Decompressive craniectomy - operative technique and perioperative care

Effectiveness of hinge craniotomy as an alternative to decompressive craniectomy for acute subdural hematoma

BACKGROUND

Acute subdural hematoma (ASDH) is a life-threatening condition, and hematoma removal is necessary as a lifesaving procedure when the intracranial pressure is highly elevated. However, whether decompressive craniectomy (DC) or conventional craniotomy (CC) is adequate remains unclear. Hinge craniotomy (HC) is a technique that provides expansion potential for decompression while retaining the bone flap. At our institution, HC is the first-line operation instead of DC for traumatic ASDH, and we present the surgical outcomes.

METHODS

From January 1, 2017, to December 31, 2022, 372 patients with traumatic ASDH were admitted to our institution, among whom 48 underwent hematoma evacuation during the acute phase. HC was performed in cases where brain swelling was observed intraoperatively. If brain swelling was not observed, CC was selected. DC was performed only when the brain was too swollen to allow replacement of the bone flap. We conducted a retrospective analysis of patient demographics, prognosis, and subsequent cranial procedures for each technique.

RESULTS

Of the 48 patients, 2 underwent DC, 23 underwent HC, and 23 underwent CC. The overall mortality rate was 20.8% (10/48) at discharge and 30.0% (12/40) at 6 months. The in-hospital mortality rates for DC, HC, and CC were 100% (2/2), 21.7% (5/23), and 13.0% (3/23), respectively. Primary brain injury was the cause of death in five patients whose brainstem function was lost immediately after surgery. No fatalities were attributed to the progression of postoperative brain herniation. In only one case, the cerebral contusion worsened after the initial surgery, leading to brain herniation and necessitating secondary DC.

CONCLUSIONS

The strategy of performing HC as the first-line operation for ASDH did not increase the mortality rate compared with past surgical reports and required secondary DC in only one case.

Serum exosomes miR-206 and miR-549a-3p as potential biomarkers of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide. However, effective diagnostic, therapeutic and prognostic biomarkers are still lacking. Our research group previously revealed through high-throughput sequencing that the serum exosomes miR-133a-3p, miR-206, and miR-549a-3p differ significantly in severe TBI (sTBI), mild or moderate TBI (mTBI), and control groups. However, convincing experimental evidence is lacking. To solve this problem, we used qPCR in this study to further verify the expression levels of serum exosomes miR-133a-3p, miR-206 and miR-549a-3p in TBI patients. The results showed that the serum exosomes miR-206 and miR-549a-3p showed good predictive value as biomarkers of TBI. In addition, in order to further verify whether serum exosomes miR-206 and miR-549a-3p can be used as potential biomarkers in patients with TBI and to understand the mechanism of their possible effects, we further determined the contents of SOD, BDNF, VEGF, VEGI, NSE and S100β in the serum of TBI patients. The results showed that, serum exosomes miR-206 and miR-549a-3p showed good correlation with BDNF, NSE and S100β. In conclusion, serum exosomes miR-206 and miR-549a-3p have the potential to serve as potential biomarkers in patients with TBI.

Duroplasty for injured cervical spinal cord with uncontrolled swelling: protocol of the DISCUS randomized controlled trial

BACKGROUND

Cervical traumatic spinal cord injury is a devastating condition. Current management (bony decompression) may be inadequate as after acute severe TSCI, the swollen spinal cord may become compressed against the surrounding tough membrane, the dura. DISCUS will test the hypothesis that, after acute, severe traumatic cervical spinal cord injury, the addition of dural decompression to bony decompression improves muscle strength in the limbs at 6 months, compared with bony decompression alone.

METHODS

This is a prospective, phase III, multicenter, randomized controlled superiority trial. We aim to recruit 222 adults with acute, severe, traumatic cervical spinal cord injury with an American Spinal Injury Association Impairment Scale grade A, B, or C who will be randomized 1:1 to undergo bony decompression alone or bony decompression with duroplasty. Patients and outcome assessors are blinded to study arm. The primary outcome is change in the motor score at 6 months vs. admission; secondary outcomes assess function (grasp, walking, urinary + anal sphincters), quality of life, complications, need for further surgery, and mortality, at 6 months and 12 months from randomization. A subgroup of at least 50 patients (25/arm) also has observational monitoring from the injury site using a pressure probe (intraspinal pressure, spinal cord perfusion pressure) and/or microdialysis catheter (cord metabolism: tissue glucose, lactate, pyruvate, lactate to pyruvate ratio, glutamate, glycerol; cord inflammation: tissue chemokines/cytokines). Patients are recruited from the UK and internationally, with UK recruitment supported by an integrated QuinteT recruitment intervention to optimize recruitment and informed consent processes. Estimated study duration is 72 months (6 months set-up, 48 months recruitment, 12 months to complete follow-up, 6 months data analysis and reporting results).

DISCUSSION

We anticipate that the addition of duroplasty to standard of care will improve muscle strength; this has benefits for patients and carers, as well as substantial gains for health services and society including economic implications. If the addition of duroplasty to standard treatment is beneficial, it is anticipated that duroplasty will become standard of care.

TRIAL REGISTRATION

IRAS: 292031 (England, Wales, Northern Ireland) - Registration date: 24 May 2021, 296518 (Scotland), ISRCTN: 25573423 (Registration date: 2 June 2021); ClinicalTrials.gov number : NCT04936620 (Registration date: 21 June 2021); NIHR CRN 48627 (Registration date: 24 May 2021).

Traumatic brain injury and immunological outcomes: the double-edged killer

Traumatic brain injury (TBI) is a significant cause of mortality and morbidity worldwide resulting from falls, car accidents, sports, and blast injuries. TBI is characterized by severe, life-threatening consequences due to neuroinflammation in the brain. Contact and collision sports lead to higher disability and death rates among young adults. Unfortunately, no therapy or drug protocol currently addresses the complex pathophysiology of TBI, leading to the long-term chronic neuroinflammatory assaults. However, the immune response plays a crucial role in tissue-level injury repair. This review aims to provide a better understanding of TBI's immunobiology and management protocols from an immunopathological perspective. It further elaborates on the risk factors, disease outcomes, and preclinical studies to design precisely targeted interventions for enhancing TBI outcomes.

Functional outcome in patients with traumatic or hemorrhagic brain injuries undergoing decompressive craniectomy versus craniotomy and 6-month rehabilitation

Decompressive craniectomy (DC) and craniotomy (CT) to treat increased intracranial pressure after brain injury are common but controversial choices in clinical practice. Studying a large cohort of patients with traumatic brain injury (TBI) and hemorrhagic stroke (HS) on rehabilitation pathways, we aimed to determine the impact of DC and CT on functional outcome/mortality, and on seizures occurrence. This observational retrospective study included patients with either TBI, or HS, who underwent DC or CT, consecutively admitted to our unit for 6-month neurorehabilitation programs between January 1, 2009 and December 31, 2018. Neurological status using Glasgow Coma Scale (GCS), and rehabilitation outcome with Functional Independence Measure, both assessed at baseline and on discharge, post-DC cranioplasty, prophylactic antiepileptic drug use, occurrence of early/late seizures, infectious complications, and death during hospitalization were evaluated and analyzed with linear and logistic regression models. Among 278 patients, DC was performed in 98 (66.2%) with HS, and in 98 (75.4%) with TBI, whilst CT in 50 (33.8%) with HS, and in 32 (24.6%) with TBI. On admission, GCS scores were lower in patients treated with CT than in those with DC (HS, p = 0.016; TBI, p = 0.024). Severity of brain injury and older age were the main factors affecting functional outcome, without between-group differences, but DC associated with worse functional outcome, independently from severity or type of brain injury. Unprovoked seizures occurred post-DC cranioplasty more frequently after HS (OR = 5.142, 95% CI 1.026-25.784, p = 0.047). DC and CT shared similar risk of mortality, which associated with sepsis (OR = 16.846, 95% CI 5.663-50.109, p < 0.0001), or acute symptomatic seizures (OR = 4.282, 95% CI 1.276-14.370, p = 0.019), independently from the neurosurgery procedures. Among CT and DC, the latter neurosurgical procedure is at major risk of worse functional outcome in patients with mild-to-severe TBI, or HS undergoing an intensive rehabilitation program. Complications with sepsis or acute symptomatic seizures increase the risk of death.

Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns

Malignant acute ischemic stroke (AIS) is characterized by acute neurological deterioration caused by progressive space-occupying brain edema, often occurring in the first hours to days after symptom onset. Without any treatment, the result is often fatal. Despite advances in treatment for AIS, up to 80% of patients with a large hemispheric stroke or cerebellar stroke are at risk of poor outcome. Decompressive surgery can be life-saving in a subgroup of patients with malignant AIS, but uncertainties exist on patient selection, predictors of malignant infarction, perioperative management, and timing of intervention. Although survivors are left disabled, most agree with the original decision to undergo surgery and would make the same decision again. In this narrative review, we focus on the clinical and radiological predictors of malignant infarction in AIS and outline the technical aspects of decompressive surgery as well as duraplasty and cranioplasty. We discuss the current evidence and recommendations for surgery in AIS, highlighting gaps in knowledge, and suggest directions for future studies. KEY POINTS: · Acute ischemic stroke from occlusion of a proximal intracranial artery can progress quickly to malignant edema, which can be fatal in 80% of patients despite medical management.. · Decompression surgery is life-saving within 48 hours of stroke onset, but the benefits beyond this time and in the elderly are unknown.. · Decompressive surgery is associated with high morbidity, particularly in the elderly. The decision to operate must be made after considering the individual's preference and expectations of quality of life in the context of the clinical condition.. · Further studies are needed to refine surgical technique including value of duraplasty and understand the role monitoring intracranial pressure during and after decompressive surgery.. · More studies are needed on the pathophysiology of malignant cerebral edema, prediction models including imaging and biomarkers to identify which subgroup of patients will benefit from decompressive surgery.. · More research is needed on factors associated with morbidity and mortality after cranioplasty, safety and efficacy of implants, and comparisons between them.. · Further studies are needed to assess the long-term effects of physical disability and quality of life of survivors after surgery, particularly those with severe neurological deficits..

Hinge craniotomy as an alternative technique for patients with refractory intracranial hypertension

Introduction

Decompressive craniectomy (DC) can save brain tissue, but unfortunately it has many limitations and complications. Hinge craniotomy (HC), as less aggressive method seems to be adequate alternative not only to DC but also to conservative treatment.

Research question

Presentation of the results of modified surgical techniques of cranial decompression and comparing with more and less aggressive medical options.

Material and methods

A prospective clinical study was conducted during 86 months. Comatose patients who suffered refractory intracranial hypertension (RIH) were treated. Altogether, 137 patients have been evaluated. The final outcome of all patients in the study was evaluated after 6 months.

Results

Both surgical options resulted in adequate control of intracranial pressure (ICP). HC method was shown to have the lowest probability of worsening from a prior state of relative stability.

Discussion and conclusion

There was no statistically significant difference between methods to treatment of DC or HC, meaning the final outcome of patients treated in any manner. There was similar rate of early and late complications.

Non-coding RNAs and Exosomal Non-coding RNAs in Traumatic Brain Injury: the Small Player with Big Actions

Nowadays, there is an increasing concern regarding traumatic brain injury (TBI) worldwide since substantial morbidity is observed after it, and the long-term consequences that are not yet fully recognized. A number of cellular pathways related to the secondary injury in brain have been identified, including free radical production (owing to mitochondrial dysfunction), excitotoxicity (regulated by excitatory neurotransmitters), apoptosis, and neuroinflammatory responses (as a result of activation of the immune system and central nervous system). In this context, non-coding RNAs (ncRNAs) maintain a fundamental contribution to post-transcriptional regulation. It has been shown that mammalian brains express high levels of ncRNAs that are involved in several brain physiological processes. Furthermore, altered levels of ncRNA expression have been found in those with traumatic as well non-traumatic brain injuries. The current review highlights the primary molecular mechanisms participated in TBI that describes the latest and novel results about changes and role of ncRNAs in TBI in both clinical and experimental research.

Risk of Migraine after Traumatic Brain Injury and Effects of Injury Management Levels and Treatment Modalities: A Nationwide Population-Based Cohort Study in Taiwan

Traumatic brain injury (TBI) causes several long-term disabilities, particularly headaches. An association between TBI and subsequent migraine has been reported. However, few longitudinal studies have explained the link between migraine and TBI. Moreover, the modifying effects of treatment remain unknown. This retrospective cohort study used records from Taiwan's Longitudinal Health Insurance Database 2005 to evaluate the risk of migraine among patients with TBI and to determine the effects of different treatment modalities. Initially, 187,906 patients, aged ≥ 18 years, who were diagnosed as TBI in 2000, were identified. In total, 151,098 patients with TBI and 604,394 patients without TBI were matched at a 1:4 ratio according to baseline variables during the same observation period. At the end of follow-up, 541 (0.36%) and 1491 (0.23%) patients in the TBI and non-TBI groups, respectively, developed migraine. The TBI group exhibited a higher risk of migraine than the non-TBI group (adjusted HR: 1.484). Major trauma (Injury Severity Score, ISS ≥ 16) was associated with a higher migraine risk than minor trauma (ISS < 16) (adjusted HR: 1.670). However, migraine risk did not differ significantly after surgery or occupational/physical therapy. These findings highlight the importance of long-term follow-up after TBI onset and the need to investigate the underlying pathophysiological link between TBI and subsequent migraine.

A prospective, randomized, controlled study comparing two surgical procedures of decompressive craniectomy in patients with traumatic brain injury: Dural closure without dural closure

Decompressive craniectomy (DC) is used to treat severe traumatic brain injury [TBI]. The present study compared dural open and closed surgical procedures for DC and their relationship with Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (E) (GOS-E) scores and survival in prospective randomized controlled TBI patients. Patients aged 10-65 (36.97 ± 13.23) with DC were hospitalized in the neurotrauma unit of King George's Medical University, Lucknow, India. The patients were randomized into test; with dural closure (n = 60) and control without dural closure (OD) (n = 60) groups. After decompressive craniectomy, patients were monitored daily until hospital discharge or death and for three months. GSC/E leakage, infection, and functional status were also assessed. Age (p = 0.795), sex (p = 0.104), mode of injury (p = 0.195), GCS score (p = 0.40, p = 0.469), Rotterdam score (p = 0.731), and preoperative midline shift (MLS) (p = 0.378) did not vary between the OD and CD groups. Neither technique affected the mortality, motor score, or pupil response (p > 0.05). After one and three months, GOS extension was associated with open and closed dural procedures (p = 0.089). Intracranial pressure, brain bulge, GCS score, and MLS were not associated with theoperative method(p > 0.05). The open dural group had a significantly shorter procedure time than the closed dural group (P = 0.026). Both groups showed no significant difference (p > 0.05) between CSF leak and post-traumatic hydrocephalus. Dural opensurgery for a compressed craniectomy is shorter and not associated with significant surgical consequences compared to close dural close surgery.

Closure intracranial pressure is an objective intraoperative determinant of the adequacy of surgical decompression in traumatic acute subdural haematoma: a multicentre observational study

PURPOSE

Acute subdural haematoma (ASDH) is associated with severe traumatic brain injury and poor outcomes. Although guidelines exist for the decompression of ASDH, the question of adequate decompression remains unanswered. The authors examined the relationship of intracranial pressure (ICP) on closure with outcomes to determine its utility in the determination of adequate ASDH decompression.

METHODS

A multicentre retrospective review of 105 consecutive patients with ASDH who underwent decompressive surgery was performed. Receiver operating characteristic (ROC) analysis with internal validation was performed to determine an ICP threshold for the division of patients into the inadequate and good ICP groups. Multivariable analyses were performed for both inpatient and long-term outcomes.

RESULTS

An ICP threshold of 10 mmHg was identified with a 91.5% specificity, 45.7% sensitivity, and a positive and negative predictive value of 80.8% and 68.4%. There were 26 patients (24.8%) and 79 patients (75.2%) in the inadequate and good ICP groups, respectively. After adjustment, the inadequate ICP group was associated with increased postoperative usage of mannitol (OR 14.2, p < 0.001) and barbiturates (OR 150, p = 0.001). Inadequate ICP was also associated with increased inpatient mortality (OR 24.9, p < 0.001), and a lower rate of favourable MRS at 1 year (OR 0.08, p = 0.008). The complication rate was similar amongst the groups.

CONCLUSIONS

Closure ICP is a novel, objective, and actionable intraoperative biomarker that correlates with inpatient and long-term outcomes in ASDH. Various surgical manoeuvres can be undertaken to achieve this target safely. Large-scale prospective studies should be performed to validate this ICP threshold.

Comparative effectiveness of different surgical procedures for traumatic acute epidural haematoma: study protocol for Prospective, Observational Real-world Treatments of AEDH in Large-scale Surgical Cases (PORTALS-AEDH)

INTRODUCTION

Controversy and variation exist in surgical management for acute epidural haematoma (AEDH). Although craniotomy for AEDH is conventionally employed, no specific evaluation on the necessity of decompressive craniectomy (DC) followed by AEDH evacuation has been performed.

METHODS AND ANALYSIS

This is a multicentre prospective, phase III observational study that evaluates different surgical managements for the AEDH. Patients of both genders, aged 18-65 years, presenting to the emergency room with a clinical and radiological diagnosis of AEDH, complying with other inclusion and exclusion criteria, are enrolled. Clinical information, including diagnosis of AEDH, radiological information, treatment procedures and follow-up data of 1, 3 and 6 months post-injury, is collected on 2000 eligible patients among 263 hospitals in China. Recruitment for the study started in April 2021, and inclusion will be continued until the sample size is obtained, expected is an inclusion period of 24 months. The interventions of concern are surgical treatments for AEDH, including craniotomy and DC. The primary outcome is the Glasgow Outcome Score-Extended 6 months post-injury. Secondary outcomes include the incidence of postoperative cerebral infarction, the incidence of additional craniocerebral surgery and other evaluation indicators within 6 months post-injury.

ETHICS AND DISSEMINATION

The study protocol has been approved by the ethics committee and institutional review board of Renji Hospital, School of Medicine, Shanghai Jiao Tong University. All study investigators strictly follow the Declaration of Helsinki and Human Biomedical Research Ethical Issues. Signed written informed consent will be obtained from all enrolled patients. The trial results will be disseminated through academic conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04229966.

Surface Area of Decompressive Craniectomy Predicts Bone Flap Failure after Autologous Cranioplasty: A Radiographic Cohort Study

Skull bone graft failure is a potential complication of autologous cranioplasty after decompressive craniectomy (DC). Our objective was to investigate the association of graft size with subsequent bone graft failure after autologous cranioplasty. This single-center retrospective cohort study included patients age ≥18 years who underwent primary autologous cranioplasty between 2010 and 2017. The primary outcome was bone flap failure requiring graft removal. Demographic, clinical, and radiographic factors were recorded; three-dimensional (3D) reconstructive imaging was used to perform accurate measurements. Univariate and multi-variate regression analysis were performed to identify risk factors for the primary outcome. Of the 131 patients who underwent primary autologous cranioplasty, 25 (19.0%) underwent removal of the graft after identification of bone flap necrosis on computed tomography (CT); 16 (64%) of these were culture positive. The mean surface area of craniectomy defect was 128.5 cm² for patients with bone necrosis and 114.9 cm² for those without bone necrosis. Linear regression analysis demonstrated that size of craniectomy defect was independently associated with subsequent bone flap failure; logistic regression analysis demonstrated a defect area >125 cm² was independently associated with failure (odds ratio [OR] 3.29; confidence interval [CI]: 0.249-2.135). Patient- and operation-specific variables were not significant predictors of bone necrosis. Our results showed that increased size of antecedent DC is an independent risk factor for bone flap failure after autologous cranioplasty. Given these findings, clinicians should consider the increased potential of bone flap failure after autologous cranioplasty among patients whose initial DC was >125 cm².

A Multilayered Dural Repair Technique Using Duragen for Early Cranioplasty Following Decompressive Craniotomy

Decompressive craniotomy is a neurosurgical emergency procedure in which a large skull bone is removed and the dura matter is extensively opened. Duraplasty is required to avoid cerebrospinal fluid (CSF) leakage during the decompressive craniotomy. DuraGen® is a safe and effective type I collagen matrix graft, which is frequently used in decompressive craniotomy procedures. Since DuraGen® does not require labor-intensive suturing, the operative time is shortened by DuraGen® closure with sufficient tightness preventing CSF leakage. Recently, early cranioplasty is preferred to achieve efficient rehabilitation after decompressive craniotomy. Although evidence of efficacy and safety of DuraGen® has been increasing in the management of duraplasty, no reports have previously discussed the condition of DuraGen® during the second surgery (cranioplasty) at this early timing. DuraGen®-derived neodura develops a mature dura 1 year post its placement, and the neodura remain fragile at this early time point. A deconstructed fragile neodura may result in postoperative CSF leakage. Here, we illustrated a multilayered dural repair technique with DuraGen® to avoid disruption of the fragile neodura during early cranioplasty.

Transcranial direct current stimulation in patients after decompressive craniectomy: a finite element model to investigate factors affecting the cortical electric field

Objective

To simulate the process of transcranial direct current stimulation (tDCS) on patients after decompressive craniectomy (DC), and to model cortical electric field distributions under different electrode montages, we constructed a finite element model that represented the human head at high resolution.

Methods

Using computed tomography images, we constructed a human head model with high geometrical similarity. The removed bone flap was simplified to be circular with a diameter of 12 cm. We then constructed finite element models according to bioelectrical parameters. Finally, we simulated tDCS on the finite element models under different electrode montages.

Results

Inward current had a linear relationship with peak electric field value, but almost no effect on electric field distribution. If the anode was not over the skull hole (configuration 2), there was almost no difference in electric field magnitude and focality between the circular and square electrodes. However, if the anode was right over the hole (configuration 1), the circular electrodes led to higher peak electric field values and worse focality. In addition, configuration 1 significantly decreased focality compared with configuration 2.

Conclusion

Our results might serve as guidelines for selecting current and electrode montage settings when performing tDCS on patients after DC.

Effects of Primary Decompressive Craniectomy on the Outcomes of Serious Traumatic Brain Injury with Mass Lesions, and Independent Predictors of Operation Decision

BACKGROUND

Although operative indications for traumatic brain injury (TBI) are known, neurosurgeons are unsure whether to remove the bone flap after mass lesion extraction, and an efficient scoring system for predicting which patients should undergo decompressive craniectomy (DC) does not exist.

METHODS

Nine parameters were assessed. In total, 245 patients with severe TBI were retrospectively assessed from June 2015 to May 2019, who underwent DC or craniotomy to remove mass lesions. The 6-month mortality and Extended Glasgow Outcome Scale scores were compared between the DC and craniotomy groups. Using univariable and multivariable logistic regression equations, receiver operating characteristic curves were obtained for predicting the decision for DC.

RESULTS

The overall 6-month mortality in the entire cohort was 11.43% (28/245). Patients undergoing DC had lower mean preoperative Glasgow Coma Scale scores (P = 0.01), and higher amounts of individuals with a Glasgow Coma Scale score of 6 (P = 0.007), unresponsive pupillary light reflex (P < 0.001), closed basal cisterns (P < 0.001), and diffuse injury (P = 0.025), compared with the craniotomy group. Because of high disease severity, individuals administered primary DC showed increased 6-month mortality compared with the craniotomy group. However, in surviving patients, favorable Extended Glasgow Outcome Scale rates were similar in both groups. Pupillary light reflex and basal cisterns were independent predictors of the DC decision. Based on receiver operating characteristic curves, the model had sensitivity and specificity of 81.6% and 84.9%, respectively, in predicting the probability of DC.

CONCLUSIONS

These preliminary data showed that primary DC may benefit some patients with severe TBI with mass lesions. In addition, unresponsive preoperative pupil reaction and closed basal cistern could predict the DC decision.

Correlations Between the Glasgow Score and the Survival Period in Patients with Severe Traumatic Brain Injury

Traumatic brain injury (TBI) contributes by 30% to the mortality induced by traumatic injuries, also being one of the major causes of invalidity worldwide. The clinical classification of the severity of mild, moderate or severe TBI is made according to the Glasgow scale, according to the patient's conscious state, motric changes, speech changes and eye opening. In our study, we evaluated the correlation between the Glasgow score at admission and the survival period of patients suffering from TBI, using the data recorded in the Forensic Medicine Institute of Craiova between 2011-2017 on 1005 cases with the diagnosis of death by TBI. We observed that TBI affects persons of all ages, starting from babies up to the elderly aged over 90 years old. Regarding the generation mechanism, most deaths were caused by fallings (438 cases, 43.58%), followed by car accidents (333 cases, representing 33.13%). The number of patients who presented a post-traumatic survival period was 802 (79.80%), of which 779 adults (77.51%) and 23 children (2.29%). Among these, 785 (78.11%-764 adults and 21 children) were hospitalized, while in 64.58% of the TBI patients there was recorded the Glasgow score at admission. 75% of the TBI patients in whom there was recorded the Glasgow score presented a 1st-4th coma degree, with a Glasgow score from 3 to 8 and only 25% had a slightly altered or preserved conscious state, with a Glasgow score=9-15. The survival period varied from less than 24 hours to over 15 days. In the hospitalized patients, there were performed emergency surgeries in 269 (26.76%) cases, the surgical intervention being temporized in 108 (10.74%) patients.

First-In-Human Experience With Integration of Wireless Intracranial Pressure Monitoring Device Within a Customized Cranial Implant

BACKGROUND

Decompressive craniectomy is a lifesaving treatment for intractable intracranial hypertension. For patients who survive, a second surgery for cranial reconstruction (cranioplasty) is required. The effect of cranioplasty on intracranial pressure (ICP) is unknown.

OBJECTIVE

To integrate the recently Food and Drug Administration-approved, fully implantable, noninvasive ICP sensor within a customized cranial implant (CCI) for postoperative monitoring in patients at high risk for intracranial hypertension.

METHODS

A 16-yr-old female presented for cranioplasty 4-mo after decompressive hemicraniectomy for craniocerebral gunshot wound. Given the persistent transcranial herniation with concomitant subdural hygroma, there was concern for intracranial hypertension following cranioplasty. Thus, cranial reconstruction was performed utilizing a CCI with an integrated wireless ICP sensor, and noninvasive postoperative monitoring was performed.

RESULTS

Intermittent ICP measurements were obtained twice daily using a wireless, handheld monitor. The ICP ranged from 2 to 10 mmHg in the supine position and from -5 to 4 mmHg in the sitting position. Interestingly, an average of 7 mmHg difference was consistently noted between the sitting and supine measurements.

CONCLUSION

This first-in-human experience demonstrates several notable findings, including (1) newfound safety and efficacy of integrating a wireless ICP sensor within a CCI for perioperative neuromonitoring; (2) proven restoration of normal ICP postcranioplasty despite severe preoperative transcranial herniation; and (3) proven restoration of postural ICP adaptations following cranioplasty. To the best of our knowledge, this is the first case demonstrating these intriguing findings with the potential to fundamentally alter the paradigm of cranial reconstruction.

Long-Term Effect of Decompressive Craniectomy on Intracranial Pressure and Possible Implications for Intracranial Fluid Movements

BACKGROUND

Decompressive craniectomy (DC) is used in cases of severe intracranial hypertension or impending intracranial herniation. DC effectively lowers intracranial pressure (ICP) but carries a risk of severe complications related to abnormal ICP and/or cerebrospinal fluid (CSF) circulation, eg, hygroma formation, hydrocephalus, and "syndrome of the trephined."

OBJECTIVE

To study the long-term effect of DC on ICP, postural ICP regulation, and intracranial pulse wave amplitude (PWA).

METHODS

Prospective observational study including patients undergoing DC during a 12-mo period. Telemetric ICP sensors (Neurovent-P-tel; Raumedic, Helmbrechts, Germany) were implanted in all patients. Following discharge from the neuro intensive care unit (NICU), scheduled weekly ICP monitoring sessions were performed during the rehabilitation phase.

RESULTS

A total of 16 patients (traumatic brain injury: 7, stroke: 9) were included (median age: 55 yr, range: 19-71 yr). Median time from NICU discharge to cranioplasty was 48 d (range: 16-98 d) and during this period, mean ICP gradually decreased from 7.8 ± 2.0 mm Hg to -1.8 ± 3.3 mm Hg (P = .02). The most pronounced decrease occurred during the first month. Normal postural ICP change was abolished after DC for the entire follow-up period, ie, there was no difference between ICP in supine and sitting position (P = .67). PWA was markedly reduced and decreased from initially 1.2 ± 0.7 mm Hg to 0.4 ± 0.3 mm Hg (P = .05).

CONCLUSION

Following NICU discharge, ICP decreases to negative values within 4 wk, normal postural ICP regulation is lost and intracranial PWA is diminished significantly. These abnormalities might have implications for intracranial fluid movements (eg, CSF and/or glymphatic flow) following DC and warrants further investigations.

Does the skull Hounsfield unit predict shunt dependent hydrocephalus after decompressive craniectomy for traumatic acute subdural hematoma?

Background and purpose

Posttraumatic hydrocephalus affects 11.9%–36% of patients undergoing decompressive craniectomy (DC) after traumatic brain injury and necessitates a ventriculo-peritoneal shunt placement. As bone and arachnoid trabeculae share the same collagen type, we investigated possible connections between the skull Hounsfield unit (HU) values and shunt-dependent hydrocephalus (SDHC) in patients that received cranioplasty after DC for traumatic acute subdural hematoma (SDH).

Methods

We measured HU values in the frontal bone and internal occipital protuberance from admission brain CT. Receiver operating characteristic curve analysis was performed to identify the optimal cut-off skull HU values for predicting SDHC in patients receiving cranioplasty after DC due to traumatic acute SDH. We investigated independent predictive factors for SDHC occurrence using multivariable logistic regression analysis.

Results

A total of 162 patients (>15 years of age) were enrolled in the study over an 11-year period from two university hospitals. Multivariable logistic analysis revealed that the group with simultaneous frontal skull HU ≤797.4 and internal occipital protuberance HU ≤586.5 (odds ratio, 8.57; 95% CI, 3.05 to 24.10; P<0.001) was the only independent predictive factor for SDHC in patients who received cranioplasty after DC for traumatic acute SDH.

Conclusions

Our study reveals a potential relationship between possible low bone mineral density and development of SDHC in traumatic acute SDH patients who had undergone DC. Our findings provide deeper insight into the association between low bone mineral density and hydrocephalus after DC for traumatic acute SDH.

Recent advances in traumatic brain injury

Traumatic brain injury (TBI) is the most common cause of death and disability in those aged under 40 years in the UK. Higher rates of morbidity and mortality are seen in low-income and middle-income countries making it a global health challenge. There has been a secular trend towards reduced incidence of severe TBI in the first world, driven by public health interventions such as seatbelt legislation, helmet use, and workplace health and safety regulations. This has paralleled improved outcomes following TBI delivered in a large part by the widespread establishment of specialised neurointensive care. This update will focus on three key areas of advances in TBI management and research in moderate and severe TBI: refining neurointensive care protocolized therapies, the recent evidence base for decompressive craniectomy and novel pharmacological therapies. In each section, we review the developing evidence base as well as exploring future trajectories of TBI research.

How I do it: supra-tentorial unilateral decompressive craniectomy

BACKGROUND

Decompressive craniectomy is a surgical way to treat intracranial hypertension, by removing a large flap of skull bone.

METHOD

We report the case of a 48 years old right-handed man presenting an acute ischaemic stroke of all the right sylvian artery area, with rapid clinic deterioration then coma. Severe intracranial hypertension was confirmed by transcranial Doppler. In emergency, we decided to perform a right-side decompressive craniectomy.

CONCLUSION

Six months later, he is in rehabilitation with "only" a left hemiplegia and a very good relational life. His modified Rankin score is 3. Decompressive craniectomy saved this patient's life, that is why we think this surgical technique must be explained and mastered.

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.

Predictors of primary autograft cranioplasty survival and resorption after craniectomy

OBJECTIVE

Craniectomy is a common neurosurgical procedure that reduces intracranial pressure, but survival necessitates cranioplasty at a later stage, after recovery from the primary insult. Complications such as infection and resorption of the autologous bone flap are common. The risk factors for complications and subsequent bone flap removal are unclear. The aim of this multicenter, retrospective study was to evaluate the factors affecting the outcome of primary autologous cranioplasty, with special emphasis on bone flap resorption.

METHODS

The authors identified all patients who underwent primary autologous cranioplasty at 3 tertiary-level university hospitals between 2002 and 2015. Patients underwent follow-up until bone flap removal, death, or December 31, 2015.

RESULTS

The cohort comprised 207 patients with a mean follow-up period of 3.7 years (SD 2.7 years). The overall complication rate was 39.6% (82/207), the bone flap removal rate was 19.3% (40/207), and 11 patients (5.3%) died during the follow-up period. Smoking (OR 3.23, 95% CI 1.50-6.95; p = 0.003) and age younger than 45 years (OR 2.29, 95% CI 1.07-4.89; p = 0.032) were found to independently predict subsequent autograft removal, while age younger than 30 years was found to independently predict clinically relevant bone flap resorption (OR 4.59, 95% CI 1.15-18.34; p = 0.03). The interval between craniectomy and cranioplasty was not found to predict either bone flap removal or resorption.

CONCLUSIONS

In this large, multicenter cohort of patients with autologous cranioplasty, smoking and younger age predicted complications leading to bone flap removal. Very young age predicted bone flap resorption. The authors recommend that physicians extensively inform their patients of the pronounced risks of smoking before cranioplasty.

Cranioplasty After Severe Traumatic Brain Injury: Effects of Trauma and Patient Recovery on Cranioplasty Outcome

Background

In patients with severe traumatic brain injury (sTBI) treated with decompressive craniectomy (DC), factors affecting the success of later cranioplasty are poorly known.

Objective

We sought to investigate if injury- and treatment-related factors, and state of recovery could predict the risk of major complications in cranioplasty requiring implant removal, and how these complications affect the outcome.

Methods

A retrospective cohort of 40 patients with DC following sTBI and subsequent cranioplasty was studied. Non-injury-related factors were compared with a reference population of 115 patients with DC due to other conditions.

Results

Outcome assessed 1 day before cranioplasty did not predict major complications leading to implant removal. Successful cranioplasty was associated with better outcome, whereas a major complication attenuates patient recovery: in patients with favorable outcome assessed 1 year after cranioplasty, major complication rate was 7%, while in patients with unfavorable outcome the rate was 42% (p = 0.003). Of patients with traumatic subarachnoid hemorrhage (tSAH) on admission imaging 30% developed a major complication, while none of patients without tSAH had a major complication (p = 0.014). Other imaging findings, age, admission Glasgow Coma Scale, extracranial injuries, length of stay at intensive care unit, cranioplasty materials, and timing of cranioplasty were not associated with major complications.

Conclusion

A successful cranioplasty after sTBI and DC predicts favorable outcome 1 year after cranioplasty, while stage of recovery before cranioplasty does not predict cranioplasty success or failure. tSAH on admission imaging is a major risk factor for a major complication leading to implant removal.

Analysis of direct costs of decompressive craniectomy in victims of traumatic brain injury

ABSTRACT Background: Decompressive craniectomy is a procedure required in some cases of traumatic brain injury (TBI). This manuscript evaluates the direct costs and outcomes of decompressive craniectomy for TBI in a developing country and describes the epidemiological profile. Methods: A retrospective study was performed using a five-year neurosurgical database, taking a sample of patients with TBI who underwent decompressive craniectomy. Several variables were considered and a formula was developed for calculating the total cost. Results: Most patients had multiple brain lesions and the majority (69.0%) developed an infectious complication. The general mortality index was 68.8%. The total cost was R$ 2,116,960.22 (US$ 661,550.06) and the mean patient cost was R$ 66,155.00 (US$ 20,673.44). Conclusions: Decompressive craniectomy for TBI is an expensive procedure that is also associated with high morbidity and mortality. This was the first study performed in a developing country that aimed to evaluate the direct costs. Prevention measures should be a priority.

[Reasonability and efficacy of decompressive craniectomy in patients with subarachnoid hemorrhage after microsurgical aneurysm exclusion]

In recent years, the so-called primary or preventive decompressive craniectomy (DC) has been increasingly used in patients with aneurysmal subarachnoid hemorrhage (SAH). The main goal of the technique is prevention of refractory intracranial hypertension (ICH) and its consequences.

PURPOSE

The study purpose was to define the CT criteria for reasonability and efficacy of DC as well as clarification of the indications for preventive DC in patients with SAH after microsurgical aneurysm exclusion.

MATERIAL AND METHODS

The study included 46 patients who underwent microsurgical clipping of aneurysms and DC in the period between 2010 and 2016. All patients underwent surgery in the period of 1 to 12 days after SAH. Preventive DC (imultaneously with clipping of aneurysms) was performed in 38 patients. Secondary (delayed) DC was performed in 8 patients.

RESULTS

Mortality in a group of all patients with DC was 15.2%. Preventive DC was considered as 'reasonable' when the patient had signs of cerebral edema in the postoperative period. The X-ray criteria of reasonable DC included a more than 5 mm brain prolapse into the trephination defect or a lateral dislocation of more than 5 mm. If the patient had no prolapse and dislocation in the postoperative period, DC was considered 'unreasonable'. Among patients with ICH in the postoperative period, including 20 patients with reasonable preventive DC and 8 patients with delayed DC, mortality was 25%. The CT signs of efficient DC were found to be a more than 5 mm brain prolapse into the trephination defect in combination with a decrease in the lateral dislocation less than 5 mm. All seven patients with inefficient DC in our group died. To clarify the indications for preventive DC, we analyzed various preoperative factors in patients with reasonable and unreasonable DC.

CONCLUSION

In most cases, preventive DC in microsurgical aneurysm exclusion is indicated for patients in an extremely grave condition (Hunt-Hess Grade V), a lateral displacement of the mline structures of more than 5 mm, an intracranial hematoma of over 30 mL, and symptoms of acute cerebral ischemia (pronounced cerebral vasospasm and emerging ischemic foci).

Decompressive craniectomy in the management of intracranial hypertension after traumatic brain injury: a systematic review and meta-analysis

We aim to perform a systematic review and meta-analysis to examine the prognostic value of decompressive craniectomy (DC) in patients with traumatic intracranial hypertension. PubMed, EMBASE, Cochrane Controlled Trials Register, Web of Science, http://clinicaltrials.gov/ were searched for eligible studies. Ten studies were included in the systematic review, with four randomized controlled trials involved in the meta-analysis, where compared with medical therapies, DC could significantly reduce mortality rate [risk ratio (RR), 0.59; 95% confidence interval (CI), 0.47–0.74, P < 0.001], lower intracranial pressure (ICP) [mean difference (MD), −2.12 mmHg; 95% CI, −2.81 to −1.43, P < 0.001], decrease the length of ICU stay (MD, −4.63 days; 95% CI, −6.62 to −2.65, P < 0.001) and hospital stay (MD, −14.39 days; 95% CI, −26.00 to −2.78, P = 0.02), but increase complications rate (RR, 1.94; 95% CI, 1.31–2.87, P < 0.001). No significant difference was detected for Glasgow Outcome Scale at six months (RR, 0.85; 95% CI, 0.61–1.18, P = 0.33), while in subgroup analysis, early DC would possibly result in improved prognosis (P = 0.04). Results from observational studies supported pooled results except prolonged length of ICU and hospital stay. Conclusively, DC seemed to effectively lower ICP, reduce mortality rate but increase complications rate, while its benefit on functional outcomes was not statistically significant.

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.

APOE ε4 positive patients suffering severe traumatic head injury are more prone to undergo decompressive hemicraniectomy

OBJECT

In this paper we tested the hypothesis if patients with severe traumatic brain injury and presence of the apolipoprotein E (APOE) ε4 allele are more prone to undergo the surgical procedure decompressive hemicraniectomy (DC) in order to bring the intracranial pressure (ICP) under control.

METHODS

In this prospective consecutive study patients with sTBI were enrolled (n=48). Inclusion criteria were arrival to our level one trauma university hospital within 24h after trauma, patient age between 15 and 70years, Glasgow Coma Scale (GCS) score ≤8 at the time of intubation and sedation, an initial cerebral perfusion pressure >10mmHg. Venous blood was sampled for APOE genotype determination. Clinical outcome at 6months after injury was assessed with the Extended Glasgow Outcome Scale (GOSE). All surgical procedures needed for each patient were registered.

RESULTS

Patients with the APOE ε4 allele were significantly overrepresented in the DC group. In the APOE ε4+DC group, ICP_max and ICP_mean during the first 36h were significantly higher and GOSE was significantly worse at 6months.

CONCLUSION

Our data suggest that patients with the APOE ε4 allele are predisposed for the need of DC more often than patients without the APOE ε4 allele. Thus, it seems to be of importance to consider the APOE genotype in patients suffering severe traumatic brain injury in order to forecast the need for a more exquisite intensive care.

Decompressive craniectomy for traumatic intracranial hypertension: application in children

Traumatic brain injury remains prevalent in children, particularly within the adolescent age group. In severe injury, the priority of treatment is to stabilise the patient initially and prevent the evolution of brain swelling and secondary ischaemia using tiers of medical therapy. The final stage of intervention for such patients is a decompressive craniectomy. Here in, we identify the current evidence for performing decompressive crainectomy in children including the results from the RESCUEicp study.

Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension

BACKGROUND

The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear.

METHODS

From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to undergo decompressive craniectomy or receive ongoing medical care. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOS-E) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 6 months. The primary-outcome measure was analyzed with an ordinal method based on the proportional-odds model. If the model was rejected, that would indicate a significant difference in the GOS-E distribution, and results would be reported descriptively.

RESULTS

The GOS-E distribution differed between the two groups (P<0.001). The proportional-odds assumption was rejected, and therefore results are reported descriptively. At 6 months, the GOS-E distributions were as follows: death, 26.9% among 201 patients in the surgical group versus 48.9% among 188 patients in the medical group; vegetative state, 8.5% versus 2.1%; lower severe disability (dependent on others for care), 21.9% versus 14.4%; upper severe disability (independent at home), 15.4% versus 8.0%; moderate disability, 23.4% versus 19.7%; and good recovery, 4.0% versus 6.9%. At 12 months, the GOS-E distributions were as follows: death, 30.4% among 194 surgical patients versus 52.0% among 179 medical patients; vegetative state, 6.2% versus 1.7%; lower severe disability, 18.0% versus 14.0%; upper severe disability, 13.4% versus 3.9%; moderate disability, 22.2% versus 20.1%; and good recovery, 9.8% versus 8.4%. Surgical patients had fewer hours than medical patients with intracranial pressure above 25 mm Hg after randomization (median, 5.0 vs. 17.0 hours; P<0.001) but had a higher rate of adverse events (16.3% vs. 9.2%, P=0.03).

CONCLUSIONS

At 6 months, decompressive craniectomy in patients with traumatic brain injury and refractory intracranial hypertension resulted in lower mortality and higher rates of vegetative state, lower severe disability, and upper severe disability than medical care. The rates of moderate disability and good recovery were similar in the two groups. (Funded by the Medical Research Council and others; RESCUEicp Current Controlled Trials number, ISRCTN66202560 .).

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.

Decompressive craniectomy following traumatic brain injury: developing the evidence base

In the context of traumatic brain injury (TBI), decompressive craniectomy (DC) is used as part of tiered therapeutic protocols for patients with intracranial hypertension (secondary or protocol-driven DC). In addition, the bone flap can be left out when evacuating a mass lesion, usually an acute subdural haematoma (ASDH), in the acute phase (primary DC). Even though, the principle of "opening the skull" in order to control brain oedema and raised intracranial pressure has been practised since the beginning of the 20th century, the last 20 years have been marked by efforts to develop the evidence base with the conduct of randomised trials. This article discusses the merits and challenges of this approach and provides an overview of randomised trials of DC following TBI. An update on the RESCUEicp study, a randomised trial of DC versus advanced medical management (including barbiturates) for severe and refractory post-traumatic intracranial hypertension is provided. In addition, the rationale for the RESCUE-ASDH study, the first randomised trial of primary DC versus craniotomy for adult head-injured patients with an ASDH, is presented.

Paradoxical Herniation After Unilateral Decompressive Craniectomy Predicts Better Patient Survival: A Retrospective Analysis of 429 Cases

Paradoxical herniation (PH) is a life-threatening emergency after decompressive craniectomy. In the current study, we examined patient survival in patients who developed PH after decompressive craniectomy versus those who did not. Risk factors for, and management of, PH were also analyzed. This retrospective analysis included 429 consecutive patients receiving decompressive craniectomy during a period from January 2007 to December 2012. Mortality rate and Glasgow Outcome Scale (GOS) were compared between those who developed PH (n = 13) versus those who did not (n = 416). A stepwise multivariate logistic regression analysis was carried out to examine the risk factors for PH. The overall mortality in the entire sample was 22.8%, with a median follow-up of 6 months. Oddly enough, all 13 patients who developed PH survived beyond 6 months. Glasgow Coma Scale did not differ between the 2 groups upon admission, but GOS was significantly higher in subjects who developed PH. Both the disease type and coma degree were comparable between the 13 PH patients and the remaining 416 patients. In all PH episodes, patients responded to emergency treatments that included intravenous hydration, cerebral spinal fluid drainage discontinuation, and Trendelenburg position. A regression analysis indicated the following independent risk factors for PH: external ventriculostomy, lumbar puncture, and continuous external lumbar drainage. The rate of PH is approximately 3% after decompressive craniectomy. The most intriguing findings of the current study were the 0% mortality in those who developed PH versus 23.6% mortality in those who did not develop PH and significant difference of GOS score at 6-month follow-up between the 2 groups, suggesting that PH after decompressive craniectomy should be managed aggressively. The risk factors for PH include external ventriculostomy, ventriculoperitoneal shunt, lumbar puncture, and continuous external lumbar drainage.

Decompressive craniectomy in neurocritical care

OPINION STATEMENT

Decompressive craniectomy (DC) involves the removal of a portion of the skull in the setting of life threatening brain edema or potentially uncontrollable intracranial pressures. Often performed on an emergent basis, evaluation and arrangement for DC should be swift and decisive. However, the evidence base for DC in the wide range of conditions for which it is currently performed is still developing. The procedure is associated with a number of complications and ethical considerations; thus, its place in contemporary practice remains controversial. While randomized trials conducted in the last decade have provided valuable data on the indications, eligibility criteria, and outcomes for DC in the treatment of traumatic brain injury and malignant middle cerebral artery infarction, important outstanding issues continue to complicate the decision to pursue DC on an individual case basis and in the number of other clinical settings presenting with brain edema and intracranial hypertension. In this review, we present the existing evidence and remaining questions regarding DC in various neurologic conditions including traumatic brain injury, ischemic stroke, subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, encephalitis, and others. We also discuss perioperative considerations and ethical issues likely to be encountered by clinicians caring for patients and families who are considering or have undergone DC.

A new improved method for assessing brain deformation after decompressive craniectomy

Background

Decompressive craniectomy (DC) is a surgical intervention used following traumatic brain injury to prevent or alleviate raised intracranial pressure. However the clinical effectiveness of the intervention remains in doubt. The location of the craniectomy (unilateral or bifrontal) might be expected to change the brain deformation associated with the operation and hence the clinical outcome. As existing methods for assessing brain deformation have several limitations, we sought to develop and validate a new improved method.

Methods

Computed tomography (CT) scans were taken from 27 patients who underwent DC (17 bifrontal patients and 10 unilateral patients). Pre-operative and post-operative images were processed and registered to determine the change in brain position associated with the operation. The maximum deformation in the herniated brain, the change in volume and estimates of the craniectomy area were determined from the images. Statistical comparison was made using the Pearson’s correlation coefficient r and a Welch’s two-tailed T-test, with statistical significance reported at the 5% level.

Results

There was a reasonable correlation between the volume increase and the maximum brain displacement (r = 0.64), a low correlation between the volume increase and the craniectomy area (r = 0.30) and no correlation between the maximum displacement and the craniectomy area (r = −0.01). The maximum deformation was significantly lower (P  = 0.023) in the bifrontal patients (mean = 22.5 mm) compared with the unilateral patients (mean = 29.8 mm). Herniation volume was significantly lower (P = 0.023) in bifrontal (mean = 50.0 ml) than unilateral patients (mean = 107.3 ml). Craniectomy area was not significantly different for the two craniectomy locations (P = 0.29).

Conclusions

A method has been developed to quantify changes in brain deformation due to decompressive craniectomy from CT images and allow comparison between different craniectomy locations. Measured displacement is a reasonable way to characterise volume changes.

Development of a finite element model of decompressive craniectomy

Decompressive craniectomy (DC), an operation whereby part of the skull is removed, is used in the management of patients with brain swelling. While the aim of DC is to reduce intracranial pressure, there is the risk that brain deformation and mechanical strain associated with the operation could damage the brain tissue. The nature and extent of the resulting strain regime is poorly understood at present. Finite element (FE) models of DC can provide insight into this applied strain and hence assist in deciding on the best surgical procedures. However there is uncertainty about how well these models match experimental data, which are difficult to obtain clinically. Hence there is a need to validate any modelling approach outside the clinical setting. This paper develops an axisymmetric FE model of an idealised DC to assess the key features of such an FE model which are needed for an accurate simulation of DC. The FE models are compared with an experimental model using gelatin hydrogel, which has similar poro-viscoelastic material property characteristics to brain tissue. Strain on a central plane of the FE model and the front face of the experimental model, deformation and load relaxation curves are compared between experiment and FE. Results show good agreement between the FE and experimental models, providing confidence in applying the proposed FE modelling approach to DC. Such a model should use material properties appropriate for brain tissue and include a more realistic whole head geometry.

Decompressive craniectomy: past, present and future

Decompressive craniectomy (DC)--a surgical procedure that involves removal of part of the skull to accommodate brain swelling--has been used for many years in the management of patients with brain oedema and/or intracranial hypertension, but its place in contemporary practice remains controversial. Results from a recent trial showed that early (neuroprotective) DC was not superior to medical management in patients with diffuse traumatic brain injury. An ongoing trial is investigating the clinical and cost effectiveness of secondary DC as a last-tier therapy for post-traumatic refractory intracranial hypertension. With regard to ischaemic stroke (malignant middle cerebral artery infarction), a recent Cochrane review concluded that DC improves survival compared with medical management, but that a higher proportion of DC survivors experience moderately severe or severe disability. Although many patients have a good outcome, the issue of DC-related disability raises important ethical issues. As DC and subsequent cranioplasty are associated with a number of complications, indiscriminate use of this surgery is not appropriate. Here, we review the evidence and present considerations regarding surgical technique, ethics and cost-effectiveness of DC. Prospective clinical trials and cohort studies are essential to enable optimization of patient care and outcomes.

Surgical treatment of elevated intracranial pressure: decompressive craniectomy and intracranial pressure monitoring

Surgical techniques that address elevated intracranial pressure include (1) intraventricular catheter insertion and cerebrospinal fluid drainage, (2) removal of an intracranial space-occupying lesion, and (3) decompressive craniectomy. This review discusses the role of surgery in the management of elevated intracranial pressure, with special focus on intraventricular catheter placement and decompressive craniectomy. The techniques and potential complications of each procedure are described, and the existing evidence regarding the impact of these procedures on patient outcome is reviewed. Surgical management of mass lesions and ischemic or hemorrhagic stroke occurring in the posterior fossa is not discussed herein.

Outcome following evacuation of acute subdural haematomas: a comparison of craniotomy with decompressive craniectomy

BACKGROUND

Acute subdural haematomas (ASDH) occur commonly following traumatic brain injury and may be evacuated by either craniotomy (CR) or decompressive craniectomy (DC). We reviewed a series of consecutive patients undergoing evacuation of a traumatic ASDH at a regional centre, comparing observed clinical outcomes (assessed by Glasgow Outcome Scale at six months) with those predicted by the CRASH-CT prognostic model.

METHODS

Retrospective review of prospectively collected data.

RESULTS

Ninety-one patients were identified (51 DC and 40 CR ). Eighty-five had available admission data sets from which predicted outcome could be calculated. The DC group were younger than the CR group (p = 0.015). The DC group also had a greater proportion of patients whose pre-intubation GCS was ≤8 (p = 0.001), with significant extracranial injuries (p = 0.001) and obliterated basal cisterns (p = 0.001) on their pre-operative CT scan. Bone flaps in the DC group (n = 45) were longer (mean 11.6 cm; 95 % CI: 11.1-12.1) in comparison to bone flaps in the CR (n = 34) group [(mean 10.2 cm; 95 % CI: 9.35 - 10.9); p = 0.0024] The mean CRASH-CT predicted risk of 14-day mortality and of unfavourable outcome at six months was significantly higher in the DC group compared with the CR group. Eighty-eight patients had available 6-month Glasgow Outcome Scale scores. Favourable outcomes were observed in 42 % of DC versus 45 % of CR (p = 0.83). The overall mortality rate was 38 % in DC versus 32 % in CR (p = 0.65). The standardised morbidity ratio (observed/expected unfavourable outcomes) was 0.75 (95 % CI: 0.51-1.07) for DC and 0.90 (95 % CI: 0.57-1.35) for CR.

CONCLUSIONS

CR and DC for traumatic ASDH are both commonly used for primary evacuation of ASDH. Primary DC may be more effective than CR for selected patients with ASDH. Class I evidence is required in order to refine the indications for DC following evacuation of ASDH.