Bai-Nan Xu

Magnetic resonance spectroscopy (MRS) is a powerful tool for preoperative grading of gliomas. We performed a meta-analysis to evaluate the diagnostic performance of MRS in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). PubMed and Embase databases were systematically searched for relevant studies of glioma grading assessed by MRS through 27 March 2015. Based on the data from eligible studies, pooled sensitivity, specificity, diagnostic odds ratio and areas under summary receiver operating characteristic curve (SROC) of different metabolite ratios were obtained. Thirty articles comprising a total sample size of 1228 patients were included in our meta-analysis. Quantitative synthesis of studies showed that the pooled sensitivity/specificity of Cho/Cr, Cho/NAA and NAA/Cr ratios was 0.75/0.60, 0.80/0.76 and 0.71/0.70, respectively. The area under the curve (AUC) of the SROC was 0.83, 0.87 and 0.78, respectively. MRS demonstrated moderate diagnostic performance in distinguishing HGGs from LGGs using tumoural metabolite ratios including Cho/Cr, Cho/NAA and NAA/Cr. Although there was no significant difference in AUC between Cho/Cr and Cho/NAA groups, Cho/NAA ratio showed higher sensitivity and specificity than Cho/Cr ratio and NAA/Cr ratio. We suggest that MRS should combine other advanced imaging techniques to improve diagnostic accuracy in differentiating HGGs from LGGs. • MRS has moderate diagnostic performance in distinguishing HGGs from LGGs. • There is no significant difference in AUC between Cho/Cr and Cho/NAA ratios. • Cho/NAA ratio is superior to NAA/Cr ratio. • Cho/NAA ratio shows higher sensitivity and specificity than Cho/Cr and NAA/Cr ratios. • MRS should combine other advanced imaging techniques to improve diagnostic accuracy.

To study the clinical characteristics and treatment strategies of mirror aneurysms. Nineteen patients with 20 pairs of mirror aneurysms from November 2007 to November 2012 were retrospectively analysed. Among the 19 patients, 13 were female and 6 were male, mean age was 56 years (ranged 32-75 years). Distribution of the lesions included 11 bilateral posterior communicating artery aneurysms (one with a pair of anterior choroidal artery aneurysm), 4 bilateral middle cerebral artery aneurysms, 3 bilateral paraclinoidal aneurysms, and 1 bilateral pericallosal-callosomarginal artery aneurysm. Surgical strategies were selected according to location of hemorrhage, Hunt-Hess grade, location and size of aneurysm, etc. Four mirror aneurysms were clipped at one stage, 3 mirror aneurysms were clipped at two stages, 2 were treated with combination of clipping and coiling and remaining 10 were clipped unilaterally. At discharge, 15 out of 19 patients had a Glasgow Outcome Scale score of 5, 4 patients had a score of 4. The mean clinical follow-up was 18.6 months (range 3-50 months). Two patients had oculomotor nerve palsy postoperatively. At 3-month follow-up, 1 improved and 1 unchanged. In 10 patients with unilateral clipping, contralateral aneurysms were unruptured, small ( < 5 mm) and regular. No remnant or recurrence of aneurysm were found in other 9 patients whose bilateral aneurysms had been treated. The mirror aneurysms are rare kinds of multiple aneurysms. The aneurysm responsible for hemorrhage should be treated with first priority. The contralateral unruptured aneurysm could be observed, clipped or coiled in one stage, or treated in two separate stages.

Unclippable fusiform basilar trunk aneurysm is a formidable condition for surgical treatment. The aim of this study was to establish a computational model and to investigate the hemodynamic characteristics in a fusiform basilar trunk aneurysm. The three-dimensional digital model of a fusiform basilar trunk aneurysm was constructed using MIMICS, ANSYS and CFX software. Different hemodynamic modalities and border conditions were assigned to the model. Thirty points were selected randomly on the wall and within the aneurysm. Wall total pressure (WTP), wall shear stress (WSS), and blood flow velocity of each point were calculated and hemodynamic status was compared between different modalities. The quantitative average values of the 30 points on the wall and within the aneurysm were obtained by computational calculation point by point. The velocity and WSS in modalities A and B were different from those of the remaining 5 modalities; and the WTP in modalities A, E and F were higher than those of the remaining 4 modalities. The digital model of a fusiform basilar artery aneurysm is feasible and reliable. This model could provide some important information to clinical treatment options.

To study the revascularization techniques in the treatment of intracranial complex aneurysms and occlusive reasons of bypass vessel. The 20 complex intracranial aneurysms who underwent saphenous bypass treatment from November 2006 to November 2008 were retrospectively analyzed and the occlusive reasons were studied. Of the 20 patients, 12 were female and 8 were male, mean age was 54.5 years (ranged 27 - 65 years). The distribution of the lesions included 13 cavernous sinus aneurysms, 4 para-clinoid aneurysms, 2 supraclinoid aneurysms, and 1 basilar trunk aneurysm. Four aneurysms were giant (diameter > 25 mm), 12 aneurysms were large (15 - 25 mm), and 4 aneurysms were medium (10 - 15 mm) size. One saphenous vein was occluded intraoperatively and one saphenous vein was occluded postoperatively. At discharge, 18 out of the 20 patients had Glasgow Outcome Scale (GOS) score of 4 or 5, 2 patients had score of 3, and 1 patient had score of 1. At 6 months follow up, 18 of 19 survivors had GOS score of 4 or 5 and 1 patient had score of 3. Extracranial-intracranial revascularization technique is a safe and effective method in the treatment of complex aneurysms. Mechanical and hemodynamic factors are two leading reasons for occlusion of bypass vessels. Long-term bypass vessels patent rate still needs further observation.

To study the surgical principles and treatment options of intracranial aneurysms. One hundred and thirty nine patients with intracranial aneurysms were retrospectively studied, including 80 open-surgery cases and 59 endovascular-treated cases from January to December in 2009. Open surgical methods included clipping, trapping or wrapping and interventional methods included simple coiling or stent-assisted coiling. Intra-operative electroencephalogram and somatosensory evoked potentials monitoring were regularly used. Microvascular doppler ultrasonography and indocyanine green videoangiography were used to assess blood flow in parent and branch vessels. Seventy-three aneurysms were directly clipped, 6 were trapped and 1 was wrapped. Thirty-three aneurysms were coiled and 26 were coiled assisted with stents. At discharge, 71 of the 80(88.8%) surgical treated patients had Glasgow Outcome Scale score of 4 or 5 points, 3 points in 6 patients (7.5%), 2 points in 1 patient (1.2%), and 1 point in 2 patients (2.5%). Fifty-four out of 59 cases underwent endovascular treatment scored 4 or 5 points (91.5%) and 3 points in 5 patients (8.5%). Surgical clipping and endovascular coiling are two major treatment choices for intracranial aneurysms. The treatment option should be individualized based on the patients' specific conditions, which could have a safe, effective and durable outcome.