Hiroaki Shimizu

Akita University Hospital, Akita, Akita, Japan

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Publications (161)276.48 Total impact

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    ABSTRACT: Objectives: Postoperative meningitis is a serious complication occurring after neurosurgical interventions. However, few investigations have focused specifically on the risk factors that predispose patients to meningitis after major craniotomy. This study identified the risk factors for postoperative meningitis after neurovascular surgery, and investigated the relationship between postoperative meningitis and clinical outcome. Patients and methods: A total of 148 consecutive patients with subarachnoid hemorrhage (SAH) who underwent clipping surgery through a pterional approach within 72h between January 2007 and September 2011 were retrospectively analyzed. The treatment strategy of our hospital for patients with SAH was based on the findings of digital subtraction angiography in the acute phase. Coil embolization was firstly considered, and clipping through craniotomy if indicated was performed as soon as possible. Prophylactic antibiotics were administered before beginning craniotomy and for at least 3 days after. Hydrocortisone was used to prevent hyponatremia if allowed by the medical condition of the patient. Intrathecal administration of nicardipine hydrochloride was given if required for vasospasm treatment. Meningitis was clinically diagnosed from the blood samplings and cerebrospinal fluid (CSF) examinations. Data were collected from the electronic and paper charts. The status of modified Rankin scale (mRS) 0-2 at discharge was defined as favorable outcome. Results: A total of 14 patients (9.5%) had meningitis during this study period. Symptomatic vasospasm was detected in 33 patients (22.3%), and 12 patients (8.1%) had permanent neurological deficits caused by vasospasm. Overall, 109 patients (73.6%) had favorable outcome. The longer duration of drainage placement, presence of CSF leakage, and intrathecal administration of vasodilatory agent showed significantly higher incidence of postoperative meningitis in univariate analysis (p=0.0093, 0.0017, and 0.0090, respectively). The proportion of favorable outcome patients at discharge (mRS 0-2) was significantly lower in patients with postoperative meningitis (35.7%) than in patients without it (77.6%) (p=0.0004). The duration of in-hospital stay was significantly longer in patients with postoperative meningitis (median 58.5, range 28-115 days) than in patients without it (median 38.5, range 19-149 days) (p<0.001). Multivariate logistic regression analysis showed that only presence of CSF leakage was associated with postoperative meningitis (p=0.0299). Conclusion: Meningitis after surgery is still a serious complication that requires preventative intervention. The clinical outcome of patients with postoperative meningitis after neurovascular surgery is not still satisfactory.
    Clinical neurology and neurosurgery 11/2015; 139. DOI:10.1016/j.clineuro.2015.10.029 · 1.13 Impact Factor
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    ABSTRACT: Resection of large acoustic tumors is challenging due to adhesion between the tumor and adjacent tissues such as brainstem and facial nerve, and higher rate of hypervascularity. The authors report a case of large and hypervascular acoustic tumor who was successfully treated by combination of intravascular embolization of the feeding pial arteries and scheduled two- stage resection. A 31- year old man with known neurofibromatosis 2(bilateral acoustic tumors; resection for the right side 13 years ago) admitted to our hospital with progressing gait disturbance with left cerebellar sign and multiple cranial nerve deficits (left VI and bilateral VIIIs) due to the large recurrent left acoustic tumor which had been partially removed one year ago, because of excessive bleeding from the tumor. Preoperative magnetic resonance images demonstrated the tumor of 7 cm in diameter severely compressing to the brainstem and angiography revealed feeding arteries from the basilar artery and an intratumoral arteriovenous shunt. He underwent intravascular embolization of the feeders using N- butyl cyanoacrylate (NBCA) followed by scheduled two- stage resection. Postoperative course was uneventful and the symptoms partially improved to walk. Staged surgery with combination of preoperative embolization may be a treatment of choice for large hypervascular acoustic tumors. © 2015, Japanese Congress of Neurological Surgeons. All rights reserved.
    Japanese Journal of Neurosurgery 08/2015; 24(8):544-550. DOI:10.7887/jcns.24.544
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    ABSTRACT: Bypass with parent artery trapping is an alternative treatment method for ruptured internal carotid artery (ICA) aneurysms when clipping or coiling is contraindicated. However, the efficacy and safety of this strategy during the acute stage of subarachnoid hemorrhage (SAH) is undetermined. A retrospective review of 955 consecutive patients presenting SAH between 2006 and 2014 identified 17 patients with ruptured ICA aneurysms treated by bypass with parent artery trapping within 72 hours after the bleeding (bypass group). The 26 cases with ruptured posterior communicating artery aneurysms treated with clipping during the same period were defined as a control group (clipping group). Postoperative cerebral blood flow (CBF) was evaluated by single photon emission computed tomography (SPECT). We analyzed the postoperative hemodynamic status, surgical complications, and the clinical outcomes. Postoperative rebleeding did not occur in any of the cases. CBF in the first postoperative week in the bypass group was lower than that in the clipping group (P = .0165). This CBF decrease improved in the second postoperative week and did not differ from that of the clipping group. The incidence of acute ischemic complications was significantly higher in the bypass group (P = .0284), but the incidence of delayed cerebral ischemia did not differ between the 2 groups. The incidence of favorable outcomes at 6 months was 82.4% in the bypass group and 81% in the clipping group. Although the transient CBF decrease with acute ischemic complications should be noted, acute bypass with parent artery trapping is safe and effective for unclippable/uncoilable ruptured ICA aneurysms. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 07/2015; 24(10). DOI:10.1016/j.jstrokecerebrovasdis.2015.06.028 · 1.67 Impact Factor
  • Moataz Mekawy · Atsushi Saito · Hiroaki Shimizu · Teiji Tominaga ·
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    ABSTRACT: Fe2O3 nanoparticles (NPs) have been synthesized and functionalized with SiO2 and -NH2 group, respectively. Conjugation to fluorescently-labeled poly-caspase inhibitor (SR-FLIVO) has been carried out for better cellular uptake studies of apoptosis arising from brain focal cerebral ischemia. Highest conjugation affinity to SR-FLIVO was found to be ca. 80% for Fe2O3-SiO-NH2 functionalized nanoparticles (FNPs). Tracking of SR-FLIVO conjugated functionalized nanoparticles (SR-FLIVO-FNPs) in vivo and in vitro has been carried out and detected using microscopic techniques after histochemical staining methods. Experimental results revealed that SR-FLIVO-FNPs probe could passively cross the blood brain barrier (BBB) and accumulated within the apoptotic cell. Optimization of SR-FLIVO-FNPs probe can effectively promise to open a new era for intracellular drug delivery and brain diagnosis.
    Nanomaterials 06/2015; 5(2):874-884. DOI:10.3390/nano5020874 · 2.08 Impact Factor
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    ABSTRACT: Background We describe a rare case with partially thrombosed fusiform anterior choroidal artery (AchA) aneurysm successfully treated with therapeutic occlusion of the AchA. Clinical presentation A 58-year-old man presented with transient mild hemiparesis of the right side. Magnetic resonance imaging (MRI) showed an ischemic lesion in the posterior limb of the left internal capsule. Digital subtraction angiography (DSA) revealed a left internal carotid artery saccular aneurysm (14.5-mm diameter) arising from the supraclinoid segment. The left AchA was not detected in the initial DSA, and MRI showed the aneurysm to be partially thrombosed. The second DSA performed 2 weeks after the onset showed recanalization of the thrombosed portion of the aneurysm with the left AchA apparently arising from its tip. The aneurysm was diagnosed as a partially thrombosed fusiform AchA aneurysm. Results Open surgery was performed and a titanium clip was applied to the base of the fusiform aneurysm under motor evoked potential monitoring, which remained unchanged after clipping. Occlusion of the aneurysm was confirmed by Doppler ultrasound and intraoperative fluorescence angiography. Furthermore, Doppler ultrasound and fluorescence angiography showed that the blood flow supplying the pyramidal tract was reconstituted by the retrograde collateral flow from the choroidal segment. The aneurysm was completely obliterated in postoperative DSA, which demonstrated retrograde filling of the AchA through the posterior circulation. The patient manifested transient weakness of the right side postoperatively, which was completely recovered after short-term rehabilitation. Conclusions This case illustrates the unique clinical course of a rare partially thrombosed fusiform AchA aneurysm, successfully treated with therapeutic clip occlusion of the AchA under the multimodal monitoring.
    Journal of Stroke and Cerebrovascular Diseases 04/2015; 24(8). DOI:10.1016/j.jstrokecerebrovasdis.2015.04.024 · 1.67 Impact Factor
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    ABSTRACT: Object: Numerous studies have attempted to reveal the pathophysiology of ischemic neuronal injury using a representative transient global cerebral ischemia (tGCI) model in rodents; however, most of them have used gerbil or rat models. Recent advances in transgene and gene-knockout technology have enabled the precise molecular mechanisms of ischemic brain injury to be investigated. Because the predominant species for the study of genetic mutations is the mouse, a representative mouse model of tGCI is of particular importance. However, simple mouse models of tGCI are less reproducible; therefore, a more complex process or longer duration of ischemia, which causes a high mortality rate, has been used in previous tGCI models in mice. In this study, the authors aimed to overcome these problems and attempted to produce consistent unilateral delayed hippocampal CA1 neuronal death in mice. Methods: C57BL/6 mice were subjected to short-term unilateral cerebral ischemia using a 4-mm silicone-coated intraluminal suture to obstruct the origin of the posterior cerebral artery (PCA), and regional cerebral blood flow (rCBF) of the PCA territory was measured using laser speckle flowmetry. The mice were randomly assigned to groups of different ischemic durations and histologically evaluated at different time points after ischemia. The survival rate and neurological score of the group that experienced 15 minutes of ischemia were also evaluated. Results: Consistent neuronal death was observed in the medial CA1 subregion 4 days after 15 minutes of ischemia in the group of mice with a reduction in rCBF of < 65% in the PCA territory during ischemia. Morphologically degenerated cells were mostly positive for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and cleaved caspase 3 staining 4 days after ischemia. The survival rates of the mice 24 hours (n = 24), 4 days (n = 15), and 7 days (n = 7) after being subjected to 15 minutes of ischemia were 95.8%, 100%, and 100%, respectively, and the mice had slight motor deficits. Conclusions: The authors established a model of delayed unilateral hippocampal neuronal death in C57BL/6 mice by inducing ischemia in the PCA territory using an intraluminal suture method and established inclusion criteria for PCAterritory rCBF monitored by laser speckle flowmetry. This model may be useful for investigating the precise molecular mechanisms of ischemic brain injury.
    Journal of Neurosurgery 02/2015; 123(1):1-11. DOI:10.3171/2014.9.JNS14778 · 3.74 Impact Factor
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    ABSTRACT: We examined whether the amino acid PET tracers, trans-1-amino-3-(18)F-fluorocyclobutanecarboxylic acid (anti-(18)F-FACBC) and (11)C-methyl-l-methionine ((11)C-Met), are suitable for detecting early responses to combination therapies including temozolomide (TMZ), interferon-β (IFN), and bevacizumab (Bev) in glioblastoma. Human glioblastoma U87MG (U87) cells were incubated with low dose TMZ to induce chemoresistance. Both trans-1-amino-3-fluoro-1-(14)C-cyclobutanecarboxylic acid (anti-(14)C-FACBC) and (3)H-methyl-l-methionine ((3)H-Met) uptake were quantified using triple-label accumulation assays to examine the relationship between tracer uptake and proliferation ((3)H-thymidine (TdR) accumulation) in vitro. U87 and U87R (TMZ-resistant subculture) cells were inoculated into the right and left basal ganglia, respectively, of F344/N-rnu rats. The efficacy of single-agent (TMZ, Bev) and combination therapy (TMZ/IFN, TMZ/Bev, TMZ/IFN/Bev) was examined in orthotopic gliomas using MRI, Evans blue extravasation, anti-(14)C-FACBC, and (3)H-Met autoradiography, and MIB-1 immunostaining. TMZ treatment decreased (3)H-TdR accumulation and the volume distribution of anti-(14)C-FACBC and (3)H-Met in U87 but not U87R cells. TMZ/IFN combination therapy significantly decreased these parameters in U87R cells; however, Bev had no additional effect in vitro. In vivo, U87R-derived gliomas were observed as equivocal tumors on MRI and T2-high intensity lesions. Bev treatment, either alone or in combination, markedly decreased U87 enhancing lesions. By contrast, autoradiographic images using anti-(14)C-FACBC and (3)H-Met clearly delineated tumor extent, which spread widely beyond T2-high intensity lesions and enhancing lesions. TMZ therapy significantly decreased tracer accumulation and proliferation of U87- but not U87R-derived tumors. TMZ/IFN combination treatment significantly decreased these parameters in U87R tumors, which were further reduced (in both tumor types) by Bev addition. Tracer uptake correlated with the MIB-1 proliferation index. However, MRI was unsuitable for tumor delineation and assessment of Bev treatment response. Triple-agent therapy (TMZ/IFN/Bev) was effective against even TMZ-resistant glioblastomas. PET with amino acid tracers provides useful information on the early response of glioblastomas to single-agent and combination therapy. Copyright © 2015. Published by Elsevier Inc.
    Nuclear Medicine and Biology 01/2015; 42(7). DOI:10.1016/j.nucmedbio.2015.01.008 · 2.41 Impact Factor
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    ABSTRACT: Surgical treatment for recurrent aneurysms after clipping or coiling is generally more difficult than the initial treatment.Patients and Methods: This study included 14 patients (3 males and 11 females, mean age 58 years-old) who were surgically treated owing to a remnant aneurysm or recurrence of an aneurysm, after initial surgery or endovascular coil embolization. Patient characteristics and strategy for reoperation were retrospectively reviewed.Results: There were 8 ruptured and 6 unruptured aneurysms before the initial treatment with surgery (7 clipping cases and 1 wrapping case: surgical group) or coil embolization (6 cases: coil group). Presentation before the second surgery was rupture in 2 cases, and remnant or enlargement of the aneurysm in 12 cases. In the surgical cases, the most frequent aneurysm sites were the internal carotidposterior communicating artery, and middle cerebral artery; in the coiled patients, the sites varied. Intervals between the initial treatment and retreatment owing to aneurysmal growth or rupture were 13.5 and 1.5 years in the surgical and coil groups, respectively. In both the surgery and coil groups, incomplete occlusion of the aneurysm was considered to be a factor of regrowth. The second surgery was neck clipping in 10 cases (71%), and bypass followed by parent artery occlusion in 3 cases. Among 10 clipping cases, a previous clip or coil had to be removed in 6, and bypass was used to assist temporary proximal occlusion. In one case treated with bypass and parent artery occlusion, transient ischemic symptoms occurred, but improved after antiplatelet administration. The Glasgow outcome scale at discharge showed good recovery in all cases, except for one with moderate disability due to preexisting hemiparesis.Conclusion: Regrowth in both the surgery and coil groups was associated with incomplete occlusion and large size in the coil group. Surgical retreatment can be successfully accomplished with a strategy that includes careful dissection of the adhesive tissues, clip/coil removal, bypass to assist temporary proximal occlusion, and bypass with parent artery occlusion.
    Surgery for Cerebral Stroke 01/2015; 43(3):212-217. DOI:10.2335/scs.43.212
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    ABSTRACT: In the treatment of cerebral aneurysms, a combination of open and endovascular surgeries may be necessary when simple clipping or coiling are difficult. The authors retrospectively analyzed such patients to clarify the current status and issues to be overcome. Between 2003 and 2012, clipping was selected as the first choice until 2007 and coiling thereafter. Five representative cases with the combination therapy are presented. Case 1 : A giant internal carotid artery (IC) aneurysm at the cavernous portion was treated with a high flow bypass and parent artery occlusion, based on the finding of the preoperative balloon test occlusion which revealed severe reduction of cerebral blood flow upon IC occlusion. Case 2 : A ruptured vertebral artery dissection involving the posterior inferior cerebellar artery (PICA) was treated with the occipital artery (OA) -PICA bypass followed by internal trapping of the dissection and the parent artery with a coil. Wallenberg syndrome developed, but the patient became independent. Case 3 : A giant basilar artery-superior cerebellar artery (SCA) aneurysm was treated with a superficial temporal artery-SCA bypass followed by coil embolization of the aneurysm sac, because the SCA originated from the dome of the aneurysm. Case 4 : Clipping was intended for so-called kissing aneurysms, comprising IC-posterior communicating artery (Pcom) and anterior choroidal aneurysms ; however, adhesion between the aneurysms and with the Pcom itself was too tight to dissect. After discussion with the endovascular surgeons, the clipping was abandoned and coil embolization was successfully performed one month later. Case 5 : A case of a subarachnoid hemorrhage with IC-PC and basilar tip aneurysms. Coiling was intended for both aneurysms in the acute stage. It was revealed during the coiling procedure for the basilar tip aneurysm that one of the two humps of the aneurysm was difficult to occlude completely. A perforating artery of the basilar tip was shown by microcatheter angiography. The surgical team was consulted and the basilar tip aneurysm was clipped successfully after coiling of the IC-PC aneurysm. For aneurysms which are difficult to treat with simple clipping or coiling, a combination of open and endovascular surgeries may play a valuable role after effective communication between the neurosurgeons and endovascular surgeons. There remain certain limitations in terms of completeness of the aneurysm occlusion and perforators which still need to be overcome.
    Japanese Journal of Neurosurgery 01/2015; 24(3):165-172. DOI:10.7887/jcns.24.165
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    ABSTRACT: We report the utility of a pulsed water jet device in meningioma surgery. The presented case is that of a 61-year-old woman with left visual disturbance. MRI demonstrated heterogeneously enhanced mass with intratumoral hemorrhage, indicating sphenoid ridge meningioma on her left side. The tumor invaded the cavernous sinus and left optic canal, engulfing the internal carotid artery in the carotid cistern and encased middle cerebral arteries. During the operation, the pulsed water jet device was useful for dissecting the tumor away from the arteries since it was safe in light of preserving parent arteries. The jet did not cause any vascular injury and did not induce vasospasm as shown by postoperative symptomatology and MRIs. With the aid of pulsed water jet, we could achieve total resection of the tumor except for the piece within the cavernous sinus. The patient had no new neurological deficits after the operation. We consider the pulsed water jet as a useful device, especially when the need to dissect meningioma from parent arteries exists. The jet can help neurosurgeons simultaneously achieve tumor resection and preservation of blood vessels.
    No shinkei geka. Neurological surgery 11/2014; 42(11):1019-25. DOI:10.11477/mf.1436200025 · 0.13 Impact Factor
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    ABSTRACT: Carotid endarterectomy (CEA) is intended to remove atheromatous plaque by dissecting a plane between the intima and the media (circular medial fibers), but this may not be the optimal dissection plane. The present technique is based on identifying the plane that divides the media from the plaque, so preserving the media on the adventitia as much as possible. This plane is more difficult to find and follow than the easy-to-dissect plane usually located between the media and the adventitia, because the plaque invades the media and so the dividing plane is located within the media. In this prospective observational study, CEA was performed in 22 patients to histologically examine the excised plaques and small samples of the whole arterial wall, and evaluate the clinical outcomes. Plaque had invaded the luminal part of the media in the whole arterial wall sample of 80% of cases. Thin medial layers covering > 80% of the surface of the plaque were found in 16 of 22 plaques (73%). Some atheromatous component was sometimes left in the preserved media, rather than completely removed with the media. No morbidity or mortality had occurred by discharge. Only 1 small ipsilateral infarction (4.5%) and no restenosis of greater than 50% were detected during the mean follow-up period of 7 years. Since the plaque usually invades the media, the optimum dissection plane may be located within the media, dividing it into two layers. The presence of some remnant atheromatous components in the preserved media was not associated with surgical complications or restenosis.
    Neurologia medico-chirurgica 09/2014; 54(10). DOI:10.2176/nmc.tn.2014-0202 · 0.72 Impact Factor
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    ABSTRACT: Progressive moyamoya disease in pregnancy and puerperium has not been reported previously. Here, we present a 39-year-old woman who had been found to have moderate stenosis of right middle cerebral artery (MCA) 4 years prior to her pregnancy, finally suffering minor completed stroke due to progressive moyamoya disease at the early postpartum period. Three days after cesarean section without any complication, she developed cerebral infraction at right hemisphere, when magnetic resonance angiography indicated apparent progression of the proximal MCA stenosis. Catheter angiography demonstrated nearly occlusion of the right terminal internal carotid artery (ICA) and the development of an abnormal vascular network at the base of the brain as well as MCA stenosis, indicating a definitive diagnosis of moyamoya disease with unilateral involvement. The patient underwent superficial temporal artery-middle cerebral artery anastomosis 1 month after the onset of stroke, and she did not manifest as further neurological events during the follow-up period of 2 years. Moyamoya disease could newly develop in pregnancy and puerperium, which should be noted as a pitfall of the management of moyamoya disease with pregnancy.
    Neurologia medico-chirurgica 09/2014; 54(10). DOI:10.2176/nmc.cr.2014-0071 · 0.72 Impact Factor
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    ABSTRACT: Laser speckle flowgraphy (LSFG) is a noninvasive technique that can measure relative blood flow velocity in the optic fundus. The authors present a case of symptomatic internal carotid artery occlusion treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in which an improvement of ocular circulation was confirmed by LSFG. A 47-year-old man presented with a 1-month history of repeated left blurred vision and motor weakness of the right leg. Diffusion-weighted magnetic resonance imaging revealed a small infarction in the left frontal lobe. Carotid angiography revealed that the left internal carotid artery was occluded at the C4 portion. Single-photon emission computed tomography indicated that the cerebral blood flow in the left MCA territory was markedly impaired. Ophthalmologic examination revealed ischemic change of the left optic fundi, and LSFG revealed decreased blood flow around the left optic disc. Left STA-MCA bypass was successfully performed. Both ischemic ocular symptoms and the ischemic symptoms of the right leg were completely recovered after surgery. Postoperative ophthalmologic examination revealed improvement of both ischemic changes of the left optic fundi. Moreover, LSFG revealed improvement of the blood flow around the left optic disc. LSFG can be a promising clinical tool for the assessment of ocular circulation before and after bypass surgery for occlusive cerebrovascular disease.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 09/2014; 23(10). DOI:10.1016/j.jstrokecerebrovasdis.2014.06.021 · 1.67 Impact Factor
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    ABSTRACT: Bilateral giant internal carotid artery (ICA) aneurysms at the cavernous portion with bilateral cranial nerve symptoms are extremely rare. Extracranial–intracranial (EC-IC) bypass with parent artery occlusion (PAO) is one of the preferred procedures for giant ICA aneurysm at the cavernous portion with cranial nerve palsy; however, optimal bypass selection and the timing of surgery are controversial, particularly in bilateral cases. A 28-year-old woman developed left third nerve palsy with giant ICA aneurysms at the bilateral cavernous portion. Because only the left aneurysm was symptomatic, she initially underwent left EC-IC bypass using a saphenous vein graft with PAO without complications, which relieved her symptoms. However, she developed right third/fifth nerve palsy 10 months later, at which time magnetic resonance (MR) imaging and MR angiography revealed an enlarged right ICA aneurysm and shrunken left ICA aneurysm. Balloon test occlusion of the right ICA identified sufficient ischemic tolerance; therefore, she underwent right superficial temporal artery–middle cerebral artery bypass with PAO. Both bypasses were confirmed by MR angiography to be patent after surgery. Cranial nerve palsy gradually improved postoperatively, and single-photon emission computed tomography confirmed static cerebral hemodynamics. In conclusion, high-flow EC-IC bypass with PAO is recommended in the first stage of surgery on a unilaterally symptomatic side to minimize postoperative hemodynamic stress to the contralateral aneurysm. Once the contralateral side becomes symptomatic, second stage EC-IC bypass with PAO, either low-flow or high-flow bypass, is recommended based on the results of balloon test occlusion.
    Journal of Stroke and Cerebrovascular Diseases 09/2014; 23(8). DOI:10.1016/j.jstrokecerebrovasdis.2014.02.020 · 1.67 Impact Factor
  • Hiroyuki Sakata · Miki Fujimura · Kenichi Sato · Hiroaki Shimizu · Teiji Tominaga ·
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    ABSTRACT: Sjögren syndrome affecting the major cerebral arteries is rare, and an optimal therapeutic strategy to counteract such a lesion has not yet been established. We herein report a case of a 39-year-old woman with a history of primary Sjögren syndrome, which had previously been treated with immunosuppressive therapy, manifesting with a crescendo transient ischemic attack because of left middle cerebral artery stenosis. Despite the administration of high doses of prednisolone and azathioprine for active Sjögren syndrome, the frequency of crescendo transient ischemic attacks increased with the progression of stenosis and magnetic resonance imaging showed the development of subacute cerebral infarction. Single-photon emission computed tomography with N-isopropyl[123I]-p-iodoamphetamine revealed apparent hemodynamic compromise in the affected cerebral hemisphere. In light of the increased risk of further progression of cerebral infarction, we decided to perform surgical revascularization in spite of her active inflammatory condition. The patient underwent extracranial–intracranial bypass without complications and was treated with intensive immunosuppressive therapy during the perioperative period. Based on our findings, we recommend surgical revascularization for occlusive cerebrovascular disease with hemodynamic compromise in combination with intensive immunosuppressive therapy, even in the active inflammatory state of autoimmune diseases, if ischemic symptoms are medically uncontrollable.
    Journal of Stroke and Cerebrovascular Diseases 09/2014; 23(8). DOI:10.1016/j.jstrokecerebrovasdis.2014.02.022 · 1.67 Impact Factor
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    ABSTRACT: Objective: Cerebral hyperperfusion syndrome (HPS) is a potential complication of extracranial-intracranial (EC-IC) bypass for moyamoya disease; however, the pathological threshold of the early cerebral blood flow (CBF) increases after EC-IC bypass has yet to be determined. The purpose of this study is to evaluate the predictive and diagnostic values of early quantitative CBF analysis for the detection of HPS after EC-IC bypass for moyamoya disease. Methods: We quantitatively evaluated regional CBF at the site of the anastomosis in 23 patients with moyamoya disease aged between 18 and 66 years (mean, 39.6) before and 1 day after superficial temporal artery-middle cerebral artery anastomosis by an auto-radiographic method using N-isopropyl-p-[(123)I]iodoamphetamine single-photon emission computed tomography. Results: Regional CBF 1 day after surgery was significantly higher in patients with HPS (n = 5; mean, 54.6 ml/100 g/minutes) than in patients without HPS (n = 18; mean, 40.5 ml/100 g/minutes) (P = 0.038). The postoperative/preoperative CBF ratio was significantly higher in patients with HPS (1.84) than in patients without HPS (1.34) (P = 0.044). Multivariate analyses showed that the regional CBF value 1 day after surgery (P = 0.036) and operating on the left hemisphere (P = 0.026) significantly correlated with HPS. All patients with HPS developed symptoms and/or intracerebral hemorrhage more than 2 days after EC-IC bypass. Receiver operating characteristic analysis indicated that the cutoff value of pathological postoperative CBF increase was 46.1 ml/100 g/minutes (sensitivity = 80%, specificity = 77.8%, AUC value = 0.81). Conclusion: Quantitative analysis of early postoperative CBF is useful for predicting and diagnosing HPS after revascularization surgery for moyamoya disease.
    Neurological Research 08/2014; 37(2):1743132814Y0000000432. DOI:10.1179/1743132814Y.0000000432 · 1.44 Impact Factor
  • Hiroyuki Sakata · Miki Fujimura · Kenichi Sato · Hiroaki Shimizu · Teiji Tominaga ·
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    ABSTRACT: A 42-year-old man with a history of hypertension and obesity presented with transient dysesthesia in his left upper and lower extremities and was found to have moyamoya syndrome associated with atherosclerosis. He underwent superficial temporal artery-middle cerebral artery anastomosis with pial synangiosis in the right hemisphere 1 month after the onset of symptoms. Prophylactic blood pressure lowering(<130 mmHg)as well as minocycline administration was introduced immediately after surgery to prevent symptomatic cerebral hyperperfusion, but he developed pulmonary edema due to congestive heart failure several hours after surgery. We subsequently allowed his systolic blood pressure to be under 140 mmHg, which dramatically improved his cardiopulmonary condition. The neurologic status of the patient was unremarkable, but (123)I-IMP-SPECT the day after surgery demonstrated an intense increase in the cerebral blood flow at the site of the anastomosis. Moreover, postoperative magnetic resonance angiography demonstrated the bypass as thick, high signal. Together, these results led us to the diagnosis of cerebral hyperperfusion. The patient did not demonstrate any neurological sign during the entire perioperative period, but CT scan performed 7 days after surgery revealed a delayed intra-cerebral hemorrhage in the right temporal lobe due to the cerebral hyperperfusion. We continued to mildly lower his blood pressure, and neither ischemic nor hemorrhagic events were subsequently observed; he was discharged without neurological deficit 2 weeks after surgery. In conclusion, congestive heart failure and pulmonary edema are potential complications of the perioperative management of moyamoya syndrome with atherosclerotic background. Moreover, cardiopulmonary complications should be mentioned as a potential pitfall of the intensive perioperative management of moyamoya disease to counteract with cerebral hyperperfusion.
    No shinkei geka. Neurological surgery 08/2014; 42(8):737-43. · 0.13 Impact Factor
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    ABSTRACT: Stachybotrys microspora triprenyl phenol-7 (SMTP-7) is a new thrombolytic agent that exhibits anti-inflammatory effects. We previously demonstrated that the hemorrhagic transformation was fewer with SMTP-7 than with recombinant tissue plasminogen activator (rt-PA) following ischemia-reperfusion in animal models. We hypothesized that SMTP-7 may decrease hemorrhagic transformation after ischemia-reperfusion under the warfarin-treated condition. Transient middle cerebral artery occlusion (MCAO) was induced for three hours using an intraluminal suture in warfarin-treated mice to produce hemorrhagic transformation. Warfarin was administered orally for a 24-hour feeding period before MCAO through bottled drinking water (5 mg in 375 ml tap water), resulting in a mean INR of 5.6±0.2. Mice were treated with vehicle, rt-PA, or SMTP-7 five minutes before reperfusion. Twenty percent of vehicle-treated and 50.0% of rt-PA-treated mice died 24 hours after reperfusion, while all SMTP-7-treated mice survived. Hemorrhagic severity in SMTP-7-treated mice was significantly lower than that in rt-PA-treated mice. Neurological deficit was significantly lower in SMTP-7-treated mice than vehicle- and rt-PA-treated mice. These results indicate that SMTP-7 decreases mortality, hemorrhagic transformation, and neurological deficits, and can be a safe thrombolytic agent following MCAO under the warfarin-treated condition.
    Brain Research 08/2014; 1578(1). DOI:10.1016/j.brainres.2014.07.004 · 2.84 Impact Factor
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    ABSTRACT: Background and Importance: Aneurysm formation after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is a rare condition with only a handful of cases reported in the literature with various presentations and management strategies. Various theories have been postulated to explain such rare complication and to determine whether it is a de novo pathology or related to operative techniques. Clinical Presentation: We report on a 33-year-old man who had undergone STA-MCA bypass and parent vessel occlusion for a giant cavernous internal carotid artery aneurysm 3 years ago. He presented to us with headache and on follow-up radiologic investigations a giant aneurysm was found at the bypass site. We present this rare case and discuss its troublesome management. Conclusions: This is the first case reported with unruptured giant partially thrombosed aneurysm developing on the site of STA-MCA bypass. We discuss its management and possible etiologies for its formation with review of similar cases in the literature for future prevention and/or management of similar cases.
    Neurosurgery Quarterly 07/2014; 25(3). DOI:10.1097/WNQ.0000000000000046 · 0.09 Impact Factor
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    ABSTRACT: BACKGROUND: Reports of cervical perimedullary arteriovenous shunt (PMAVS) are limited, and treatment strategies have not been established. OBJECTIVE: To describe angioarchitecture and optimal treatment strategies for cervical PMAVS. METHODS: We treated 22 patients with cervical PMAVS between 2000 and 2012 (8 women and 14 men; age, 9-80 years). According to the classification, our patients included type IVa (4 patients), type IVb (16 patients), and type IVc (2 patients). Seventeen patients presented with subarachnoid hemorrhage. RESULTS: A total of 41 shunting points were localized in 22 patients, of which 34 points were located ventral or ventrolateral to the spinal cord. The anterior spinal artery (ASA) contributed to the shunts in 16 patients. Aneurysm formation was identified in 8 patients. Endovascular treatment was attempted in 3 patients, resulting in complete obliteration in 1 patient (type IVc). Overall, 21 patients underwent open surgery. An anterior approach with corpectomy was elected for 2 patients; the other 19 patients underwent the posterior approaches using indocyanine green videoangiography, intraoperative angiography, endoscopy (8 patients), and neuromonitoring. Twenty patients were rated as having a good recovery at 6 months after surgery. No recurrence was observed in any patients during the follow-up (mean, 59.7 months). CONCLUSION: Shunting points of the cervical PMAVS were predominantly located ventral or ventrolateral to the spinal cord and were often fed by the ASA. Even for ventral lesions, posterior exposure assisted with neuromonitoring and endoscopy, and intraoperative angiography provided a view sufficient to understand the relationships between the shunts and the ASA and contributed to good surgical outcomes. ABBREVIATIONS: ASA, anterior spinal artery AVM, arteriovenous malformation AVS, arteriovenous shunt ICG, indocyanine green PMAVS, perimedullary arteriovenous shunt SAH, subarachnoid hemorrhage
    Neurosurgery 05/2014; 75(3). DOI:10.1227/NEU.0000000000000401 · 3.62 Impact Factor

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  • 2014
    • Akita University Hospital
      Akita, Akita, Japan
  • 1996-2014
    • Kohnan Hospital
      Sendai, Kagoshima, Japan
    • Japan BCG Laboratory
      Edo, Tōkyō, Japan
  • 2002-2013
    • Tohoku University
      • • Department of Neurosurgery
      • • Department of Neuroendovascular Therapy
      • • Department of Physiology II
  • 2005
    • Muroran Institute of Technology
      • Division of Mechanical Systems and Materials Engineering
      Муроран, Hokkaidō, Japan