Development of the SAFETEA Scores for Predicting Risks of Complications of Preventive Endovascular or Microneurosurgical Intracranial Aneurysm Occlusion

BACKGROUND AND OBJECTIVES

Preventive unruptured intracranial aneurysm (UIA) occlusion can reduce the risk of subarachnoid hemorrhage, but both endovascular and microneurosurgical treatment carry a risk of serious complications. To improve individualized management decisions, we developed risk scores for complications of endovascular and microneurosurgical treatment based on easily retrievable patient, aneurysm, and treatment characteristics.

METHODS

For this multicenter cohort study, we combined individual patient data from patients with UIA aged 18 years or older undergoing preventive endovascular treatment (standard, balloon-assisted or stent-assisted coiling, Woven EndoBridge-device, or flow-diverting stent) or microneurosurgical clipping at one of the 10 participating centers from 3 continents between 2000 and 2018. The primary outcome was death from any cause or clinical deterioration from neurologic complications ≤30 days. We selected predictors based on previous knowledge about relevant risk factors and predictor performance and studied the association between predictors and complications with logistic regression. We assessed model performance with calibration plots and concordance (c) statistics.

RESULTS

Of the 1,282 included patients, 94 (7.3%) had neurologic symptoms that resolved <30 days, 140 (10.9%) had persisting neurologic symptoms, and 6 died (0.5%). At 30 days, 52 patients (4.1%) were dead or dependent. Predictors of procedural complications were size of aneurysm, aneurysm location, familial subarachnoid hemorrhage, earlier atherosclerotic disease, treatment volume, endovascular modality (for endovascular treatment) or extra aneurysm configuration factors (for microneurosurgical treatment, branching artery from aneurysm neck or unfavorable dome-to-neck ratio), and age (acronym: SAFETEA). For endovascular treatment (n = 752), the c-statistic was 0.72 (95% CI 0.67-0.77) and the absolute complication risk ranged from 3.2% (95% CI 1.6%-14.9%; ≤1 point) to 33.1% (95% CI 25.4%-41.5%; ≥6 points). For microneurosurgical treatment (n = 530), the c-statistic was 0.72 (95% CI 0.67-0.77) and the complication risk ranged from 4.9% (95% CI 1.5%-14.9%; ≤1 point) to 49.9% (95% CI 39.4%-60.6%; ≥6 points).

DISCUSSION

The SAFETEA risk scores for endovascular and microneurosurgical treatment are based on 7 easily retrievable risk factors to predict the absolute risk of procedural complications in patients with UIAs. The scores need external validation before the predicted risks can be properly used to support decision-making in clinical practice.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that SAFETEA scores predict the risk of procedural complications after endovascular and microneurosurgical treatment of unruptured intracranial aneurysms.

Novel role of STAT3 in microglia-dependent neuroinflammation after experimental subarachnoid haemorrhage

Background and purpose

Signal transducer and activator of transcription 3 (STAT3) may contribute to the proinflammation in the central nervous system diseases by modulating the microglial responses. Thus, this study was intended to investigate the effect of STAT3 on microglia-dependent neuroinflammation and functional outcome after experimental subarachnoid haemorrhage (SAH).

Methods

The SAH model was established by endovascular perforation in the mouse. Real-time PCR (RtPCR) and western blot were used to examine the dynamic STAT3 signalling pathway responses after SAH. To clarify the role of the STAT3 signalling pathway in the microglia-dependent neuroinflammation after SAH, the microglia-specific STAT3 knockout (KO) mice were generated by the Cre-LoxP system. The neurological functions were assessed by Catwalk and Morris water maze tests. Neuronal loss after SAH was determined by immunohistochemistry staining. Microglial polarisation status after STAT3 KO was then examined by RtPCR and immunofluorescence.

Results

The STAT3 and Janus kinase-signal transducer 2 activated immediately with the upregulation and phosphorylation after SAH. Downstream factors and related mediators altered dynamically and accordingly. Microglial STAT3 deletion ameliorated the neurological impairment and alleviated the early neuronal loss after SAH. To investigate the underlying mechanism, we examined the microglial reaction after STAT3 KO. STAT3 deletion reversed the increase of microglia after SAH. Loss of STAT3 triggered the early morphological changes of microglia and primed microglia from M1 to M2 polarisation. Functionally, microglial STAT3 deletion suppressed the SAH-induced proinflammation and promoted the anti-inflammation in the early phase.

Conclusions

STAT3 is closely related to the microglial polarisation transition and modulation of microglia-dependent neuroinflammation. Microglial STAT3 deletion improved neurological function and neuronal survival probably through promoting M2 polarisation and anti-inflammatory responses after SAH. STAT3 may serve as a promising therapeutic target to alleviate early brain injury after SAH.

Risk of Rupture After Intracranial Aneurysm Growth

Importance

Unruptured intracranial aneurysms not undergoing preventive endovascular or neurosurgical treatment are often monitored radiologically to detect aneurysm growth, which is associated with an increase in risk of rupture. However, the absolute risk of aneurysm rupture after detection of growth remains unclear.

Objective

To determine the absolute risk of rupture of an aneurysm after detection of growth during follow-up and to develop a prediction model for rupture.

Design, Setting, and Participants

Individual patient data were obtained from 15 international cohorts. Patients 18 years and older who had follow-up imaging for at least 1 untreated unruptured intracranial aneurysm with growth detected at follow-up imaging and with 1 day or longer of follow-up after growth were included. Fusiform or arteriovenous malformation-related aneurysms were excluded. Of the 5166 eligible patients who had follow-up imaging for intracranial aneurysms, 4827 were excluded because no aneurysm growth was detected, and 27 were excluded because they had less than 1 day follow-up after detection of growth.

Exposures

All included aneurysms had growth, defined as 1 mm or greater increase in 1 direction at follow-up imaging.

Main Outcomes and Measures

The primary outcome was aneurysm rupture. The absolute risk of rupture was measured with the Kaplan-Meier estimate at 3 time points (6 months, 1 year, and 2 years) after initial growth. Cox proportional hazards regression was used to identify predictors of rupture after growth detection.

Results

A total of 312 patients were included (223 [71%] were women; mean [SD] age, 61 [12] years) with 329 aneurysms with growth. During 864 aneurysm-years of follow-up, 25 (7.6%) of these aneurysms ruptured. The absolute risk of rupture after growth was 2.9% (95% CI, 0.9-4.9) at 6 months, 4.3% (95% CI, 1.9-6.7) at 1 year, and 6.0% (95% CI, 2.9-9.1) at 2 years. In multivariable analyses, predictors of rupture were size (7 mm or larger hazard ratio, 3.1; 95% CI, 1.4-7.2), shape (irregular hazard ratio, 2.9; 95% CI, 1.3-6.5), and site (middle cerebral artery hazard ratio, 3.6; 95% CI, 0.8-16.3; anterior cerebral artery, posterior communicating artery, or posterior circulation hazard ratio, 2.8; 95% CI, 0.6-13.0). In the triple-S (size, site, shape) prediction model, the 1-year risk of rupture ranged from 2.1% to 10.6%.

Conclusion and Relevance

Within 1 year after growth detection, rupture occurred in approximately 1 of 25 aneurysms. The triple-S risk prediction model can be used to estimate absolute risk of rupture for the initial period after detection of growth.

Rescue therapy for vasospasm following aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis with machine learning

OBJECTIVE

Rescue therapies have been recommended for patients with angiographic vasospasm (aVSP) and delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH). However, there is little evidence from randomized clinical trials that these therapies are safe and effective. The primary aim of this study was to apply game theory-based methods in explainable machine learning (ML) and propensity score matching to determine if rescue therapy was associated with better 3-month outcomes following post-SAH aVSP and DCI. The authors also sought to use these explainable ML methods to identify patient populations that were more likely to receive rescue therapy and factors associated with better outcomes after rescue therapy.

METHODS

Data for patients with aVSP or DCI after SAH were obtained from 8 clinical trials and 1 observational study in the Subarachnoid Hemorrhage International Trialists repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and the 3-month Glasgow Outcome Scale (GOS) score. Favorable outcome was defined as a 3-month GOS score of 4 or 5. Shapley Additive Explanation (SHAP) values were calculated for each patient-derived model to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy administration were used in a propensity score-matched analysis of rescue therapy and 3-month GOS scores.

RESULTS

The authors identified 1532 patients with aVSP or DCI. Predictive, explainable ML models revealed that aneurysm characteristics and neurological complications, but not admission neurological scores, carried the highest relative importance rankings in predicting whether rescue therapy was administered. Younger age and absence of cerebral ischemia/infarction were invariably linked to better rescue outcomes, whereas the other important predictors of outcome varied by rescue type (interventional or noninterventional). In a propensity score-matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS scores of 4-5 (OR 1.63, 95% CI 1.22-2.17).

CONCLUSIONS

Rescue therapy may increase the odds of good outcome in patients with aVSP or DCI after SAH. Given the strong association between cerebral ischemia/infarction and poor outcome, trials focusing on preventative or therapeutic interventions in these patients may be most able to demonstrate improvements in clinical outcomes. Insights developed from these models may be helpful for improving patient selection and trial design.

Topical application of adipose tissue-derived mesenchymal stem cells (ADMSCs) reduced cerebral edema in experimental traumatic brain injury (TBI)-a preliminary study

Background

Our previous studies showed that topical application of mesenchymal stem cells (MSCs) improved functional recovery in rat traumatic brain injury (TBI) model, and hypoxic precondition further enhanced the therapeutic effects of MSCs. There was no previous study on the attenuation of cerebral edema by MSCs.

We investigated whether topical application of normoxic and hypoxic MSCs could reduce cerebral edema in an experimental TBI model.

Methods

Two million normoxic (N = 24) and hypoxic (N = 24) MSCs were applied topically to exposed the cerebral cortex in a controlled cortical impact (CCI) model. The MSCs were fixed in position with fibrin glue. No treatment was given to control animals (TBI only: n = 24). After surgery, four animals in each group were sacrificed daily (day 1 to day 6) for edema evaluation. Normal animals without TBI were used as reference (n = 4). The expressions of GFAP, AQP4, and MMP9 were also investigated by immunofluorescence staining and RT-PCR at day 3.

Results

The edema peaked within 3 days after TBI. Compared with the control, hypoxic MSCs reduced brain water content significantly (p < 0.05). Both hypoxic and normoxic MSCs downregulated the expression of MMP9 and normalized AQP4 distribution to astrocyte end feet.

Conclusion

Our preliminary study showed that topical application of hypoxic MSCs suppressed both vasogenic and cytotoxic edema formation.

Long term treatment efficacy & complications of hypofractionated stereotactic radiosurgery in brain arteriovenous malformations

OBJECTIVE

To evaluate long term treatment efficacy and complications of hypofractionated stereotactic radiosurgery (hfSRS) and identify factors that predict outcomes.

METHODS

A retrospective review was conducted on 34 consecutive patients who received hfSRS from 2008 to 2017. Demographic, clinical, angio-architectural characteristics, and radiosurgery data were extracted from the Clinical Data Analysis and Reporting System and our unit's iPlan (BrainLAB, Munich) system. Data was analysed using SPSS.

RESULTS

5-year obliteration rate was 39.1%. Most patients (n = 29, 85.3%) recovered well with GOS of 4-5. 26.9% (n = 9) patients have at least one post-radiosurgery complication including hemorrhage, neurological deficits, radionecrosis. Neurological morbidity and mortality was 17.6% (n = 6). A higher modified radiosurgery arteriovenous malformation score (mRBAS) is associated with a lower 5-year obliteration rate (Rho = -0.486, p = 0.025). None of the bAVM were obliterated once mRBAS exceeds 5.35. As expected, a larger 20-Gy volume outside lesion is associated with more complications and poorer GOS. Interestingly, irradiated drainage vein volume indexed to AVM volume (iiDVV) correlates with increased risks of post-hfSRS haemorrhage (Rho = 0.472, p = 0.031) and reduced event-free survival (Rho = -0.472, p = 0.031). Once iiDVV exceeds 20%, a high rebleeding rate after hfSRS is anticipated (AUC under ROC 0.889).

CONCLUSION

Hypofractionated stereotactic radiosurgery is an alternative radiosurgery treatment for bAVM unsuitable for single-fraction SRS. mRBAS predicts obliteration rate and morbidity in hfSRS. Index irradiated drainage vein volume (iiDVV) is associated with event-free survival and rebleeding and should be minimized if feasible.

Impact of metformin on immunological markers: Implication in its anti-tumor mechanism

Metformin, an anti-hyperglycemic drug, has been known to have antitumor properties for around 15 years. Although there are a number of reports attributing the antitumor function of metformin to its impact on energy homeostasis and oxygen re-distribution in tumor microenvironment, detailed mechanisms remain largely unknown. In the past several years, there is an increasing number of publications indicating that metformin can affect various immunological components including lymphocytes, macrophages, cytokines and several key immunological molecules in both human and animal studies. These interesting results appear to be in line with emerging data that suggest associations between immune responses and energy homeostasis/oxygen re-distribution, which may explain effective impacts of metformin on immunotherapies against autoimmune diseases as well as cancers. This review article is to analyse and discuss recent development in the above areas with aim to justify metformin as a new adjuvant for immunotherapy against human cancers. We hope that our summary will help to optimize the application of metformin for various types of human cancers.

Development and validation of outcome prediction models for aneurysmal subarachnoid haemorrhage: the SAHIT multinational cohort study

OBJECTIVE

To develop and validate a set of practical prediction tools that reliably estimate the outcome of subarachnoid haemorrhage from ruptured intracranial aneurysms (SAH).

DESIGN

Cohort study with logistic regression analysis to combine predictors and treatment modality.

SETTING

Subarachnoid Haemorrhage International Trialists' (SAHIT) data repository, including randomised clinical trials, prospective observational studies, and hospital registries.

PARTICIPANTS

Researchers collaborated to pool datasets of prospective observational studies, hospital registries, and randomised clinical trials of SAH from multiple geographical regions to develop and validate clinical prediction models.

MAIN OUTCOME MEASURE

Predicted risk of mortality or functional outcome at three months according to score on the Glasgow outcome scale.

RESULTS

Clinical prediction models were developed with individual patient data from 10 936 patients and validated with data from 3355 patients after development of the model. In the validation cohort, a core model including patient age, premorbid hypertension, and neurological grade on admission to predict risk of functional outcome had good discrimination, with an area under the receiver operator characteristics curve (AUC) of 0.80 (95% confidence interval 0.78 to 0.82). When the core model was extended to a "neuroimaging model," with inclusion of clot volume, aneurysm size, and location, the AUC improved to 0.81 (0.79 to 0.84). A full model that extended the neuroimaging model by including treatment modality had AUC of 0.81 (0.79 to 0.83). Discrimination was lower for a similar set of models to predict risk of mortality (AUC for full model 0.76, 0.69 to 0.82). All models showed satisfactory calibration in the validation cohort.

CONCLUSION

The prediction models reliably estimate the outcome of patients who were managed in various settings for ruptured intracranial aneurysms that caused subarachnoid haemorrhage. The predictor items are readily derived at hospital admission. The web based SAHIT prognostic calculator (http://sahitscore.com) and the related app could be adjunctive tools to support management of patients.

Interactome and reciprocal activation of pathways in topical mesenchymal stem cells and the recipient cerebral cortex following traumatic brain injury

In this study, GFP-MSCs were topically applied to the surface of cerebral cortex within 1 hour of experimental TBI. No treatment was given to the control group. Three days after topical application, the MSCs homed to the injured parenchyma and improved the neurological function. Topical MSCs triggered earlier astrocytosis and reactive microglia. TBI penumbra and hippocampus had higher cellular proliferation. Apoptosis was suppressed at hippocampus at 1 week and reduced neuronal damaged was found in the penumbral at day 14 apoptosis. Proteolytic neuronal injury biomarkers (alphaII-spectrin breakdown products, SBDPs) and glial cell injury biomarker, glial fibrillary acidic protein (GFAP)-breakdown product (GBDPs) in injured cortex were also attenuated by MSCs. In the penumbra, six genes related to axongenesis (Erbb2); growth factors (Artn, Ptn); cytokine (IL3); cell cycle (Hdac4); and notch signaling (Hes1) were up-regulated three days after MSC transplant. Transcriptome analysis demonstrated that 7,943 genes were differentially expressed and 94 signaling pathways were activated in the topical MSCs transplanted onto the cortex of brain injured rats with TBI. In conclusion, topical application offers a direct and efficient delivery of MSCs to the brain.

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

BACKGROUND AND PURPOSE

A noninvasive investigation with high spatial resolution and without metal artifacts is necessary for long-term imaging follow-up after flow-diverter implantation. We aimed to evaluate the diagnostic value of conebeam CT angiography with intravenous contrast enhancement in the assessment of vascular status following implantation of the Pipeline Embolization Device and to analyze the preliminary results of vascular status following long-term Pipeline Embolization Device implantation.

MATERIALS AND METHODS

This was an ongoing prospective study of consecutive patients with intracranial aneurysms treated with the Pipeline Embolization Device. Patients with a modified Rankin Scale score of 4-5 were excluded. The median and interquartile range of the time interval of Pipeline Embolization Device implantation to conebeam CT angiography with intravenous contrast enhancement were 56.6 and 42.9-62.4 months, respectively. Conebeam CT angiography with intravenous contrast enhancement was performed with the patient fully conscious, by using a C-arm CT with a flat panel detector.

RESULTS

There were 34 patients and 34 vascular segments. In all 34 cases, contrast effect and image quality were good and not substantially different from those of intra-arterial conebeam CTA. Metal artifacts occurred in all 14 cases with coil masses; the Pipeline Embolization Device was obscured in 3 cases. In all 34 cases, there was no residual aneurysm, no vascular occlusion, 1 vascular stenosis (50%), good Pipeline Embolization Device apposition to the vessel, and no Pipeline Embolization Device-induced calcification. All 28 Pipeline Embolization Device-covered side branches were patent.

CONCLUSIONS

Conebeam CT angiography with intravenous contrast enhancement is potentially promising and useful for effective evaluation of the vascular status following intracranial flow diverters. The Pipeline Embolization Device for intracranial aneurysms is probably safe and promising for long-term placement, with favorable morphologic outcome and without delayed complications.

Topical Therapy with Mesenchymal Stem Cells Following an Acute Experimental Head Injury Has Benefits in Motor-Behavioral Tests for Rodents

BACKGROUND

The neuroprotective effects of mesenchymal stem cells (MSCs) have been reported in rodent and in preliminary clinical studies. MSCs are usually transplanted to patients by systemic infusion. However, only a few of the infused MSCs are delivered to the brain because of pulmonary trapping and the blood-brain barrier. In this study, MSCs were topically applied to the site of traumatic brain injury (TBI) and the neuroprotective effects were assessed.

MATERIALS AND METHODS

TBI was induced in Sprague-Dawley (SD) rats with an electromagnetically controlled cortical impact device after craniotomy was performed between the bregma and lambda, 1 mm lateral to the midline. We applied 1.5 million MSCs, derived from the adipose tissue of transgenic green fluorescent protein (GFP)-SD rats, to the exposed cerebral cortex at the injured site. The MSCs were held in position by a thin layer of fibrin. Neurological function in the test (n = 10) and control (n = 10) animals was evaluated using the rotarod test, the water maze test, and gait analysis at different time points.

RESULTS

Within 5 days following topical application, GFP-positive cells were found in the brain parenchyma. These cells co-expressed with markers of Glial fibrillary acidic protein (GFAP), nestin, and NeuN. There was less neuronal death in CA1 and CA3 of the hippocampus in the test animals. Neurological functional recovery was significantly improved.

CONCLUSION

Topically applied MSCs can migrate to the injured brain parenchyma and offer neuroprotective effects.

Screening for intracranial aneurysms? Prevalence of unruptured intracranial aneurysms in Hong Kong Chinese

OBJECT The objective of this study was to generate data on the local prevalence of unruptured intracranial aneurysms (UIAs) in asymptomatic Hong Kong Chinese individuals. First-degree relatives of patients with aneurysmal subarachnoid hemorrhage (aSAH) were recruited as surrogates of the general population and to explore the potential role of screening in this locality. METHODS The authors identified first-degree relatives of consecutive patients with subarachnoid hemorrhage from a ruptured aneurysm who were admitted to a university hospital in Hong Kong from June 2008 to December 2010. Magnetic resonance angiography (MRA) was the imaging modality used to screen the cerebral vasculature of these asymptomatic individuals. If MRA showed abnormal findings, CT angiography was performed to confirm the MRA findings. RESULTS In total, 7 UIAs were identified from the 305 MR angiograms obtained. The prevalence of UIAs in first-degree relatives of patients with aSAH in the Hong Kong Chinese population was 2.30% (95% CI1.02%-4.76%). This percentage was lower than the prevalence rate of 3.2% from a meta-analysis of the literature. The sizes of the UIAs detected ranged from 1.4 mm to 7.5 mm; 85.7% of the UIAs detected in this study were < 5 mm, in contrast to 66% noted in the literature. One of the UIAs identified underwent endovascular stent placement with a flow diverter. None of the UIAs identified ruptured or became symptomatic during a median follow-up period of 3.5 years. CONCLUSIONS The prevalence of UIAs in first-degree relatives of patients with aSAH in the Hong Kong Chinese population was lower than that in Caucasians. At the same time, most of the UIAs detected in this study were small (85.7% were < 5 mm, vs 66% in a meta-analysis). With a similar incidence of aSAH in Hong Kong (7.5 per 100,000 person-years) as compared with data cited in the literature, the hypothesis that UIA rupture risk size threshold is different in Chinese patients should be further investigated.

Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis

BACKGROUND AND PURPOSE

Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis. We performed an individual patient data meta-analysis to study whether magnesium is effective when given within different time frames within 24 hours after the SAH.

METHODS

Patients were divided into categories according to the delay between symptom onset and start of the study medication: <6, 6 to 12, 12 to 24, and >24 hours. We calculated adjusted risk ratios with corresponding 95% confidence intervals for magnesium versus placebo treatment for poor outcome and DCI.

RESULTS

We included 5 trials totaling 1981 patients; 83 patients started treatment<6 hours. For poor outcome, the adjusted risk ratios of magnesium treatment for start <6 hours were 1.44 (95% confidence interval, 0.83-2.51); for 6 to 12 hours 1.03 (0.65-1.63), for 12 to 24 hours 0.84 (0.65-1.09), and for >24 hours 1.06 (0.87-1.31), and for DCI, <6 hours 1.76 (0.68-4.58), for 6 to 12 hours 2.09 (0.99-4.39), for 12 to 24 hours 0.80 (0.56-1.16), and for >24 hours 1.08 (0.88-1.32).

CONCLUSIONS

This meta-analysis suggests no beneficial effect of magnesium treatment on poor outcome or DCI when started early after SAH onset. Although the number of patients was small and a beneficial effect cannot be definitively excluded, we found no justification for a new trial with early magnesium treatment after SAH.

The unruptured intracranial aneurysm treatment score: a multidisciplinary consensus

OBJECTIVE

We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research.

METHODS

An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement).

RESULTS

The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019-0.033).

CONCLUSIONS

This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.

High-dose simvastatin for aneurysmal subarachnoid hemorrhage: multicenter randomized controlled double-blinded clinical trial

BACKGROUND AND PURPOSE

Experimental evidence has indicated the benefits of simvastatin for the treatment of subarachnoid hemorrhage. Two randomized placebo-controlled pilot trials that used the highest clinically approved dose of simvastatin (80 mg daily) gave positive results despite the fact that a lower dose of simvastatin (40 mg daily) did not improve clinical outcomes. We hypothesized that a high dose of 80 mg of simvastatin daily for 3 weeks would reduce the incidence of delayed ischemic deficits after subarachnoid hemorrhage compared with a lower dose (40 mg of simvastatin daily) and lead to improved clinical outcomes.

METHODS

The study design was a randomized controlled double-blinded clinical trial. Patients with aneurysmal subarachnoid hemorrhage (presenting within 96 hours of the ictus) from 6 neurosurgical centers were recruited for 3 years. The primary outcome measure was the presence of delayed ischemic deficits, and secondary outcome measures included a modified Rankin disability score at 3 months and an analysis of cost-effectiveness.

RESULTS

No difference was observed between the groups treated with the higher dose or the lower dose of simvastatin in the incidence of delayed ischemic deficits (27% versus 24%; odds ratio, 1.2; 95% confidence interval, 0.7-2.0; P=0.586) or in the rate of favorable outcomes (modified Rankin Scale score, 0-2) at 3 months (73% versus 72%; odds ratio, 1.1; 95% confidence interval, 0.6-1.9; P=0.770).

CONCLUSIONS

High-dose simvastatin treatment should not be prescribed routinely for aneurysmal subarachnoid hemorrhage.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01077206.

Magnesium therapy within 48 hours of an aneurysmal subarachnoid hemorrhage: neuro-panacea

Whereas advances in neurosurgical treatment and intensive care management improve the results from many of the devastating complications associated with aneurysmal subarachnoid hemorrhage, cerebral vasospasm remains a major cause of neurological morbidity and mortality. Experimental studies suggested that MgSO(4) inhibits excitatory amino acid release, blocks N-methyl-D-aspartate (NMDA) receptors and prevents calcium entry into the cell. Magnesium also increases red blood cell deformability. These changes may reduce the occurrence of cerebral vasospasm and minimize neuronal injury during episodes of cerebral vasospasm. Our group is currently hosting the intravenous magnesium sulfate to improve outcome after aneurysmal subarachnoid hemorrhage (IMASH) trial, which is a randomized, placebo-controlled, double-blinded, multicentered trial to evaluate the effect of magnesium sulfate infusion on the clinical outcome of patients with aneurysmal subarachnoid hemorrhage since 2002. The pilot result showed a trend towards decreased clinical vasospasm and better patient outcome. Magnesium sulfate infusion may prove to be an effective and inexpensive way to reduce the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage, which is a major breakthrough in the current management.

Angioplasty and stenting for intracranial atherosclerotic stenosis: position statement of the Hong Kong Society of Interventional and Therapeutic Neuroradiology

As a means of preventing secondary ischaemic stroke, angioplasty and stenting are considered potentially beneficial for patients with severe intracranial atherosclerotic stenosis. However, the role of stenting has been challenged since the publication of the first randomised controlled trial on Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial arterial Stenosis (SAMMPRIS). This indicated that aggressive medical management was superior to stenting using Wingspan to prevent recurrent stroke, because stenting has a high peri-procedural stroke and death rate. In this paper, we review the management of intracranial atherosclerosis, revisit the skepticism on stenting, and state our position on the topic in the form of recommendations. These are based on the prevalence of the disease in Hong Kong, the high risk of recurrent stroke despite medical therapy in the presence of haemodynamic intracranial stenosis without sufficient collaterals, an analysis of the weak points of SAMMPRIS, and results of clinical studies in Hong Kong.

An uncommon mimic of spontaneous subarachnoid haemorrhage

We here presented a rare disease entity with a clinical presentation mimicking aneurysmal subarachnoid haemorrhage. A 43-year-old woman presented with a 1-week history of neck pain and dizziness. Computed tomography of brain showed communicating hydrocephalus and subarachnoid hyperintensity suspicious of previous subarachnoid haemorrhage. Investigations revealed no underlying vascular lesion and leptomeningeal biopsy showed diffuse melanocytosis. We go on to discuss the diagnostic features and clinical course of this entity.

Subarachnoid Hemorrhage International Trialists data repository (SAHIT)

The outcome of patients with aneurysmal subarachnoid hemorrhage (SAH) has improved slowly over the past 25 years. This improvement may be due to early aneurysm repair by endovascular or open means, use of nimodipine, and better critical care management. Despite this improvement, mortality remains at about 40%, and many survivors have permanent neurologic, cognitive, and neuropsychologic deficits. Randomized clinical trials have tested pharmacologic therapies, but few have been successful. There are numerous explanations for the failure of these trials, including ineffective interventions, inadequate sample size, treatment side effects, and insensitive or inappropriate outcome measures. Outcome often is evaluated on a good-bad dichotomous scale that was developed for traumatic brain injury 40 years ago. To address these issues, we established the Subarachnoid Hemorrhage International Trialists (SAHIT) data repository. The primary aim of the SAHIT data repository is to provide a unique resource for prognostic analysis and for studies aimed at optimizing the design and analysis of phase III trials in aneurysmal SAH. With this aim in mind, we convened a multinational investigator meeting to explore merging individual patient data from multiple clinical trials and observational databases of patients with SAH and to create an agreement under which such a group of investigators could submit data and collaborate. We welcome collaboration with other investigators.

Pseudoprogression of malignant glioma in Chinese patients receiving concomitant chemoradiotherapy

OBJECTIVES

To investigate the frequency of pseudoprogression of glioblastoma in Chinese patients receiving concomitant chemoradiotherapy and investigate its association with pseudoprogression and tumour molecular marker O(6)-methylguanine-DNA methyltransferase promoter methylation status.

DESIGN

Case series with internal comparisons.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Patients with glioblastoma treated with concomitant chemoradiotherapy during April 2005 to June 2010 were reviewed. Magnetic resonance imaging brain scans, pre- and post-concomitant chemoradiotherapy and 3-monthly thereafter were reviewed by an independent neuroradiologist according to Macdonald's criteria. Relevant patient information (clinical condition, performance score, development of new neurological deficits, use of steroids, and survival) was retrieved. For each patient, O(6)-methylguanine-DNA methyltransferase methylation status was investigated with genomic DNA from formalin-fixed or paraffin-embedded sections of tumour tissues by methylation-specific polymerase chain reaction.

RESULTS

During the study period, 28 primary glioblastoma patients underwent concomitant chemoradiotherapy. The mean age of the patients was 48 (range, 16-71) years. Thirteen patients (13/28, 46%) developed early radiological progression of the tumour after completion of concomitant chemoradiotherapy, of whom five (39%) were subsequently found to have had pseudoprogression. Patients with pseudoprogression showed a trend towards longer survival (22 months in pseudoprogression vs 17 months in all others vs 11 months in those with genuine progression). Among the 27 patients tested for O(6)-methylguanine-DNA methyltransferase promoter status, 12 (44%) were methylated. Two (2/12, 17%) in the methylated group had pseudoprogression, while three (3/15, 20%) in the unmethylated group had pseudoprogression.

CONCLUSIONS

Nearly half of all patients (46%) developed early radiological progression (within 3 months of completing concomitant chemoradiotherapy). Moreover, about one in three of such patients had pseudoprogression. Pseudoprogression is an important clinical condition to be aware of to prevent premature termination of an effective treatment.

Health-related quality of life after aneurysmal subarachnoid hemorrhage: profile and clinical factors

BACKGROUND

Health-related quality of life has recently been suggested as a supplement to the traditional neurological outcome measures from the patient's perspective according to the World Health Organization model and may capture the effects of other factors such as posttraumatic stress disorder and neuroendocrine dysfunction.

OBJECTIVE

To explore the profile and clinical factors of quality of life after aneurysmal subarachnoid hemorrhage using the data we obtained from the recently completed Intravenous Magnesium Sulphate After Aneurysmal Subarachnoid Hemorrhage (IMASH) trial.

METHODS

This study was registered at www.strokecenter.org/trials and www.ClinicalTrials.gov (NCT00124150). Data from a patient cohort obtained with the Short Form-36 questionnaire completed at 6 months were used for analysis.

RESULTS

Patients with aneurysmal subarachnoid hemorrhage demonstrated a decrease in quality of life according to the Short Form-36 at 6 months. The physical and mental health scores correlated with the Extended Glasgow Outcome Scale and had the potential to avoid the ceiling effect. Multiple regression analyses showed that the physical component scores were related to age, World Federation of Neurological Surgeons grade, and chronic hydrocephalus and that the mental component scores were not related to the traditional prognostic factors.

CONCLUSION

Subarachnoid hemorrhage caused a decrease in quality of life. Chronic hydrocephalus is related to a decrease in physical health quality of life.

Neurological outcomes of neurosurgical operations for multiple trauma elderly patients in Hong Kong

Background:

We aimed to investigate neurological outcomes in elderly patients with multiple trauma, and to review their clinical outcomes following neurosurgical operations.

Patients and Methods:

The study was conducted in a regional trauma center in Hong Kong. We collected prospective data on consecutive trauma patients from January 2001 to December 2008. Patients with multiple trauma (as defined by Injury Severity Score of 15 or more), with both head injury and extracranial injury, were included for analysis.

Results:

Age over 65 years, admission Glasgow Coma Scale (GCS), and Injury Severity Score were significantly poor prognostic factors in logistic regression analysis. Eleven (32%) of the 34 patients aged over 65 who underwent neurosurgical operations attained favorable neurological outcomes (GCS 4-5) at 6 months.

Conclusions:

Age was an important prognostic factor in multiple trauma patients requiring neurosurgical operations. Future randomized controlled clinical trials should be designed to recruit elderly patients (such as age between 65 and 75 years) at clinical equipoise for traumatic hematoma (such as subdural hematoma or traumatic intracerebral hematoma) evacuation and assess the quality of life, neurological, and cognitive outcomes.

Neurological outcome in patients with traumatic brain injury and its relationship with computed tomography patterns of traumatic subarachnoid hemorrhage

Object

Traumatic subarachnoid hemorrhage (SAH) is a poor prognostic factor for traumatic brain injury. The authors aimed to further investigate neurological outcome among head injury patients by examining the prognostic values of CT patterns of traumatic SAH, in particular, the thickness and distribution.

Methods

The study was conducted using a database in a regional trauma center in Hong Kong. Data had been prospectively collected in consecutive trauma patients between January 2006 and December 2008. Patients included in the study had significant head injury (as defined by a head Abbreviated Injury Scale [AIS] score of 2 or more) with traumatic SAH according to admission CT.

Results

Over the 36-month period, 661 patients with significant head injury were admitted to the Prince of Wales Hospital in Hong Kong. Two hundred fourteen patients (32%) had traumatic SAH on admission CT. The mortality rate was significantly greater and a 6-month unfavorable outcome was significantly more frequent in patients with traumatic SAH. Multivariate analysis showed that the maximum thickness (mm) of traumatic SAH was independently associated with neurological outcome (OR 0.8, 95% CI 0.7–0.9) and death (OR 1.3, 95% CI 1.2–1.5) but not with the extent or location of hemorrhage.

Conclusions

Maximum thickness of traumatic SAH was a strong independent prognostic factor for death and clinical outcome. Anatomical distribution per se did not affect clinical outcome.

Early risk stratification of patients with major trauma requiring massive blood transfusion

BACKGROUND

There is limited evidence to guide the recognition of patients with massive, uncontrolled hemorrhage who require initiation of a massive transfusion (MT) protocol.

OBJECTIVE

To risk stratify patients with major trauma and to predict need for MT.

DESIGNS

Retrospective analysis of an administrative trauma database of major trauma patients. A REGIONAL TRAUMA CENTRE: A regional trauma centres in Hong Kong.

PATIENTS

Patients with Injury Severity Score ≥ 9 and age ≥ 12 years were included. Burn patients, patients with known severe anemia and renal failure, or died within 24h were excluded.

MAIN OUTCOME MEASURES

Delivery of ≥ 10 units of packed red blood cells (RBC) within 24h.

RESULTS

Between 01/01/2001 and 30/06/2009, 1891 patients met the inclusion criteria. 92 patients required ≥ 10 units RBC within 24h. Seven variables which were easy to be measured in the ED and significantly predicted the need for MT are heart rate ≥ 120/min; systolic blood pressure ≤ 90 mm Hg; Glasgow coma scale ≤ 8; displaced pelvic fracture; CT scan or FAST positive for fluid; base deficit >5 mmol/L; hemoglobin ≤ 7 g/dL; and hemoglobin 7.1-10 g/dL. At a cut off of ≥ 6, the overall correct classification for predicting need for MT was 96.9%, with a sensitivity of 31.5% and specificity of 99.7%, and an incidence of MT of 82.9%. The area under the curve was 0.889.

CONCLUSION

A prediction rule for determining an increased likelihood for the need for massive transfusion has been derived. This needs validation in an independent data set.

Triple coaxial catheter technique for transfacial superior ophthalmic vein approach for embolization of dural carotid-cavernous fistula

We report a triple coaxial catheter technique to facilitate the venous access to the superior ophthalmic vein during transvenous embolization of dural carotid-cavernous fistula (DCCF) via the transfacial venous route. Two patients with transvenous embolization of DCCFs by coils were treated with transfacial superior ophthalmic vein (SOV) approach by the triple coaxial catheter technique. The triple coaxial catheter system consisted of a 6F guiding catheter as the outer catheter and a 4F guiding catheter as the middle catheter and a microcatheter as the inner catheter to help navigation and manipulation. The DCCFs were completely obliterated in both cases. There were no complications associated with the procedure. The ophthalmic symptoms of the patients had totally resolved at two-month follow-up. The triple coaxial catheter technique can be used with the transfacial SOV approach in embolization of DCCF. This technique has two advantages over the double coaxial catheter technique because it offers additional length and support for the distal navigation of microcatheter into the SOV.

Antibiotics-impregnated ventricular catheter versus systemic antibiotics for prevention of nosocomial CSF and non-CSF infections: a prospective randomised clinical trial

BACKGROUND

In recent years, cranial ventricular catheters impregnated with antimicrobial agents have become available. Theoretically, they provide antibiotic prophylaxis locally without the associated complications of opportunistic nosocomial infections. This study aims to compare antibiotic impregnated catheters with conventional catheters coupled with systemic antibiotics.

METHODS

Patients undergoing emergency neurosurgical operations were recruited. Patients were randomly assigned to antibiotic impregnated catheters (Bactiseal, Codman, Johnson & Johnson, Raynham, MA, USA) or conventional catheters coupled with systemic antibiotics.

RESULTS

184 neurosurgical patients were enrolled between April 2004 and December 2008. Mean duration of ventricular catheter was 10 days for both groups. The proportion of patients with nosocomial infection was not significantly different: 57% (51/90) in the Bactiseal group and 51% (48/94) in the conventional group (OR 1.3, 0.7 to 2.2). There were also no differences in secondary outcome measures (CSF infection, intensive care unit stay, acute hospital stay and functional outcome) between the two groups.

CONCLUSIONS

Antibiotic impregnated catheters are as effective as systemic antibiotics in the prevention of CSF infection and their corresponding nosocomial infection rates are not significantly different. The study is registered at http://www.ClinicalTrials.gov (NCT00286104).

Intracellular free magnesium of brain and cerebral phosphorus-containing metabolites after subarachnoid hemorrhage and hypermagnesemic treatment: a 31P–magnetic resonance spectroscopy study

Object

Disturbance of cerebral phosphorus-containing metabolites occurs in many disease entities and has not been widely studied in patients with subarachnoid hemorrhage (SAH). Pilot studies have indicated that hypermagnesemic treatment may improve outcome in patients with aneurysmal SAH, but the precise mechanism is not known. The authors hypothesized that, by raising intracellular brain free magnesium in aneurysmal SAH, hypermagnesemic treatment would alter the cerebral energy status.

Methods

The authors designed the current study to use 31P-MR spectroscopy (MRS) to investigate intracellular brain free magnesium and cerebral phosphorus-containing metabolites in patients with good-grade aneurysmal SAH, both those receiving and not receiving hypermagnesemic therapy. A total of 37 eligible patients and 23 healthy volunteers were recruited. A total of 81 MRS studies were performed.

Results

Hypermagnesemic treatment after aneurysmal SAH produced a small (mean difference 0.018 ± 0.007 mM [+ 13.0%]) but significant elevation of intracellular free magnesium during the 1st week. Aneurysmal SAH produced a depressed membrane metabolism with lower phosphodiester/total phosphate.

Conclusions

The MRS finding of elevated brain free intracellular magnesium after intravenous magnesium sulfate infusion is novel, and the changes in membrane metabolism provide insight into the metabolic effects of aneurysmal SAH and future pathophysiological studies.

Clinical study on cognitive dysfunction after spontaneous subarachnoid haemorrhage: patient profiles and relationship to cholinergic dysfunction

PURPOSE

We aimed to explore the cognitive profiles of subarachnoid haemorrhage patients who returned to the community, along with the associated risk factors.

METHODS

We recruited 40 Chinese patients with spontaneous subarachnoid haemorrhage 7-27 months after the initial presentation. They had all been discharged to their homes or to care homes for the elderly. For cognitive assessment, we employed the Cognitive Subscale of the Alzheimer Disease Assessment Scale (ADAS-cog) for global cognitive function, the Frontal Assessment Battery (FAB) for frontal lobe function, and the Rivermead Behavioural Memory Test (RBMT) for everyday memory function.

RESULTS

An ADAS-cog of more than 21/85 (poor global cognitive function) was noted in 14 (35%) patients. A FAB of less than 12/18 (poor frontal lobe function) was noted in 13 (27.5%) patients. An RBMT score of less than 15/26 (poor everyday memory function) was noted in 17 (43.6%) patients. Poor cognitive function was found to be associated with chronic hydrocephalus (in terms of FAB), with clinical vasospasm (in terms of RBMT), and with cerebral infarction (in terms of RBMT).

CONCLUSIONS

Poor cognitive function was common and occurred in up to 43.6% of the patients, with the verbal and behavioural memory aspects predominantly affected. We did not find a significant association between cholinergic dysfunction and cognitive dysfunction. Organization of future drug trials and cognitive rehabilitation should take into account the association between frontal lobe dysfunction and chronic hydrocephalus.

Use of Onyx (a patented ethylene-vinyl alcohol copolymer formulation) embolisation of cerebral arteriovenous malformations in Hong Kong: initial experience

OBJECTIVE

To review the experience with Onyx embolisation of cerebral arteriovenous malformation.

DESIGN

Prospective study.

SETTING

A regional neurosurgical centre in Hong Kong.

PATIENTS

Data of patients with cerebral arteriovenous malformation who underwent Onyx embolisation over a 14-month period were prospectively collected.

RESULTS

Eleven sessions of Onyx embolisation were performed in nine patients with cerebral arteriovenous malformations, seven of which had ruptured. Total occlusion was achieved in three (33%) of the patients, and subtotal occlusion (over 80% occlusion) in three out of four with Spetzler-Martin grade-III/IV malformations. One patient developed mild permanent neurological deficit.

CONCLUSION

Onyx embolisation of cerebral arteriovenous malformations is feasible in Hong Kong. Careful patient and target selection are important.

Stereoscopic virtual reality simulation for microsurgical excision of cerebral arteriovenous malformation: case illustrations

BACKGROUND

Use of virtual reality planning and rehearsal for planning and training of cerebral aneurysm clipping was recently reported. We aimed to illustrate its applications in preoperative planning and training for cerebral AVM excision.

CASE DESCRIPTION

We illustrated the application of preoperative rehearsal for excision of cerebral AVM for 2 patients in a stereoscopic virtual reality environment. One patient was a 44-year-old lady with a right posterior temporal AVM, and 1 patient was a 23-year-old lady with a left frontal AVM. Through Dextroscope, an anatomical understanding of arterial feeders, nidus, and draining veins in relationship to surrounding cerebral cortex was obtained. It allowed one to see the exposure with the different angles of visualization, similar to what happened under the operative microscope.

CONCLUSION

Dextroscopic virtual reality stimulation provided an illustrated preoperative planning and training for excision of cerebral AVM.

Epithelioid haemangioendothelioma of the anterior skull base: what is the optimal treatment?

We report an unusual malignant tumour affecting an unusual site. Epithelioid haemangioendothelioma was formerly considered a tumour of intermediate malignancy but has been reclassified as fully malignant. It is important to be aware of this clinical entity as the best hope of cure is timely radical resection. There is a paucity of evidence concerning the efficacy of alternative treatments because the tumour is very rare.

The effect of hypermagnesemic treatment on cerebrospinal fluid magnesium level in patients with aneurysmal subarachnoid hemorrhage

Preliminary evidence has suggested that magnesium sulfate infusion reduces delayed ischemic neurological deficit and improves clinical outcome after aneurysmal subarachnoid hemorrhage. However, little is known about its site of action in vivo. We studied 22 aneurysmal subarachnoid hemorrhage patients with or without magnesium sulfate infusion for 10-14 days. Thirteen patients had external ventricular drains inserted for hydrocephalus and daily cerebrospinal fluid magnesium levels were measured. For patients given magnesium sulfate infusion, the aim was to raise the plasma magnesium level to double the baseline level. We found that the magnesium sulfate infusion bought an 11% to 21% increase in cerebrospinal fluid magnesium. The elevation of cerebrospinal fluid magnesium was sustained for at least nine days. Whether this mild elevation in cerebrospinal fluid magnesium level was adequate for neuroprotection awaits the results of ongoing clinical trials.

Meteorological factors and aneurysmal subarachnoid haemorrhage in Hong Kong

OBJECTIVE

To evaluate the influence of meteorological factors on the onset of aneurysmal subarachnoid haemorrhage in Hong Kong.

DESIGN

Retrospective review of prospectively collected data.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

A total of 135 consecutive patients with acute aneurysmal subarachnoid haemorrhage presenting to the hospital within 48 hours after ictus from October 2002 to October 2006.

MAIN OUTCOME MEASURES

Occurrence of aneurysmal subarachnoid haemorrhage in relation to daily changes in atmospheric pressure, temperature, and humidity.

RESULTS

The peak incidence of aneurysmal subarachnoid haemorrhage occurred in winter (December to February), especially January. The mean (+/-standard deviation) daily atmospheric pressure change was significantly higher on days with aneurysmal subarachnoid haemorrhage onset as opposed to days without (1.75+/-1.47 hPa vs 1.48+/-1.28 hPa; P=0.032).

CONCLUSIONS

A seasonal variation and relationship to atmospheric pressure change in aneurysmal subarachnoid haemorrhage was noted in the current study carried out in Hong Kong. The mechanism linking atmospheric pressure change and aneurysmal rupture remained to be explored.

Chronic hydrocephalus that requires shunting in aneurysmal subarachnoid haemorrhage [a-SAH]: its impact on clinical outcome

BACKGROUND

Chronic hydrocephalus is a common occurrence following aneurismal subarachnoid haemorrhage [a-SAH] but its impact on neurological outcome has not been re reviewed systematically.

PATIENTS AND METHODS

One hundred and eleven patients were recruited from a prospectively collected a-SAH registry over a 3-year period between 2002 and 2004. Their 6-month extended Glasgow Outcome Scale [GOSE] scores were correlated with routine clinical data and the need for CSF shunting [chronic hydrocephalus that required shunting, CHS].

RESULTS

Thirty patients with CHS were identified and they were associated with an initial poor WFNS grading [median 4 versus 2, p = 0.028]. Among patients with poor WFNS grading, CHS was associated with a better GOSE [median 4 versus 2, p = 0.041] and among patients with good WFNS grading, CHS paradoxically was associated with a poor GOSE [median 3.5 versus 7, p = 0.016].

CONCLUSION

The relationships between CHS and GOSE in a-SAH were complex. Their true clinical significance requires a more in-depth prospective study.

Vermal hemorrhage with fourth ventricle extension due to ruptured posterior inferior cerebellar artery aneurysm

Distal posterior inferior cerebellar artery (PICA) aneurysm located at the choroidal branch is uncommon. We report a ruptured distal PICA aneurysm in a 50-year-old man who presented with sudden onset of coma. The management and clinical significance are highlighted.

CRANIOTOMY AND CLIPPING OF INTRACRANIAL ANEURYSM IN A STEREOSCOPIC VIRTUAL REALITY ENVIRONMENT

OBJECTIVE

The release of results of International Subarachnoid Aneurysm Trial in 2003 caused a shift in the paradigm of management of ruptured intracranial aneurysms. The cases selected for microsurgical clipping nowadays are usually those patients with aneurysms that are not suitable for embolization, and are often complex and difficult. We devised an innovative application of operative planning and training for craniotomy and microsurgical clipping of intracranial aneurysms in a stereoscopic virtual reality environment.

METHODS

Patient-specific Digital Imaging and Communications in Medicine data from computed tomographic angiography of the intracranial circulation and cranium were transferred to the workstation (Dextroscope; Volume Interactions Pte. Ltd., Singapore, Singapore). An aneurysm clip database was loaded into the patient data set. Three-dimensional volume rendering was followed by data coregistration and fusion.

RESULTS

Virtual head positioning and craniotomy were carried out to simulate the microscopic visualization. Clip selection could be carried out with reference to the angle of application. This allows one to see the exposure and degree of obliteration of an aneurysm with the various angles of approach.

CONCLUSION

The virtual craniotomy and microsurgical clipping application simulated the operative environment. Its role in neurosurgical training is encouraging and should be further developed.

Transvenous embolization for dural transverse sinus fistulas with occluded sigmoid sinus

Dural transverse sinus arteriovenous fistulas with cortical venous drainage were associated with a high hemorrhagic risk. Dural transverse sinus arteriovenous dural fistulas could be treated by embolization (transarterial or transvenous), surgery or a combination of both. Transvenous packing of the diseased sinus was considered to be a less invasive and effective method of treatment. Occluded sigmoid sinus proximally, especially cases with isolated transverse sinus, could make the transvenous approach difficult. Craniotomy for sinus packing or surgical excision remained the treatment of choice when the percutaneous transvenous approach was not feasible. We reviewed the techniques of transvenous embolization described in the literature and illustrated our techniques in two consecutive cases of transvenous embolization of the dural arteriovenous fistulas through the occluded sigmoid sinus. We concluded that transvenous embolization remains a safe and feasible technique other than surgery for patients with transverse sinus dural fistula, achieving a long-term occlusion of the pathology.