Vessel Rupture Complication due to Ballooning of the Distal Segment of a JET 7 Xtra Flex Reperfusion Catheter during Angiogram.

Objective: We present a case of intraprocedural device malfunction related to the JET 7 Xtra Flex reperfusion catheter during mechanical thrombectomy. Case Presentation: A 92-year-old man presented with sudden right hemiparesis with a National Institutes of Health Stroke Scale score of 22. His left middle cerebral artery (M1) was occluded, and emergency mechanical thrombectomy was performed. After partial recanalization was achieved, angiography through a JET 7 Xtra Flex was attempted. After manual injection of contrast media via a 10-mL syringe through the JET 7 Xtra Flex, the catheter moved, jumping forward, and the distal tip of the catheter expanded and ruptured. This resulted in intracranial vessel damage and subsequent patient death. Conclusion: Contrast media must not be injected through the JET 7 Xtra Flex. If contrast media needs to be injected for angiography during mechanical thrombectomy with a reperfusion catheter, it should always be through the guide catheter.

In-hospital Ischemic Stroke Treated by Mechanical Thrombectomy.

Objective: We investigated in-hospital stroke (IHS) treated by mechanical thrombectomy in comparison with out-of-hospital stroke (OHS) to clarify the points of concern in IHS at our institution. Methods: Between September 2015 and June 2018, 19 patients with IHS who underwent mechanical thrombectomy (IHS group) were enrolled, and compared with 154 patients with OHS (OHS group) regarding patient characteristics, technical results, and outcome. In this study, we set the detection time in the IHS group as patient arrival time, termed "Door" in the OHS group. Results: Cardiology and gastroenterology were the two main admitting departments, including four (21%) patients of IHS group. In all, 15 (79%) patients had atrial fibrillation; however, less than one-third of them was taking anticoagulant drugs at onset. There were only two cases of direct consultation to the stroke specialists, although IHS onset was mainly recognized by nurses. The median age in the IHS group was 81 (interquartile range (IQR), 76-86.5) versus 80 in the OHS group (IQR, 73-85; p = 0.43), and the median initial National Institutes of Health Stroke Scale score was 21 (IQR, 16-23) versus 21 (IQR, 14-26; p = 0.92), respectively. Sex, Alberta Stroke Program Early CT Score, etiology, and occlusion site did not differ between groups. The rate of use of intravenous tissue plasminogen activator (IV-tPA) was 26% in the IHS group versus 49% in the OHS group (p = 0.065). The median time of detection to imaging, detection to needle for IV-tPA, and detection to puncture were 32, 69, and 87 minutes, respectively, in the IHS group, being significantly longer than those in the OHS group (11, 30, and 50 minutes; p <0.01, p <0.01, and p <0.01, respectively). The median time of puncture to reperfusion was 39 minutes, being significantly shorter than that in the OHS group (82 minutes; p <0.01). Successful reperfusion defined as thrombolysis in cerebral infarction (TICI) 2b-3 was obtained in 94.7% of the IHS group versus 83.1% of the OHS group (p = 0.19). A favorable outcome (modified Rankin Scale score 0-2) at 90 days was achieved by 36.8% (IHS) versus 35.1% (OHS) of patients (p = 0.88). The rate of symptomatic procedural complications was 0% (IHS) versus 7.1% (OHS; p = 0.23). The rate of death at 90 days was 15.8% (IHS) versus 12.3% (OHS; p = 0.67). Conclusion: The times of detection to imaging and of detection to puncture in the IHS group were longer than those in the OHS group; however, patients in the IHS group had shorter reperfusion. The outcome of the IHS group did not differ from that of OHS group. Our study suggests that the time course of treatment should be improved and rapid stroke pathways involved in consultation with the stroke specialists for IHS should be organized.

Hemodynamic characteristics of hyperplastic remodeling lesions in cerebral aneurysms.

BACKGROUND & PURPOSE: Hyperplastic remodeling (HR) lesions are sometimes found on cerebral aneurysm walls. Atherosclerosis is the results of HR, which may cause an adverse effect on surgical treatment for cerebral aneurysms. Previous studies have demonstrated that atherosclerotic changes had a correlation with certain hemodynamic characteristics. Therefore, we investigated local hemodynamic characteristics of HR lesions of cerebral aneurysms using computational fluid dynamics (CFD). METHODS: Twenty-four cerebral aneurysms were investigated using CFD and intraoperative video recordings. HR lesions and red walls were confirmed on the intraoperative images, and the qualification points were determined on the center of the HR lesions and the red walls. The qualification points were set on the virtual operative images for evaluation of wall shear stress (WSS), normalized WSS (NWSS), oscillatory shear index (OSI), relative residence time (RRT), and aneurysm formation indicator (AFI). These hemodynamic parameters at the qualification points were compared between HR lesions and red walls. RESULTS: HR lesions had lower NWSS, lower AFI, higher OSI and prolonged RRT compared with red walls. From analysis of the receiver-operating characteristic curve for hemodynamic parameters, OSI was the most optimal hemodynamic parameter to predict HR lesions (area under the curve, 0.745; 95% confidence interval, 0.603-0.887; cutoff value, 0.00917; sensitivity, 0.643; specificity, 0.893; P<0.01). With multivariate logistic regression analyses using stepwise method, NWSS was significantly associated with the HR lesions. CONCLUSIONS: Although low NWSS was independently associated with HR lesions, OSI is the most valuable hemodynamic parameter to distinguish HR lesions from red walls.

A Case of Vertebral Artery Fusiform Aneurysm Treated by Flow Alteration: Successful Prediction of Therapeutic Effects Using Computational Fluid Dynamics.

The treatment of intracranial complicated aneurysms remains challenging. In patients with complicated aneurysms that are neither clippable nor coilable, flow alteration treatment (FAT) with a combined procedure of proximal/distal occlusion or trapping of an aneurysm with bypass surgery has been reported. However, it is difficult to predict whatever FAT can achieve aneurysmal obliteration without ischemic complications. A 69-year-old female was incidentally diagnosed with a left vertebral artery (VA) fusiform aneurysm distal to the left posterior inferior cerebellar artery (PICA). Because one-year follow-up three-dimensional computed tomography angiography showed that the aneurysm grew significantly, surgical management was considered the therapy of choice. For determining treatment strategies, we assumed left VA occlusion at the proximal to the left PICA as a FAT model and performed computational fluid dynamics (CFD) analyses. The FAT model had much lower wall shear stress and shear rate at the aneurysm dome than presumed thresholds necessary to thrombus formation, while those at the PICA were obviously higher than the thresholds, and streamlines into the left PICA from the distal VA were preserved. These findings theoretically meant that surgical occlusion of the left VA proximal to the left PICA and aneurysm would induce intra-aneurysmal thrombus formation with preservation of the left PICA flow. The treatment was performed successfully and achieved the predicted results. CFD simulations may be useful to predict effects of FAT for complicated aneurysms.

Stagnation and complex flow in ruptured cerebral aneurysms: a possible association with hemostatic pattern.

OBJECT Histopathological examination has revealed that ruptured cerebral aneurysms have different hemostatic patterns depending on the location of the clot formation. In this study, the authors investigated whether the hemostatic patterns had specific hemodynamic features using computational fluid dynamics (CFD) analysis. METHODS Twenty-six ruptured middle cerebral artery aneurysms were evaluated by 3D CT angiography and harvested at the time of clipping. The hemostatic patterns at the rupture points were assessed by means of histopathological examination, and morphological parameters were obtained. Transient analysis was performed, and wall shear stress-related hemodynamic parameters and invariant Q (vortex core region) were calculated. The morphological and hemodynamic parameters were compared among the hemostatic patterns. RESULTS Hematoxylin and eosin staining of the aneurysm wall showed 13 inside-pattern, 9 outside-pattern, and 4 other-pattern aneurysms. Three of the 26 aneurysms were excluded from further analysis, because their geometry models could not be generated due to low vascular CT values. Mann-Whitney U-tests showed that lower dome volume (0.04 cm3 vs 0.12 cm3, p = 0.014), gradient oscillatory number (0.0234 vs 0.0289, p = 0.023), invariant Q (-0.801 10-2/sec2 vs -0.124 10-2/sec2, p = 0.045) and higher aneurysm formation indicator (0.986 vs 0.963, p = 0.041) were significantly related to inside-pattern aneurysms when compared with outside-pattern aneurysms. CONCLUSIONS Inside-pattern aneurysms may have simpler flow patterns and less flow stagnation than outside-pattern aneurysms. CFD may be useful to characterize the hemostatic pattern of ruptured cerebral aneurysms.

Aneurysm Organization Effects of Gellan Sulfate Core Platinum Coil with Tenascin-C in a Simulated Clinical Setting and the Possible Mechanism.

BACKGROUND: This study aimed to deliver gellan sulfate core platinum coil with tenascin-C (GSCC-TNC) into rabbit side-wall aneurysms endovascularly and to evaluate the organization effects in a simulated clinical setting. METHODS: Elastase-induced rabbit side-wall aneurysms were randomly coiled via a transfemoral route like clinical settings with platinum coils (PCs), gellan sulfate core platinum coils (GSCCs), or GSCC-TNCs (n = 5, respectively). Aneurysm-occlusion status was evaluated angiographically and histologically at 2 weeks post coiling. As each rabbit coiled aneurysm provided only 2-3 tissue slices due to technical limitations and prevented immunohistochemical evaluations, a PC, GSCC, or GSCC-TNC was randomly implanted in a rat blind-ended model (n = 3, respectively) and the organization effects were immunohistochemically evaluated for expressions of tenascin-C (TNC), transforming growth factor-beta (TGF-ß), and matrix metalloproteinase-9 (MMP-9) 2 weeks later. RESULTS: Coil handling was similar among the 3 kinds of coils. GSCCs showed a significantly higher ratio of organized area to the aneurysmal cavity than PCs, but GSCC-TNCs had the greatest organization-promoting effects on aneurysms (the ratio of organized area/aneurysmal luminal area: PC, 17.9 ± 7.1%; GSCC, 54.2 ± 18.3%; GSCC-TNC, 82.5 ± 5.8%). GSCC-TNCs had intense immunoreactivities for TNC, TGF-ß, and MMP-9 in the organized thrombosis and tunica media. GSCCs also showed intense immunoreactivities for TNC, TGF-ß, and MMP-9, although the extent was less than GSCC-TNCs. The immunoreactivities were hardly found in unorganized thrombus and the tunica media of aneurysm wall in the PC group. CONCLUSIONS: This study first showed that GSCC-TNCs promote intra-aneurysmal clot organization in simulated clinical settings using rabbits possibly through the TGF-ß and MMP-9 upregulation.

Inflammatory biomarkers in atherosclerosis: pentraxin 3 can become a novel marker of plaque vulnerability.

Inflammation is crucially involved in the development of carotid plaques. We examined the relationship between plaque vulnerability and inflammatory biomarkers using intraoperative blood and tissue specimens. We examined 58 patients with carotid stenosis. Following carotid plaque magnetic resonance imaging, 41 patients underwent carotid artery stenting (CAS) and 17 underwent carotid endarterectomy (CEA). Blood samples were obtained from the femoral artery (systemic) and common carotid artery immediately before and after CAS (local). Seventeen resected CEA tissue samples were embedded in paraffin, and histopathological and immunohistochemical analyses for IL-6, IL-10, E-selectin, adiponectin, and pentraxin 3 (PTX3) were performed. Serum levels of IL-6, IL-1ß, IL-10, TNFα, E-selectin, VCAM-1, adiponectin, hs-CRP, and PTX3 were measured by multiplex bead array system and ELISA. CAS-treated patients were classified as stable plaques (n = 21) and vulnerable plaques (n = 20). The vulnerable group showed upregulation of the proinflammatory cytokines (IL-6 and TNFα), endothelial activation markers (E-selectin and VCAM-1), and inflammation markers (hs-CRP and PTX3) and downregulation of the anti-inflammatory markers (adiponectin and IL-10). PTX3 levels in both systemic and intracarotid samples before and after CAS were higher in the vulnerable group than in the stable group. Immunohistochemical analysis demonstrated that IL-6 was localized to inflammatory cells in the vulnerable plaques, and PTX3 was observed in the endothelial and perivascular cells. Our findings reveal that carotid plaque vulnerability is modulated by the upregulation and downregulation of proinflammatory and anti-inflammatory factors, respectively. PTX3 may thus be a potential predictive marker of plaque vulnerability.

Effect of pitavastatin on preventing ischemic complications with carotid artery stenting: a multicenter prospective study--EPOCH-CAS study.

PURPOSE: Periprocedural ischemic stroke is one problem associated with carotid artery stenting (CAS). This study was designed to assess whether preoperative statin therapy reduces the risk of periprocedural ischemic complications with CAS. METHODS: In this prospective study at 11 centers, patients with carotid artery stenosis (symptomatic ≥50%, asymptomatic ≥80%) and a high risk of carotid endarterectomy but without previous statin treatments were divided into two groups by low-density lipoprotein cholesterol (LDL-C) levels. With LDL-C ≥120 mg/dl, the pitavastatin-treated (PS) group received pitavastatin at 4 mg/day. With LDL-C <120 mg/dl, the non-PS group received no statin therapy. After 4 weeks, both groups underwent CAS. Frequencies of new ipsilateral ischemic lesions on diffusion-weighted imaging within 72 h after CAS and cerebrovascular events (transient ischemic attack, stroke, or death) within 30 days were assessed. RESULTS: Among the 80 patients enrolled, 61 patients (PS group, n = 31; non-PS group, n = 30) fulfilled the inclusion criteria. New ipsilateral ischemic lesions were identified in 8 of 31 patients (25.8%) in the PS group and 16 of 30 patients (53.3%) in the non-PS group (P = 0.028). Cerebrovascular events occurred in 0 patients in the PS group and in 3 of 30 patients (10.0%) in the non-PS group (P = 0.071). Multivariate analyses demonstrated the pitavastatin treatment (ß = 0.74, 95% confidence interval 0.070-1.48, P = 0.042) to be an independent factor for decreasing post-CAS ischemic lesions. CONCLUSION: Pretreatment with pitavastatin significantly reduced the frequency of periprocedural ischemic complications with CAS.

Changes in hemodynamics after placing intracranial stents.

Stent-assisted coil embolization has enabled the endovascular treatment of wide-necked cerebral aneurysms. Moreover, recent reports demonstrated that stent-assisted coil embolization was associated with a significant decrease in angiographic recurrences of coiled cerebral aneurysms. One of the possible explanations for this adjunctive effect of stent-assisted coil embolization is changes in the local hemodynamics caused by placing intracranial stents. This study investigated the hemodynamic effect of intracranial stents using computational fluid dynamics (CFD) analysis. The geometry of the intracranial stent, Enterprise(TM) VRD, was acquired by using micro computed tomography and virtually placed across the aneurysm orifice of a saccular aneurysm model (saccular model) and a blister-like aneurysm model (blister-like model) constructed from patient-specific three-dimensional (3D) rotational angiography data. Transient CFD analysis was performed with these models with and without stents. Stent placement induced no significant changes in the 3D streamline in the saccular model and slight changes in the blister-like model. Both saccular and blister-like models with stents had lower wall shear stress (WSS) and flow velocity, and higher oscillatory shear index, WSS gradient, and relative residence time than the equivalent models without stents, indicating the possibility that stent placement induced stagnant and disturbed blood flow. Cross-sectional vector velocity around the stent strut revealed complex blood flow patterns with variable direction and velocity. Although this study was a simulation under limited conditions, similar hemodynamic changes might be induced in the neck remnants treated with stent-assisted coil embolization.

Low wall shear stress is independently associated with the rupture status of middle cerebral artery aneurysms.

BACKGROUND AND PURPOSE: We determined which hemodynamic parameter independently characterizes the rupture status of middle cerebral artery (MCA) aneurysms using computational fluid dynamics analysis. METHODS: In 106 patient-specific geometries of MCA aneurysms (43 ruptured, 63 unruptured), morphological and hemodynamic parameters were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine parameters that independently characterized the rupture status of MCA aneurysms. RESULTS: Univariate analyses showed that the aspect ratio, wall shear stress (WSS), normalized WSS, oscillatory shear index, WSS gradient, and aneurysm-formation index were significant parameters. The size of the aneurysmal dome and the gradient oscillatory number were not significantly different between the 2 groups. With multivariate analyses, only lower WSS was significantly associated with the rupture status of MCA aneurysms. CONCLUSIONS: WSS may be the most reliable parameter characterizing the rupture status of MCA aneurysms.

High-risk plaque for carotid artery stenting evaluated with 3-dimensional T1-weighted gradient echo sequence.

BACKGROUND AND PURPOSE: Preventing cerebral embolisms is a major concern with carotid artery stenting (CAS). This study evaluated 3-dimensional T1-weighted gradient echo (3D T1GRE) sequence to predict cerebral embolism related to CAS. METHODS: We performed quantitative analyses of the characteristics of 47 carotid plaques before CAS by measuring the signal intensity ratio (SIR) and plaque volume using 3D T1GRE images. We used T1-weighted turbo field echo sequence to obtain 3D T1GRE images. We also evaluated diffusion-weighted images (DWI) of the brain before and after CAS to detect ischemic lesions (DWI lesions) from cerebral emboli. RESULTS: SIR (2.17 [interquartile range 1.50-3.07] versus 1.35 [interquartile range 1.08-1.97]; P=0.010) and plaque volume (456 mm(3) [interquartile range 256-696] versus 301 mm(3) [interquartile range 126-433]; P=0.008) were significantly higher in the group of patients positive for DWI lesions (P-group: n=26) than DWI lesion-negative patients (N-group: n=21). In multivariate logistic regression analysis, SIR (P=0.007) and plaque volume (P=0.042) were independent predictors of DWI lesions with CAS. Furthermore, SIR (rs=0.42, P=0.005) and plaque volume (rs=0.36, P=0.012) were positively correlated with the number of DWI lesions. From analysis of a receiver-operating characteristic curve, the most reliable cutoff values of SIR and plaque volume to predict DWI lesions related to CAS were 1.80 and 373 mm(3), respectively. CONCLUSIONS: Quantitative evaluation of carotid plaques using 3D T1GRE images may be useful in predicting cerebral embolism related to CAS.

Diffusion-weighted magnetic resonance imaging in carotid angioplasty and stenting with balloon embolic protection devices.

We compared the results of two procedures to protect against distal embolism caused by embolic debris from carotid angioplasty with stent deployment (CAS) using diffusion-weighted magnetic resonance imaging (MRI). The study group comprised 39 men and 3 women (42 and 3 CAS procedures, respectively) with severe carotid stenosis (average age 70.0 +/- 6.6 years). During 20 CAS procedures the internal carotid artery was protected with a single balloon. A PercuSurge GuardWire was used for temporary occlusion. During 25 CAS procedures the internal and external carotid arteries were simultaneously temporarily occluded with a PercuSurge GuardWire and a Sentry balloon catheter, respectively. Diffusion-weighted MRI was performed 1 to 3 days after CAS. Data from 26 patients undergoing conventional angiography for diagnosis of cerebral ischemic disease, cerebral aneurysm or brain tumors were included as controls. Diffusion-weighted MRI after conventional diagnostic angiography showed ischemic spots in 3 of the 26 controls (11.5%). Ischemic spots were observed during 11 of 20 CAS procedures with the internal carotid artery protected with a single balloon (55.0%), and were observed during 9 of 25 CAS procedures with both the internal and external carotid arteries protected (36.0%). This difference was significant (P = 0.0068). Ischemic lesions appeared not only ipsilateral to the carotid stenosis but also in the contralateral carotid artery (31.9%) and vertebrobasilar territory (25.3%). Better protection was obtained with simultaneous double occlusion of both the internal and external carotid artery than with single protection of the internal carotid artery during CAS.

Angioscopic observation during carotid angioplasty with stent placement.

This clinical report is the first to describe angioscopy during carotid angioplasty with stent placement. The average observation time was 3 minutes 43 seconds in 18 cases. The view was clear in 67% of cases. Lesions in the endothelium, rupture of the fibrous cap, clots, debris detaching from plaque, and stent struts were observed. No symptomatic ischemic complications occurred. Diffusion-weighted MR imaging after angioscopy showed asymptomatic ischemic lesions in 47% of cases.