The current role of decompressive craniectomy for severe traumatic brain injury

Prolonged course of brain edema and neurological recovery in a translational model of decompressive craniectomy after closed head injury in mice

Background

The use of decompressive craniectomy in traumatic brain injury (TBI) remains a matter of debate. According to the DECRA trial, craniectomy may have a negative impact on functional outcome, while the RescueICP trial revealed a positive effect of surgical decompression, which is evolving over time. This ambivalence of craniectomy has not been studied extensively in controlled laboratory experiments.

Objective

The goal of the current study was to investigate the prolonged effects of decompressive craniectomy (both positive and negative) in an animal model.

Methods

Male mice were assigned to the following groups: sham, decompressive craniectomy, TBI and TBI followed by craniectomy. The analysis of functional outcome was performed at time points 3d, 7d, 14d and 28d post trauma according to the Neurological Severity Score and Beam Balance Score. At the same time points, magnetic resonance imaging was performed, and brain edema was analyzed.

Results

Animals subjected to both trauma and craniectomy presented the exacerbation of the neurological impairment that was apparent mostly in the early course (up to 7d) after injury. Decompressive craniectomy also caused a significant increase in brain edema volume (initially cytotoxic with a secondary shift to vasogenic edema and gliosis). Notably, delayed edema plus gliosis appeared also after decompression even without preceding trauma.

Conclusion

In prolonged outcomes, craniectomy applied after closed head injury in mice aggravates posttraumatic brain edema, leading to additional functional impairment. This effect is, however, transient. Treatment options that reduce brain swelling after decompression may accelerate neurological recovery and should be explored in future experiments.

Current status and outlook for the management of intracranial hypertension after traumatic brain injury: decompressive craniectomy, therapeutic hypothermia, and barbiturates

INTRODUCTION

Increased intracranial pressure (ICP) has been associated with poor neurological outcomes and increased mortality in patients with severe traumatic brain injury (TBI). Traditionally, ICP-lowering therapies are administered using an escalating approach, with more aggressive options reserved for patients showing no response to first-tier interventions, or with refractory intracranial hypertension.

DEVELOPMENT

The therapeutic value and the appropriate timing for the use of rescue treatments for intracranial hypertension have been a subject of constant debate in literature. In this review, we discuss the main management options for refractory intracranial hypertension after severe TBI in adults. We intend to conduct an in-depth revision of the most representative randomised controlled trials on the different rescue treatments, including decompressive craniectomy, therapeutic hypothermia, and barbiturates. We also discuss future perspectives for these management options.

CONCLUSIONS

The available evidence appears to show that mortality can be reduced when rescue interventions are used as last-tier therapy; however, this benefit comes at the cost of severe disability. The decision of whether to perform these interventions should always be patient-centred and made on an individual basis. The development and integration of different physiological variables through multimodality monitoring is of the utmost importance to provide more robust prognostic information to patients facing these challenging decisions.

[Surgical treatment of patients with skull defects and cerebrospinal fluid flow disorders after previous decompressive craniectomy]

Decompressive craniectomy (DC) is performed for refractory intracranial hypertension following severe traumatic brain injury, vascular and oncological diseases. This fact increases the number of patients with extensive and giant skull defects. Cerebrospinal fluid (CSF) flow disorders after DC are often accompanied by ventriculomegaly. However, only some patients with ventriculomegaly have hydrocephalus and require CSF bypass procedures. Differentiation of post-traumatic hydrocephalus requiring surgical treatment and atrophic dilation of ventricular system «ex vacuo» caused by brain injury is still an important issue. Skull sealing as a way to normalize CSF circulation and eliminate hydrocephalus is also an open question. Currently, there is no unified approach to patients with extensive and giant cranial defects combined with post-traumatic hydrocephalus. There is no unified algorithm for sequence of reconstructive and CSF bypass operations in these patients. Literature data on risks of infectious complications for different surgical strategies are controversial.

Characterisation of Selected Materials in Medical Applications

Tissue engineering is an interdisciplinary field of science that has developed very intensively in recent years. The first part of this review describes materials with medical and dental applications from the following groups: metals, polymers, ceramics, and composites. Both positive and negative sides of their application are presented from the point of view of medical application and mechanical properties. A variety of techniques for the manufacture of biomedical components are presented in this review. The main focus of this work is on additive manufacturing and 3D printing, as these modern techniques have been evaluated to be the best methods for the manufacture of medical and dental devices. The second part presents devices for skull bone reconstruction. The materials from which they are made and the possibilities offered by 3D printing in this field are also described. The last part concerns dental transitional implants (scaffolds) for guided bone regeneration, focusing on polylactide–hydroxyapatite nanocomposite due to its unique properties. This section summarises the current knowledge of scaffolds, focusing on the material, mechanical and biological requirements, the effects of these devices on the human body, and their great potential for applications.

Variation in neurosurgical intervention for severe traumatic brain injury: The challenge of measuring quality in trauma center verification

BACKGROUND

Intracranial pressure monitor (ICPm) procedure rates are a quality metric for American College of Surgeons trauma center verification. However, ICPm procedure rates may not accurately reflect the quality of care in TBI. We hypothesized that ICPm and craniotomy/craniectomy procedure rates for severe TBI vary across the United States by geography and institution.

METHODS

We identified all patients with a severe traumatic brain injury (head Abbreviated Injury Scale, ≥3) from the 2016 Trauma Quality Improvement Program data set. Patients who received surgical decompression or ICPm were identified via International Classification of Diseases codes. Hospital factors included neurosurgeon group size, geographic region, teaching status, and trauma center level. Two multiple logistic regression models were performed identifying factors associated with (1) craniotomy with or without ICPm or (2) ICPm alone. Data are presented as medians (interquartile range) and odds ratios (ORs) (95% confidence interval).

RESULTS

We identified 75,690 patients (66.4% male; age, 59 [36-77] years) with a median Injury Severity Score of 17 (11-25). Overall, 6.1% had surgical decompression, and 4.8% had ICPm placement. Logistic regression analysis showed that region of the country was significantly associated with procedure type: hospitals in the West were more likely to use ICPm (OR, 1.34 [1.20-1.50]), while Northeastern (OR, 0.80 [0.72-0.89]), Southern (OR, 0.84 [0.78-0.92]), and Western (OR, 0.88 [0.80-0.96]) hospitals were less likely to perform surgical decompression. Hospitals with small neurosurgeon groups (<3) were more likely to perform surgical intervention. Community hospitals are associated with higher odds of surgical decompression but lower odds of ICPm placement.

CONCLUSION

Both geographic differences and hospital characteristics are independent predictors for surgical intervention in severe traumatic brain injury. This suggests that nonpatient factors drive procedural decisions, indicating that ICPm rate is not an ideal quality metric for American College of Surgeons trauma center verification.

LEVEL OF EVIDENCE

Epidemiological, level III; Care management/Therapeutic level III.

Outcomes of patients undergoing craniotomy and decompressive craniectomy for severe traumatic brain injury with brain herniation: A retrospective study

The treatment of severe traumatic brain injury (TBI) with brain herniation is challenging because outcomes are often associated with high mortality and morbidity. Our aim was to identity factors contributing to decompressive craniectomy (DC) and evaluate treatment outcomes in patients with severe TBI with brain herniation.In this retrospective study, we analyzed medical records of severe TBI with brain herniation from May 2009 to December 2013. We reviewed their demographic data, mechanism of injury, Glasgow Coma Scale (GCS) score, pupil status, computed tomography findings, surgical treatment methods, time interval between brain herniation and surgery, as well as outcomes. GCS and pupil status are clinical parameters for detecting increase intracranial pressure while brain parenchyma bulged above the inner plate of the skull during operation indicated brain swelling as well as increased intracranial pressure on which basis the decision to perform DC or craniotomy was determined intraoperatively.One hundred ninety-four patients were included in the study. We performed DC in 143 of the patients while 51 of them we performed craniotomy. There were no statistically significant differences in the age, gender, or injury mechanism between the 2 groups. GCS, pupillary dilation, midline shift, hematoma type and timing of surgery were associated with DC. Nevertheless, logistic regression analysis revealed that hematoma type and timing of surgery were significantly associated with favorable DC outcomes (P < .001 and P = .023). Subdural hematoma and timing of surgery >1 hour were both identified as risk factors for DC. Six months after TBI, 34.0% of patients exhibited favorable outcomes. Overall mortality rate was 30.4%. Age, GCS, pupil dilation, hematoma type, and timing of surgery were all associated with patient outcomes. Further logistic regression analysis revealed that, lower GCS, bilateral pupil dilation, timing of surgery >1 hour, and advanced age were independent risk factors for poor outcomes (P = .001, P = .037, P = .028, and P = .001, respectively).Our study revealed that, DC is not mandatory for all TBI patients with brain herniation. Nevertheless, DC decreases mortality rate in severe TBI patients with brain herniation. Subdural hematoma and timing of surgery >1 hour are key indicators for DC. Lower GCS, bilateral pupil dilation, delayed timing of surgery and advance age are indicators of poor outcomes.

Current status and outlook for the management of intracranial hypertension after traumatic brain injury: decompressive craniectomy, therapeutic hypothermia, and barbiturates

INTRODUCTION

Increased intracranial pressure has been associated with poor neurological outcomes and increased mortality in patients with severe traumatic brain injury. Traditionally, intracranial pressure-lowering therapies are administered using an escalating approach, with more aggressive options reserved for patients showing no response to first-tier interventions, or with refractory intracranial hypertension.

DEVELOPMENT

The therapeutic value and the appropriate timing for the use of rescue treatments for intracranial hypertension have been a subject of constant debate in literature. In this review, we discuss the main management options for refractory intracranial hypertension after severe traumatic brain injury in adults. We intend to conduct an in-depth revision of the most representative randomised controlled trials on the different rescue treatments, including decompressive craniectomy, therapeutic hypothermia, and barbiturates. We also discuss future perspectives for these management options.

CONCLUSIONS

The available evidence appears to show that mortality can be reduced when rescue interventions are used as last-tier therapy; however, this benefit comes at the cost of severe disability. The decision of whether to perform these interventions should always be patient-centred and made on an individual basis. The development and integration of different physiological variables through multimodality monitoring is of the utmost importance to provide more robust prognostic information to patients facing these challenging decisions.

Neurocritical Management of Traumatic Acute Subdural Hematomas

Acute subdural hematoma (ASDH) has been a major part of traumatic brain injury. Intracranial hypertension may be followed by ASDH and brain edema. Regardless of the complicated pathophysiology of ASDH, the extent of primary brain injury underlying the ASDH is the most important factor affecting outcome. Ongoing intracranial pressure (ICP) increasing lead to cerebral perfusion pressure (CPP) decrease and cerebral blood flow (CBF) decreasing occurred by CPP decrease. In additionally, disruption of cerebral autoregulation, vasospasm, decreasing of metabolic demand may lead to CBF decreasing. Various protocols for ICP lowering were introduced in neuro-trauma field. Usage of anti-epileptic drugs (AEDs) for ASDH patients have controversy. AEDs may reduce the risk of early seizure (<7 days), but, does not for late-onset epilepsy. Usage of anticoagulants/antiplatelets is increasing due to life-long medical disease conditions in aging populations. It makes a difficulty to decide the proper management. Tranexamic acid may use to reducing bleeding and reduce ASDH related death rate. Decompressive craniectomy for ASDH can reduce patient's death rate. However, it may be accompanied with surgical risks due to big operation and additional cranioplasty afterwards. If the craniotomy is a sufficient management for the ASDH, endoscopic surgery will be good alternative to a conventional larger craniotomy to evacuate the hematoma. The management plan for the ASDH should be individualized based on age, neurologic status, radiologic findings, and the patient's conditions.

Determinants affecting the prognosis of decompressive craniectomy for traumatic brain injury

Objective:

This research was designed to investigate the prognostic determinants of patients with traumatic brain injury (TBI) undergoing decompressive craniectomy (DC).

Methods:

The present study was a retrospective single center research including a total of 112 patients undergoing DC for TBI in Liaocheng People’s Hospital between January 2017 and December 2018. The results were measured by Extended Glasgow Outcome Sale (GOSE). The prognostic determinants were identified by univariate and binary logistic regression analysis between the deaths and survivors or favorable and unfavorable outcomes.

Results:

At the six-month follow-up, the mortality was 45.5% including 37 (33.0%) patients died within 30 days. The independent prognostic factors of 30-day mortality were age (p=0.033), D-dimer level at admission (p=0.032) and postoperative hypernatremia (p=0.014). Seventy five patients survived more than 30 days after DC, among which 27 (36.0%) patients had unfavorable prognosis (GOSE 1-4) and 48 (64.0%) patients presented favorable prognosis (GOSE 5-8). After 30 days from DC, the occurrence of post-traumatic hydrocephalus(PTH) (p= 0.008) was associated with unfavorable prognosis.

Conclusions:

Although DC is an effective treatment for TBI patients, the mortality and morbidity risk remain high. A combination of age, D-dimer level at admission and postoperative hypernatremia may be a good prognostic factor for 30-day mortality. Developing an accurate therapy strategy to prevent and control PTH may be beneficial to the 6-month prognosis for TBI patients undergoing DC.

Custom-Made Porous Hydroxyapatite Cranioplasty in Patients with Tumor Versus Traumatic Brain Injury: A Single-Center Case Series

BACKGROUND

Cranioplasty is a common neurosurgical procedure with the goal of restoring skull integrity. Custom-made porous hydroxyapatite prostheses have long been used for cranial reconstruction in patients with traumatic brain injury. We present a large consecutive series of 2 groups of patients undergoing cranioplasty with hydroxyapatite custom bone and compare the adverse events (AEs) between the 2 groups.

METHODS

We examined a series of consecutive patients who underwent cranioplasty using custom-made porous hydroxyapatite implants following tumor resection and traumatic brain injury at a single center between March 2003 and May 2018. The implants were designed and produced according to the surgeon's specifications and based on the patient's computed tomography scan data obtained through a standardized protocol. AEs were recorded.

RESULTS

Information on 38 patients with tumor and 39 patients with traumatic brain injury was collected and analyzed. A significant difference in the timing of surgery was found between the 2 groups; single-stage surgery was performed in 84% of patients in the tumor versus 8% of those in the traumatic brain injury group (P < 0.0001). The rate of AEs was not significantly different between the 2 groups (P = 0.4309) and was not related to the timing of surgery.

CONCLUSIONS

Custom-made hydroxyapatite cranioplasty is a solution for cranial reconstruction in patients with cranial tumors. The low incidence of AEs in a consecutive series of patients with either trauma or tumors demonstrates that these prostheses represent a safe solution independent of the characteristics of cases.

Implementation of cisternostomy as adjuvant to decompressive craniectomy for the management of severe brain trauma

OBJECTIVE

To evaluate the value of an adjuvant cisternostomy (AC) to decompressive craniectomy (DC) for the management of patients with severe traumatic brain injury (sTBI).

METHODS

A single-center retrospective quality control analysis of a consecutive series of sTBI patients surgically treated with AC or DC alone between 2013 and 2018. A subgroup analysis, "primary procedure" and "secondary procedure", was also performed. We examined the impact of AC vs. DC on clinical outcome, including long-term (6 months) extended Glasgow outcome scale (GOS-E), the duration of postoperative ventilation, and intensive care unit (ICU) stay, mortality, Glasgow coma scale at discharge, and time to cranioplasty. We also evaluated and analyzed the impact of AC vs. DC on post-procedural intracranial pressure (ICP) and brain tissue oxygen (PbO₂) values as well as the need for additional osmotherapy and CSF drainage.

RESULTS

Forty patients were examined, 22 patients in the DC group, and 18 in the AC group. Compared with DC alone, AC was associated with significant shorter duration of mechanical ventilation and ICU stay, as well as better Glasgow coma scale at discharge. Mortality rate was similar. At 6-month, the proportion of patients with favorable outcome (GOS-E ≥ 5) was higher in patients with AC vs. DC [10/18 patients (61%) vs. 7/20 (35%)]. The outcome difference was particularly relevant when AC was performed as primary procedure (61.5% vs. 18.2%; p = 0.04). Patients in the AC group also had significant lower average post-surgical ICP values, higher PbO₂ values and required less osmotic treatments as compared with those treated with DC alone.

CONCLUSION

Our preliminary single-center retrospective data indicate that AC may be beneficial for the management of severe TBI and is associated with better clinical outcome. These promising results need further confirmation by larger multicenter clinical studies. The potential benefits of cisternostomy should not encourage its universal implementation across trauma care centers by surgeons that do not have the expertise and instrumentation necessary for cisternal microsurgery. Training in skull base and vascular surgery techniques for trauma care surgeons would avoid the potential complications associated with this delicate procedure.

Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). It is usually treated with general maneuvers (normothermia, sedation, etc.) and a set of first-line therapeutic measures (moderate hypocapnia, mannitol, etc.). When these measures fail, second-line therapies are initiated, which include: barbiturates, hyperventilation, moderate hypothermia, or removal of a variable amount of skull bone (secondary decompressive craniectomy).

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcomes of patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH METHODS

The most recent search was run on 8 December 2019. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP) and ISI Web of Science (SCI-EXPANDED & CPCI-S). We also searched trials registries and contacted experts.

SELECTION CRITERIA

We included randomized studies assessing patients over the age of 12 months with severe TBI who either underwent DC to control ICP refractory to conventional medical treatments or received standard care.

DATA COLLECTION AND ANALYSIS

We selected potentially relevant studies from the search results, and obtained study reports. Two review authors independently extracted data from included studies and assessed risk of bias. We used a random-effects model for meta-analysis. We rated the quality of the evidence according to the GRADE approach.

MAIN RESULTS

We included three trials (590 participants). One single-site trial included 27 children; another multicenter trial (three countries) recruited 155 adults, the third trial was conducted in 24 countries, and recruited 408 adolescents and adults. Each study compared DC combined with standard care (this could include induced barbiturate coma or cooling of the brain, or both). All trials measured outcomes up to six months after injury; one also measured outcomes at 12 and 24 months (the latter data remain unpublished). All trials were at a high risk of bias for the criterion of performance bias, as neither participants nor personnel could be blinded to these interventions. The pediatric trial was at a high risk of selection bias and stopped early; another trial was at risk of bias because of atypical inclusion criteria and a change to the primary outcome after it had started. Mortality: pooled results for three studies provided moderate quality evidence that risk of death at six months was slightly reduced with DC (RR 0.66, 95% CI 0.43 to 1.01; 3 studies, 571 participants; I² = 38%; moderate-quality evidence), and one study also showed a clear reduction in risk of death at 12 months (RR 0.59, 95% CI 0.45 to 0.76; 1 study, 373 participants; high-quality evidence). Neurological outcome: conscious of controversy around the traditional dichotomization of the Glasgow Outcome Scale (GOS) scale, we chose to present results in three ways, in order to contextualize factors relevant to clinical/patient decision-making. First, we present results of death in combination with vegetative status, versus other outcomes. Two studies reported results at six months for 544 participants. One employed a lower ICP threshold than the other studies, and showed an increase in the risk of death/vegetative state for the DC group. The other study used a more conventional ICP threshold, and results favoured the DC group (15.7% absolute risk reduction (ARR) (95% CI 6% to 25%). The number needed to treat for one beneficial outcome (NNTB) (i.e. to avoid death or vegetative status) was seven. The pooled result for DC compared with standard care showed no clear benefit for either group (RR 0.99, 95% CI 0.46 to 2.13; 2 studies, 544 participants; I² = 86%; low-quality evidence). One study reported data for this outcome at 12 months, when the risk for death or vegetative state was clearly reduced by DC compared with medical treatment (RR 0.68, 95% CI 0.54 to 0.86; 1 study, 373 participants; high-quality evidence). Second, we assessed the risk of an 'unfavorable outcome' evaluated on a non-traditional dichotomized GOS-Extended scale (GOS-E), that is, grouping the category 'upper severe disability' into the 'good outcome' grouping. Data were available for two studies (n = 571). Pooling indicated little difference between DC and standard care regarding the risk of an unfavorable outcome at six months following injury (RR 1.06, 95% CI 0.69 to 1.63; 544 participants); heterogeneity was high, with an I² value of 82%. One trial reported data at 12 months and indicated a clear benefit of DC (RR 0.81, 95% CI 0.69 to 0.95; 373 participants). Third, we assessed the risk of an 'unfavorable outcome' using the (traditional) dichotomized GOS/GOS-E cutoff into 'favorable' versus 'unfavorable' results. There was little difference between DC and standard care at six months (RR 1.00, 95% CI 0.71 to 1.40; 3 studies, 571 participants; low-quality evidence), and heterogeneity was high (I² = 78%). At 12 months one trial suggested a similar finding (RR 0.95, 95% CI 0.83 to 1.09; 1 study, 373 participants; high-quality evidence). With regard to ICP reduction, pooled results for two studies provided moderate quality evidence that DC was superior to standard care for reducing ICP within 48 hours (MD -4.66 mmHg, 95% CI -6.86 to -2.45; 2 studies, 182 participants; I² = 0%). Data from the third study were consistent with these, but could not be pooled. Data on adverse events are difficult to interpret, as mortality and complications are high, and it can be difficult to distinguish between treatment-related adverse events and the natural evolution of the condition. In general, there was low-quality evidence that surgical patients experienced a higher risk of adverse events.

AUTHORS' CONCLUSIONS

Decompressive craniectomy holds promise of reduced mortality, but the effects of long-term neurological outcome remain controversial, and involve an examination of the priorities of participants and their families. Future research should focus on identifying clinical and neuroimaging characteristics to identify those patients who would survive with an acceptable quality of life; the best timing for DC; the most appropriate surgical techniques; and whether some synergistic treatments used with DC might improve patient outcomes.

Optic Nerve Sheath Measurements by Computed Tomography to Predict Intracranial Pressure and Guide Surgery in Patients with Traumatic Brain Injury

BACKGROUND

Research has shown that the optic nerve sheath diameter (ONSD) is a good predictor of intracranial pressure (ICP) and may predict the need for surgery in patients with head injury. The objective was to test the value of ONSD in predicting the requirement for surgery in patients with traumatic brain injury (TBI).

METHODS

In this retrospective cohort study, we first verified the correlation between ICP and ONSD using data from 62 patients with TBI who had undergone ICP monitoring. Second, we analyzed head computed tomography images from patients with TBI who were admitted to the emergency department where patients had been divided into surgery or conservative treatment groups, dependent on the assessment of a neurosurgeon. The correlation between ICP and ONSD was measured using linear regression analysis. Biologistic and receiver operating characteristic curve analyses were used to test the diagnostic value of ONSD to predict surgery.

RESULTS

ONSD was significantly correlated with ICP (r = 0.606; P < 0.01), and there was a significant linear regression equation (ŷ = 0.071 × ICP + 3.533; P < 0.01), with ONSD predicting the requirement for surgery in patients with TBI (area under the curve, 0.920; P < 0.01; 95% confidence interval, 0.877-0.962).

CONCLUSIONS

ONSD measured via head computed tomography correlates with ICP and can predict the requirement for surgery in patients with TBI following admission to the emergency department.

Rapid, label-free detection of cerebral ischemia in rats using hyperspectral imaging

BACKGROUND

Stroke is the third most common cause of disability and the second most common cause of death worldwide. Ischemia, one of the two broad categories of stroke, is characterized by a lack of sufficient amounts of blood in order to supply an adequate amount of oxygen and nutrients. It is important to assess the part of the brain that becomes ischemic and necrotic during neurosurgery or experiments in real time. However, there is currently no effective means to achieve this goal.

NEW METHOD

We proposed a method based on hyperspectral imaging (HSI) for the real-time detection of a varied range of ischemic brain tissues in vivo or ex vivo and assessed the practical utility of a model of ischemic stroke in rats.

RESULTS

The results showed that hyperspectral images processed with a ratio of spectral reflectance at 545 and 560 nm (R545/R560) could identify early brain ischemia and accurately show regions of ischemia.

COMPARISON WITH EXISTING METHODS

We verified the area imaged by HSI using hematoxylin and eosin (HE) and 2, 3, 5-triphenyltetrazolium chloride (TTC) staining methods. This technique could precisely image the ischemic part of the brain in vivo and ex vivo.

CONCLUSIONS

These results demonstrate the practical utility of HSI for the real-time detection of cerebral ischemia in rats. By providing rapid assessment of brain tissue perfusion, HSI may help doctors recognize ischemic regions quickly and precisely during surgery as well as have great utility in the experimental process.

Decompressive Craniectomy for Traumatic Brain Injury: The Role of Cranioplasty and Hydrocephalus on Outcome

OBJECTIVE

After severe traumatic brain injury (sTBI) associated with uncontrollable high intracranial pressure (ICP), today the main challenge for neurosurgeons remains to identify who may obtain benefit from decompressive craniectomy (DC) and which factors after DC influence the prognosis of these patients. The aim of this paper was to identify the pre- and postoperative determinants of outcome after DC.

METHODS

This retrospective study included all patients undergoing DC for sTBI from 2003 to 2011. The 6-month outcome, assessed using the Glasgow Outcome Scale (GOS), was dichotomized into favorable (GOS scores 4 and 5) and unfavorable (GOS scores 1-3) outcome. Predictors of outcome were identified by uni- and multivariate analysis.

RESULTS

There were 190 patients who underwent DC for sTBI in this study. Sixty patients (31.6%) died within 30 days after DC. Independent prognostic factors for survival after 30 days were Glasgow Coma Scale score at admission greater than 5 (P = 0.002) and bilateral pupil reactivity (P < 0.0001). Thirty days after DC, 67 patients (51.5%) out of 130 had unfavorable outcome (GOS scores 1-3) and 63 patients (49.5%) presented favorable outcome (GOS scores 4 and 5). The independent preoperative prognostic factors for poor outcome were age over 65 years (P < 0.0001) and bilateral absence of pupil reactivity (P = 0.0165). After DC, onset of postoperative hydrocephalus and delayed cranioplasty (3 months after DC) was associated with unfavorable outcome at multivariate analysis (P = 0.002 and P < 0.0001, respectively).

CONCLUSIONS

In our study, the development of hydrocephalus after DC for sTBI and delayed cranial reconstruction were associated with unfavorable outcome.

Relationship of calcitonin gene-related peptide with disease progression and prognosis of patients with severe traumatic brain injury

Calcitonin gene-related peptide (CGRP) has been implicated in multiple functions across many bioprocesses; however, whether CGRP is associated with severe traumatic brain injury (TBI) remains poorly understood. In this study, 96 adult patients with TBI (enrolled from September 2015 to December 2016) were divided into a mild/moderate TBI group (36 males and 25 females, aged 38 ± 13 years) and severe TBI group (22 males and 13 females, aged 38 ± 11 years) according to Glasgow Coma Scale scores. In addition, 25 healthy individuals were selected as controls (15 males and 10 females, aged 39 ± 13 years). Radioimmunoassay was used to detect serum levels of CGRP and endothelin-1 at admission and at 12, 24, 48, 72 hours, and 7 days after admission. CGRP levels were remarkably lower, but endothelin-1 levels were obviously higher in the severe TBI group compared with mild/moderate TBI and control groups. Levels of CGRP were remarkably lower, but endothelin-1 levels were obviously higher in deceased patients compared with patients who survived. Survival analysis and logistic regression showed that both CGRP and endothelin-1 levels were associated with patient mortality, with each serving as an independent risk factor for 6-month mortality of severe TBI patients. Moreover, TBI patients with lower serum CGRP levels had a higher risk of death. Thus, our retrospective analysis demonstrates the potential utility of CGRP as a new biomarker, monitoring method, and therapeutic target for TBI.