Hemodynamic and metabolic effects of decompressive hemicraniectomy in normal brain. An experimental PET-study in cats

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.

Surgery for acute subdural hematoma: the value of pre-emptive decompressive craniectomy by propensity score analysis

BACKGROUND

Acute subdural hematomas (ASDH) are found frequently following traumatic brain injury (TBI) and they are considered the most lethal type of mass lesions. The decision to perform a procedure to evacuate ASDH and the approach, either via craniotomy or decompressive craniectomy (DC), remains controversial.

METHODS

We reviewed a prospectively collected series of 343 moderate to severe TBI patients in whom ASDH was the main lesion (ASDH volumes ≥10 cc). Patients with early comfort measures (early mortality prediction >50% and not ICP monitored), bilateral ASDH or the presence of another intracranial hematoma with volumes exceeding two times the volume of the ASDH were excluded. Among them, 112 were managed conservatively, 65 underwent ASDH evacuation by craniotomy and 166 by DC (103 pre-emptive DC, 63 obligatory DC). We calculated the average treatment effect by propensity score (PS) analysis using the following covariates: age, year, hypoxia, shock, pupils, major extracranial injury, motor score, midline shift, ASDH volume, swelling, intraventricular and subarachnoid hemorrhage presence. Then, multivariable binary regression and ordinal logistic regression analysis were performed to estimate associations between predictors and mortality and 12 months-GOS respectively. The patients' inverse probability weights were included as an independent variable in both regression models.

RESULTS

The main variables associated with outcome were year, age, falls from patient´s own height, hypoxia, early deterioration, pupillary abnormalities, basal cistern effacement, compliance to ICP monitoring guidelines and type of surgical approach (craniotomy and pre-emptive DC).

CONCLUSIONS

According to sliding dichotomy analysis, we found that patients in the intermediate or worst bands of unfavorable outcome prognosis seemed to achieve better than expected outcome if they underwent pre-emptive DC rather than craniotomy.

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.

The Boundless World of Cranioplasty: A Multicenter Retrospective Study and Therapeutic Flow-Chart Patient-Specific Based

BACKGROUND

Cranioplasty is both a functional and aesthetical therapeutic option. In the clinical scenario every cranioplasty's material is potentially qualified to achieve the goal of calvarian reconstruction but there is a lack of agreement about the optimum choice, especially between the heterologous ones. The choice of cranioplasty widely depends on surgeon's personal preferences. In this retrospective multicentric study a comparative analysis of hydroxyapatite or titanium cranioplasties was carried on analyzing the main factors considered by the surgeon to choose a material rather than another one. Our results and data were compared with those reported in the scientific literature and a flow-chart regarding the therapeutic approach in the choice of the most suitable cranioplasty was proposed and discussed.

METHODS

The authors present a multicentric study considering 2 groups of patients who underwent 2 different kinds of cranioplasty: hydroxyapatite and titanium. The outcomes measures included the surgical timing and the maintenance of post-operative subgaleal drain.

RESULTS

A total of 40 patients that had cranioplasty treatment were evaluated. The surgical technique was analyzed. In patients that underwent titanium cranioplasty we observed a reduction in the operative times and in subgaleal drain maintenance. In relation to the age, comorbidity, and neurological status a score, called most suitable material (MSM), was elaborated and a therapeutic algorithm is proposed.

CONCLUSIONS

This study confirms the known advantages and drawback of titanium and hydroxyapatite prostheses. Thanks to the lessons learned from our experience on this field, we elaborated the MSM score that coupled with the therapeutic flow-chart proposed could address the choice of the MSM for a specific patient.

Clinical, Surgical and Outcome Predictive Factor Analysis of Operated Acute Subdural Hematoma Cases: A Retrospective Study of 114 Operated Cases at Tertiary Centre

Objective To analyze clinical, surgical and outcome predictive factors of operated acute subdural hematoma (SDH) cases for prognostication and surgical outcome prediction.

Material and Methods This retrospective study includes 114 patients operated for acute SDH in the Department of Neurosurgery of IMS BHU, Varanasi, India, a tertiary care center, between 1 August 2018 and 1 November 2019. Each patient was evaluated for age, sex, mode of injury, localization of hematoma, clinical presentation, comorbidity, severity of injury, best motor response, CT findings, and Glasgow outcome scale (GOS) at discharge. The outcome was also evaluated by further making a dichotomized group using GOS in death/dependent (1–3) versus independent (4–5). Statistical tests were done using the GraphPad Prism version 8.3.0.

Results The most common age group operated upon in this study was the 40 to 60 years age group (n = 45, 39.48%). Males were 78% with male to female ratio of 3.56:1. The most common clinical presentation was altered sensorium (98.25%). The most common comorbidity was hypertension (n = 32, 28.07%). GCS at admission, severity of injury, pupillary changes, and best motor response (p < 0.0001) were significantly associated with surgical outcome.

Conclusion GCS at admission, severity of injury, pupillary changes, and best motor response were significantly (p < 0.05) associated with surgical outcome. Age and gender of patients were not found to be significantly associated.

Functional hyperemia drives fluid exchange in the paravascular space

The brain lacks a conventional lymphatic system to remove metabolic waste. It has been proposed that directional fluid movement through the arteriolar paravascular space (PVS) promotes metabolite clearance. We performed simulations to examine if arteriolar pulsations and dilations can drive directional CSF flow in the PVS and found that arteriolar wall movements do not drive directional CSF flow. We propose an alternative method of metabolite clearance from the PVS, namely fluid exchange between the PVS and the subarachnoid space (SAS). In simulations with compliant brain tissue, arteriolar pulsations did not drive appreciable fluid exchange between the PVS and the SAS. However, when the arteriole dilated, as seen during functional hyperemia, there was a marked exchange of fluid. Simulations suggest that functional hyperemia may serve to increase metabolite clearance from the PVS. We measured blood vessels and brain tissue displacement simultaneously in awake, head-fixed mice using two-photon microscopy. These measurements showed that brain deforms in response to pressure changes in PVS, consistent with our simulations. Our results show that the deformability of the brain tissue needs to be accounted for when studying fluid flow and metabolite transport.

Cranioplasty: A Comprehensive Review of the History, Materials, Surgical Aspects, and Complications

Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The materials used to replace bone defects have evolved throughout history. Cranioplasty materials can be broadly divided into biological and synthetic materials. Biological materials can be further subdivided into autologous grafts, allografts, and xenografts. Allografts (bony materials and cartilage from cadavers) and xenografts (bony materials from animals) are out of favor for use in cranioplasty because of their high rates of infection, resorption, and rejection. In autologous cranioplasty, either the cranial bone itself or bones from other parts of the body of the patient are used. Synthetic bone grafts have reduced the operation time and led to better cosmetic results because of the advancement of computer-based customization and three-dimensional printing. Aluminum was the first synthetic bone graft material used, but it was found to irritate neural tissue, induce seizures, and dissolve over time. Acrylic, in the form of methyl methacrylate, is the most widely used material in cranioplasty. Hydroxyapatite is a natural component of bone and is believed to enhance bone repair, resulting in decreased tissue reactions and promoting good osteointegration. Polyetheretherketones are light and nonconductive and do not interfere with imaging modalities. The complication rates of cranioplasty are high, and surgical site infection is the most common complication. The effect of cranioplasty timing on cognitive function remains debatable. However, the timing of cranioplasty is independent of neurologic outcomes. In this article, the history, materials, complications, and evolution of current practices used in cranioplasty are comprehensively reviewed.

Three-Dimensional CAD in Skull Reconstruction: A Narrative Review with Focus on Cranioplasty and Its Potential Relevance to Brain Sciences

In patients suffering from severe traumatic brain injury and massive stroke (hemorrhagic or ischemic), decompressive craniectomy (DC) is a surgical strategy used to reduce intracranial pressure, and to prevent brainstem compromise from subsequent brain edema. In surviving patients, cranioplasty surgery helps to protect brain tissue, and correct the external deformity. The aesthetic outcome of cranioplasty using an asymmetrical implant can negatively influence patients physically and mentally, especially young patients. Advancements in the development of biomaterials have now made three-dimensional (3-D) computer-assisted design/manufacturing (CAD/CAM)-fabricated implants an optimal choice for the repair of skull defects following DC. Here, we summarize the various materials for cranioplasty, including xenogeneic, autogenous, and alloplastic grafts. The processing procedures of the CAD/CAM technique are briefly outlined, and reflected our experiences to reconstruct skull CAD models using commercial software, published previously, to assess aesthetic outcomes of regular 3-D CAD models without contouring elevation or depression. The establishment of a 3-D CAD model ensures a possibility for better aesthetic outcomes of CAM-derived alloplastic implants. Finally, clinical consideration of the CAD algorithms for adjusting contours and their potential application in prospective healthcare are briefly outlined.

Three-Dimensional CAD in Skull Reconstruction: A Narrative Review with Focus on Cranioplasty and Its Potential Relevance to Brain Sciences

In patients suffering from severe traumatic brain injury and massive stroke (hemorrhagic or ischemic), decompressive craniectomy (DC) is a surgical strategy used to reduce intracranial pressure, and to prevent brainstem compromise from subsequent brain edema. In surviving patients, cranioplasty surgery helps to protect brain tissue, and correct the external deformity. The aesthetic outcome of cranioplasty using an asymmetrical implant can negatively influence patients physically and mentally, especially young patients. Advancements in the development of biomaterials have now made three-dimensional (3-D) computer-assisted design/manufacturing (CAD/CAM)-fabricated implants an optimal choice for the repair of skull defects following DC. Here, we summarize the various materials for cranioplasty, including xenogeneic, autogenous, and alloplastic grafts. The processing procedures of the CAD/CAM technique are briefly outlined, and reflected our experiences to reconstruct skull CAD models using commercial software, published previously, to assess aesthetic outcomes of regular 3-D CAD models without contouring elevation or depression. The establishment of a 3-D CAD model ensures a possibility for better aesthetic outcomes of CAM-derived alloplastic implants. Finally, clinical consideration of the CAD algorithms for adjusting contours and their potential application in prospective healthcare are briefly outlined.

Decompressive hemicraniectomy without clot evacuation in spontaneous intracranial hemorrhage: A systematic review

OBJECTIVE

Decompressive hemicraniectomy (DH) effectively alleviates increased intracranial pressure (ICP) in patients with traumatic brain injury (TBI) and malignant middle cerebral artery (MCA) infarction. Its role in the management of spontaneous intracranial hemorrhage (SICH) however remains uncertain. This study aims to review the efficacy and safety of DH without clot evacuation in SICH.

PATIENTS AND METHODS

A systematic literature search of PubMEd, EMBASE, Scopus and Cochrane Library Central Register of Control Trials was performed. Studies were reviewed independently for methodology, inclusion and exclusion criteria and end points. Primary endpoint was overall mortality. Secondary endpoint was functional outcome using modified Rankin scale (mRs) or Glasgow outcome scale (GOS).

RESULTS

Nine studies with a total of 146 patients who underwent DH without clot evacuation include: 1 RCT, 3 cohort, 2 case series, and 3 case-control studies. Age range was 40-60 years, with majority of patients presenting with a relatively depressed preoperative sensorium (GCS 6-8), large hematoma volumes (>50 mL), and deep locations (basal ganglia and thalamus). Pooled analysis showed a favorable outcome in 53 %, a mortality rate of 26 % and a complication rate of 35.8 %.

CONCLUSION

DH without clot evacuation may offer functional and mortality benefit in patients with spontaneous ICH, based on limited and heterogeneous studies.

Early or late cranioplasty following decompressive craniotomy for traumatic brain injury: A systematic review and meta-analysis

Objective To evaluate the effectiveness of early (<3 months) cranioplasty (CP) and late CP (>3 months) on post-operative complications in patients receiving decompressive craniotomy (DC) for traumatic brain injury (TBI). Methods The Cochrane Library, PubMed and EMBASE databases were systematically searched for studies published prior to May 21, 2017. A meta-analysis examined post-operative overall complication rates, infection rates, subdural fluid collection and operating times according to early and late CP. Results Of the initial 1675 references, five studies, all cohort, involving a total of 413 patients, were selected for the review. There was no difference between early and late CP in post-operative overall complication rate (RR=0.68, 95%CI [0.36, 1.29]) and the post-operative infection rate (RR=0.50, 95%CI [0.20, 1.24]) in patients receiving DC for TBI. However, there was a significant difference in post-operative subdural effusion (RR=0.24, 95%CI [0.07, 0.78]) and mean operative time (mean difference = -33.02 min, 95%CI [-48.19, -17.84]) both in favour of early CP. Conclusions No differences were found between early and late CP in post-operative overall complications and procedural related infections in patients receiving DC for TBI, but early CP reduced the complication of subdural effusion and the mean operating time. These findings need to be confirmed by large, randomised controlled trials.

Acute Subdural Hematoma Evacuation: Predictive Factors of Outcome

BACKGROUND

Acute subdural hematoma (aSDH) is a major cause of admission at Neurosurgical Emergency Department. Nevertheless, concerns regarding surgical indication in patients with multiple comorbidities, poor neurological status, antithrombotic therapy, and older age still persist. Therefore, a correct recognition of predictive outcome factors at hospital discharge is crucial to an appropriate neurosurgical treatment.

METHODS

Eighty-nine medical records of consecutive patients with age ≥18 years old who were submitted to aSDH evacuation between January 2008 and May 2012 were reviewed. Demographic characteristics, neurological status on admission, anticoagulant or antiplatelet therapy, and outcome on discharge were collected. Patients with insufficient data concerning these variables were excluded from the study.

RESULTS

Sixty-nine patients were included; 52% were male; 74% were older than 65 years; 41% were under oral antithrombotic therapy (OAT); at admission, 54% presented with Glasgow coma scale (GCS) ≤8; 23% were submitted to a craniectomy instead of a craniotomy; 26% of the patients died, 32% were dependent, and 42% were independent on discharge. Crude analysis revealed craniectomy, A/A pupils, GCS ≤8 at admission statistically significant related with the worst outcome (P < 0.05). In the adjusted evaluation only A/A pupils (P = 0.04) was associated to poor outcome (spontaneous etiology P = 0.052). Considering daily living independency at hospital discharge, either male gender (P = 0.044) and A/A pupils (P = 0.030) were related to the worst outcome. No effect of age in outcome was observed.

CONCLUSIONS

Male gender and A/A pupils are associated with lower probability of achieving independency living at hospital discharge. A/A pupils, low GCS at admission, spontaneous etiology, and craniectomy were associated with the worst outcome. Age and OAT were not predictive factors in this series. Caution should be taken when considering these factors in the surgical decision.

The effect of cranioplasty following decompressive craniectomy on cerebral blood perfusion, neurological, and cognitive outcome

OBJECTIVE

Decompressive craniectomy is an established therapy for refractory intracranial hypertension. Cranioplasty following decompressive craniectomy not only provides protection to the brain along with cosmetic benefits, but also enhances rehabilitation with meaningful functional recovery of potentially reversible cortical and subcortical damaged areas of the affected as well as the contralateral hemisphere. The aim of the study was to assess neurological and cognitive outcome as well as cerebral blood flow after cranioplasty.

METHODS

Thirty-four patients admitted for replacement cranioplasty after decompressive craniectomy for head injury were studied prospectively. Clinical, neurological, and cognitive outcomes were assessed by the Glasgow Outcome Scale (GOS), the Glasgow Coma Scale, and a battery of cognitive tests, respectively. Simultaneously, cerebral blood perfusion was assessed by technetium-99m ethyl cysteinate dimer (99mTc-ECD) brain SPECT imaging 7 days prior to and 3 months after cranioplasty.

RESULTS

Prior to cranioplasty 9 patients (26.5%) had GOS scores of 5 and 25 patients (73.5%) had GOS scores of 4, whereas postcranioplasty all 34 patients (100%) improved to GOS scores of 5. Approximately 35.3%–90.9% patients showed cognitive improvement postcranioplasty in various tests. Also, on comparison with brain SPECT, 94% of patients showed improvement in cerebral perfusion in different lobes.

CONCLUSIONS

Cranioplasty remarkably improves neurological and cognitive outcomes supported by improvement in cerebral blood perfusion.

Sequential PET estimation of cerebral oxygen metabolism with spontaneous respiration of 15O-gas in mice with bilateral common carotid artery stenosis

Positron emission tomography with ¹⁵O-labeled gases (¹⁵O-PET) is important for in vivo measurement of cerebral oxygen metabolism both in clinical and basic settings. However, there are currently no reports concerning ¹⁵O-PET in mice. Here, we developed an ¹⁵O-PET method applicable to mice with spontaneous respiration of ¹⁵O-gas without a tracheotomy catheter. Sequential ¹⁵O-PET was also performed in a mouse model of chronic cerebral hypoperfusion with bilateral common carotid artery stenosis (BCAS) induced by placement of microcoils. ¹⁵O-gas with isoflurane was supplied to the nose of mouse with evacuation of excess ¹⁵O-gas surrounding the body. ¹⁵O-PET was performed on days 3, 7, 14, 21, and 28 after surgery. Cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO₂) were calculated in whole brains. A significant decrease in CBF and compensatory increase in OEF in the BCAS group produced CMRO₂ values comparable to that of the sham group at three days post-operation. Although CBF and OEF in the BCAS group gradually recovered over the first 28 days, the CMRO₂ showed a gradual decrease to 68% of sham values at 28 days post-operation. In conclusion, we successfully developed a noninvasive ¹⁵O-PET method for mice.

Artificial neural network predicts hemorrhagic contusions following decompressive craniotomy in traumatic brain injury

BACKGROUND

This study aimed to explore relevant factors of hemorrhagic contusions following decompressive craniotomy (DC) in traumatic brain injury (TBI) and create an artificial neural network (ANN) prediction model of the risk factors of hemorrhagic contusions.

METHODS

This study analyzed 425 patients with TBI who underwent DC in the Neurosurgery Department of Shaoxing People's Hospital between 2009 and 2014. Patients were divided into two groups according to the first postoperative CT scans: hemorrhage group and non-hemorrhage group. Gender, age, preoperative situations (Initial Rotterdam CT Score, GCS Score, pupillary response, laboratory data and preoperative hematoma), the time gap between trauma and DC, postoperative CT scans, and Glasgow Outcome Scale (GOS) scores were recorded. ANN was used to predict hematoma. Correlation analysis was used to state the relationship between increased hemorrhage volumes and GOS scores.

RESULTS

The ANN prediction model was established. This model included 11 parameters: initial Rotterdam CT score, GCS score, C-reactive protein, age, the time gap between trauma and DC, pupillary response, platelet count, bone-flap size, glucose level, hernia magnitude and preoperative hematoma volume. The overall predictive accuracy of the model was 73.0%.

CONCLUSIONS

Initial Rotterdam CT scores and GCS scores may predict the risk of expansion contusions following DC. The ANN prediction model has a high accuracy to forecast hemorrhage.

Comparison of neuroendoscopic surgery and craniotomy for supratentorial hypertensive intracerebral hemorrhage: A meta-analysis

BACKGROUND

In recent years, neuroendoscopy has been used as a method for treating intracerebral hemorrhages (ICHs). However, the efficacy and safety of neuroendoscopic surgery is still controversial compared with that of craniotomy. Our aim was to compare the outcomes of neuroendoscopic surgery and craniotomy in patients with supratentorial hypertensive ICH using a meta-analysis.

METHODS

We searched on PubMed, EMBASE, and Cochrane Central Register of Controlled Trials to identify relevant studies in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Quality of eligible studies was evaluated and the related data were extracted by 2 reviewers independently. This study assessed clinical outcomes, evacuation rates, complications, operation time, and hospital stay for patients who underwent neuroendoscopic surgery (NE group) or craniotomy (craniotomy group).

RESULTS

Meta-analysis included 1327 subjects from verified studies of acceptable quality. There was no significant heterogeneity between the included studies based on clinical outcomes. Compared with craniotomy, neuroendoscopic surgery significantly improved clinical outcomes in both randomized controlled studies (RCTs) group (relative risk: 0.62; 95% confidence interval [CI], 0.47-0.81, P < .001) and non-RCTs group (relative risk: 0.84; 95% CI: 0.75-0.95, P = .005); decreased the rate of death (relative risk: 0.53; 95% CI, 0.37-0.76, P < .001) in non-RCTs group but not in RCTs group (relative risk: 0.58; 95% CI, 0.26-1.29, P = .18); increased evacuation rates in non-RCTs group (standard mean differences: 0.75; 95% CI, 0.24-1.26, P = .004) and had a tendency of higher evacuation rates in RCTs group (standard mean differences: 1.34; 95% CI, 0.01-2.68, P = .05); reduced the total risk of complications in non-RCTs group (relative risk: 0.45; 95% CI, 0.25-0.83, P = .01) and RCTs group (relative risk: 0.37; 95% CI, 0.28-0.49, P < .001); reduced the operation time in non-RCTs group (standard mean differences: 3.26; 95% CI: 1.20-5.33, P < .001) and RCTs group (standard mean differences: 4.37; 95% CI: 3.32-5.41, P < .001).

CONCLUSIONS

Our results suggested that the NE group showed better clinical outcomes than the craniotomy group for patients with supratentorial hypertensive ICH. Moreover, the patients who underwent neuroendoscopy had a higher evacuation rate, lower risk of complications, and shorter operation time compared with those that underwent a craniotomy.

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.

Cranioplasty: Indications, procedures, and outcome - An institutional experience

BACKGROUND

Cranioplasty, the repair of a skull vault defect by insertion of an object (bone or nonbiological materials such as metal or plastic plates), is a well-known procedure in modern neurosurgery. Brain protection and cosmetic aspects are the major indications of cranioplasty. A retroprospective study was conducted for evaluating the indications, materials used, complications, and outcome of cranioplasty.

METHODS

This study was prospective from August 2013 to September 2015 and retrospective from August 2010 to July 2013. In the retrospective study, patients files were retrieved from the mentioned date (August 2010 to July 2013) from the medical records and the findings were recorded. Abstracted data included age at the time of cranioplasty (years), sex (male or female), medical comorbidities (hypertension, diabetes), indications for craniectomy [Road traffic accident (RTA), fall from height (FFH), hit by stone or cricket ball, physical assault, stroke, infection, shell injury, bullet injury, and intraoperative swelling], laterality of cranioplasty (bilateral, unilateral, or bifrontal), time between craniectomy and cranioplasty (weeks), type of graft (autologous or artificial), type of prosthesis if used (methylmethacrylate, titanium), storage of bone flap if used (subcutaneous or deep freezer), operative time (minutes), and complications fallowing cranioplasty.

RESULTS

Of the 236 patients included in the study, maximum were in the age group of 21-30 years i.e., 30.93% (n = 73). Mean age of the patients was 33.44 years. A total of 196 (83.05%) were autologous and 40 (16.95%) were artificial. Out of the 40 patients who underwent artificial cranioplasty, 36 (15.25%) had methylmethacrylate graft and 4 (1.7%) had titanium mesh implant. Bone was not preserved in 16.95% (n = 40), preserved in subcutaneous tissue in abdominal wall in 2.54% (n = 6), and preserved in deep freezer in 80.51% (n = 190) of the patients.

CONCLUSION

Cranioplasty as a procedure is not without complications; however, if performed properly and at proper time with an aseptic technique, good results are achieved.

Ketamine modulation of the haemodynamic response to spreading depolarization in the gyrencephalic swine brain

Spreading depolarization (SD) generates significant alterations in cerebral haemodynamics, which can have detrimental consequences on brain function and integrity. Ketamine has shown an important capacity to modulate SD; however, its impact on SD haemodynamic response is incompletely understood. We investigated the effect of two therapeutic ketamine dosages, a low-dose of 2 mg/kg/h and a high-dose of 4 mg/kg/h, on the haemodynamic response to SD in the gyrencephalic swine brain. Cerebral blood volume, pial arterial diameter and cerebral blood flow were assessed through intrinsic optical signal imaging and laser-Doppler flowmetry. Our findings indicate that frequent SDs caused a persistent increase in the baseline pial arterial diameter, which can lead to a diminished capacity to further dilate. Ketamine infused at a low-dose reduced the hyperemic/vasodilative response to SD; however, it did not alter the subsequent oligemic/vasoconstrictive response. This low-dose did not prevent the baseline diameter increase and the diminished dilative capacity. Only infusion of ketamine at a high-dose suppressed SD and the coupled haemodynamic response. Therefore, the haemodynamic response to SD can be modulated by continuous infusion of ketamine. However, its use in pathological models needs to be explored to corroborate its possible clinical benefit.

Decompressive craniectomy in acute brain injury

Decompressive surgery to reduce pressure under the skull varies from a burrhole, bone flap to removal of a large skull segment. Decompressive craniectomy is the removal of a large enough segment of skull to reduce refractory intracranial pressure and to maintain cerebral compliance for the purpose of preventing neurologic deterioration. Decompressive hemicraniectomy and bifrontal craniectomy are the most commonly performed procedures. Bifrontal craniectomy is most often utilized with generalized cerebral edema in the absence of a focal mass lesion and when there are bilateral frontal contusions. Decompressive hemicraniectomy is most commonly considered for malignant middle cerebral artery infarcts. The ethical predicament of deciding to go ahead with a major neurosurgical procedure with the purpose of avoiding brain death from displacement, but resulting in prolonged severe disability in many, are addressed. This chapter describes indications, surgical techniques, and complications. It reviews results of recent clinical trials and provides a reasonable assessment for practice.

Neurologic Functional Outcomes of Decompressive Hemicraniectomy Versus Conventional Treatment for Malignant Middle Cerebral Artery Infarction: A Systematic Review and Meta-Analysis

OBJECTIVE

The aims of this study were to evaluate decompressive hemicraniectomy (DHC) versus conventional treatment (CT) for patients with malignant middle cerebral artery (MCA) infarction and to investigate the impact of age and surgical timing on neurologic function and mortality.

METHODS

We searched English and Chinese databases for randomized controlled trials or observational studies published before August 2016. Outcomes included good functional outcome (GFO), mortality, and National Institutes of Health Stroke Scale and Barthel index scores.

RESULTS

This meta-analysis included 25 studies (1727 patients). There were statistically significant differences between DHC and CT groups in terms of GFO (P < 0.0001), mortality (P < 0.00001), and National Institutes of Health Stroke Scale and Barthel index scores (P < 0.0001) at different follow-up points. Significant differences were observed between the groups in survival with moderately severe disability (P < 0.00001); no differences were observed in survival with severe disability. In the subgroup analysis, in the DHC group, GFO was less in patients >60 years old (9.65%) versus ≤60 years old (38.94%); more patients >60 years old had moderately severe or severe disability (55.27%) compared with patients ≤60 years old (44.21%).

CONCLUSIONS

DHC could significantly improve GFO and reduces mortality of patients of all ages with malignant MCA infarction compared with CT, without increasing the number of patients surviving with severe disability. However, patients in the DHC group more frequently had moderately severe disability. Patients >60 years old with malignant MCA infarction had a higher risk of surviving with moderately severe or severe disability and less GFO.

Outcomes of Early Decompressive Craniectomy Versus Conventional Medical Management After Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis

This meta-analysis examined whether early decompressive craniectomy (DC) can improve control of intracranial pressure (ICP) and mortality in patients with traumatic brain injury (TBI).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until May 14, 2015, using the following terms: traumatic brain injury, refractory intracranial hypertension, high intracranial pressure, craniectomy, standard care, and medical management. Randomized controlled trials in which patients with TBI received DC and non-DC medical treatments were included.Of the 84 articles identified, 8 studies were selected for review, with 3 randomized controlled trials s having a total of 256 patients (123 DCs, 133 non-DCs) included in the meta-analysis. Patients receiving DC had a significantly greater reduction of ICP and shorter hospital stay. They also seemed to have lower odds of death than patients receiving only medical management, but the P value did not reach significance (pooled odds ratio 0.531, 95% confidence interval 0.209-1.350, Z = 1.95, P = 0.183) with respect to the effect on overall mortality; a separate analysis of 3 retrospective studies yielded a similar result.Whereas DC might effectively reduce ICP and shorten hospital stay in patients with TBI, its effect in decreasing mortality has not reached statistical significance.

The influence of decompressive craniectomy for major stroke on early cerebral perfusion

OBJECT

Multiple trials have shown improved survival and functional outcome in patients treated with decompressive craniectomy (DC) for brain swelling following major stroke. It has been assumed that decompression induces an improvement in cerebral perfusion. This observational study directly measured cerebral perfusion before and after decompression.

METHODS

Sixteen patients were prospectively examined with perfusion CT within 6 hours prior to surgery and 12 hours after surgery. Preoperative and postoperative perfusion measurements were compared and correlated.

RESULTS

Following DC there was a significant increase in cerebral blood flow in all measured territories and additionally an increase in cerebral blood volume in the penumbra (p = 0.03). These changes spread as far as the contralateral hemisphere. No significant changes in mean transit time or Tmax (time-to-peak residue function) were observed.

CONCLUSIONS

The presurgical perfusion abnormalities likely reflected local pressure-induced hypoperfusion with impaired autoregulation. The improvement in perfusion after decompression implied an increase in perfusion pressure, likely linked to partial restoration of autoregulation. The increase in perfusion that was observed might partially be responsible for improved clinical outcome following decompressive surgery for major stroke. The predictive value of perfusion CT on outcome needs to be evaluated in larger trials.

3-D titanium mesh reconstruction of defective skull after frontal craniectomy in traumatic brain injury

INTRODUCTION

Decompressive craniectomy (DC) is a treatment strategy used to reduce intracranial pressure in patients with traumatic brain injuries. However, this procedure has a number of shortcomings, such as excessive sinking of the skin flap, which can lead to cerebral compromise and negatively affect the appearance of the patient. The reconstruction of skull defects has been proposed as a means to overcome these disadvantages. Few previous studies have reported the reconstruction of frontal skull defects using titanium mesh. The aim of this study was to provide a comprehensive review of aesthetic and surgical outcomes associated with this procedure and to list the complications encountered during the repair of frontal skull defects using three-dimensional (3-D) titanium mesh.

METHODS

A retrospective review was conducted using records from seven adult patients (32-60 years of age) who received titanium mesh implants at a university hospital in Taiwan between January 2011 and June 2012. Aesthetic outcomes, the function of cranial nerves V and VII, and complications (hardware extrusions, meningitis, osteomyelitis, brain abscess, and pneumocephalus) were evaluated.

RESULTS

An algorithm capable of accounting for bifrontal skull defects and median bone ridges was developed to improve computer-assisted design/manufacturing (CAD/CAM) of one-piece 3-D titanium mesh implants, thereby making it possible to repair bifrontal skull defects in a single operation. Following this procedure, aesthetic and functional outcomes were excellent and the implants in all patients appeared stable. However, extended healing times in two of the patients resulted in subclinical infections, which were resolved by administering antibiotics over a period of 2 weeks. No patients suffered trigeminal or facial dysfunction.

CONCLUSIONS

Our findings support the use of 3-D titanium mesh in frontal skull reconstruction. Few complications were encountered, the contours of the forehead were faithfully rendered, and the cosmetic appearance of patients was excellent. For patients with bifrontal skull defects, the use of one-piece implants in a single operation provides numerous advantages over conventional staged surgeries. This application helps to reduce operating time, which is particularly beneficial for elderly patients and those requiring bifrontal cranioplasties.

Divergent Temporal Expression of Hyaluronan Metabolizing Enzymes and Receptors with Craniotomy vs. Controlled-Cortical Impact Injury in Rat Brain: A Pilot Study

Traumatic brain injury (TBI) triggers many secondary changes in tissue biology, which ultimately determine the extent of injury and clinical outcome. Hyaluronan [hyaluronic acid (HA)] is a protective cementing gel present in the intercellular spaces whose degradation has been reported as a causative factor in tissue damage. Yet little is known about the expression and activities of genes involved in HA catabolism after TBI. Young adult male Sprague-Dawley rats were assigned to three groups: naïve control, craniotomy, and controlled-cortical impact-induced TBI (CCI-TBI). Four animals per group were sacrificed at 4 h, 1, 3, and 7 days post-CCI. The mRNA expression of hyaluronan synthases (HAS1-3), hyaluronidases (enzymes for HA degradation, HYAL 1–4, and PH20), and CD44 and RHAMM (membrane receptors for HA signaling and removal) were determined using real-time PCR. Compared to the naïve controls, expression of HAS1 and HAS2 mRNA, but not HAS3 mRNA increased significantly following craniotomy alone and following CCI with differential kinetics. Expression of HAS2 mRNA increased significantly in the ipsilateral brain at 1 and 3 days post-CCI. HYAL1 mRNA expression also increased significantly in the craniotomy group and in the contralateral CCI at 1 and 3 days post-CCI. CD44 mRNA expression increased significantly in the ipsilateral CCI at 4 h, 1, 3, and 7 days post-CCI (up to 25-fold increase). These data suggest a dynamic regulation and role for HA metabolism in secondary responses to TBI.

Role of colloids in traumatic brain injury: Use or not to be used?

Trauma is a leading cause of death worldwide and traumatic brain injury is one of the commonest injuries associated with it. The need for urgent resuscitation is warranted for prevention of secondary insult to brain. However, the choice of fluid in such cases is still a matter of conflict. The literature does not provide enough data pertaining to role of colloids in head injury patients. In this article, we have tried to explore the present role of colloid resuscitation in patient with head injury.

The "Skull Flap" a new conceived device for decompressive craniectomy experimental study on dogs to evaluate the safety and efficacy in reducing intracranial pressure and subsequent impact on brain perfusion

Background:

Decompressive craniectomy (DC) is a procedure performed increasingly often in current neurosurgical practice. Significant perioperative morbidity may be associated to this procedure because of the large skull defect; also, later closure of the skull defect (cranioplasty) may be associated to post-operative morbidity as much as any other reconstructive operation. The authors present a newly conceived/developed device: The “Skull Flap” (SF). This system, placed at the time of the craniectomy, offers the possibility to provide cranial reconstruction sparing patients a second operation. In other words, DC and cranioplasty essentially take place at the same time and in addition, patients retain their own bone flap. The current study conducted on animal models, represents the logical continuation of a prior recent study, realized on cadaver specimens, to assess the efficacy and safety of this recently developed device.

Materials and Methods:

This is an experimental pilot study on dogs to assess both safety and efficacy of the SF device. Two groups of experimental raised intracranial pressure animal models underwent DC; in the first group of dogs, the bone flap was left in raised position above the skull defect using the SF device; on the second group the flap was discarded. All dogs underwent transcranial Doppler (TCD) to assess brain perfusion. Head computed tomography (CT) scan to determine flap position was also obtained in the group in which the SF device was placed.

Results:

SF has proved to be a strong fixation device that allows satisfactory brain decompression by keeping the bone flap elevated from the swollen brain; later on, the SF allows cranial reconstruction in a simple way without requiring a second staged operation. In addition, it is relevant to note that brain perfusion was measured and found to be better in the group receiving the SF (while the flap being in a raised as well as in its natural position) comparing to the other group.

Conclusion:

The SF device has proved to be very easy to place, well-adaptable to a different type of flaps and ultimately very effective in maintaining satisfactory brain decompression and later on, making easy bone flap repositioning after brain swelling has subsided.

Decompressive hemicraniectomy for spontaneous intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is devastating, with high mortality rates, but its optimum management has not been fully established. Decompressive hemicraniectomy is a surgical procedure used to relieve the malignant elevation of intracranial pressure. The application of decompressive hemicraniectomy in patients with hemispheric ICH has been much less common, although several studies have shown the usefulness of this procedure for large hemispheric ICH. In this review, the present knowledge of the safety and efficacy of this procedure are evaluated. The authors conclude that decompressive hemicraniectomy with hematoma evacuation for large ICH might be a safe and effective procedure in patients with severely disturbed consciousness and large hematoma volume.

The "Skull Flap" a new conceived device for decompressive craniectomy/cranioplasty: Feasibility study on cadaver specimen

Background:

Decompressive craniectomy (DC) is a procedure that is currently performed with increasing frequency. The reason is that its indications have become much broader. This procedure may be associated with the relevant morbidity in the postoperative stage due to the creation of a large bone defect. On the other hand, cranioplasty is associated too with some of the common complications related to any reconstructive head surgery. The authors present a newly developed device: The “Skull Flap” (SF). This new device allows the surgeon to complete a DC, yet providing at the same time a cranial reconstruction that will not require the patient to undergo a second reconstructive procedure.

Materials and Methods:

Different size and location craniectomies were carried out on four human cadaveric heads; the bone flaps were then repositioned in a more elevated position with respect to the skull edges. The flaps were placed at a distance of 12 and 15 mm from the skull edges using the SF system. Crash tests were conducted on each flap while in open and closed positions to assess its reliability and efficacy.

Results:

SF was shown to be a strong fixation device that allows satisfactory brain decompression by keeping the original bone flap away from the swollen brain; at the same time, in a later stage, it allows cranial reconstruction in a simple way.

Conclusion:

The SF device was shown to be very easy to use, adaptable, and practical to apply; thus, allowing both satisfactory brain decompression as well as bone flap repositioning at a later time after the brain swelling has subsided.

[The impact of early cranioplasty on cerebral blood flow and its correlation with neurological and cognitive outcome. Prospective multi-centre study on 24 patients]

INTRODUCTION

Cranioplasty after decompressive craniectomy in patients suffering from severe head injury often leads to a functional improvement although, to date, the pathophysiology of this phenomenon remains unclear. A few hypotheses have been proposed. The impact of cranioplasty on cerebral perfusion could be one explanation. We have evaluated the impact of cranioplasty on the functional status of patients undergoing decompressive craniectomy for severe head injury with its influence on cerebral perfusion.

MATERIALS AND METHODS

Twenty-four patients undergoing craniectomy for severe head injury were included in this multi-centric and prospective study. All of them had a cranioplasty within 12 weeks following decompressive craniectomy. A clinical and radiological evaluation was performed prior to and after cranioplasty. Neurological and cognitive evaluation was performed with the Glasgow Outcome Score (GOS), the Frontal Assessment Battery (FAB) and the Mini Mental State Examination (MMSE). Radiological evaluation was performed by perfusion CT scan and transcranial Doppler.

RESULTS

A statistically significant neurological and cognitive improvement was observed in 92% of patients at 6 months follow-up (F-U). Brain perfusion was improved at 6 weeks F-U, predominantly in the affected hemisphere. Systolic and diastolic blood velocity flow were improved in both middle cerebral arteries.

CONCLUSION

Cranioplasty after decompressive craniectomy for patients suffering from severe head injury probably improves the functional outcome of these patients, thanks to a global improvement of cerebral perfusion.

Pyruvate dehydrogenase phosphatase1 mRNA expression is divergently and dynamically regulated between rat cerebral cortex, hippocampus and thalamus after traumatic brain injury: a potential biomarker of TBI-induced hyper- and hypo-glycaemia and neuronal vulnerability

Cerebral pyruvate depletion and lactate acidosis are common metabolic characteristics of patients with traumatic brain injury (TBI) and are associated with poor prognosis. Pyruvate dehydrogenase (PDH) is the rate-limiting enzyme coupling glycolysis to mitochondrial tricarboxylic acid (TCA) cycle. Brain PDH activity is regulated by its phosphorylation status and other effectors. Phosphorylation of PDH E1α1 subunit by PDH kinase inhibits PDH activity while dephosphorylation of phosphorylated PDHE1α1 by PDH phosphatase (PDP1) restores PDH activity. In situ hybridization showed that PDP1 mRNA is highly expressed in the cerebral cortex, hippocampus and thalamus of rat. Controlled cortical impact (CCI) induced a significant increase in PDP1 mRNA expression in ipsilateral cerebral cortex at 4 h (P<0.05) and 24 h post CCI (P<0.01) that returned to basal level 72 h post CCI. PDP1 mRNA level increased transiently in ipsilateral hippocampal dentate gyrus and CA1-3 subfields 4 h post CCI (P<0.01) but decreased significantly 24 h and 72 h (P<0.01) post CCI, coinciding with a marked increase in neuronal apoptosis in ipsilateral hippocampus 24 h post CCI. PDP1 mRNA expression in thalamus and other subcortical regions decreased persistently post CCI. Contralateral CCI and craniotomy showed similar effects on PDP1 mRNA expression as ipsilateral CCI. Because GFAP mRNA expression was induced in brain regions where PDP1 expression was altered, further study should determine the potential relationship between astrocyte activation, PDP1 alteration, and pyruvate metabolism following TBI.

Spontaneous resolution of diabetes insipidus after cranioplasty and cranial defect repair

We describe the resolution of persistent diabetes insipidus after cranioplasty with autogenous bone and bone morphogentic protein 2-infused collagen matrix in a patient who had large bilateral craniectomies for trauma. A potential pathogenic mechanism is presented.

Controlled cortical impact injury and craniotomy result in divergent alterations of pyruvate metabolizing enzymes in rat brain

Dysregulated glucose metabolism and energy deficit is a characteristic of severe traumatic brain injury (TBI) but its mechanism remains to be fully elucidated. Phosphorylation of pyruvate dehydrogenase (PDH) is the rate-limiting mitochondria enzyme reaction coupling glycolysis to the tricarboxylic acid cycle. Phosphorylation of PDH E1α1 subunit catalyzed by PDH kinase (PDK) inhibits PDH activity, effectively decoupling aerobic glycolysis whereas dephosphorylation of phosphorylated PDHE1α1 by PDH phosphatase (PDP) restores PDH activity. We recently reported altered expression and phosphorylation of pyruvate dehydrogenase (PDH) following TBI. However, little is known about PDK and PDP involvement. We determined PDK (PDK1-4) and PDP isoenzyme (PDP1-2) mRNA and protein expression in rat brain using immunohistochemistry and in situ hybridization techniques. We also quantified PDK and PDP mRNA and protein levels in rat brain following TBI using quantitative real-time PCR and Western blot, respectively. Controlled cortical impact-induced TBI (CCI-TBI) and craniotomy significantly enhanced PDK1-2 isoenzyme mRNA expression level but significantly suppressed PDP1 and PDK4 mRNA expression after the injury (4h to 7days). CCI-TBI and craniotomy also significantly increased PDK1-4 isoenzyme protein expression but suppressed PDP1-2 protein expression in rat brain. In summary, the divergent changes between PDK and PDP expression indicate imbalance between PDK and PDP activities that would favor increased PDHE1α1 phosphorylation and enzyme inhibition contributing to impaired oxidative glucose metabolism in TBI as well as craniotomy.

Decompressive craniectomy and early cranioplasty for the management of severe head injury: a prospective multicenter study on 147 patients

OBJECTIVE

In emergency care of patients with severe blunt head injury, uncontrollable high intracranial pressure is one of major causes of morbidity and mortality. The purpose of this study was to evaluate the efficacy of aggressive surgical treatment in managing uncontrollable elevated intracranial pressure coupled with early skull reconstruction.

METHODS

This was a prospective study on a series of 147 consecutive patients, managed according to the same protocol by five different neurosurgical units, for severe head injuries (Glasgow coma scale score ≤8/15 and high intracranial pressure >25 mm Hg) during a five-year period. All patients received a wide decompressive craniectomy and duroplasty in the acute phase, and a cranioplasty was also performed within 12 weeks (median 6 weeks, range 4-12 weeks).

RESULTS

The emergency decompressive surgery was performed within 28 hours (median 16 hours, range 6-28 hours) after sustaining the head injury. The median preoperative Glasgow coma scale score was 6/15 (range 3-8/15). At a mean follow-up of 26 months (range 14-74 months) 14 patients were lost to long-term follow-up, leaving only 133 patients available for the study. The outcome was favorable in 89 (67%, Glasgow outcome score 4 or 5), it was not favorable in 25 (19%, Glasgow outcome score 2 and 3), and 19 patients (14%) died. A younger age (<50 years) and earlier operation (within 9 hours from trauma) had a significant effect on positive outcomes (P < 0.0001 and P < 0.03, respectively).

CONCLUSIONS

A prompt aggressive surgery, including a wide decompressive craniectomy coupled with early cranioplasty, could be an effective treatment method to improve the outcome after a severe closed head injury reducing, perhaps, many of the complications related to decompressive craniectomy.

Current molecular imaging of spinal tumors in clinical practice

Energy metabolism measurements in spinal cord tumors, as well as in osseous spinal tumors/metastasis in vivo, are rarely performed only with molecular imaging (MI) by positron emission tomography (PET). This imaging modality developed from a small number of basic clinical science investigations followed by subsequent work that influenced and enhanced the research of others. Apart from precise anatomical localization by coregistration of morphological imaging and quantification, the most intriguing advantage of this imaging is the opportunity to investigate the time course (dynamics) of disease-specific molecular events in the intact organism. Most importantly, MI represents one of the key technologies in translational molecular neuroscience research, helping to develop experimental protocols that may later be applied to human patients. PET may help monitor a patient at the vertebral level after surgery and during adjuvant treatment for recurrent or progressive disease. Common clinical indications for MI of primary or secondary CNS spinal tumors are: (i) tumor diagnosis, (ii) identification of the metabolically active tumor compartments (differentiation of viable tumor tissue from necrosis) and (iii) prediction of treatment response by measurement of tumor perfusion or ischemia. While spinal PET has been used under specific circumstances, a question remains as to whether the magnitude of biochemical alterations observed by MI in CNS tumors in general (specifically spinal tumors) can reveal any prognostic value with respect to survival. MI may be able to better identify early disease and to differentiate benign from malignant lesions than more traditional methods. Moreover, an adequate identification of treatment effectiveness may influence patient management. MI probes could be developed to image the function of targets without disturbing them or as treatment to modify the target's function. MI therefore closes the gap between in vitro and in vivo integrative biology of disease. At the spinal level, MI may help to detect progression or recurrence of metastatic disease after surgical treatment. In cases of nonsurgical treatments such as chemo-, hormone- or radiotherapy, it may better assess biological efficiency than conventional imaging modalities coupled with blood tumor markers. In fact, PET provides a unique possibility to correlate topography and specific metabolic activity, but it requires additional clinical and experimental experience and research to find new indications for primary or secondary spinal tumors.

Technical considerations in decompressive craniectomy in the treatment of traumatic brain injury

Refractory intracranial hypertension is a leading cause of poor neurological outcomes in patients with severe traumatic brain injury. Decompressive craniectomy has been used in the management of refractory intracranial hypertension for about a century, and is presently one of the most important methods for its control. However, there is still a lack of conclusive evidence for its efficacy in terms of patient outcome. In this article, we focus on the technical aspects of decompressive craniectomy and review different methods for this procedure. Moreover, we review technical improvements in large decompressive craniectomy, which is currently recommended by most authors and is aimed at increasing the decompressive effect, avoiding surgical complications, and facilitating subsequent management. At present, in the absence of prospective randomized controlled trials to prove the role of decompressive craniectomy in the treatment of traumatic brain injury, these technical improvements are valuable.

Cerebral Blood Flow and Metabolism Following Decompressive Craniectomy for Control of Increased Intracranial Pressure

OBJECTIVE

Decompressive craniectomy (DC) is a common practice for control of intracranial pressure (ICP) following traumatic brain injury (TBI), although the impact of this procedure on the fate of operated patients is still controversial.

METHODS

Cerebral blood flow (CBF) and metabolic rates were monitored prospectively and daily as a surrogate of neuronal viability in 36 TBI patients treated by DC and compared with those of 86 nonoperated patients. DC was performed either on admission (n = 29) or within 48 hours of admission (n = 7).

RESULTS

DC successfully controlled ICP levels and maintained CBF within a normal range although the cerebral metabolic rate of oxygen (CMRO2) was significantly lower in this group. In 7 patients, pre- and postoperative recordings showed a significant ICP decrease that correlated with CBF augmentation but not with concurrent improvement of CMRO2 that remained particularly low. Logistic regression analysis of all investigated variables showed that DC was not associated with higher mortality despite more severe injuries in this group. However, operated patients were 7-fold more likely to have poor functional outcomes than nonoperated patients. Good functional outcome was strongly associated with higher CMRO2 but not with higher CBF values. CMRO2 levels were significantly lower in the DC group, even after adjustment for injury severity, and showed a progressive and sustained trend of deterioration significantly different from that of the non-DC group.

CONCLUSION

These results suggest that DC may enhance survival in the presence of severe brain swelling, although it is unlikely to represent an adequate answer to mitochondrial damage responsible for cellular energy crisis and edema.

Neurosurgical outcomes after intracerebral hemorrhage: results of the Factor Seven for Acute Hemorrhagic Stroke Trial (FAST)

The value of neurosurgical interventions after spontaneous intracerebral hemorrhage (SICH) is uncertain. We evaluated clinical outcomes in patients diagnosed with SICH within 3 hours of symptom onset who underwent hematoma evacuation or external ventricular drainage (EVD) of the hematoma in the Factor Seven for Acute Hemorrhagic Stroke Trial (FAST). FAST was a randomized, multicenter, double-blind, placebo-controlled trial conducted between May 2005 and February 2007 at 122 sites in 22 countries. Neurosurgical procedures (hematoma evacuation and external ventricular drainage) performed at any point after hospital admission were prospectively recorded. Clinical outcomes evaluated were post-SICH disability, as assessed by the modified Rankin Scale; neurologic impairment, as assessed by the National Institutes of Health Stroke Scale; and mortality at 90 days after SICH onset. The impact of neurosurgical procedures on clinical outcomes was evaluated using multivariate logistic regression analysis, controlling for relevant baseline characteristics. Fifty-five of 821 patients underwent neurosurgery. Patients who underwent hematoma evacuation or EVD were on average younger, had greater baseline neurologic impairment, and lower levels of consciousness compared with patients who did not undergo neurosurgery. After adjusting for these differences and other relevant baseline characteristics, we found that neurosurgery was generally associated with unfavorable outcomes at day 90. Among the patients who underwent hematoma evacuation, those with lobar ICH had less ICH expansion than those with deep gray matter ICH, and the smaller expansion was associated with lower mortality. ICH volume was substantially decreased in patients who underwent hematoma evacuation between 24 and 72 hours after hospital admission, and this was associated with better clinical outcome. In conclusion, a small number of patients who underwent neurosurgery in FAST exhibited no overall clinical benefit from neurosurgical intervention, although outcomes varied by type of surgery, time of surgery, and hematoma location. Our findings support the need for further research into the value of neurosurgery in patients with SICH.

Comparative study of decompressive craniectomy after mass lesion evacuation in severe head injury

OBJECTIVE

This study was conducted to evaluate outcome after decompressive craniectomy (DC) in the setting of mass evacuation with or without intracranial pressure (ICP) monitoring.

METHODS

Over a 48-month period (March 2000 to March 2004), 54 of 967 consecutive head injury patients underwent DC for evacuation of a mass lesion. DC was performed without ICP monitoring in 27 patients who required urgent decompression (group A) and in 27 patients who did not require urgent surgery and who had their ICP monitored for 1 to 14 days before surgery (group B).

RESULTS

In group A, the mean Glasgow Coma Scale score was 6.0; 80% had computed tomographic evidence of a shift greater than 5 mm; and 25 patients underwent DC immediately after resuscitation. In group B, the mean Glasgow Coma Scale score was 7.3; 40% had computed tomographic evidence of shift; and 75% underwent DC 24 hours or longer after presentation. Overall, 22 patients died (12 in group A and 10 in group B), 11 remained vegetative or severely disabled (3 in group A and 8 in group B), and 19 had good recovery (11 in group A and 8 in group B). Two patients were lost to follow-up. In 18 group B patients with ICP greater than 20 mm Hg before mass evacuation, ICP dropped an average of 13 mm Hg (P < 0.001). A mass lesion greater than 50 mL (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.04-7.89) and evidence of low attenuation on computed tomography before (OR, 3.3; 95% CI, 1.1-10.3) or after (OR, 2.92; 95% CI, 1.02-8.34) DC were predictors of death. A good outcome occurred in 42% of patients with and in 63% of patients without delayed traumatic injury (OR, 0.3; 95% CI, 0.1-1.1). Outcome was favorable in 78.6% of patients who had no ICP monitoring before DC versus 47.1% of patients with ICP monitoring (OR, 0.2; 95% CI, 0.1-1.2).

CONCLUSION

In this study, mortality after DC for mass lesion was greater than expected, and outcome did not differ between patients with or without ICP monitoring.

Surgical complications secondary to decompressive craniectomy in patients with a head injury: a series of 108 consecutive cases

BACKGROUND

Decompressive craniectomy is an important method for managing refractory intracranial hypertension in patients with head injury. We reviewed a large series of patients who underwent this surgical procedure to establish the incidence and type of postoperative complications.

METHODS

From 1998 to 2005, decompressive craniectomy was performed in 108 patients who suffered from a closed head injury. The incidence rates of complications secondary to decompressive craniectomy and risk factors for developing these complications were analysed. In addition, the relationship between outcome and clinical factors was analysed.

FINDINGS

Twenty-five of the 108 patients died within the first month after surgical decompression. A lower GCS at admission seemed to be associated with a poorer outcome. Complications related to surgical decompression occurred in 54 of the 108 (50%) patients; of these, 28 (25.9%) patients developed more than one type of complication. Herniation through the cranial defect was the most frequent complication within 1 week and 1 month, and subdural effusion was another frequent complication during this period. After 1 month, the "syndrome of the trephined" and hydrocephalus were the most frequent complications. Older patients and/or those with more severe head trauma had a higher occurrence rate of complications.

CONCLUSIONS

The potential benefits of decompressive craniectomy can be adversely affected by the occurrence of complications. Each complication secondary to surgical decompression had its own typical time window for occurrence. In addition, the severity of head injury was related to the development of a complication.

Comparative Study of Outcomes between Shunting after Cranioplasty and in Cranioplasty after Shunting in Large Concave Flaccid Cranial Defect with Hydrocephalus

OBJECTIVE

The cranioplasty and ventriculoperitoneal (VP) shunt operation have been used to treat a large cranial defect with posttraumatic hydrocephalus (PTH). The aim of this study was to evlauate the difference of outcomes between in the shunting after the cranioplasty (group 1) and the cranioplasty after the shunting (group 2) in a large flaccid cranial defect with PTH.

METHODS

In this study, a retrospective review was done on 23 patients undergoing the cranioplasty and VP shunt operation after the decompressive craniectomy for a refractory intracranial hypertension from 2002 to 2005. All of 23 cases had a large flaccid concave cranial defect and PTH. Ten cases belong to group 1 and 13 cases to group 2. The outcomes after operations were compared in two groups 6 months later.

RESULTS

The improvement of Glasgow outcome scale (GOS) was seen in 8 cases (80.0%) of total 10 cases in group 1, and 6 cases (46.2%) of 13 cases in group 2. Three (75.0%) of 4 cases with hemiparesis in group 1 and 3 of 6 cases (50.0%) in group 2 were improved. All cases (2 cases) with decrease of visual acuity were improved in each group. Dysphasia was improved in 3 of 5 cases (60%) in group 1 and 4 of 6 cases (66.6%) in group 2.

CONCLUSION

These results suggest that outcomes in group 1 may be better than in group 2 for a large flaccid concave cranial defect with PTH.

Cranioplasty of large cranial defect at an early stage after decompressive craniectomy performed for severe head trauma

Large cranial defects resulting from decompressive craniectomy performed for refractory intracranial hypertension after head trauma is one of the indications for cranioplasty, and this procedure is commonly performed 3 months after craniectomy. However, the large cranial defect would lead to the kinds of complications early during the phase of these patients' recovery, which would go against rehabilitation. This study retrospectively reviewed 23 patients undergoing early cranioplasty (5-8 weeks after craniectomy) in the last 4 years with a detailed choice of patients, outcome of complications after head trauma and large craniectomy, as well as assessment of prognosis. The early outcome (1 month later) revealed most of the patients who had conscious disturbance before the cranioplasty recovered their consciousness and presented an improved neurologic function. The long-dated prognosis (18 months later) revealed that 17 patients were good (independent patients) in this series (74%), whereas four patients survived with a severe disability (17%) and two remained in a vegetative state (9%). No dead patients or intracranial infection after the procedure were found in this study. Most patients' complications were relieved after the cranioplasty with improvements of symptoms or image of computed tomography scan. In conclusion, we consider that with the appropriate choice of patients and materials, early cranioplasty for large cranial defects after decompressive craniectomy would be safe and helpful for the improvement of patients' neurologic function and prognosis. To our knowledge, this series may be the first detailed report in English about early cranioplasty after decompressive craniectomy. We are going to perform prospective and retrospective contrastive studies to further confirm the effects of this procedure on the patients with large cranial defects after decompressive craniectomy.