Are hemodynamics of irregular small carotid-ophthalmic aneurysms different from those of regular ones and large aneurysms based on numerical simulation?

PURPOSE: The purpose of this study is to investigate whether hemodynamics of unruptured, irregular small intracranial aneurysms (SIAs) are different from those of regular ones and large intracranial aneurysms (LIAs) in ophthalmic artery segment of internal carotid artery (ICA). METHODS: Between April 2015 and June 2018, 106 carotid-ophthalmic artery aneurysms were retrospectively analyzed using 3D angiographic images and computational fluid dynamics (CFD). Three categories were stratified: regular SIAs, irregular SIAs and LIAs. Statistical comparisons of the differences in clinical, morphological and hemodynamic parameters among regular SIA, irregular SIA and LIA groups were performed by one-way analysis of variance (ANOVA) or Kruskal-Wallis Test. RESULTS: The median maximal height of regular SIA, irregular SIA and LIA were 3.03 (interquartile range: 2.49-4.22) mm, 4.59 (interquartile range: 3.86-5.32) mm and 11.06 (interquartile range: 9.28-13.69) mm, all P < 0.05). Low shear-stress area percentage (LSA%) and oscillatory shear index (OSI) of irregular SIAs and LIAs were not significantly different (P = 0.72, P = 0.27 respectively), and were significantly higher than those of regular SIAs (all P < 0.01). Wall shear stress (WSS) and normalized wall shear stress (NWSS) of irregular SIAs were significantly higher than those of LIAs (P < 0.01, P < 0.01 respectively), but lower than those of regular SIAs (P < 0.01, P < 0.01 respectively). CONCLUSIONS: Special unruptured irregular SIAs share a similarity of hemodynamic characteristics with LIAs in high LSA% and high OSI, and are different from regular SIAs in hemodynamics.

Diffusion-weighted imaging helps differentiate multiple sclerosis and neuromyelitis optica-related acute optic neuritis.

PURPOSE: To evaluate the apparent diffusion coefficient (ADC) values between multiple sclerosis (MS) and neuromyelitis optica (NMO)-related acute optic neuritis (ON) patients and predict their optic nerve atrophy of optic coherence tomography (OCT) parameters. MATERIALS AND METHODS: Nineteen MS and 15 NMO-related acute ON patients who underwent a diffusion-weighted imaging sequence in 3.0 Tesla MR scanner and a follow-up OCT examination after 6 months were included. The ADC values, thickness of the retinal nerve fiber layer (RNFL) and the macular ganglion cell complex (GCC) between MS and NMO related ON were assessed. RESULTS: The mean ADC value of the NMO-ON, (0.691 ± 0.195[SD]) × 10-3 mm2 /s, was significantly smaller (P = 0.0133) than that of MS-ON. The mean ADC value of MS-ON, (0.879 ± 0.144) × 10-3 mm2 /s, was significantly smaller (P < 0.0001) than that of control group, (1.025 ± 0.067) × 10-3 mm2 /s. Using an ADC value smaller than 0.830 × 10-3 mm2 /s as the threshold value for differentiating MS-ON from NMO-ON patients, the highest accuracy of 76.7%, with 75.0% sensitivity and 78.3% specificity, was obtained. The ADC value measured at the acute stage of ON was correlated with the thickness of the RNFL (r = 0.441; P = 0.006) and the GCC (r = 0.526; P < 0.0001) after 6 months. CONCLUSION: The ADC value might be helpful for differentiating MS-ON from NMO-ON patients. The decreased ADC value was correlated with optic nerve atrophy on OCT. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1780-1785.

Assessment of nonarteritic anterior ischemic optic neuropathy with intravoxel incoherent motion diffusion-weighted imaging using readout-segmented echo-planar imaging, parallel imaging, and 2D navigator-based reacquisition.

PURPOSE: To determine the feasibility of intravoxel incoherent motion (IVIM) for characterizing perfusion properties and its potential diagnostic utility for nonarteritic anterior ischemic optic neuropathy (NAION). IVIM diffusion-weighted imaging is a promising technique that can measure perfusion and diffusion characteristics simultaneously in a noninvasive manner. MATERIALS AND METHODS: Orbital IVIM in a 3.0T scanner was performed on 33 patients with NAION and 15 controls using readout-segmented echo-planar imaging, parallel imaging, and 2D navigator-based reacquisition (RESOLVE-IVIM). Both visual field (VF) and visual acuity (VA) examinations were performed in 19 of the patients. The vascular volume fraction (f), diffusion coefficient (D), and pseudodiffusion coefficient (D*) were calculated for quantitative analysis. Additionally, correlation analyses of IVIM parameters with visual function were also performed. RESULTS: Affected optic nerves showed significantly lower f values than both unaffected contralateral nerves of the patients and nerves of the controls (P < 0.0001), and no significant difference for f was found between unaffected contralateral nerves and nerves of the controls (P = 0.1602). In addition, D and D* values showed no significant differences among the three groups (P = 0.0979, 0.0600, 0.6136 for D and 0.1779, 0.6253, 0.4743 for D*). Correlation analysis only demonstrated significant correlations between f values and the mean deviation of the visual field (r = 0.576, P = 0.0051). CONCLUSION: RESOLVE-IVIM measurement may reflect the perfusion abnormality and visual function impairment in NAION patients, demonstrating its potential application for the diagnosis and clinical evaluation of NAION. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1760-1766.

Role of coronal high-resolution diffusion-weighted imaging in acute optic neuritis: a comparison with axial orientation.

PURPOSE: Through a comparison with the axial orientation, we aimed to evaluate the role of coronal high-resolution diffusion-weighted imaging (DWI) in acute optic neuritis based on diagnostic accuracy and the reproducibility of apparent diffusion coefficient (ADC) measurements. METHODS: Orbital DWI, using readout-segmented, parallel imaging, and 2D navigator-based reacquisition (RESOLVE-DWI), was performed on 49 patients with acute vision loss. The coronal (thickness = 3 mm) and axial (thickness = 2 mm) diffusion images were evaluated by two neuroradiologists retrospectively. The sensitivity, specificity, and accuracy were calculated through diagnostic test; the inter- and intra-observer reliabilities were assessed with a weighted Cohen's kappa test. In addition, the agreement of ADC measurement among observers was evaluated by the intra-class correlation coefficient (ICC), coefficient of variation (CV), and Bland-Altman plots. Comparison of ADC values was also performed by unpaired t test. RESULTS: Among the 49 patients, 47 clinically positive optic nerves and 51 clinically negative optic nerves were found. The sensitivity, specificity, and accuracy were 85.1/87.2%, 90.2/94.12%, and 87.8/90.8%, respectively, for coronal RESOLVE-DWI and 83.0/85.1%, 66.7/76.5%, and 75.5/79.6%, respectively, for axial RESOLVE-DWI. The inter-observer kappa values were 0.710 and 0.806 for axial and coronal RESOLVE-DWI, respectively, and the intra-observer kappa values were 0.822 and 0.909, respectively (each P < 0.0001). Regarding the reproducibility of ADC measurements on axial and coronal RESOLVE-DWI, the ICCs among observers were 0.846 and 0.941, respectively, and the CV values were 7.046 and 4.810%, respectively. Bland-Altman plots revealed smaller inter-observer variability on coronal RESOLVE-DWI. ADC values were significantly lower in positive group (each P < 0.0001). CONCLUSION: Higher specificity and better reproducibility of ADC measurements were found for coronal RESOLVE-DWI, which demonstrated the feasibility of the use of coronal RESOLVE-DWI to examine acute optic neuritis patients.

High-Resolution Diffusion-Weighted Imaging Improves the Diagnostic Accuracy of Dynamic Contrast-Enhanced Sinonasal Magnetic Resonance Imaging.

OBJECT: The aim of the study was to evaluate the incremental value of high-resolution diffusion-weighted imaging and apparent diffusion coefficient (ADC) mapping compared with that of dynamic contrast-enhanced (DCE) sinonasal magnetic resonance imaging (MRI) in the characterization of benign versus malignant sinonasal tumors at 3.0T. MATERIALS AND METHODS: Ninety-eight patients (61 females, 37 males; mean age, 48 years) with sinonasal lesions who underwent high-resolution DW-MRI and DCE-MRI were included in this study. The lesions were divided into malignant and benign groups on the basis of pathological examination. In total, 58 malignant tumors and 40 benign tumors were evaluated. Apparent diffusion coefficients were acquired with 0 and 1000 s/mm b values. Semiquantitative parameters (time-signal intensity curve [TIC] type, time of peak enhancement within the first 2 minutes [Tpeak], peak percentage enhancement within the first 2 minutes [PEpeak], the last time point percentage enhancement [PElast], and the washout percentage-enhancement difference [PEwashout]) were derived from DCE-MRI. The DCE-MRI parameters and ADCs were included in multivariate models to predict a diagnosis of a benign versus malignant lesion. RESULTS: The accuracy using semiquantitative DCE-MRI parameters alone was 70.4% (0.693 area under the ROC curve, 57.5% sensitivity, 79.3% specificity). Adding absolute ADCs to dynamic contrast-enhanced MR data showed the higher diagnostic accuracy of 85.7% (0.873 area under the ROC curve, 85.0% sensitivity, 86.2% specificity). Moreover, the absolute ADCs differed significantly between the benign (mean [SD] ADC, 1.211 [0.32] × 10 mm/s) and malignant (mean [SD] ADC, 0.702 [0.28] × 10 mm/s) sinonasal tumors (P < 0.001). In addition, a significant difference was found between the ADC values of malignant and benign lesions in washout enhancement TICs (t = 7.039, P < 0.001). CONCLUSIONS: High-resolution DWI with ADC mapping significantly improved the diagnostic accuracy of dynamic contrast-enhanced sinonasal MRI at 3.0T. In addition, ADC values could distinguish benign lesions from malignant tumors in washout enhancement TICs.

Diffusion-weighted imaging using readout-segmented echo-planar imaging, parallel imaging, and two-dimensional navigator-based reacquisition in detecting acute optic neuritis.

PURPOSE: To evaluate the accuracy of diffusion-weighted imaging (DWI) in comparison to contrast-enhanced, fat-suppressed T1 -weighted imaging (CET1WI) in detecting acute optic neuritis (ON). MATERIALS AND METHODS: The clinical data and magnetic resonance imaging (MRI) findings of 42 patients who presented with decreased vision were retrospectively reviewed. Both 3.0T MRI DWI and CET1WI orbital imaging studies were performed. Two neuroradiologists independently evaluated the DWI and CET1WI. The sensitivity, specificity, and accuracy of the DWI and CET1WI were individually calculated using the clinical diagnosis as the reference standard. The interobserver and intraobserver reliability of DWI and CET1WI were assessed by using a weighted Cohen's kappa (κ) test; a value of P < 0.05 was set as the threshold for statistical significance. RESULTS: Of the 42 patients, 34 patients (41 nerves) had clinically confirmed acute ON, two had ischemic optic neuropathy, and three had chronic recurrent ON. The sensitivities of DWI and CET1WI for acute ON were 82.9-82.9% and 68.3-85.4%, respectively; the specificities were 81.4-83.7% and 79.1-93.0%, respectively; and the accuracies were 82.1-83.3% and 82.1-90.0%, respectively. The interobserver kappa values were 0.596-0.643 and 0.694-0.734 for DWI and CET1WI, respectively; the intraobserver kappa values were 0.809-0.905 and 0.834-0.924 for DWI and CET1WI, respectively (each P < 0.0001). CONCLUSION: Given that its sensitivity and specificity are similar to those of dedicated CET1WI for acute ON, DWI can play an important complementary role in detecting acute ON, especially in atypical ON cases, and can provide a quantitative modality that can be used to evaluate axonal damage in the optic nerves.

Measurement of sinus wall thickness and wall enhancement index in dural arteriovenous fistulae by magnetic resonance vessel wall imaging.

BACKGROUND: Dural sinus wall thickness and wall enhancement index (WEI) of dural arteriovenous fistulae (DAVFs) have not been well characterized. This study aimed to measure the sinus wall thickness and WEI by using magnetic resonance vessel wall imaging (MR-VWI). METHODS: A total 27 DAVF patients and 30 normal healthy individuals were enrolled in this study. All participants were scanned by a 3 T MR scanner with the black blood sequence. The wall thickness and the WEI of the great cerebral vein, the intracranial main dural sinuses with DAVFs, and the contralateral sinuses were measured by two independent neuroradiologists. RESULTS: The DAVF-affected sinuses had significantly thicker walls (2.277 ±â€¯0.311 mm vs. 1.446 ±â€¯0.188 mm, P < 0.001) and significantly higher WEI (2.253 ±â€¯0.462 vs. 1.173 ±â€¯0.418, P < 0.001) compared to the contralateral ones. They also had significantly thicker walls (2.277 ±â€¯0.311 mm vs. 1.643 ±â€¯0.173 mm, P < 0.001) and significantly higher WEI (2.253 ±â€¯0.462 vs. 1.124 ±â€¯0.254, P < 0.001) compared to the normal controls. Neither the sinus wall thickness (r = -0.317, P = 0.107) nor the WEI (r = 0.019, P = 0.923) was significantly correlated with the Cognard types in DAVF patients. The WEI of the DAVF draining vein was significantly higher compared to the static venous wall (1.972 ±â€¯0.629 vs. 0.532 ±â€¯0.243, P < 0.001). CONCLUSION: T1-CUBE MRI is useful in measuring sinus all thickness and WEI of DAVFs, providing a new method for diagnosing this disease.

Comparison of Solitaire and Neuroform Stenting for Coiling of Intracranial Bifurcation Aneurysms.

PURPOSE: To compare the technical performance and outcomes of Solitaire and Neuroform stents for treatment of intracranial bifurcation aneurysms (IBAs). METHODS: IBAs treated by stent-assisted coiling using a Solitaire or Neuroform stent between October 2010 and December 2019 were retrospectively evaluated. Patient demographics, aneurysm information, treatment technique, periprocedural and device-related complications, parent artery angle change, along with initial and follow-up angiographic results were analyzed. RESULTS: One hundred twenty-one patients with 121 IBAs treated with Solitaire (n = 101) or Neuroform (n = 20) stent-assisted coiling were included. Aneurysm size, thrombotic and hemorrhagic complication rate, initial occlusion rate and in-stent stenosis between the two cohorts were not significantly different. Aneurysm location was significantly different between the two groups (p = 0.032). Jailing technique rate for coiling was significantly higher in the Solitaire than the Neuroform group (70.3% vs. 35.0%, p < 0.01). Follow-up DSA demonstrated a significantly lower recurrence rate for the Solitaire cohort (2.9% vs. 22.2%, p = 0.016). Parent artery angle changes, immediately post-operative and on follow-up were significantly greater in the Solitaire stent group (p < 0.05). CONCLUSIONS: For intracranial bifurcation aneurysms, Solitaire stent-assisted coiling achieved a significantly lower recurrence rate and induced more favorable parent artery angular remodeling than Neuroform stenting.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula: A case report.

A dural arteriovenous fistula (DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization (TAE), transvenous embolization (TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging (MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.

Wall enhancement predictive of abnormal hemodynamics and ischemia in vertebrobasilar non-saccular aneurysms: a pilot study.

Objective: To analyze how wall enhancement affects hemodynamics and cerebral ischemic risk factors in vertebrobasilar non-saccular intracranial aneurysms (VBNIAs). Materials and methods: Ten consecutive non-saccular aneurysms were collected, including three transitional vertebrobasilar dolichoectasia (TVBD). A wall enhancement model was quantitatively constructed to analyze how wall enhancement interacts with hemodynamics and cerebral ischemic factors. Results: Enhanced area revealed low wall shear stress (WSS) and wall shear stress gradient (WSSG), with high oscillatory shear index (OSI), relative residence time (RRT), and gradient oscillatory number (GON) while the vortex and slow flow region in fusiform aneurysms are similar to TVBD fusiform aneurysms. With low OSI, high RRT and similar GON in the dilated segment, the enhanced area still manifests low WSS and WSSG in the slow flow area with no vortex. In fusiform aneurysms, wall enhancement was negatively correlated with WSS (except for case 71, all p values < 0.05, r = -0.52 ~ -0.95), while wall enhancement was positively correlated with OSI (except for case 5, all p values < 0.05, r = 0.50 ~ 0.83). For the 10 fusiform aneurysms, wall enhancement is significantly positively correlated with OSI (p = 0.0002, r = 0.75) and slightly negatively correlated with WSS (p = 0.196, r = -0.30) throughout the dataset. Aneurysm length, width, low wall shear stress area (LSA), high OSI, low flow volume (LFV), RRT, and high aneurysm-to-pituitary stalk contrast ratio (CRstalk) area plus proportion may be predictive of cerebral ischemia. Conclusion: A wall enhancement quantitative model was established for vertebrobasilar non-saccular aneurysms. Low WSS was negatively correlated with wall enhancement, while high OSI was positively correlated with wall enhancement. Fusiform aneurysm hemodynamics in TVBD are similar to simple fusiform aneurysms. Cerebral ischemia risk appears to be correlated with large size, high OSI, LSA, and RRT, LFV, and wall enhancement.

Modeling of end-pumped Yb:YAG thin-disk lasers with nonuniform temperature distribution.

A plane wave model with nonuniform temperature distribution in the thin-disk crystal is developed to describe the dynamic behavior of an end-pumped Yb:YAG thin-disk laser. A set of couple-rate equations and 2D stationary heat-conduction equations are derived. The stable temperature distribution in the disk crystal is calculated using a numerical iterative method. The analytic expression is capable of dealing with more practical laser systems than previous works on this subject as it allows for nonuniform temperature distribution in the disk crystal. Based on these results, we examined laser output intensity as a function of pump intensity, dopant concentration, resonator coupler reflectivity, crystal thickness and temperature of cooling liquid.

Overview of multimodal MRI of intracranial Dural arteriovenous fistulas.

Dural arteriovenous fistulas (DAVFs) include a wide range of pathological conditions that are associated with intracranial vessel abnormalities. While some types of DAVFs present with typical neuroimaging characteristics, others share overlapping pathological and neuroimaging features that can hinder accurate differentiation. Hence, misclassification of the various types of DAVFs is common. Thorough knowledge of DAVF imaging findings is essential to avoid such misinterpretations. Traditional digital subtraction angiography (DSA) is considered the gold standard for diagnosing and evaluating DAVFs. However, angiography cannot detect changes in a patient's brain structure. Conventional magnetic resonance imaging (MRI) sequences, including MR angiography (MRA), allow the evaluation of DAVFs without ionizing radiation or invasiveness. Advanced MRI techniques, such as susceptibility-weighted imaging (SWI) and dynamic contrast-enhanced MRA, provide added value to real-time physio-pathological data regarding the hemodynamics of DAVFs. Beyond these techniques, new insights using high-resolution vascular wall MRI are incorporated for the noninvasive evaluation of DAVFs. This article reviews the pathophysiology of DAVFs, focusing on the specifics of MRI findings that facilitate their classification. The role of conventional and advanced MRI sequences for DAVFs was assessed using insights derived from the data provided by structured reports of multimodal MRIs to evaluate DAVFs.

Long-Term Outcomes of Stenting on Non-Acute Phase Extracranial Supra-Aortic Dissections.

OBJECTIVE: Extracranial supra-aortic dissections (ESADs) with severe stenosis, occlusion and/or pseudoaneurysm presents potential risk of stroke. Endovascular stenting to reconstruct non acute phase ESADs (NAP-ESADs) is an alternative to anticoagulant or antiplatelet therapy. However, its feasibility, safety and efficacy of stenting in NAP-ESADs is unclear. This study aims to investigate the long-term outcomes of the feasibility, safety and efficacy of stenting in NAP-ESADs. METHODS: Seventy-four patients with 91 NAP-ESAD vessels with severe stenosis, occlusion and/or pseudoaneurysm presents potential risk of stroke who underwent stent remodeling were enrolled into this respective study from December 2008 to March 2020. Technical success rate, complications, clinical and angiographic results were harvested and analyzed. RESULTS: Success rate of stent deployment was 99% (90/91) with no procedural mortality or morbidity. Transient ischemic attack occurred in three patients during operation (4.1%, 3/74). Asymptomatic embolisms of distal intracranial vessels were found in two patients (2.7%, 2/74). One hundred and forty-two stents deployed at 85 carotid (135 stents) and six vertebral (seven stents) vessels. Six stent types (Wingspan, 28/135, 20.7%; Solitaire, 10/135, 7.4%; Neuroform, 8/135, 5.9%; LVIS, 2/135, 1.5%; Precise, 75/135, 55.6%; Acculink, 12/135, 8.9%) were deployed at carotid arterial dissection while two types (Wingspan, 5/7, 71.4%; Solitaire 2/7, 28.6%) at vertebral arterial dissection. Digital subtracted angiography (56%, 51/91), computational tomography angiography (41.8%, 38/91) and high resolution magnetic resonance imaging (2.2%, 2/91) were adopted for follow up, with a mean time of 17.2±15.4 months (5-77). All patient modified Rankin Scale scores showed no increase at discharge or follow-up. Angiographically, dissections in 86 vessels in 69 patients (94.5%, 86/91) were completely reconstructed with only minor remnant dissections in four vessels in four patients (4.4%, 4/91). Severe re-stenosis in the stented segment required re-stenting in one patient (1.1%, 1/91). CONCLUSION: Stent remodeling technique provides feasible, safe and efficacious treatment of ESADs patients with severe stenosis, occlusion and/or pseudoaneurysm.

A low-grade cerebral arteriovenous malformation suspected of being a metastatic tumor: A case report and literature review.

Cases of low-grade cerebral arteriovenous malformations (cAVMs) showing dynamic changes and large areas of brain edema on short-term MRI follow-up have rarely been reported. This report describes an incidentally discovered and initially misdiagnosed cAVM in a patient with malignancies. The presence of abnormal signals surrounded by large areas of brain edema combined with tortuous or dilated vessels indicates the possibility of an AVM, especially in young people.

Onyx embolization of a spinal epidural hemorrhage caused by thoracic spinal epidural arteriovenous fistula: A case report and literature review.

Spinal epidural hemorrhages (SEDH) caused by spinal epidural arteriovenous fistulas (SEAVFs) are rare; thus, their specific pathogenesis has not been explained. Furthermore, the standard treatment for SEAVFs has not yet been defined. Here we report the case of a 36-year-old Chinese man who experienced acute onset chest pain and tightness. His symptoms rapidly aggravated until the lower limbs were unable to support him. Spinal magnetic resonance angiography (MRA) revealed a localized SEAVF and a secondary spinal cord lesion at the T4 level. Digital subtraction angiography (DSA) confirmed the presence of the SEDH/SEAVF at the T3-4 level with the left radicular artery feeding the fistula. Based on DSA and MRA findings, SEDH, local spinal cord infarction, and spinal venous reflux disorder were conditionally diagnosed. Using the arterial route, Onyx-34 was injected into the fistula to embolize the feeding arteries and the venous system. Angiography was performed after the microcatheter was withdrawn, and no residual fistula or anterior spinal artery was observed. The six-week follow-up MRI showed acceptable healing of the SEAVF, and the patient improved neurologically. This case suggests that endovascular treatment with Onyx-34 embolization should be considered a promising treatment strategy for this type of complicated SEAVF.

Large postoperative inflow area predictive of recurrence for paraclinoid aneurysms treated by simple coiling.

OBJECTIVES: This study aims to investigate recurrence risk factors of simply coiled unruptured paraclinoid aneurysms based on a porous medium model (POM). METHODS: Twenty unruptured coiled paraclinoid aneurysms with digital subtract angiography (DSA) follow-up were enrolled to analyze morphological and hemodynamic variables to predict recurrence. RESULTS: Recurrent aneurysms have larger neck areas than stable aneurysms (34.43 ± 21.46 mm2 vs. 16.12 ± 7.10 mm2; p = 0.048). For hemodynamic variables, recurrent aneurysms had larger preoperative (16.40 ± 11.38 mm2 vs. 7.87 ± 3.75 mm2; p = 0.048) and postoperative inflow areas (14.07 ± 6.80 mm2 versus 6.73 ± 4.20 mm2; p = 0.021) than the stable group. Only the postoperative inflow area (p = 0.031, OR = 1.289; 95% CI 1.024-1.624) was an independent predictor of recurrence after multivariate regression analysis. The receiver operating characteristic (ROC) curve analysis efficiently predicted recurrence (AUC = 0.833, p = 0.021) with an inflow area cutoff value (9.15 mm2; sensitivity, 0.833; specificity, 0.857). CONCLUSIONS: Neck area along with pre- and postoperative inflow areas were associated with aneurysm recurrence. These findings suggest that a large postoperative inflow area independently predicts the recurrence of coiled paraclinoid aneurysms.

A fibrin targeted molecular imaging evaluation of microvascular no-reflow in acute ischemic stroke.

OBJECTIVE: To investigate the relationship between fibrin deposition and "no-reflow" within microcirculation after thrombolysis in acute ischemic stroke (AIS). MATERIALS AND METHODS: Experiments were approved by the institutional animal care and use committee. An experimental AIS model was induced in C57BL/6 mice by middle cerebral artery occlusion (MCAO) via the photothrombotic method. Mice were randomly assigned to non-thrombolytic or thrombolytic treated groups (n = 12 per group). The modified Neurological Severity Score and Fast Beam Balance Test were performed by a researcher blinded to the treatment method. MRI was utilized to evaluate all of the mice. An FXIIIa-targeted probe was applied to detect fibrin deposition in acute ischemic brain regions by fluorescence imaging. Necrosis and pathological changes of brain tissue were estimated via Hematoxylin and eosin staining while fibrin deposition was observed by immunohistochemistry. RESULTS: Thrombolytic therapy improved AIS clinical symptoms. The infarct area of non-thrombolytic treated mice was significantly greater than that of the thrombolytic treated mice (p < .0001). Fluorescent imaging indicated fibrin deposition in ischemic brain tissue in both groups, with less fibrin in non-thrombolytic treated mice than thrombolytic treated mice, though the difference was not significant. Brain cells with abnormal morphology, necrosis, and liquefication were observed in the infarcted area for both groups. Clotted red blood cells (RBCs) and fibrin build-up in capillaries were found near the ischemic area in both non-thrombolytic and thrombolytic treated groups of mice. CONCLUSION: Fibrin deposition and stacked RBCs contribute to microcirculation no-reflow in AIS after thrombolytic therapy.

Hemodynamic Comparison of Treatment Strategies for Intracranial Vertebral Artery Fusiform Aneurysms.

Objective: This study comparatively analyzed the hemodynamic changes resulting from various simulated stent-assisted embolization treatments to explore an optimal treatment strategy for intracranial vertebral artery fusiform aneurysms. An actual vertebral fusiform aneurysm case treated by large coil post-stenting (PLCS) was used as a control. Materials and Methods: A single case of an intracranial vertebral artery fusiform aneurysm underwent a preoperative and eight postoperative finite element treatment simulations: PLCS [single and dual Low-profile Visualized Intraluminal Support (LVIS)], Jailing technique (single and dual LVIS both simulated twice, Pipeline Embolization Device (PED) with or without large coils (LCs). Qualitative and quantitative assessments were performed to analyze the most common hemodynamic risk factors for recurrence. Results: Jailing technique and PED-only had a high residual flow volume (RFV) and wall shear stress (WSS) on the large curvature of the blood flow impingement region. Quantitative analysis determined that PLSC and PED had a lower RFV compared to preoperative than did the jailing technique [PED+LC 2.46% < PLCS 1.2 (dual LVIS) 4.75% < PLCS 1.1 (single LVIS) 6.34% < PED 6.58% < Jailing 2.2 12.45% < Jailing 1.2 12.71% < Jailing 1.1 14.28% < Jailing 2.1 16.44%]. The sac-averaged flow velocity treated by PLCS, PED and PED+LC compared to preoperatively was significantly lower than the jailing technique [PED+LC = PLCS 1.2 (dual LVIS) 17.5% < PLCS 1.1 (single LVIS) = PED 27.5% < Jailing 1.2 = Jailing 2.2 32.5% < Jailing 1.1 37.5% < Jailing 2.1 40%]. The sac-averaged WSS for the PLCS 1.2 (dual LVIS) model was lower than the PED+LC, while the high WSS area of the Jailing 1 model was larger than for Jailing 2 [PLCS 1.2 38.94% (dual LVIS) < PED+LC 41% < PLCS 1.1 43.36% (single LVIS) < PED 45.23% < Jailing 2.1 47.49% < Jailing 2.2 47.79% < Jailing 1.1 48.97% < Jailing 1.2 49.85%]. Conclusions: For fusiform aneurysms, post large coil stenting can provide a uniform coil configuration potentially reducing the hemodynamic risk factors of recurrence. Flow diverters also may reduce the recurrence risk, with long-term follow-up required, especially to monitor branch blood flow to prevent postoperative ischemia.

Reducing tumescent anesthetic injection pain by topical anesthesia pretreatment among patients undergoing endovenous radiofrequency ablation of varicose veins: A double-blind randomized controlled trial.

OBJECTIVES: Tumescent anesthesia frequently causes the intraoperative and postoperative pain during radiofrequency ablation (RFA) of varicose veins. We have to find a way to reduce pain caused by these injections. This randomized controlled trial investigated the effectiveness of topical anesthesia pretreatment (TAP) on relieving needle puncture pain during administration of tumescent anesthesia among patients undergoing RFA of varicose veins. METHODS: Eligible patients treated with RFA were recruited and randomized to either application of TAP with lidocaine-prilocaine cream (EMLA) or water-based cream (placebo). The primary outcome was patient described pain scores on the visual analogue scale (VAS) at different time points during the procedure. Secondary outcomes were technical success rate, complications, satisfaction level, expense, and extra analgesia use. RESULTS: Sixty-two patients were randomized: 32 to EMLA and 30 to placebo. Both groups had comparable baseline demographics, CEAP classification, and Venous Clinical Severity Score (VCSS). Less tumescent anesthetic needle puncture pain was found in the EMLA group (22 ± 7 vs 42 ± 8, p < .01). Pain scores of other time points were equivalent. There was less pain in EMLA pretreated area compared to non-pretreated area in the same patient during needle puncture (22 ± 7 vs 45 ± 7, p < .01), and similar phenomena did not appear in the placebo group. There was no statistical difference in complications, satisfaction level, expense, and technical success between the two groups. And no extra analgesia was used in all patients. CONCLUSION: We recommend the routine use of TAP to reduce the needle puncture pain during tumescent anesthesia in RFA of lower extremity varicose veins.

Hemodynamic Effects of Stent-Induced Straightening of Parent Artery vs. Stent Struts for Intracranial Bifurcation Aneurysms.

OBJECTIVE: This study aims to compare the hemodynamic impact of stent-mesh and stent-induced straightening of the parent artery in intracranial bifurcation aneurysms using finite element method simulation. MATERIAL AND METHODS: Three intracranial bifurcation aneurysms treated with different stent-assisted coil embolization were evaluated. Simulation using the finite element method was conducted for Solitaire, LVIS and Neuroform stents. Four models of each stent were established, including a pre-treatment baseline, stenting without parent artery straightening (presented as stent-mesh effect), no-stent with parent artery reconstruction (to reveal the straightening impact), and stenting with straightening (categorized as Models I-IV respectively). Hemodynamic characteristics of the four models for each stent were compared. RESULTS: In the Neuroform stent, compared with the pre-treatment model (100%), the mean WSS decreased to 82.3, 71.4, and 57.0% in Models II-IV, velocity to 88.3, 74.4, and 62.8%, and high flow volume (HFV, >0.3 m/s) to 77.7, 44.0, and 19.1%. For the LVIS stent, the mean WSS changed to 105.0, 40.2, and 39.8% in Models II to IV; velocity to 91.2, 58.1, and 52.5%, and HFV to 92.0, 56.1, and 43.9%. For the Solitaire stent, compared with the pre-treatment model (100%), the mean WSS of Models II-IV changed altered by 105.7, 42.6, and 39.4%, sac-averaged velocity changed to 111.3, 46.6, and 42.8%, and HFV 115.6, 15.1, and 13.6%. CONCLUSION: The hemodynamic effect of straightening the parent artery of intracranial bifurcation aneurysms by stenting was noticeably improved over stent mesh diversion in all three stents tested. Therefore stent-induced remodeling of the parent artery appears to be the best method of decreasing recurrence in intracranial bifurcation aneurysms.