct showed the highest sensitivity (77.5%) and highest specificity (89.4%). When using this combination to predict prognosis, we could achieve an accuracy of 94.5%. ISS (β = -0.172, P = 0.022), initial Hct (β = 0.243, P = 0.001), principal hematoma location (β = -2.628, P < 0.001), hours of operation (β = -0.884, P = 0.048), and colloid quantity (β = -0.002, P = 0.001) were independent contributing factors for ΔHct, which was similar to postoperative Hct.

CONCLUSIONS

A combination of postoperative Hct and ΔHct could better predict short-term survival of patients with TBI. Developing an appropriate treatment strategy to increase postoperative Hct and reduce the ΔHct may be good for the short-term prognosis of patients with TBI after DC.

Prognostic Predictors of Early Outcomes and Discharge Status of Patients Undergoing Decompressive Craniectomy After Severe Traumatic Brain Injury

OBJECTIVE

Although several prognostic factors for traumatic brain injury (TBI) have been evaluated, a useful predictive scoring model for the outcomes has not been developed for patients with severe TBI who undergo decompressive craniectomy (DC). The aim of the present study was to determine independent predictors and develop a multivariate logistic regression equation to predict the early outcome and discharge status for patients with severe TBI who have undergone DC.

METHODS

A total of 13 different variables were evaluated. The data from all 278 patients with severe TBI who had undergone DC in the present study were retrospectively evaluated from July 2011 to June 2017. Using univariate, multiple logistic regression and prognostic regression scoring equations it was possible to draw receiver operating characteristic curves to predict the early outcomes and discharge status after TBI.

RESULTS

We found that younger age (P = 0.012), no significant medical history (P = 0.044), diameter of both pupils <4 mm (P = 0.032), higher admission Glasgow coma scale score (P = 0.004), no tracheotomy (P < 0.001), and DC for severe TBI were associated with a favorable early outcome and discharge status. Using receiver operating characteristic curves to predict the probability of a favorable outcome, the sensitivity was 80.0% and the specificity was 79.5%.

CONCLUSIONS

Our preliminary findings have shown that 5 variables can be used as independent predictors in assessing the early outcome and discharge status for patients with severe TBI after DC.

Early and late clinical outcomes after decompressive craniectomy for traumatic refractory intracranial hypertension: a systematic review and meta-analysis of current evidence

INTRODUCTION

Decompressive craniectomy (DC) to control refractory intracranial hypertension in patients with traumatic brain injury (TBI), has been listed as possible but controversial therapeutic approach in the latest version of TBI management guidelines. This study aimed to perform a systematic review and meta-analysis on efficacy and safety of DC compared to standard care in TBI patients.

EVIDENCE ACQUISITION

A database search from 2011 to 2017 was conducted to identify studies pertinent to DC compared to standard care after TBI. The primary outcomes were mortality and functional outcome upon hospital discharge and at 6 and 12 months after intervention, whereas secondary outcomes were intracranial pressure (ICP) control, hospitalization data and occurrence of adverse events.

EVIDENCE SYNTHESIS

Three randomized controlled trials and two observational studies enrolling 3451 patients were selected for qualitative analysis, among which four were included in the meta-analysis. DC-treated patients showed a significant reduction of overall mortality (RR, 0.57; 95% CI: 0.5-0.66; P<0.001; I2=17%) with no profound beneficial effect on functional outcome (RR, 0.89; 95% CI: 0.78-1.02; P=0.09; I2=58%) compared to those receiving standard care. A more efficient ICP reduction and a tendency towards shorter duration of hospitalization were recorded in DC versus standard care group. Adverse events are more common in DC-treated patients.

CONCLUSIONS

It seems that, in TBI patients with intracranial hypertension, the use of DC is associated with survival benefit when compared to medical therapy alone, but with no clear improvement of functional outcome. Yet no definite conclusion can be drawn due to limited quantity and considerable heterogeneity of available data.

Management of Traumatic Brain Injury: An Update

The care of patients with traumatic brain injury can be one of the most challenging and rewarding aspects of clinical neurocritical care. This article reviews the approach to unique aspects specific to the care of this patient population. These aspects include appropriate use of sedation and analgesia, and the principles and the clinical use of intracranial monitors. Common clinical challenges encountered in these patients are also discussed, including the treatment of intracranial hypertension, temperature management, and control of sympathetic hyperactivity.

Should We Use the IMPACT-Model for the Outcome Prognostication of TBI Patients? A Qualitative Study Assessing Physicians' Perceptions

Introduction. Shared Decision-Making may facilitate information exchange, deliberation, and effective decision-making, but no decision aids currently exist for difficult decisions in neurocritical care patients. The International Patient Decision Aid Standards, a framework for the creation of high-quality decision aids (DA), recommends the presentation of numeric outcome and risk estimates. Efforts are underway to create a goals-of-care DA in critically-ill traumatic brain injury (ciTBI) patients. To inform its content, we examined physicians’ perceptions, and use of the IMPACT-model, the most widely validated ciTBI outcome model, and explored physicians’ preferences for communicating prognostic information towards families. Methods. We conducted a qualitative study using semi-structured interviews in 20 attending physicians (neurosurgery,neurocritical care,trauma,palliative care) at 7 U.S. academic medical centers. We used performed qualitative content analysis of transcribed interviews to identify major themes. Results. Only 12 physicians (60%) expressed awareness of the IMPACT-model; two stated that they “barely” knew the model. Seven physicians indicated using the model at least some of the time in clinical practice, although none used it exclusively to derive a patient’s prognosis. Four major themes emerged: the IMPACT-model is intended for research but should not be applied to individual patients; mistrust in the IMPACT-model derivation data; the IMPACT-model is helpful in reducing prognostic variability among physicians; concern that statistical models may mislead families about a patient’s prognosis. Discussion: Our study identified significant variability of the awareness, perception, and use of the IMPACT-model among physicians. While many physicians prefer to avoid conveying numeric prognostic estimates with families using the IMPACT-model, several physicians thought that they “ground” them and reduce prognostic variability among physicians. These findings may factor into the creation and implementation of future ciTBI-related DAs.

Medical Management of the Severe Traumatic Brain Injury Patient

Severe traumatic brain injury (sTBI) is a major contributor to long-term disability and a leading cause of death worldwide. Medical management of the sTBI patient, beginning with prehospital triage, is aimed at preventing secondary brain injury. This review discusses prehospital and emergency department management of sTBI, as well as aspects of TBI management in the intensive care unit where advances have been made in the past decade. Areas of emphasis include intracranial pressure management, neuromonitoring, management of paroxysmal sympathetic hyperactivity, neuroprotective strategies, prognostication, and communication with families about goals of care. Where appropriate, differences between the third and fourth editions of the Brain Trauma Foundation guidelines for the management of severe traumatic brain injury are highlighted.

Management of Traumatic Brain Injury: An Update

The care of patients with traumatic brain injury can be one of the most challenging and rewarding aspects of clinical neurocritical care. This article reviews the approach to unique aspects specific to the care of this patient population. These aspects include appropriate use of sedation and analgesia, and the principles and the clinical use of intracranial monitors. Common clinical challenges encountered in these patients are also discussed, including the treatment of intracranial hypertension, temperature management, and control of sympathetic hyperactivity.

Indicators of Survival and Favorable Functional Outcomes after Decompressive Craniectomy: A Multi-Institutional Retrospective Study

The role of decompressive craniectomy (DC) for severe traumatic brain injury (STBI) remains controversial. The purpose of this study was to identify factors that are indicators of survival and improved functional outcome in patients who undergo DC for STBI. A retrospective review of STBI patients who underwent DC was performed at four trauma centers during a 45-month period. Data collected included age, gender, mechanism of injury, Injury Severity Score (ISS), admission Glasgow Coma Scale (GCS), time from admission to DC, mortality, and extended Glasgow Outcome Score before discharge. Sixty-nine STBI patients were treated with DC during the study period. A higher initial GCS, lower ISS, and longer time to DC were all statistically significant for improved survival after DC. A younger age, higher initial GCS, and lower ISS were all statistically significant for a favorable functional outcome after DC. Patients with a higher initial GCS and lower ISS are more likely to survive DC and have a favorable functional outcome, whereas a longer time to DC was indicative of improved survival after DC.

Primary decompressive craniectomy is associated with worse neurological outcome in patients with traumatic brain injury requiring acute surgery

BACKGROUND

The role of decompressive craniectomy in treating raised intracranial pressure (ICP) after traumatic brain injuries (TBI) is controversial. The aim of this study was to assess the differences in prognosis of patients initially treated by decompressive craniectomy, craniotomy, or conservatively.

METHODS

We conducted a single-center retrospective study on adult blunt TBI patients admitted to a neurosurgical intensive care unit during 2009-2012. Patients were divided into three groups based on their initial treatment - decompressive craniectomy, craniotomy, and conservative. Primary outcome was 6-month Glasgow Outcome Scale (GOS) dichotomized to favorable outcome (independent) and unfavorable outcome (dependent). The association between initial treatment and outcome was assessed using a logistic regression model adjusting for case-mix using known predictors of outcome.

RESULTS

Of the 822 included patients, 58 patients were in the craniectomy group, 401 patients in the craniotomy group, and 363 patients in the conservatively treated group. Overall, 6-month unfavorable outcome was 48%. After adjusting for case-mix, patients in the decompressive craniectomy group had a statistical significantly higher risk for poor neurological outcome compared to patients in the conservative group (OR 3.06, 95% CI 1.45-6.42) and craniotomy group (OR 3.61, 95% CI 1.74-7.51).

CONCLUSION

In conclusion, patients requiring primary decompressive craniectomy had a higher risk for poor neurological outcome compared to patients undergoing craniotomy or were conservatively treated. It is plausible that the poor prognosis is related to the TBI severity itself rather than the intervention. Further prospective randomized trials are required to establish the role of decompressive craniectomy in the treatment of patients with TBI.