Kousuke Iwaisako

Osaka City University, Ōsaka-shi, Osaka-fu, Japan

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Publications (9)12.81 Total impact

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    ABSTRACT: Hemifacial spasms (HFS) are usually caused by vascular compression on the extra-axial facial nerve. In this case, we concluded that an intra-axial brainstem cavernous angioma with a venous angioma diagnosed by MRI must have been responsible for HFS, because no other possible causes were found during intraoperative observations.
    British Journal of Neurosurgery 10/2011; 26(2):281-3. · 0.86 Impact Factor
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    S Toyota, S Sugiura, K Iwaisako
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    ABSTRACT: We investigated the efficacy and safety of combined intravenous (IV) recombinant tissue plasminogen activator (rtPA) and simultaneous endovascular therapy (ET) for hyperacute middle cerebral artery (MCA) M1 occlusion. Between October 2005 and April 2007, in the combined group, 22 patients eligible for IV rtPA, who were diagnosed as having MCA M1 occlusion, were treated with IV rtPA and simultaneous ET was initiated as soon as possible. The other patients were treated with IV rtPA alone (IV group A: n = 11). Between May 2007 and November 2008, all patients eligible for IV rtPA, who were diagnosed as having MCA M1 occlusion, underwent thrombolysis by IV rtPA alone (IV group B: n = 24). The improvement of the National Institutes of Health Stroke Scale score at 24 hours was highest in the combined group (10 ± 4.1). In contrast, it was 5.1 ± 4.7 in the IV group A (P = 0.017) and 5.6 ± 5.6 in IV group B (P = 0.006). In the combined group, successful recanalization was observed in 18 of 22 patients with one symptomatic intracranial hemorrhage. The rate of mRS0-2 at three months was highest in the combined group, 36% in the IV group A and 33% in the IV group B (P = 0.008).Simultaneous treatment with IV rtPA and ET improved the clinical outcome of MCA M1 occlusion without a significant increase of adverse effects in our study.
    Interventional Neuroradiology 03/2011; 17(1):115-22. · 0.77 Impact Factor
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    ABSTRACT: Anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA) is useful for treating certain patients with internal carotid artery occlusion or MCA occlusion. However, in the case of common carotid artery (CCA) occlusion, since the blood flow in the STA is insufficient, another artery should be used as the donor artery. The cortical branches of the MCA are usually selected as recipients in the STA-MCA bypass. However, the intracranial vascular filling gradually increases over a few months after conventional cortical MCA bypass grafting, while early or even immediate vascular filling is observed after proximal MCA bypass grafting. This study aims to develop an elongation technique of the contralateral STA to reach the proximal segment of the ipsilateral MCA. Anastomosis of the contralateral STA to the secondary trunk of the ipsilateral MCA was performed in 2 patients with occlusion of the CCA and ipsilateral vertebral artery (VA). The contralateral STA was extended with a radial artery (RA) graft in order to supply blood to the ischemic area. Elongation of the STA by using an RA interposition graft sufficiently lengthens the graft to enable its anastomosis with the contralateral M2 segment. Postoperative imaging revealed good bypass patency even at 1 year after the surgery. This novel technique of performing the "bonnet" bypass was effective in treating both CCA and ipsilateral VA occlusion; moreover, this procedure of elongation of the STA can increase candidates of the recipient, and enables one to perform a double bypass to the anterior cerebral artery (ACA) or posterior cerebral artery (PCA).
    min - Minimally Invasive Neurosurgery 08/2010; 53(4):203-6. · 0.62 Impact Factor
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    ABSTRACT: A 76-year-old woman presented with an enlarged right intracavernous carotid artery aneurysm first identified incidentally when she was hospitalized for thalamic hemorrhage. She was managed conservatively for 1 year, then suffered right total ophthalmoplegia associated with enlargement of the aneurysm. Two months later, she became comatose due to intracerebral hemorrhage in the right temporal lobe. Magnetic resonance imaging demonstrated further enlargement of the aneurysm. Emergency craniotomy found the lateral dural wall of the cavernous sinus was markedly expanded and torn by compression from the aneurysm. Rupture of the aneurysm into the intradural space through this dural defect was confirmed. The aneurysm was trapped after high-flow bypass, but the patient did not recover and died. Symptomatic enlarged intracavernous carotid artery aneurysm is potentially fatal and may indicate prompt surgical management.
    Neurologia medico-chirurgica 05/2009; 49(4):155-8. · 0.49 Impact Factor
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    S Sugiura, K Iwaisako, S Toyota, H Takimoto
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    ABSTRACT: Because intravenous (IV) recombinant tissue plasminogen activator (rtPA) does not always lead to a good outcome in a considerable proportion of patients, combined IV rtPA and rescue endovascular therapy (ET) have been performed in several recent studies. However, rescue therapy after completion of IV rtPA often results in late ineffective recanalization. We examined the efficacy and safety of combined IV rtPA and simultaneous ET as primary rather than rescue therapy for hyperacute middle cerebral artery (MCA) occlusion. A total of 29 patients eligible for IV rtPA, who were diagnosed as having MCA (M1 or M2) occlusion within 3 hours of onset, underwent thrombolysis. In the combined group, patients were treated by IV rtPA (0.6 mg/kg for 60 minutes) and simultaneous ET (intra-arterial rtPA, mechanical thrombus disruption with microguidewire, and balloon angioplasty) initiated as soon as possible. In the IV group, patients were treated by IV rtPA only. The improvement of the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours was 11 +/- 4.8 in the combined group versus 5 +/- 4.3 in the IV group (P < .001). In the combined group, successful recanalization was observed in 14 (88%) of 16 patients with no symptomatic intracranial hemorrhage, and 10 (63%) of 16 patients had favorable outcomes (modified Rankin Scale [mRS] 0, 1) at 3 months. Aggressive combined therapy with IV rtPA and simultaneous ET markedly improved the clinical outcome of hyperacute MCA occlusion without significant adverse effect. Additional randomized study is needed to confirm our results.
    American Journal of Neuroradiology 06/2008; 29(6):1061-6. · 3.17 Impact Factor
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    ABSTRACT: Recent progress in digital subtraction angiography (DSA) devices makes it possible to perform rotational angiography with high resolution and high sensitivity. We tried intravenous (IV) 3D DSA in patients who had undergone MR angiography (MRA) suggestive of unruptured intracranial aneurysms. IV 3D DSA can be used as an alternative method for imaging unruptured intracranial aneurysms suggested on MRA.
    American Journal of Neuroradiology 02/2008; 29(1):107-9. · 3.17 Impact Factor
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    ABSTRACT: Concerning the treatment of moyamoya disease with hemorrhagic onset, there has not been a consensus on the validity of surgical revascularization to prevent recurrent hemorrhage. The authors retrospectively investigated the effect of revascularization for hemorrhagic moyamoya disease, and it was proved effective for adult and pediatric patients. Twenty-nine cases with hemorrhagic onset among 597 pediatric moyamoya pediatric patients were targeted for this study as well as 70 cases with hemorrhagic onset among 216 adult patients. Revascularization, mainly consisting of superficial temporal-middle cerebral artery (MCA) anastomosis, was performed in 25 of 29 pediatric patients, and only 1 demonstrated late hemorrhage after the procedure. Of 70 adult patients, 52 underwent revascularization procedures; only 5 (9.6%) presented with recurrent hemorrhage, whereas 6 (33%) of 18 patients without revascularization did, yielding a significant difference in the rate of recurrent hemorrhage between these 2 groups (P < 0.05). The hemorrhage was frequently found in the periventricular area, where an anastomotic junction of perforating arteries and medullary arteries is located, and in ventricles, where the distal part of choroidal arteries is located. Less frequently, the hemorrhagic sites were concentrated in the thalamus, lenticular nucleus, and caudate head, which are the terminal points of perforating arteries of the posterior cerebral artery, MCA, and anterior cerebral artery, respectively. In the patients with recurrent hemorrhage following the revascularization, the extent of hemorrhage was small and caused mild neurologic deficits when the blood flow was markedly improved on postoperative angiography. In the nonsurgical group, the degree of recurrent hemorrhage was extensive and the patients presented with severe neurologic deficits. Moyamoya arteries, which are formed as a result of gradual occlusion of main cerebral arteries, are considered to be a type of bypass vessel. Moyamoya disease shows various pathologic manifestations in the brain, including intracerebral hemorrhage. It is speculated that abnormal hemodynamic stress resulting from the changes in the cerebral arteries specific to moyamoya disease causes the rupture of an aneurysm or pseudoaneurysm that could be formed within the small arteries as well as the rupture of a dilated moyamoya artery. The histologic changes of the hemorrhagic sites have not been confirmed, however. Before the computed tomography (CT) era, these events were clinically recognized as subarachnoid hemorrhages until 1983, when Suzuki diagnosed them as intracerebral hemorrhages. 1 Because the natural history of hemorrhagic moyamoya disease is not clearly understood to date, 2 whether revascularization is effective or not in treating hemorrhagic moyamoya disease is also not clarified. The effectiveness of surgical revascularization was studied in the patients who have been cared for and are under observation at our institution for hemorrhagic moyamoya disease.
    Neurosurgery Quarterly 02/2004; 14(1):36-40. · 0.09 Impact Factor
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    ABSTRACT: The authors advocate the use of a 1.7-mm fiberscope to evaluate a hypertensive bilateral tegmental pontine hemorrhage that has ruptured, in part, into the fourth ventricle. In applying this new technique, a fiberscope, which contains a guide tube in the working channel, is inserted into the aqueduct. After the endoscope has been removed, a silicone tube is slid along the guide tube. The hematoma is evacuated through the silicone tube and a potassium titanyl phosphate laser is used to achieve hemostasis.
    Journal of Neurosurgery 05/2003; 98(4):917-9. · 3.15 Impact Factor
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    ABSTRACT: A 48-year-old man underwent ventriculoperitoneal shunting for hydrocephalus secondary to subarachnoid hemorrhage due to left vertebral artery dissection, which had been successfully treated by trapping. The peritoneal catheter was correctly positioned via a right upper abdominal incision, and symptoms related to the hydrocephalus disappeared. One month later, the patient began to complain of pain on the right side of the neck. Chest radiography revealed that the peritoneal end of the catheter had migrated into the right pulmonary artery. The catheter route was explored through a small neck incision, and was found to enter the external jugular vein. The catheter was extracted and repositioned into the peritoneum. This type of shunt migration is quite unusual, but could be lethal by causing pulmonary infarction or arrhythmia. The catheter had probably entered the external jugular vein through a perforation caused by the shunt guide during the ventriculoperitoneal shunt operation. Follow-up radiography should be scheduled to detect such a complication.
    Neurologia medico-chirurgica 01/2003; 42(12):572-4. · 0.49 Impact Factor