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Intracranial aneurysm can lead to hemorrhagic stroke upon rupture. Deployment of flow diverters can restrict the blood flow into aneurysm and mitigate the rupture risk. Computational fluid dynamics (CFD) and ultrasonography with pulse-wave and color Doppler ultrasound measurements were employed jointly to investigate the complex flow pattern in cerebral aneurysms, both before and after the deployment of flow diverters. Patient-specific configurations of both bifurcation and side-wall aneurysms were selected. The effect of downstream flow resistance was investigated by adjusting the volume flow rate and pressure at the outlet vessels computationally and experimentally. Velocity profiles in the aneurysm measured from ultrasonography showed good agreement with those from computer simulations. The discrepancy in velocity between the computational and experimental sets of data is less than 10%. The downstream resistance can alter the volume flux into a bifurcation aneurysm with a flow diverter deployed by 236%, while the corresponding value of a side-wall aneurysm is negligible. The vorticity of the aneurysmal flow was reduced by more than 80% in both cases after stenting. This study demonstrated that careful investigation of downstream flow resistance of a bifurcation aneurysm is essential to provide an accurate assessment of the aneurysmal flow dynamics after flow diverter deployment.

The rupture of intracranial aneurysms might lead to permanent disability or even death. One possible endovascular treatment is the deployment of flow diverters (FDs), which reduces flow into the sac and promotes thrombosis. Computational fluid dynamics simulations were used to assess the flow patterns and dynamics. The concept of energy loss, as a measure of necessary work done to overcome flow resistance, was utilized to correlate with clinical outcome. If a surgical operation is successful, the flow would be diverted to a shorter path and energy loss should be reduced. Conversely, persistent flow in the sac, associated with treatment failure, would display an increased energy loss as blood is then squeezed through the stent pores. Four illustrative clinical cases, involving both bifurcation and sidewall aneurysms, were selected. To reduce the numerical complexity, earlier works in the literature had used a porous medium approximation for the FDs. Here, the FD was simulated explicitly as a virtual (or computer-generated) stent, which would likely provide a more accurate description. Furthermore, quantitative comparisons between the approaches of virtual stenting and a porous medium with typical parameters were conducted by examining the effective flow influx into the aneurysm.

The city of Shenzhen, China, is planning to establish a trauma system. At present, there are few data on the geographical distribution of incidents, which is key to deciding on the location of trauma centres. The aim of this study was to perform a geographical analysis in order to inform the development of a trauma system in Shenzhen. Retrospective analysis of trauma incidents attended by Shenzhen Emergency Medical Services (EMS) in 2014. Data were obtained from Shenzhen EMS. Incident distribution was explored using dot and kernel density estimate maps. Clustering was determined using the nearest neighbour index. The type of healthcare facilities which patients were taken to was compared against patients’ needs, as assessed using the Field Triage Decision Scheme. There were 49,082 recorded incidents. A total of 3513 were classed as major trauma. Mapping demonstrates that incidents predominantly occurred in the western part of Shenzhen, with identifiable clusters. Nearest neighbour index was 0.048. Of patients deemed to have suffered major trauma, 8.5% were taken to a teaching hospital, 13.6% to a regional hospital, 42.6% to a community hospital, and 35.3% to a private hospital. The proportions of Step 1 or 2 negative patients were almost identical. The majority of trauma patients, including trauma patients who are at greater likelihood of severe injury, are taken to regional and community hospitals. There are areas with identifiable concentrations of volume, which should be considered for the siting of high-level trauma centres, although further modelling is required to make firm recommendations.

The chemotherapeutic agent temozolomide (TMZ) is widely used in the treatment of glioblastoma multiforme (GBM). Rutin, a citrus flavonoid ecglycoside found in edible plants, has neuroprotective and anticancer activities. This study aimed to investigate the efficacy and the underlying mechanisms of rutin used in combination with TMZ in GBM. In vitro cell viability assay demonstrated that rutin alone had generally low cytotoxic effect, but it enhanced the efficacy of TMZ in a dose-dependent manner. Subcutaneous and orthotopic xenograft studies also showed that tumor volumes were significantly lower in mice receiving combined TMZ/Rutin treatment as compared to TMZ or rutin alone treatment. Moreover, immunoblotting analysis showed that TMZ activated JNK activity to induce protective response autophagy, which was blocked by rutin, resulting in decreased autophagy and increased apoptosis, suggesting that rutin enhances TMZ efficacy both in vitro and in vivo via inhibiting JNK-mediated autophagy in GBM. The combination rutin with TMZ may be a potentially useful therapeutic approach for GBM patient.

Rupture of a cerebral aneurysm (abnormal swelling of blood vessel in the brain) will cause subarachnoid hemorrhage, and will result in an alarming rate of mortality and morbidity. A joint computational-experimental study is conducted to assess the importance of the aspect ratio in the dynamics of blood flow. The aspect ratio is defined here to be the ratio of the height of the aneurysm to the linear dimension of the neck. Idealized models of such aneurysms located near a bifurcation point were investigated. Numerical simulations for hemodynamic properties like shear stress and flow rate were performed. The computational results were verified experimentally with specially fabricated phantoms, blood mimicking fluid and Doppler ultrasound imaging. Excellent agreements were obtained. Two features are highlighted, providing information in the intensely debated link between rupture risk and geometric factors. On increasing the aspect ratios, firstly, a jet impinging on the distal part of the neck can be observed, and secondly, a region of positive shear stress gradient can be found there. Furthermore, computational analyses for four patient-specific models were conducted to correlate with the results of idealized models and to provide further clinical insight.

A middle-aged lady in good health presented right abducens nerve palsy. Magnetic resonance imaging (MRI) of the brain showed bilateral cavernous ICA aneurysms. The left aneurysm measured 9 × 7 mm whereas the right aneurysm measured 22 × 15 mm, with mass effect on the cavernous sinus, explaining her symptoms (Fig. 1). Both were wide-neck aneurysms and were treated with PED alone sequentially, 3 months apart. She was loaded with Aspirin 300 mg and Clopidogrel 300 mg before treatment, with Aspirin continuing for 6 months and Clopidogrel for 3 months afterwards. There were no procedural complications. Digital subtraction angiogram at 1 year showed that the left aneurysm was completely occluded, whereas the right aneurysm had partially thrombosed but with a persistent filling. The right aneurysm persisted on CT angiogram at 2 years but with significant shrinkage and finally occluded at a 3-year follow-up (Fig. 2). The patient’s diplopia gradually improved after 3 years.

Studies directly comparing the outcomes of intracranial meningioma resection between elderly and younger patients are currently limited. This study aimed to assess the perioperative complications, mortalities and functional outcomes in these two groups. Consecutive elderly patients (aged ≥ 65) and tumor-location-matched younger patients who underwent intracranial meningioma resections were retrospectively reviewed. Outcomes were assessed at 30-day, 90-day, 6-month and 1-year. We used a standardized classification of operative complications, and conducted subgroup analyses based on tumor location [convexity, parasagittal and falcine (CPF) as one group; skull base (SB) as another]. There were 92 patients in each group. The mean age was 74.6 ± 6.4 years in the elderly and 49.3 ± 10.1 years in the younger groups. The cumulative 30-day, 90-day and 1-year mortality rates were 0, 2.2 and 4.3 % for the elderly, respectively, and 1.1 % for all time points in the young. These differences were not statistically significant. Overall, the elderly suffered from more perioperative complications (P = 0.010), and these were mostly minor complications according to the classification of operative complications. However, these differences were observed only in the SB but not in the CPF subgroup. More elderly patients had impaired functional outcome 1-year after surgery. Significantly more elderly patients had new neurological deficits 1-year after surgery (26.1 vs. 6.6 %; P = 0.001). Comparable mortality rates were observed in elderly and younger patients. However, the elderly had more minor complications and poorer functional outcomes. Patient selection remains key to good clinical outcome.

OBJECTIVE: To investigate the profile of concomitant use of Chinese medicine (CM) and Western medical treatment in neurosurgical patients. METHODS: A guided questionnaire survey was conducted on 309 Chinese patients under neurosurgical care in a teaching hospital in Hong Kong from June to July 2006. RESULTS: Concomitant use of CM was reported by 25.9% of patients. Age was identified to be associated with the use of CM. Half of the CM-users were unaware of there being potential risks of adverse interactions between neurosurgical and CM treatments. Among the CM-users 85% would continue to receive both treatments but only 52.0% would inform neurosurgeons on their CM use. Patients' perceived lack of benefit from CM was the main reason for not using it although 47.0% indicated their willingness to try CM given better access to information. CONCLUSIONS: Informal source was the major channel of CM use amongst patients with neurosurgical conditions. A need for improved patient education and service provision was identified and should become an important consideration for healthcare systems which anticipate an increased use of CM amongst patients. Strategies to enhance doctor-patient communications in mainstream care such as pre-operative checklists for herbal medications and post-operative advice may facilitate the safe and complementary use of both treatment systems.