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ABSTRACT: BACKGROUND: Dual antiplatelet therapy for stent-assisted coiling of cerebral aneurysms is essential to prevent thromboembolic complications. There is concern that Y-stent-assisted coiling may increase thromboembolic complications compared with coiling with a single stent. Several reports have demonstrated that cilostazol may improve clopidogrel responsiveness. We investigated whether triple antiplatelet therapy with addition of cilostazol to aspirin plus clopidogrel for Y-stents can prevent thromboembolic events. METHODS: Between July 2010 and October 2012, we treated 40 consecutive aneurysms with coil embolization using Enterprise stents. At the peri-procedural period, dual antiplatelet agents (100 mg aspirin and 75 mg clopidogrel) were used for the single stent group (n = 36), and triple antiplatelet agents (addition of 200 mg cilostazol) were used for the Y-stent group (n = 4). We evaluated post-operative diffusion-weighted imaging (DWI) and any complications. We assessed the following for statistical analysis: age, sex, aneurysm location, shape, and size, neck size, size of parent vessels, and stent length. RESULTS: We found two neurological peri-procedural complications: one transient ischemic attack and one infarction. Both complications belonged to the Y-stent group, which was a significant factor of thromboembolic events (P = 0.008). There were no other significant factors related to neurological complications or positive DWI. For subgroup analysis of the single stent group, stent length was significantly longer in positive DWI than negative DWI (P = 0.04). In the follow-up period of 20 ± 8.6 months, there were no symptomatic late complications in any patients. CONCLUSIONS: Although the number of patients in the Y-stent group is small, this group had a significantly higher risk of thromboembolic complications. While our protocol of a routine dose of dual antiplatelet therapy may be sufficient for single stent therapy, our protocol of a routine dose of triple antiplatelet therapy for Y-stents may not prevent thromboembolic events. This suggests that evaluation of platelet function may be essential, especially for Y-stents.
Acta Neurochirurgica 05/2013; · 1.52 Impact Factor
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ABSTRACT: Stent-assisted coil embolization has been recently accepted as a treatment option for wide-neck or complex cerebral aneurysms. Delayed in-stent occlusion is described due to stent-related changes in vascular geometry. A 66-year-old man underwent stent-assisted coil embolization for an unruptured aneurysm of the vertebral artery. The treatment was successfully performed using the Enterprise stent. Follow-up angiography at 6 months showed asymptomatic in-stent occlusion. Three-dimensional analysis of the vascular geometry revealed that the left vertebral artery was straightened by 40° due to the stent placement. Such straightening of the vessel presumably caused kinking and occlusion of the vessel. Stent-related changes in vascular geometry may cause kinking of a vessel and result in occlusion after the treatment of cerebral aneurysms. Pre-treatment strategy may avoid this risk.
Neurologia medico-chirurgica 01/2013; 53(3):182-5. · 0.61 Impact Factor
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ABSTRACT: Silicone models of cerebral aneurysms are used for evaluation of devices, training, or hemodynamic studies. We report preoperative simulations of endovascular treatment for a case with an unruptured wide-neck aneurysm of the anterior communicating artery using a patient-specific silicone model. Using a rapid prototyping system, we created a silicone model based on the vascular image obtained by three-dimensional rotational angiogram. The aneurysm and vessels formed a cavity in the silicone block model. We performed endovascular simulations using several difference devices and attempted possible methods for coil embolization. We designed treatment strategies based on the simulations and performed balloon-assisted coil embolization of the aneurysm. The simulations were especially useful in navigation of a microcatheter by planning the shape of its tip beforehand. There was one significant difference between the silicone model simulations and actual treatment: the shape of the vessel in the silicone block model was not changed by insertion of a catheter or guidewire. This is the first study to describe preoperative endovascular simulations using a patient-specific silicone model. Our methods of creating a patient-specific model are relatively simple and easy. Although this is a single case, we demonstrate that the simulations are feasible and helpful for designing a treatment strategy and safe manipulation of endovascular devices by experiencing their behavior before actual treatment.
Neurologia medico-chirurgica 01/2013; 53(5):347-351. · 0.61 Impact Factor
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ABSTRACT: BACKGROUND AND IMPORTANCE:: A vertebral artery dissecting aneurysm (VADA) is a relatively rare cause of subarachnoid hemorrhage. Bilateral VADAs are even rarer, and management strategies are controversial. We report a case of bilateral VADAs presenting with subarachnoid hemorrhage. We treated the patient by stent-assisted coil embolization of both aneurysms at a single session based on the results of pre-operative computational fluid dynamic simulations. CLINICAL PRESENTATION:: A 48-year-old man presented with subarachnoid hemorrhage due to bilateral VADAs. We treated the patient by stent-assisted coil embolization of both aneurysms at a single session. Before the treatment, we performed computational fluid dynamics simulations to predict the ruptured side. We also estimated the increase in wall shear stress on an aneurysm in case of trapping of another aneurysm, which might cause enlargement and rupture of the aneurysm. The treatment was successfully performed. The patient remains neurologically intact at 14 months from the onset. CONCLUSION:: Stent-assisted coil embolization of subarachnoid hemorrhage with bilateral VADAs for both sides is a reasonable treatment because it prevents rebleeding and preserves bilateral vertebral arteries without increasing hemodynamic stress. To the best of our knowledge, this is the first report to describe this type treatment for bilateral VADAs with subarachnoid hemorrhage. Computational fluid dynamics simulations may be useful for developing treatment strategies for aneurysms.
Neurosurgery 08/2012; · 2.79 Impact Factor
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ABSTRACT: BACKGROUND AND IMPORTANCE:: Hemodynamics play an important role in the mechanisms of aneurysm formation, growth, and rupture. However, little is known regarding hemodynamics of rupture sites. CLINICAL PRESENTATION:: We incidentally acquired three-dimensional images before and at the moment of rebleeding of a cerebral aneurysm in a patient. Comparison of these two images enabled precise identification of the rupture site. Based on computational fluid dynamics simulation, we propose there are characteristic hemodynamic parameters of the rupture site in cerebral aneurysms. We evaluated flow velocity, wall shear stress (WSS), pressure, and the oscillatory shear index to determine characteristic parameters at the rupture site.Among the hemodynamic parameters in the cardiac cycle, the rupture site was most markedly distinguished by a combination of low WSS at end-diastole and high-pressure at peak systole. The flow patterns around the rupture site uniquely changed in the cardiac cycle. The rupture site was an impingement zone at peak systole. Flow separation at the rupture site was observed at end-diastole. CONCLUSION:: In this case, a region with low WSS at end-diastole and high pressure at peak systole was at the rupture site. A possible mechanism of rupture in this particular aneurysm is that low WSS at end-diastole caused degeneration and thinning of the aneurysm wall, and high pressure at peak systole (impingement zone) resulted in rupture of the thinning wall.
Neurosurgery 08/2012; · 2.79 Impact Factor
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Acta Neurochirurgica 09/2011; 153(11):2175-80. · 1.52 Impact Factor
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Tomoaki Terada,
Hideo Okada,
Masataka Nanto, Aki Shintani,
Ryo Yoshimura,
Koji Kakishita,
Osamu Masuo,
Hiroyuki Matsumoto,
Toru Itakura,
Kosuke Ohshima,
Hiroo Yamaga
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ABSTRACT: The efficacy and pitfalls of endovascular recanalization were evaluated in cases of internal carotid artery (ICA) occlusion in the subacute to chronic stage.
Fourteen cases (15 lesions) of symptomatic ICA occlusion with hemodynamic compromise or recurrent symptoms were treated at the subacute to chronic stage using an endovascular technique. The Parodi embolic protection system was used during the recanalization procedure to prevent embolic stroke by reversing the flow from the distal ICA to the common carotid artery.
Recanalization of the occluded ICA was possible in 14 of 15 lesions. The occlusion points were 10 cervical ICAs and 4 petrous/cavernous ICAs in successfully recanalized cases. Ischemic symptoms disappeared completely after the treatment, and new ischemic symptoms did not appear related to the treated lesion. Single photon emission computed tomography findings demonstrated the improvement of hemodynamic compromise in all cases. One case showed right middle cerebral artery branch occlusion during the procedure, but this patient's neurological symptoms were stable due to preexisting hemiparesis. Endovascular recanalization was possible and effective in improving hemodynamic compromise. However, there are still several problems with this technique, such as hyperperfusion syndrome after recanalization, cerebral embolism during treatment, durability after treatment, and identification of the occlusion point before treatment.
Endovascular recanalization using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise or refractoriness to antiplatelet therapy, even in the subacute to chronic stage of the illness.
Journal of Neurosurgery 08/2009; 112(3):563-71. · 2.96 Impact Factor
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ABSTRACT: Stromal cell lines such as PA6 and MS5 have been employed for generating dopamine (DA) neurons from embryonic stem (ES) cells. The present study was designed to test whether bone marrow stromal cells (BMSC) derived from adult mice might be available as a feeder layer to produce DA cells efficiently from ES cells. When ES cells were grown on BMSC in the presence of fibroblast growth factor 8 (FGF8) and sonic hedgehog (SHH), about 40% of TuJ1-positive neurons expressed tyrosine hydroxylase (TH). Because these cells labeled with TH were negative for dopamine-beta-hydroxylasae (DBH), the marker for noradrenergic and adrenergic neurons, the TH-positive cells were most likely DA neurons. They indeed expressed midbrain DA neuron markers such as Nurr 1, Ptx-3, and c-ret and were capable of synthesizing and releasing DA in vitro. Furthermore, DA neurons differentiated from ES cells in this differentiation protocol survived transplantation in rats with 6-hydroxydopamine lesions and reversed the lesion-induced circling behavior. The data indicate that BMSC can facilitate an efficient induction of DA neurons from ES cells and that the generated DA neurons are biologically functional both in vitro and in vivo. Insofar as BMSC have recently been employed in autologous cell therapy for ischemic heart and arteriosclerotic limb diseases, the present study raises the possibility that autologous BMSC can be applied in future cell transplantation therapy in Parkinson's disease.
Journal of Neuroscience Research 07/2008; 86(13):2829-38. · 2.74 Impact Factor
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ABSTRACT: Transplantation of bone marrow stromal cells (BMSC) has recently been demonstrated to provide neuroprotection in animal models of brain injuries such as ischemia and trauma. The present study was undertaken to explore whether BMSC can promote the survival of dopamine (DA) neurons in neuronal insult models in vitro. We also examined whether BMSC can increase the survival rate of embryonic DA neurons grafted into the striatum of a rat model of Parkinson's disease (PD). Treatment with conditioned media derived from BMSC cultures was found to significantly prevent the death of DA neurons in in vitro cell injury models such as serum deprivation and exposure to the neurotoxin 6-OHDA. In a transplantation study, we also found that the survival of grafted DA cells was significantly enhanced by treating donor cells with the conditioned media at the steps of both cell dissociation and implantation. The results suggest that BMSC may secrete diffusible factors able to protect DA neurons against neuronal injuries. Indeed, BMSC expressed mRNA encoding brain-derived neurotrophic factor, fibroblast growth factor-2 and glial cell line-derived neurotrophic factor, all of which have previously been shown to exhibit potent neurotrophic effects on DA cells. Enzyme-linked immunosorbent assay revealed that the cells release these growth factors into culture media. The present data indicate that BMSC may be a potential donor source of cell-based regenerative therapy for PD where the progressive loss of the midbrain DA neurons takes place.
Brain Research 01/2008; 1186:48-55. · 2.73 Impact Factor
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ABSTRACT: A 61-year-old man presented with the complaint of headache. Investigations revealed a fusiform middle cerebral artery aneurysm at the M2 part. The formation of the aneurysm rapidly developed to a partially thrombosed aneurysm in the course of four months. As regards the treatment of the aneurysm, at first we tried surgery with a superficial temporal artery middle cerebral artery bypass (STA-MCA bypass) and trapping of the aneurysm. However, during the procedure, it was difficult to control bleeding from the temporal muscle, bone flap, and subdural space. Because of this, we finished the STA-MCA bypass without trapping of the aneurysm and then, four days later, we confirmed bypass patency and treated the aneurysm using endovascular coil embolization. Based on both surgical and interventional investigations in this case and a review of the reported literature, the authors propose that there are two mechanisms causing the middle cerebral artery fusiform aneurysm to develop thrombosed formation rapidly: (i) Peripheral middle cerebral artery branches demand less blood flow than other major trunk arteries. (ii) Bypass flow maintains perfusion to the distal branches. On the other hand, this flow alteration caused by surgical vascular bypass may promote the development of the aneurysm to thrombosed formation. The treatment of a fusiform middle cerebral artery aneurysm at the M2 part is also discussed.
No shinkei geka. Neurological surgery 12/2007; 35(11):1109-13. · 0.13 Impact Factor
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No shinkei geka. Neurological surgery 07/2007; 35(6):607-14. · 0.13 Impact Factor
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Hirotaka OKUMURA,
Tomoaki TERADA, Yoshinari NAKAMURA, Aki SHINTANI,
Yoshikazu MATSUDA,
Isao CHOKYU, Hiroyuki MATSUMOTO,
Osamu MASUO,
Tomoyuki TSUMOTO,
Hiroo YAMAGA,
Yoshinori OURA,
Toru ITAKURA
Surgery for Cerebral Stroke 01/2007; 35(5):376-381.
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ABSTRACT: We present the first case of intraoperative hemorrhage in a medulloblastoma.
A 10-year-old girl presented with a 4-week history of headache, nausea, and vomiting. Radiological examination showed a space-occupying mass in the cerebellar vermis. Surgical removal was performed via a midline suboccipital approach. When the dura was incised and the occipital sinus was ligated after suboccipital craniectomy, bleeding occurred in the tumor. Macroscopically, hematoma was found only in the left part of the tumor and not in the right part. Microscopically, different architectures of tumor vessels, thin-walled and thick-walled, were found between the left part and the right part, respectively. The tumoral contents and hematoma were totally removed. Histological examination revealed a medulloblastoma.
We experienced a very rare case of medulloblastoma in which intratumoral hemorrhage occurred during operation. We speculate that ligation of the occipital sinus and thin-walled vessels within the tumor might have caused the hemorrhage in our case.
Child s Nervous System 08/2002; 18(6-7):356-60. · 1.54 Impact Factor
