Giant basilar artery aneurysms encorporating the posterior cerebral artery: bypass surgery and coil occlusion--two case reports.
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Giant aneurysms of the basilar artery are rare. With a diameter of 25 mm or more they are often partially thrombosed and show atheromatous plaques. There are some problems in the treatment especially when the aneurysm is broadbased with bulbous origin encorporating the origin of the posterior cerebral artery (PCA). In many of these cases neither operative clipping alone nor coil embolization alone will be practical without causing an ischemia in the depending brain areas. We will report about two patients with giant aneurysms of the basilar artery involving the origin of the PCA and a combined surgical and interventional neuroradiological approach. Preoperatively both patients showed only mild neurological symptoms (slight left hemiparesis, incomplete hemianopsia). We anastomosed the superficial temporal artery as an extracranial-intracranial bypass end-to-side to the PCA followed by clipping the PCA out of the aneurysm. Next day embolization of the aneurysm with Guglielmi ditachable coils was done. Both patients recovered without complications. An angiographic control showed no more filling of the aneurysm and a free running bypass feeding the PCA. In our opinion this combined approach is an effective method to treat giant aneurysms of the basilar artery which involve the origin of the PCA when clipping alone is impossible. (+info)
An indirect revascularization method in the surgical treatment of moyamoya disease--various kinds of indirect procedures and a multiple combined indirect procedure.
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The indirect non-anastomotic bypass procedures for moyamoya disease are herein reviewed, and our multiple combined indirect procedure, i.e. a fronto-parieto-temporal combined indirect bypass procedure, is also introduced. Direct procedures such as superficial temporal artery-middle cerebral artery anastomosis are able to form collaterals with a high reliability, but these procedures are often difficult to technically perform in small children, and complications, when they occur, tend to be severe. Indirect procedures, such as encephalo-duro-arterio-synangiosis (EDAS), encephalo-myo-synangiosis (EMS), and encephalo-myo-arterio-synangiosis (EMAS) etc., are safe and easy and also successfully form collaterals especially in children with moyamoya disease. However, there are a few drawbacks with such procedures. They do not always form sufficient collaterals. The area where the original EDAS using the posterior branch of the superficial temporal artery can be done is also limited. Moreover, because the area covered by each single procedure is small, the collateral formation obtained by a single procedure is not always satisfactory. For these reasons we developed a fronto-temporoparietal combined indirect bypass procedure for child patients in order to overcome these problems. This multiple combined indirect procedure can cover a wider area of the ischemic brain through the EMAS in the frontal and the EDAS and EMS in the temporo-parietal regions. It is also safe and easy to perform, and one or two of these three procedures form sufficient collaterals with a relatively high reliability. This technique is described and the results are presented. (+info)
Surgical reconstruction of the extracranial vertebral artery: management and outcome.
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PURPOSE: The purpose of this study was to identify the risk and outcome of reconstruction of the extracranial vertebral artery (ECVA). METHOD: The study was conducted as a retrospective review of 369 consecutive ECVA reconstructions. RESULTS: The clinical presentations consisted of hemispheric symptoms alone in 4% of the cases, hemispheric and vertebrobasilar symptoms in 30%, and vertebrobasilar symptoms alone in 60%. The cause of the lesion was atherosclerosis (n = 300), extrinsic compression (n = 42), dissection (n = 7), radiation arteritis (n = 5), intimal hyperplasia (n = 3), fibromuscular dysplasia (n = 2), previous surgical ligation (n = 3), aneurysm (n = 2), and other (n = 5). All the patients underwent preoperative arteriography. There were 252 proximal ECVA reconstructions (218 transpositions, 42 bypass grafting procedures, and two other) and 117 distal ECVA reconstructions (85 bypass grafting procedures, 25 transpositions, and seven other). In 83 patients, the ECVA operation was performed concomitant with a carotid or supraaortic trunk reconstruction. This series was analyzed in two separate sets: before 1991 (n = 215), when changes in indications and management were occurring; and after 1991 (n = 154), when we acquired a dedicated anesthesia team and digital arteriography in the operating room and established uniform protocols for the management of ECVA disease. The stroke, death, and stroke/death rates for the period before 1991 were, respectively, 4. 1%, 3.2% and 5.1%. The stroke, death, and stroke/death rates for the period after 1991 were, respectively, 1.9%, 0.6% and 1.9%. The patency rate at 5 years was 80%. The survival rate at 5 years was 70%. Most of the deaths during the follow-up period were caused by cardiac disease. Among the survivors, the protection rate from stroke was 97%. CONCLUSION: The changes in operative selection and management have improved the results of ECVA reconstruction. The data reported for ECVA reconstruction in patients who underwent operation since 1991 reflect the outcome of ECVA reconstruction today. In our experience, a reconstruction of the ECVA is less risky than a carotid reconstruction. (+info)
Dynamic CT perfusion to assess the effect of carotid revascularization in chronic cerebral ischemia.
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We present the case of a female patient who was studied with dynamic contrast-enhanced CT perfusion before and after carotid revascularization. Before treatment, there was decreased perfusion in the ipsilateral insula, which was shown to be resolved on the scan obtained 1 day after treatment, indicating the technical success of the revascularization. In the ipsilateral basal ganglia, there was delayed contrast agent clearance from the tissue, which was attributed to vasodilation; after revascularization, there remained a subtle stenotic effect. The observed changes in the dynamic CT perfusion study suggest that this technique may be a useful tool in the evaluation of patients with asymmetrical cerebral blood flow. (+info)
Cost-effectiveness analysis of therapy for symptomatic carotid occlusion: PET screening before selective extracranial-to-intracranial bypass versus medical treatment.
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The St. Louis Carotid Occlusion Study (STLCOS) demonstrated that increased cerebral oxygen extraction fraction (OEF) detected by PET scanning predicted stroke in patients with symptomatic carotid occlusion. Consequently, a trial of extracranial-to-intracranial (EC/IC) arterial bypass for these patients was proposed. The purpose of this study was to examine the cost-effectiveness of using PET in identifying candidates for EC/IC bypass. METHODS: A Markov model was created to estimate the cost-effectiveness of PET screening and treating a cohort of 45 symptomatic patients with carotid occlusion. The primary outcome was incremental cost for PET screening and EC/IC bypass (if OEF was elevated) per incremental quality-adjusted life year (QALY) saved. Rates of stroke and death with surgical and medical treatment were obtained from EC/IC Bypass Trial and STLCOS data. Costs were estimated from the literature. Sensitivity analyses were performed for all assumed variables, including the PET OEF threshold used to select patients for surgery. RESULTS: In the base case, PET screening of the cohort followed by EC/IC bypass on 36 of the 45 patients yielded 23.2 additional QALYs at a cost of $20,000 per QALY, compared with medical therapy alone. A more specific PET threshold, which identified 18 surgical candidates, gained 22.6 QALYs at less cost than medical therapy alone. The results were sensitive to the perioperative stroke rate and the stroke risk reduction conferred by EC/IC bypass surgery. CONCLUSION: If postoperative stroke rates are similar to stroke rates observed in the EC/IC Bypass Trial, EC/IC bypass will be cost-effective in patients with symptomatic carotid occlusion who have increased OEF. A clinical trial of medical therapy versus PET followed by EC/IC bypass (if OEF is elevated) is warranted. (+info)
Frontal lobe infarction due to hemodynamic change after surgical revascularization in moyamoya disease--two case reports.
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A 60-year-old female and a 40-year-old male underwent surgical revascularization for moyamoya disease and suffered small infarction in the ipsilateral frontal lobe 3 or 4 days postoperatively. Neuroimaging suggested that the bypass flow had caused rapid progression of occlusive changes in the carotid forks, a diminishing of moyamoya vessels, and flow reduction in the anterior cerebral artery ipsilateral to surgery, leading to critical ischemia in the frontal lobe. Surgical revascularization improves the outcome of patients with moyamoya disease, but postoperative management such as hydration is important to avoid ischemic complications due to frontal lobe infarction. (+info)
Intracerebral hemorrhage from a ruptured pseudoaneurysm after STA-MCA anastomosis--case report.
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A 43-year-old hypertensive male developed a pseudoaneurysm at the site of a superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, causing massive intracerebral hemorrhage 5 years after the operation. He first experienced repeated transient ischemic attacks, and cerebral angiography disclosed complete occlusion in the cervical portion of the left internal carotid artery. STA-MCA anastomosis was performed, and the ischemic attacks stopped. Postoperative angiography confirmed patency of the anastomosis and good filling of the cortical branches of the left MCA. Five years after surgery, the patient suffered sudden onset of generalized convulsions and consciousness disturbance. Computed tomography disclosed a massive intracerebral hemorrhage in the left frontoparietal region, and angiography revealed an aneurysmal dilatation at the site of the anastomosis that was not seen before. Emergency evacuation of the hematoma and clipping of the aneurysmal dilatation were performed. The patient recovered well and became ambulatory. Histological examination of the surgical specimen showed collagen tissue, indicating a pseudoaneurysm. Patients who undergo STA-MCA anastomosis, especially hypertensive patients, should be followed up by repeated magnetic resonance angiography to confirm the patency of the anastomosis and cerebral perfusion, and to detect the formation of pseudoaneurysms at the anastomosis site, which can cause fatal bleeding. (+info)
Intraoperative sonographic assessment of graft patency during extracranial-intracranial bypass.
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Extracranial-intracranial (EC-IC) bypass may be necessary to facilitate treatment of unclippable posterior circulation fusiform aneurysms. Although intraoperative digital subtraction angiography (DSA) allows assessment of graft patency, this technique, because of difficulties inherent in performing selective catheterization and angiography in the operating room, has limitations. Duplex sonography, in contrast, is easily performed, and provides information regarding graft patency and blood flow direction during EC-IC bypass procedures. This latter information proved useful in determining the time of parent artery occlusion after two EC-IC bypass procedures performed for treatment of a fusiform midbasilar artery aneurysm. (+info)