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.

Endovascular management of vertebral artery dissecting aneurysms: review of 25 patients.

AIM: Management of Vertebral Artery (VA) dissections remains controversial. The clinical and angiographic variables of VA dissections were evaluated to demonstrate the safety and efficacy of endovascular intervention in treatment of VA dissecting aneurysms. MATERIAL AND METHODS: 25 patients with 27 VAdissecting aneurysms were treated with endovascular intervention during the last 10 years.17 patients were admitted with subarachnoid hemorrhage. 23 aneurysms treated using destructive endovascular trapping, while reconstructive techniques were used in 3 aneurysms treated with stent-assisted coiling and one aneurysm treated with false lumen embolization. RESULTS: The right VA was involved in 14 patients, the left VA in 9 patients, while 2 patients had bilateral VA dissection. The pearl and string sign was the commonest angiographic sign in 12 aneurysms. Perioperative complications included; rebleeding in one patient, symptomatic brain stem infarction in two patients and silent cerebellar ischemic lesion in one patient. Afavorable outcome was evident more in patients with unruptured VA dissection (100%) versus (76.5%) in patients presented with SAH. CONCLUSION: The endovascular technique should be individualized according to the clinical status of the patient, angiographic variables, condition of the posterior circulation and the available supplies.

Periprocedural hemodynamic instability with carotid angioplasty and stenting.

BACKGROUND: Carotid angioplasty and stenting is used for treatment of carotid stenosis. Stent deployment may induce HDI and thereby cause systemic or neurologic deficits. This study defines characteristics and predictors of HDI with CAS. METHODS: A total of 132 patients who had undergone CAS were evaluated for periprocedural and postprocedural HDI (hypertension, systolic blood pressure >160 mm Hg; hypotension, systolic blood pressure <90 mm Hg; or bradycardia, heart rate <60 beats per minute). RESULTS: Frequencies of HDI were 6.8% for hypertension, 32.6% for hypotension, and 15.9% for bradycardia. In addition, CAS of the right side (P < .01), carotid bulb lesions (P < .05), eccentric posterior carotid plaque (P < .0001), and general anesthesia (P < .05) were associated significantly with postprocedural HDI. Male sex (OR, 3.4; 95% CI, 1.8-67.2; P < .001), age of 80 years or older (OR, 0.4; 95%CI, 0.1-1.4; P = .011), and plaque ulceration (OR, 0.5; 95% CI, 0.1-9.5; P = .008) independently predicted postprocedural hypertension. Male sex (OR, 2.5; 95% CI, 1.3-24.9; P < .001), preprocedural major stroke (OR, 0.1; 95% CI, 0.01-0.8; P = .002), carotid bulb lesions (OR, 1.6; 95% CI, 1.1-25.9; P = .024), and contralateral carotid occlusion (OR, 0.6; 95% CI, 0.2-4.9; P = .040) all predicted postprocedural hypotension. Bradycardia was associated with diabetes mellitus (OR, 0.7; 95% CI, 0.3-2.4; P = .033), preprocedural TIA (OR, 1.7; 95% CI, 1.4-17.9; P = .020), and minor stroke (OR, 1.5; 95% CI, 1-10.9; P = .037). In 5 patients, HDI predisposed neurologic or systemic deterioration. CONCLUSIONS: Hemodynamic instability is common with CAS; hypotension and bradycardia are more frequent than hypertension. Some clinical, angiographic, and procedural variables can predict these HD changes.

Tiny Falx Meningioma Causing Massive Interhemispheric Subdural Hematoma: A Case Report.

Bleeding from meningiomas is well known, but massive subdural hemorrhage from a very small meningioma is rare. A 61-year-old woman presented with a sudden-onset headache and slight right hemiparesis without a history of trauma. Computed tomographic scan showed bilateral acute/subacute interhemispheric subdural hematoma, but contrast-enhanced computed tomography (CT) scan, non-enhanced magnetic resonance imaging (MRI) and digital subtraction angiography failed to detect the cause. The hematoma was conservatively treated. Three weeks later, CT scans showed a vestige of the hematoma along the falx. However, repeated angiogram revealed a tumor stain on the falx supplied by the middle meningeal arteries, leading to the tentative diagnosis of meningioma. The tumor was removed and histologically diagnosed as angiomatous meningioma. It is rare that falx meningioma causes massive interhemispheric subdural hematoma, and the diagnosis of the causative lesion is challenging if tumor is small. We review the literature and discuss the characteristics.

Access site complications with carotid angioplasty and stenting.

BACKGROUND: Carotid angioplasty and stenting is a relatively new therapeutic alternative to CEA for treatment of carotid stenosis. The percutaneous transfemoral approach, the standard technique for angioplasty and stent deployment, may not be feasible in all patients. We present our experience with access site complications that occurred with CAS. METHODS: One hundred thirty-two CAS procedures were performed at our institution in the past 5 years for symptomatic (62.1%) or asymptomatic (37.9%) carotid stenosis. Mean age of patients was 70.72 +/- 6.53 years and the mean degree of stenosis of the treated carotids was 80.74% +/- 11.83%. The transfemoral approach was the access route in 126 CAS, the transbrachial approach was used in 2 CAS procedures, and direct carotid exposure was used in 5 patients. RESULTS: All CAS procedures were done successfully; 4 (3%) access site complications were detected, 3 (2.4%) groin hematomas with transfemoral approach and 1 hematoma on the left side of the neck, in patients treated with direct carotid cutdown. Surgical repair of FSA was successfully performed for the patients with groin hematoma, whereas surgical wound exploration in the neck for the remaining patient revealed no identifiable cause. All patients received blood transfusion for correction of associated hypovolemia or hemorrhagic anemia. No patients had experienced access site-related additional cardiac, systemic, or neurologic events. CONCLUSIONS: The authors' experience demonstrates that access site complications are rare events with CAS despite the large diameter of implantable devices and liberal anticoagulant and antiplatelet therapy. Transbrachial and direct carotid approaches are relatively safe, accepted alternatives in the setting of contraindicated femoral access.

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.

Evaluation of intra-aneurysmal blood flow by digital subtraction angiography: blood flow change after coil embolization.

BACKGROUND: The natural course of cerebral aneurysms is related to many factors, and it is very important that intra-aneurysmal blood flow is considered. Our group developed a method that allowed the simultaneous evaluation of blood flow in human cerebral aneurysms using digital subtraction angiography (DSA) with no special devices. The intra-aneurysmal blood flow measurement would also be very useful for coil embolization. Since the Guglielmi detachable coil (GDC) was developed, many patients with cerebral aneurysm have been treated with GDC, but coil compaction has sometimes caused a problem after the coil embolization of a cerebral aneurysm. We believed that an intra-aneurysmal flow measurement would suggest the final result of embolization during the procedure. METHODS: We performed DSA to examine 17 aneurysms in 17 patients. The video signal of serial DSA images was stored on a personal computer, and time-density curves were obtained for each individual pixel. The formula, determined by a two-exponential model, was fitted to the time-density curve 1000 times by least square approximation for each individual pixel. We indirectly substituted the coefficient of the flow-in curve for the blood flow. We were therefore able to display the distribution of intra-aneurysmal blood flow in color. We could compare the blood flow in each portion of the cerebral aneurysm and parent artery during coil embolization. RESULTS: The blood flow k(a) in a small aneurysm was faster than that in a large aneurysm, and it slowed in accordance with the coil embolization. The blood flow in a large aneurysm was sometimes accelerated by incomplete coil embolization. CONCLUSION: We can detect the flow distribution in cerebral aneurysms and the flow change during coil embolization, using existing equipment. Our method would be useful in elucidating the natural history of cerebral aneurysms, treating cerebral aneurysms with coils, and following patients after treatment.

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.

Simple immersion of filter devices into an urokinase solution prevents fibrin net formation during carotid artery stenting.

Slow-flow phenomenon is frequently observed during carotid artery stenting (CAS) with a filter embolic protection device. It results in technical difficulties and can lead to adverse neurological events. Flow impairment is thought to be caused by plaque entrapped by the filter and/or blood coagulation on the filter. Characteristics of heparin- or urokinase-treated polyurethanes were analyzed by surface plasmon resonance, and the fibrinolytic activity of the urokinase-treated filter of Angioguard XP was estimated by the fibrin plate assay. A filter membrane of Angioguard XP protection device was treated with a heparin or urokinase solution. In clinical studies, six and nine patients were treated by CAS using Angioguard XP modified with heparin and urokinase, respectively. Filter membranes were examined by scanning electron microscopy (SEM). From in vitro studies, it appeared that urokinase adsorbed and remained on the Angioguard XP filter, and its fibrinolytic activity was demonstrated even after washing with saline; heparin, however, was easily washed out from the surface. From clinical study, some filter pores were obstructed in all six patients in the heparin group and in three patients in the urokinase group. Fibrin net was found on the filter in five of six patients in the heparin group and in one of nine patients in the urokinase group. Treatment of an Angioguard XP filter with a urokinase solution is effective in preventing pore occlusion and may reduce occurrence of the slow-flow phenomenon.

Preclinical testing of a new clot-retrieving wire device using polyvinyl alcohol hydrogel vascular models.

INTRODUCTION: Cerebral embolism is the principal cause of cerebral infarction. Recently, mechanical embolectomy has been proposed as an effective method. We performed a preclinical evaluation of a new mechanical clot-retrieving wire. METHODS: This clot-retrieving wire consisted of three nitinol loops at the tip of a microguidewire. These three loops could be collapsed into a 0.018-inch wire compatible microcatheter. Each loop was 8 mm long and 3.5 mm wide. For simulation, polyvinyl alcohol (PVA) vascular anatomical models of the human carotid (eight models) and vertebrobasilar (three models) circulation were constructed. A pulsatile flow circulation system was used. Embolic clots were produced using pig blood plasma. The microcatheter and the microguidewire were advanced beyond the clot. The wire was then exchanged for the retrieving wire. The microcatheter was then pulled slightly back to open the loops. The clot was then caught by withdrawal of the system. Once caught, the clot was retrieved to the guiding catheter tip. We investigated the following points: ease of device deployment, clot capture ability, clot removal against blood flow and removal of the clot out of the introducer system. RESULTS: A total of 104 procedures were performed in 11 PVA models and evaluated. The drop rate was 19%. We succeeded in partial and total recanalization in 51.0% of the procedures (53/104) within 30 minutes. CONCLUSION: This new clot-retrieving wire could be useful for mechanical clot extraction in stroke.

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.