[Neuroendovascular therapy for acute stroke].
Explore the source record for details and available documents.
Angioplasty, Balloon, Coronary↗
Biomedical subjects
Masayuki Ezura
Publications and source records attributed to Masayuki Ezura.
Diagnostic value of super-selective bilateral cavernous sinus sampling with hypothalamic stimulating hormone loading in patients with ACTH-producing pituitary adenoma.
AIMS: Early diagnosis and early treatment by transsphenoidal surgery is desirable for ACTH-producing pituitary microadenoma, but accurate localization of the functional lesion is not always possible before surgery because magnetic resonance (MR) imaging may provide false negative and/or positive findings. The diagnostic value of super-selective bilateral cavernous sinus sampling with the administration of corticotropin-releasing hormone (CRH) was assessed in patients with functioning ACTH-producing pituitary adenoma. METHODS: Fifteen patients with pituitary adenoma (14 with microadenoma) aged from 23 to 74 years (mean 46.7 years) underwent cavernous sinus sampling with or without the CRH loading test and subsequent transsphenoidal surgery in our institute from October 1997 through to November 2002. MR imaging including dynamic scan failed to detect the adenomatous lesion in all patients. To eliminate the bias due to uneven blood flow in the cavernous sinuses and the multi-hormonal response to CRH administration, the ACTH/FSH ratios were evaluated. The inter-cavernous gradient (ICG) was calculated as the higher/lower ACTH venous blood levels in the right and left cavernous sinuses with or without CRH loading. The adjusted ICG was calculated using the ACTH/FSH ratios. The results were compared with the surgical findings. An ICG of 1.4 or greater was considered to indicate the localization of the responsible lesion. RESULTS: Transsphenoidal surgery revealed the functioning lesion on the right in five cases, the left in six, the midline in three and the bilateral lateral wings (double adenoma) in one. Adjusted ICG with CRH loading had a localization accuracy of 93.3% (14/15), which was significantly higher than that of 73.3% (11/15) using ICG without hypothalamic stimulating hormone loading (p = 0.0402). CONCLUSIONS: Super-selective cavernous sinus sampling with hypothalamic stimulating hormone administration can provide accurate localization of the responsible lesion in patients with ACTH-producing pituitary adenoma.
Adenoma↗
A proposed parent vessel geometry-based categorization of saccular intracranial aneurysms: computational flow dynamics analysis of the risk factors for lesion rupture.
OBJECT: The authors created a simple, broadly applicable classification of saccular intracranial aneurysms into three categories: sidewall (SW), sidewall with branching vessel (SWBV), and endwall (EW) according to the angiographically documented patterns of their parent arteries. Using computational flow dynamics analysis (CFDA) of simple models representing the three aneurysm categories, the authors analyzed geometry-related risk factors such as neck width, parent artery curvature, and angulation of the branching vessels. METHODS: The authors performed CFDAs of 68 aneurysmal geometric formations documented on angiograms that had been obtained in patients with 45 ruptured and 23 unruptured lesions. In successfully studied CFDA cases, the wall shear stress, blood velocity, and pressure maps were examined and correlated with aneurysm rupture points. Statistical analysis of the cases involving aneurysm rupture revealed a statistically significant correlation between aneurysm depth and both neck size (p < 0.0001) and caliber of draining arteries (p < 0.0001). Wider-necked aneurysms or those with wider-caliber draining vessels were found to be high-flow lesions that tended to rupture at larger sizes. Smaller-necked aneurysms or those with smaller-caliber draining vessels were found to be low-flow lesions that tended to rupture at smaller sizes. The incidence of ruptured aneurysms with an aspect ratio (depth/neck) exceeding 1.6 was 100% in the SW and SWBV categories, whereas the incidence was only 28.75% for the EW aneurysms. CONCLUSIONS: The application of standardized categories enables the comparison of results for various aneurysms' geometric formations, thus assisting in their management. The proposed classification system may provide a promising means of understanding the natural history of saccular intracranial aneurysms.
Aged↗
Treatment of giant fusiform aneurysms of the basilar trunk with intra-aneurysmal and basilar artery coil embolization.
OBJECTIVE: The authors report their experience in endovascular treatment of basilar artery (BA) trunk aneurysms by intra-aneurysmal and BA occlusion. METHODS: Four patients were referred to our hospital from 1995 until 2002 with variable clinical presentations and radiologic appearances. All the patients were subjected for tolerability to balloon BA occlusion test to verify the collateral supply from the posterior communicating arteries. The patients were treated by intra-aneurysmal embolization together with basilar artery occlusion. RESULTS: All the aneurysms were successfully isolated from the circulation. Transient postoperative neurologic deficits were constant findings in all the cases. Outcome was finally good for all the patients. CONCLUSIONS: Endovascular treatment of complex BA trunk aneurysm by intra-aneurysmal embolization and BA occlusion method is a valuable alternative for management and successful isolation in patients with good collateral arterial flow.
Adult↗
Dissection of the superior cerebellar artery: a report of two cases and review of the literature.
Arterial dissections frequently involve the main trunk of the posterior circulation and are recognised as an important cause of stroke in young individuals. However, dissection confined to cerebellar arteries is rare. We encountered two patients with superior cerebellar artery (SCA) dissection. A 37-year-old man presented with dysarthria, right limb ataxia, and severe headache. Magnetic resonance imaging revealed cerebellar infarction in the right SCA territory. Angiography demonstrated stenosis and fusiform dilation of the SCA in the anterior pontine segment. Recovery with antiplatelet treatment was nearly complete. A 45-year-old man was admitted with decreased consciousness after sudden onset of headache. Computed tomography demonstrated subarachnoid haemorrhage with hydrocephalus. Angiography revealed fusiform dilation of the left SCA in the anterior pontine segment. After ventricular drainage, endovascular embolisation was performed without ischaemic complications. The patient's condition improved sufficiently to return to daily life. In our search only four reported cases involved the SCA. Clinical manifestation and treatment for patients with cerebellar arterial dissections are discussed.
Adult↗
Spontaneous regression of a primary cerebral tumor following vasospasm caused by subarachnoid hemorrhage due to rupture of an intracranial aneurysm--case report.
A 40-year-old man demonstrated spontaneous regression of a malignant glioma following vasospasm caused by subarachnoid hemorrhage due to rupture of an intracranial aneurysm. The patient had been treated under a diagnosis of malignant glioma for 5 years. He presented with a ruptured aneurysm manifesting as subarachnoid hemorrhage. Single photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine and diffusion-weighted magnetic resonance (MR) imaging revealed severe flow reduction due to vasospasm in the bilateral temporoparietal cortical regions, including the tumor. MR imaging performed 5 months later showed marked tumor regression. The present case suggests that treatment targeting angiogenesis of malignant gliomas may be effective as a part of multimodality treatment.
Adult↗
Intracranial dural arteriovenous fistula with venous reflux to the brainstem and spinal cord mimicking brainstem infarction--case report.
A 73-year-old man presented with a rare transverse sinus dural arteriovenous fistula (dAVF) with venous reflux to the brainstem and medulla manifesting as brainstem and spinal cord edema mimicking brainstem infarction. Complete occlusion of the fistula was achieved by transvenous embolization, resulting in angiographic cure of the fistula and progressive improvement of the symptoms. Intracranial dAVFs with perimedullary venous drainage, type V according to the Cognard classification, are rare lesions with distinctive clinical, radiological, and therapeutic aspects. This case demonstrates that the symptoms of dAVF with perimedullary venous reflux are variable, so dAVF should be considered in patients with clinical and radiological findings suggestive of congestion in the brainstem and spinal cord. Dysfunction of the medulla and spinal cord caused by venous hypertension is the most probable cause of the neurological symptoms in such cases. Interventional therapy can lead to angiographic cure and resolution of the symptoms.
Aged↗
Computational simulation of therapeutic parent artery occlusion to treat giant vertebrobasilar aneurysm.
We applied computational fluid dynamics (CFD) analysis to assess 3D digital subtraction angiography findings in a patient with a giant vertebrobasilar aneurysm to simulate and compare the consequences of left and right vertebral artery occlusion. The balloon occlusion test suggested that occlusion of the right vertebral artery is the better way to treat this patient's aneurysm from the point of view of aneurysmal thrombosis and isolation from the circulation. The computer simulation supported this conclusion, at the same time indicating that from the point of view of pressure distribution on the wall of the aneurysm, the right vertebral occlusion may be also accompanied by an undesirable effect. A high-pressure area on the aneurysm wall in systole was revealed. This high pressure potentially could lead to subsequent aneurysmal growth, which indeed occurred, as was revealed by a follow-up examination 6 months later. This study is a good example of possible future applications of CFD in patients with cerebrovascular disease before therapeutic intervention.
Aged↗
Computational replicas: anatomic reconstructions of cerebral vessels as volume numerical grids at three-dimensional angiography.
BACKGROUND AND PURPOSE: We present a relatively simple approach that physicians can use to reconstruct cerebral vessels as 3D numerical grids or computational replicas. The method accurately duplicates their geometry to provide computer simulations of their blood flow. METHODS: Initial images were obtained by using any medical imaging technique, such as MR angiography, CT angiography, or 3D digital subtraction angiography. The data were collected in DICOM format and converted by a DICOM reader into a 3D gray-scale raster image. The image was then processed by using commercial visualization and mesh generation software, which allowed extraction of the luminal surface of the blood vessel (by using the isosurfacing technique). The subsequent final output was an unstructured tetrahedral grid that can be directly used for detailed analysis of cerebral vascular geometry for patient-specific simulations of blood flow. RESULTS: Four examples of grid reconstruction and blood flow simulation for patients with ruptured aneurysms were validated with angiographic and operative findings. The ruptured areas were correlated with areas of high fluid-induced wall-shear stress. CONCLUSION: This approach promises to be a practical tool for planning treatment and follow-up of patients after neurosurgical or endovascular interventions with 3D angiography. The proposed commercial packages or conceptually similar ones seem to be relatively simple and suitable for direct use by neurosurgeons or neuroradiologists.
Aneurysm, Ruptured↗
Combined embolization and microsurgery for cerebral arteriovenous malformation.
Thirty-seven of 396 patients with arteriovenous malformations (AVMs) were treated by preoperative embolization and surgical excision in our medical center between 1991 and 1997. The AVMs were Spetzler-Martin grade I in six, grade II in 11, grade III in 12, grade IV in four, and Grade V in four. A total of 69 embolization procedures were performed using estrogen alcohol and polyvinyl acetate as liquid embolization materials. AVM grades improved following embolization in 10 patients. Three hemorrhages occurred several days after the final embolization, probably due to hemodynamic stress on the unoccluded perforating feeders or drainer occlusion. Surgical resection was performed under guidance of intraoperative digital subtraction angiography. Although the AVMs were excised totally in one stage with no major neurological deficits, normal perfusion pressure breakthrough occurred in a patient with prominent collateral circulation of the AVM which developed after the main feeder embolization. Preoperative staged embolization with estrogen alcohol and polyvinyl acetate is effective to expand the surgical indication and to achieve complete resection of difficult AVMs. Direct surgery should be performed as soon as possible if hemodynamic changes are observed following embolization.
Adolescent↗
Bypass surgery for occluded internal carotid artery revascularized by vasa vasorum--case report.
A 47-year-old woman presented with two transient ischemic attacks due to occlusion of the left internal carotid artery. The affected artery was revascularized by vasa vasorum. Angiography showed occlusion of the left common carotid artery including the origin of the internal carotid artery. The distal internal carotid artery was revascularized by vasa vasorum at the level of the second cervical vertebral body. Left subclavian artery-internal carotid artery bypass surgery using a saphenous vein graft was performed successfully, during which the narrowed but patent lumen of the internal carotid artery was confirmed. Follow-up angiography showed enlargement of the left internal carotid artery distal to the patent bypass. Reconstructive bypass surgery is a possible treatment for patients with occluded internal carotid artery revascularized by vasa vasorum. Angiographic detection of the lumen of the internal carotid artery is important for surgical consideration.
Carotid Artery, Internal↗
Intraoperative angiography to prevent vertebral artery injury during reduction of a dislocated hangman fracture. Case report.
The authors report on a 38-year-old woman with a dislocated hangman fracture associated with unilateral vertebral artery (VA) occlusion. The patient presented with a mild central cord syndrome, as well as anterior subluxation of the C-2 vertebral body upon C-3, bilateral neural arch fractures, and a unilateral locked facet joint. Digital subtraction angiography revealed occlusion of the right VA, with the posterior cerebral circulation entirely dependent on the left VA. Intraoperative angiography demonstrated that complete reduction of the dislocation would have caused severe stenosis of the left VA; partial reduction and anterior fixation were performed instead, with excellent neurological outcome. In this case, intraoperative angiography was particularly useful for preventing brain-related ischemic complications during reduction.
Adult↗
Hemodynamic analysis of an adult vein of Galen aneurysm malformation by use of 3D image-based computational fluid dynamics.
We applied computational fluid dynamic (CFD) analysis on the numerical grid of a 3D rotational digital subtraction angiogram obtained in a 22-year-old male patient, with an accidentally discovered vein of Galen malformation associated with single feeder aneurysm, to understand the flow pattern through the two aneurysms and improve our general understanding of hemodynamic characteristics of this variety of fusiform aneurysm. This technical note provides a good example of the application of CFD to 3D digital subtraction angiography for studying the flow pattern in patients with cerebrovascular disease.
Adult↗