Tomoaki Terada

Wakayama Medical University, Wakayama, Wakayama, Japan

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Publications (184)241.35 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: There is a controversy regarding the safety and efficacy of intracranial stenting. We describe our experience with primary balloon angioplasty without stenting for symptomatic middle cerebral artery (MCA) stenosis. All patients who underwent balloon angioplasty without stenting for MCA stenosis between 1996 and 2010 were retrospectively reviewed. We evaluated technical success rates, degrees of stenosis, and stroke or death within 30 days. Among patients who were followed-up for > 1 year we evaluated latest functional outcomes, stroke recurrence at 1 year, and restenosis. In total 45/47 patients (95.7%) were successfully treated. Average pre- and postprocedure stenosis rates were 79.9% and 39.5%, respectively. Three neurological complications occurred within 30 days: one thromboembolism during the procedure; one lacunar infarction; and one fatal intraparenchymal hemorrhage after the procedure. Stroke or death rate within 30 days was 6.4%. Thirty-three patients were available for follow-up analysis with a mean period of 51.5 months. The combined rate of stroke or death within 30 days and ipsilateral ischemic stroke of the followed-up patients within 1 year beyond 30 days was 9.4%. Restenosis was observed in 26.9% of patients and all remained asymptomatic. In our retrospective series, balloon angioplasty without stenting was a safe, effective modality for symptomatic MCA stenosis. For patients refractory to medical therapy, primary balloon angioplasty may offer a better supplemental treatment option.
    Neurologia medico-chirurgica 02/2015; 55(2):133-40. DOI:10.2176/nmc.oa.2014-0156 · 0.65 Impact Factor
  • Kenichi Kono, Takeshi Fujimoto, Tomoaki Terada
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    ABSTRACT: Hemodynamic parameters, such as wall shear stress (WSS), WSS gradient (WSSG), aneurysm formation indicator (AFI), or gradient oscillatory number (GON), have been proposed to be linked to initiation of cerebral aneurysms. However, how such conditions occur in humans is unclear. We encountered a rare and interesting case to address this issue. A patient had a newly formed aneurysm with proximal stenosis, which was confirmed by serial imagings. We made two pre-aneurysm models: one with stenosis and the other without stenosis. We performed computational fluid dynamics simulations for these models. Owing to jet flow caused by the stenosis, the maximum WSS and WSSG on the aneurysm initiation site were approximately doubled and tripled, respectively. However, the oscillatory shear index (OSI), AFI, and GON did not change substantially by the stenosis. Computer simulations using artificial vascular models with different degrees of proximal stenosis at different distances demonstrated that oscillatory shear index, AFI, and GON did not change substantially by the stenosis. These results showed that proximal stenosis caused high WSS and high WSSG at the aneurysm initiation site, possibly leading to aneurysm initiation. Proximal stenosis may be a potential factor to induce initiation of one class of cerebral aneurysms by increasing WSS and WSSG. Copyright © 2014 John Wiley & Sons, Ltd.
    10/2014; 30(10). DOI:10.1002/cnm.2637
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Flow patterns in cerebral aneurysms are clinically important. Information on inflow patterns into aneurysms is especially helpful in preventing a recurrence after coil embolization. Computational fluid dynamics (CFD) simulations of patient-specific cerebral aneurysms are feasible and provide information on flow patterns. However, flow visualization by CFD simulations is challenging for recurrent aneurysms after coil embolization because coils make it difficult to obtain precise geometry of the recurrent aneurysms. In this study, we assessed the feasibility of flow visualization of recurrent aneurysms using 3D phase-contrast magnetic resonance imaging (PC-MRI).
    Acta Neurochirurgica 09/2014; 156(11). DOI:10.1007/s00701-014-2231-5 · 1.79 Impact Factor
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    Kenichi Kono, Aki Shintani, Tomoaki Terada
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    ABSTRACT: BackgroundRecent clinical studies have shown that recanalization rates are lower in stent-assisted coil embolization than in coiling alone in the treatment of cerebral aneurysms.ObjectiveThis study aimed to assess and compare the hemodynamic effect of stent struts and straightening of vessels by stent placement on reducing flow velocity in sidewall aneurysms, with the goal of reducing recanalization rates.MethodsWe evaluated 16 sidewall aneurysms treated with Enterprise stents. We performed computational fluid dynamics simulations using patient-specific geometries before and after treatment, with or without stent struts.ResultsStent placement straightened vessels by a mean (±standard deviation) of 12.9°±13.1° 6 months after treatment. Placement of stent struts in the initial vessel geometries reduced flow velocity in aneurysms by 23.1%±6.3%. Straightening of vessels without stent struts reduced flow velocity by 9.6%±12.6%. Stent struts had significantly stronger effects on reducing flow velocity than straightening (P = 0.004, Wilcoxon test). Deviation of the effects was larger by straightening than by stent struts (P = 0.01, F-test). The combination of stent struts and straightening reduced flow velocity by 32.6%±12.2%. There was a trend that larger inflow angles produced a larger reduction in flow velocity by straightening of vessels (P = 0.16).ConclusionIn sidewall aneurysms, stent struts have stronger effects (approximately 2 times) on reduction in flow velocity than straightening of vessels. Hemodynamic effects by straightening vary in each case and can be predicted by inflow angles of pre-operative vessel geometry. These results may be useful to design a treatment strategy for reducing recanalization rates.
    PLoS ONE 09/2014; 9(9):e108033. DOI:10.1371/journal.pone.0108033 · 3.53 Impact Factor
  • Masayuki Kawabata, Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Posterior cerebral artery(PCA)aneurysms are rare, especially those at the P4 segment. We report such a case involving a 77-year-old man who suffered from a sudden-onset headache. Computed tomography showed intracerebral hemorrhage in the left occipital lobe, intraventricular hemorrhage, and subarachnoid hemorrhage at the left occipital sulcus. Magnetic resonance angiography failed to reveal any aneurysms or abnormal vessels. Because the patient had renal dysfunction, we refrained from conventional angiography. Five days after the initial onset, rebleeding occurred, and conventional angiography revealed a small(2-mm)PCA aneurysm in the left P4 segment. We performed endovascular treatment and occluded the parent artery with a liquid embolic material, n-butyl-2-cyanoacrylate. The etiology of the aneurysm was not determined. The patient did not suffer from any apparent visual field deficits and was transferred to a rehabilitation hospital. Reviewing previous reports of distal PCA aneurysms indicated that PCA aneurysms in the P4 segment have two characteristics that distinguish them from other PCA aneurysms:P4 segment aneurysms are relatively small and the resulting hematoma distribution tends to be manifest as a combination of intracerebral hemorrhage, intraventricular hemorrhage, and subarachnoid hemorrhage at the occipital sulcus. With respect to these characteristics, our case was a typical P4 segment aneurysm. In conclusion, although P4 segment aneurysms are rare, if the characteristic hematoma distribution is observed, conventional angiography should be performed to confirm a possible P4 segment aneurysm. Parent artery occlusion with a liquid embolic material may be a treatment option for selected cases.
    No shinkei geka. Neurological surgery 09/2014; 42(9):873-878. · 0.13 Impact Factor
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Cerebral proliferative angiopathy (CPA) is a rare clinical entity. This disorder is characterized by diffuse vascular abnormalities with intermingled normal brain parenchyma, and is differentiated from classic arteriovenous malformations. The management of CPA in patients presenting with nonhemorrhagic neurological deficits due to cerebral ischemia is challenging and controversial. The authors report a case of adult CPA with cerebral ischemia in which neurological deficits were improved after encephaloduroarteriosynangiosis (EDAS). A 28-year-old man presented with epilepsy. Magnetic resonance imaging and angiography showed a diffuse vascular network (CPA) in the right hemisphere. Antiepileptic medications were administered. Four years after the initial onset of epilepsy, the patient's left-hand grip strength gradually decreased over the course of 1 year. The MRI studies showed no infarcts, but technetium-99m-labeled ethyl cysteinate dimer ((99m)Tc-ECD) SPECT studies obtained with acetazolamide challenge demonstrated hypoperfusion and severely impaired cerebrovascular reactivity over the affected hemisphere. This suggested that the patient's neurological deficits were associated with cerebral ischemia. The authors performed EDAS for cerebral ischemia, and the patient's hand grip strength gradually improved after the operation. Follow-up angiography studies obtained 7 months after the operation showed profound neovascularization through the superficial temporal artery and the middle meningeal artery. A SPECT study showed slight improvement of hypoperfusion at the focal region around the right motor area, indicating clinical improvement from the operation. The authors conclude that EDAS may be a treatment option for CPA-related hypoperfusion.
    Journal of Neurosurgery 08/2014; DOI:10.3171/2014.7.JNS132793 · 3.23 Impact Factor
  • Kenichi Kono, Aki Shintani, Tomoaki Terada
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    ABSTRACT: It is necessary to consider possibility of recanalization and retreatment after coil embolization for cerebral aneurysms. There is concern that retreatment for recanalized aneurysms after Y-stent-assisted coil embolization may be difficult because of double stents, especially in Y-stents with double closed-cell stents owing to narrowed structures. However, no detailed reports of retreatment after Y-stent have been reported. Between July 2010 and June 2013, we treated four aneurysms with Y-stent-assisted coil embolization using Enterprise closed-cell stents. Recanalization occurred in one case (25%), and retreatment was performed. We easily navigated a microcatheter into the target portions of the aneurysm through the Y-stent and occluded the aneurysm with coils. Additionally, by systematically searching in PubMed, we found 105 cases of Y-stent-assisted coil embolization using Enterprise stents or Neuroform stents with more than 6 months of follow-up. Among them, retreatment was performed in 10 cases (9.5%). There were no significant differences in retreatment rates among different stent combinations (P=0.91; Fisher's exact test). In conclusion, navigation of a microcatheter into the aneurysm through the Y-stent with double Enterprise stents was feasible, and retreatment rates after Y-stent-assisted coiling may not depend on stent combinations.
    Turkish neurosurgery 07/2014; 24(4):593-597. DOI:10.5137/1019-5149.JTN.9288-13.0 · 0.53 Impact Factor
  • Kenichi Kono, Aki Shintani, Tomoaki Terada
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    ABSTRACT: Carotid artery stenting (CAS) requires follow-up imaging to assess in-stent restenosis (ISR). This study aimed to determine whether non-enhanced magnetic resonance angiography (NE-MRA) is useful for evaluating ISR. Between 2009 and 2013, we performed 118 consecutive CAS procedures using the Precise stent (n = 78) and the Carotid Wallstent (n = 40). We reviewed 1.5 T NE-MRA and examined visualization of the stent lumen and the degree of ISR if present. Other imaging modalities were used as references. NE-MRA performed just after CAS was not able to visualize the stent lumen in all patients because of metal artifacts. In the Carotid Wallstent group, follow-up NE-MRA was available in 22 patients. The stent lumen was visible more than three months after CAS in all patients. Among them, > 40 % ISR was observed by other modalities in eight lesions. The degree of restenosis measured by NE-MRA (y%) had a linear relationship with that measured by conventional angiography (x%) (y = 0.97x-0.4, r = 0.79, P = 0.021). In one case among 17 without ISR (6 %), NE-MRA showed false ISR. In the Precise stent group, NE-MRA did not visualize the stent lumen in the follow-up period. NE-MRA can visualize the stent lumen in the Carotid Wallstent more than three months after CAS, but not in the Precise stent at follow-up. This delayed visualization might depend on endothelialization of the stent lumen. The degree of ISR measured by NE-MRA is comparable to that by conventional angiography. NE-MRA can evaluate ISR after CAS with the Carotid Wallstent (100 % sensitivity and 94 % specificity).
    Acta Neurochirurgica 06/2014; 156(9). DOI:10.1007/s00701-014-2142-5 · 1.79 Impact Factor
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Simultaneous multiple hypertensive intracranial hemorrhage is rare, and its mechanism is unclear. We report a case of simultaneous hypertensive bilateral thalamic hemorrhage. A 58-year-old man presented with sudden mild right hemiparesis. Computed tomography 1 hour after the onset showed bilateral thalamic hemorrhage. Gradient-echo T2 < sup > * < /sup > -weighted magnetic resonance imaging showed 17 microbleeds. The patient was treated with medication, discharged home, and achieved a modified Rankin scale of 1 at 3 months from the onset. Additionally, by systematically searching in PubMed, we found 41 cases of simultaneous bilateral hypertensive putaminal or thalamic hemorrhage, including our case: 18 bilateral putaminal, 12 bilateral thalamic, and 11 unilateral putaminal and contralateral thalamic hemorrhage. Symmetric hemorrhage occurred more frequently than expected ratios of hemorrhage occurring randomly in terms of location (p=0.013; Fisher's exact test). These new findings raise the hypothesis that patients may have symmetrically vulnerable vessels. Such conditions would result in coincidence or subsequent rupture of perforating arteries or micro-aneurysms by increased blood pressure and cause symmetric hemorrhages. Studies on the distribution of microbleeds may address these issues.
    Turkish neurosurgery 05/2014; 24(3):434-7. DOI:10.5137/1019-5149.JTN.8552-13.0 · 0.53 Impact Factor
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    ABSTRACT: Object The authors previously reported a case of complex arteriovenous fistula (AVF) at C-1 with multiple dural and spinal feeders that were linked with a common medullary venous channel. The purpose of the present study was to collect similar cases and analyze their angioarchitecture to gain a better understanding of this malformation. Methods Three such cases, affecting 2 males and 1 female in their 60s who had presented with hematomyelia (2) or progressive myelopathy (1), were treated surgically, and the operative findings from all 3 cases were compared using digital subtraction angiography (DSA) to determine the angioarchitecture. Results The C-1 and C-2 radicular arteries and anterior and posterior spinal arteries supplied feeders to a single medullary draining vein in various combinations and via various routes. The drainage veins ran along the affected ventral nerve roots and lay ventral to the spinal cord. The sites of shunting to the vein were multiple: dural, along the ventral nerve root in the subarachnoid space, and on the spinal cord, showing a vascular structure typical of dural AVF, that is, a direct arteriovenous shunt near the spinal root sleeve fed by one or more dural arteries and ending in a single draining vein, except for intradural shunts fed by feeders from the spinal arteries. In 2 cases with hemorrhagic onset the drainer flowed rostrally, and in 1 case associated with congestive myelopathy the drainer flowed both rostrally and caudally. Preoperative determination of the shunt sites and feeding arteries was difficult because of complex recruitment of the feeders and multiple shunt sites. The angioarchitecture in these cases was clarified postoperatively by meticulous comparison of the DSA images and operative video. Direct surgical intervention led to a favorable outcome in all 3 cases. Conclusions A high cervical complex AVF has unique angioarchitectural characteristics different from those seen in the other spinal regions.
    Journal of neurosurgery. Spine 01/2014; DOI:10.3171/2013.11.SPINE13402 · 2.36 Impact Factor
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    ABSTRACT: A patient received a ventriculoperitoneal shunt operation for hydrocephalus after subarachnoid hemorrhage. Postoperative computed tomography incidentally revealed asymptomatic pneumothorax caused by a shunt tube passing through the thoracic space. The patient was observed without removal of the tube or chest drainage, with the expectation of spontaneous recovery. However, the pneumothorax was not cured, and chest drainage was performed and eventually resolved the pneumothorax. The ventriculoperitoneal shunt worked well, and the patient recovered from consciousness disturbance. We discuss treatment strategies for this rare complication and how to avoid it. A review of the literature suggests that female or obese patients may be associated with this complication.
    Turkish neurosurgery 01/2014; 24(1):123-6. DOI:10.5137/1019-5149.JTN.7928-13.0 · 0.53 Impact Factor
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Basic research on cerebral aneurysms using computational fluid dynamics (CFD) simulations has recently progressed. We describe a clinical case with the use of CFD simulations. A 76-year-old woman had an unruptured anterior communicating artery aneurysm associated with pseudo-occlusion of the internal carotid artery (ICA). Pre-operative CFD simulations demonstrated that carotid artery stenting (CAS) would decrease hemodynamic stress on the aneurysm and might reduce the risk of aneurysm rupture. We performed CAS, and did not surgically treat the aneurysm because of her advanced age. A 7-month follow-up angiogram showed no change in the aneurysm size. We performed CFD simulations using the patient-specific flow waveforms at the bilateral ICAs before and 7 months after CAS. Maximum time-averaged wall shear stress of the aneurysm decreased from 8.3 Pa to 4.4 Pa. The pressure loss coefficient of the aneurysm, a proposed hemodynamic value for rupture risk, increased from 1.83 to 2.75. These findings indicated that CAS might reduce the rupture risk of the aneurysm according to previous reports on CFD studies. The aneurysm remains unruptured for 14 months from the CAS. This is the first report to attempt to reduce the rupture risk of an unruptured aneurysm with flow alteration based on CFD simulations.
    Turkish neurosurgery 01/2014; 24(1):111-6. DOI:10.5137/1019-5149.JTN.7861-13.0 · 0.53 Impact Factor
  • Hideo Okada, Tomoaki Terada
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    ABSTRACT: Objective: Endovascular treatment for a very small aneurysm with a diameter less than 3 mm is challenging because of its technical difficulties and high complication rates. The smallest coil diameter available today is 1.0 mm, so we defined an aneurysm with a short axis of less than 1.0 mm and a long axis of less than 3.0 mm as “the ultra small aneurysm.” We present a case of ruptured ultra small aneurysm successfully embolized by a single Target nano coil (1.5 mm×3.0 cm) and discuss about the technical points of the embolization for the ultra small aneurysm.Case: A 64-year-old woman presented with subarachnoid hemorrhage. Rupture site was an anterior communicating artery aneurysm with a long axis of 2.9 mm and a short axis of 1.0 mm. We performed coil embolization through the triple coaxial guiding system and used manually shaped microcatheter by hot air gun. A single Target nano coil was successfully inserted into the aneurysm from the microcatheter positioned just at the neck of the aneurysm, and the aneurysm was completely obliterated.Conclusion: Target nano is a highly soft coil and useful for the embolization of a ultra small ruptured cerebral aneurysm.
    01/2014; 8(5):298-304. DOI:10.5797/jnet.2014-0022
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    ABSTRACT: Internal carotid artery (ICA) occlusion with or without a bypass surgery is the traditional treatment for cavernous sinus (CS) aneurysms with cranial nerve (CN) dysfunction. Coil embolization without stents frequently requires retreatment because of the large size of CS aneurysms. We report the mid-term results of six unruptured CS aneurysms treated with stent-assisted coil embolization (SACE). The mean age of the patients was 72 years. The mean size of the aneurysms was 19.8 mm (range: 13-26 mm). Before treatment, four patients presented with CN dysfunction and two patients had no symptoms. SACE was performed under local or general anesthesia in three patients each. Mean packing density was 29.1% and tight packing was achieved. There were no neurological complications. CN dysfunction was cured in three patients (75%) and partly resolved in one patient (25%). Transient new CN dysfunction was observed in two patients (33%). Clinical and imaging follow-up ranged from 6 to 26 months (median: 16 months). Recanalization was observed in three patients (50%; neck remnant in two patients and dome filling in one patient), but no retreatment has yet been required. No recurrence of CN dysfunction has occurred yet. In summary, SACE increases packing density and may reduce requirement of retreatment with an acceptable cure rate of CN dysfunction. SACE may be a superior treatment for coiling without stents and be an alternative treatment of ICA occlusion for selected patients, such as older patients and those who require a high-flow bypass surgeryor cannot receive general anesthesia.
    Neurologia medico-chirurgica 11/2013; 54(2). DOI:10.2176/nmc.oa2013-0013 · 0.65 Impact Factor
  • Kenichi Kono, Tomoaki Terada
    Acta Neurochirurgica 11/2013; 156(1). DOI:10.1007/s00701-013-1942-3 · 1.79 Impact Factor
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: In Y-stent-assisted coil embolization for cerebral aneurysms, open or closed cell stents are used. Different microcatheters for coil insertion are available. We investigated which microcatheter could be navigated into an aneurysm through a Y-stent with different stents. Double Neuroform open-cell stents or double Enterprise closed-cell stents were deployed in Y-configuration in a silicon model of a bifurcation aneurysm. Two endovascular neurosurgeons independently tried to navigate an SL-10 microcatheter for 0.010" coils or a PX Slim microcatheter for 0.020" Penumbra coils into the aneurysm through the Y-stent. In addition, we measured lengths of stent pores of the Y-stents with double Enterprise stents deployed in the model by micro-computed tomography. It was feasible to navigate an SL-10 microcatheter into the aneurysm through the Y-stent with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter was feasible in the Y-stents only with Neuroform stents. In the Y-stent with double Enterprise stents, the lengths of the second stent pores were significantly smaller than those of the first stent (0.41 ± 0.18 mm vs 0.69 ± 0.20 mm; P = 0.008). The SL-10 microcatheter was smaller than approximately 80 % of the stent pores of the first stent and 30 % of those of the second stent. The PX Slim microcatheter was smaller than 20 % of the stent pores of the first stent and 0 % of those of the second stent. It was feasible to insert an SL-10 microcatheter into the aneurysm through Y-stents with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter for 0.020" Penumbra coils was feasible in Y-stents with Neuroform stents, but not with double Enterprise stents. The measurements of stent pores by micro-computed tomography supported this feasibility study. These results may be helpful to select appropriate stents and microcatheters in Y-stent-assisted coil embolization, especially in case of retreatments.
    Acta Neurochirurgica 11/2013; 156(1). DOI:10.1007/s00701-013-1925-4 · 1.79 Impact Factor
  • Kenichi Kono, Tomoaki Terada
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    ABSTRACT: Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
    ASME 2013 Summer Bioengineering Conference; 06/2013
  • Kenichi Kono, Hideo Okada, Tomoaki Terada
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    ABSTRACT: BACKGROUND:: and Importance: In endovascular treatment for cerebral aneurysms using balloons, stents, or flow-diverters, a microguidewire or microcatheter needs to be navigated distally across the neck of the aneurysm. However, this is sometimes difficult when there is a wide-neck or large aneurysm with a tortuous or atherosclerotic parent vessel. In this case report, we describe a new technique to navigate a microcatheter into a distal vessel. CLINICAL PRESENTATION:: An 81-year-old woman presented with trigeminal neuralgia and diplopia due to abducens nerve palsy because of a giant cavernous carotid artery aneurysm. We planned stent-assisted coil embolization for the aneurysm and tried to advance a microcatheter into a distal vessel across the neck of the aneurysm. Although we attempted several previously reported techniques, these were unsuccessful. We then navigated a balloon into the aneurysm, slowly inflated it within the aneurysm, pulled it back gently, and sealed the neck orifice of the aneurysm with the balloon. We easily navigated a microcatheter into the distal vessel. The stent-assisted coil embolization was completed with no complications. CONCLUSION:: This novel neck-sealing technique with a balloon for distal access may be useful in cases where other methods are unsuccessful. In addition, this technique offers the advantages of not producing a loop in the microcatheter within an aneurysm, and not requiring retraction of the microcatheter to reduce the loop.
    Neurosurgery 06/2013; 73. DOI:10.1227/NEU.0000000000000011 · 3.03 Impact Factor
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    ABSTRACT: Computational fluid dynamics (CFD) studies on cerebral aneurysms have attempted to identify surrogate hemodynamic parameters to predict rupture risk. We present a case of bilateral mirror image aneurysms, one of which ruptured soon after imaging. Wall shear stress values of the ruptured aneurysm changed by 20-30 % after rupture because of change in the aneurysm shape. Findings from our case suggest that CFD studies comparing unruptured and ruptured aneurysms may not yield valid estimation on aneurysm rupture risk because of changes in aneurysm shape after rupture. Changes in aneurysm shape after rupture should be considered in CFD research.
    Acta Neurochirurgica 05/2013; 155(8). DOI:10.1007/s00701-013-1773-2 · 1.79 Impact Factor
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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; 155(8). DOI:10.1007/s00701-013-1771-4 · 1.79 Impact Factor

Publication Stats

1k Citations
241.35 Total Impact Points


  • 1992–2008
    • Wakayama Medical University
      Wakayama, Wakayama, Japan
  • 2006
    • Minami Okayama Medical Center
      Okayama, Okayama, Japan
  • 2002
    • Osaka Medical College
      Takatuki, Ōsaka, Japan
  • 1988–2000
    • Hidaka Hospital
      Takasaki, Gunma Prefecture, Japan
  • 1996
    • Wakayama University
      Wakayama, Wakayama, Japan
  • 1994–1996
    • University of California, San Francisco
      • Department of Neurological Surgery
      San Francisco, California, United States