Tatsuya Ishikawa

Research Institute for Brain and Blood Vessels-Akita, Akita, Akita, Japan

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Publications (139)187.92 Total impact

  • Takeshi Okada · Tatsuya Ishikawa · Junta Moroi · Akifumi Suzuki
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    ABSTRACT: Background: Some patients require a second surgical intervention for recurrence of treated aneurysms, untreated aneurysms in patients with multiple lesions, or de novo aneurysm. This retrospective review of the data was undertaken to evaluate when retreatment is necessary after initial aneurysm treatment. Methods: Cerebral aneurysms in 1755 patients were treated via clipping or coiling between January 1995 and September 2012. Postoperative follow-up was performed at 6 months after treatment and was repeated every 12 months (or longer) after treatment using three-dimensional computed tomography angiography or magnetic resonance angiography. Results: A cumulative total of 156 patients (8.9%) (117 women, 39 men; mean age: 55.0 years; range: 25-79 years) needed retreatment for rupture or regrowth of aneurysm (n = 31; ruptured (R)/remaining unruptured (U), 26/5), formation of de novo aneurysm (n = 45; R/U, 23/22), known untreated aneurysm in patients with multiple lesions (n = 78; R/U, 5/73), and hemorrhage from undetected aneurysm (n = 2). The regrowth risk is higher after endovascular treatment than after craniotomy and clipping. Median time to retreatment was 187 months (range: 11-280 months) for regrowth, 165 months (range: 22-330 months) for de novo, and 24 months (range: 2.8-417 months) for known untreated aneurysm. Regrowth or known with subarachnoid hemorrhage were frequently treated within 2 years from initial treatment. Conclusions: Aneurysms with residua or untreated aneurysms in patients with multiple lesions carry a risk of bleeding during a relatively short period, whereas there is a small but significant risk of de novo formation and subsequent hemorrhage at over 10 years after previous treatment.
    No preview · Article · Feb 2016 · Surgical Neurology International
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    ABSTRACT: Neurogenic pulmonary edema (NPE) is a potentially catastrophic but treatable systemic event after subarachnoid hemorrhage (SAH). The development of NPE most frequently occurs immediately after SAH, and the severity is usually self-limiting. Despite extensive research efforts and a breadth of collective clinical experience, accurate diagnosis of NPE can be difficult, and effective hemodynamic treatment options are limited. Recently, a bedside transpulmonary thermodilution device has been introduced that traces physiological patterns consistent with current theories regarding the mechanism (hydrostatic or permeability PE) of NPE. This article provides an overview of the clinical usefulness of the advanced technique for use in the neurointensive care unit for the diagnosis and management of post-SAH NPE. Copyright (C) 2015 by the Southern Society for Clinical Investigation. Unauthorized reproduction of this article is prohibited.
    No preview · Article · Sep 2015 · The American Journal of the Medical Sciences

  • No preview · Conference Paper · Feb 2015

  • No preview · Article · Dec 2014 · Critical Care Medicine
  • Jun Tanabe · Junta Moroi · Shotaro Yoshioka · Tatsuya Ishikawa
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    ABSTRACT: Background: Internal trapping in which the dissecting aneurysm is occluded represents reliable treatment to prevent rebleeding of ruptured vertebral artery (VA) dissecting aneurysms. Various methods of internal trapping are available, but which is most appropriate for preventing both recanalization of the VA and procedural complications is unclear. Case Description: A 61-year-old male presented with subarachnoid hemorrhage caused by rupture of a left VA dissecting aneurysm. Only the dilated segment of the aneurysm was occluded by coil embolization. Sixteen days after embolization, angiography showed recanalization of the treated left VA with blood supplying the dilated segment of the aneurysm, which showed morphological change between just proximal to the coil mesh and just distal to a coil, and antegrade blood flow through this part. Pathological examination showed that the rupture site that had appeared to be the most dilated area on angiography was located just above the orifice of the entrance. However, we think that this case of ruptured aneurysm had an entrance into a pseudolumen that existed proximal to the dilated segment, with antegrade recanalization occurring through the pseudolumen with morphological change because of insufficient coil obliteration of the entrance in the first therapy. Conclusions: This case suggests that occlusion of both the proximal and dilated segments of a VA dissecting aneurysm will prevent recanalization, by ensuring that any entrance to a pseudolumen of the aneurysm is completely closed. Careful follow-up after internal trapping is important, since antegrade recanalization via a pseudolumen may occur in the acute stage.
    No preview · Article · Oct 2014 · Surgical Neurology International
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    Shinya Kobayashi · Tatsuya Ishikawa · Jun Tanabe · Junta Moroi · Akifumi Suzuki
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    ABSTRACT: Background: Intraoperative qualitative indocyanine green (ICG) angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS) after STA-MCA anastomosis. Methods: Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs) on the cortex, corresponding to ROIs on positron emission tomography (PET) study, was recorded. Maximum intensity (IMAX), cerebral blood flow index (CBFi), rise time (RT), and time to peak (TTP) were evaluated. Results: RT/TTP, but not IMAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01) with mean transit time (MTT)/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland–Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017). The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017). Conclusions: Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative HPS.
    Preview · Article · Sep 2014 · Surgical Neurology International
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    ABSTRACT: Objective: Aging is considered to cause atherosclerotic changes in the carotid artery, but few studies have evaluated this relationship. In this study, we used carotid plaques removed from patients with carotid artery stenosis and investigated how aging contributes to carotid plaque morphology and symptoms. Materials and methods: A total of 60 patients(55 men, 5 women; mean age, 70.5 years; range, 53-85 years) treated at our hospital between January 2009 and April 2012 were enrolled in this study. All patients underwent carotid endarterectomy; their carotid plaques were stained with hematoxylin-eosin and/or Elastica-Masson stain and examined by a pathologist. Using these data, the carotid systolic velocity and plaque morphology were analyzed considering the age by decade as well as the symptomatology. Results: Of the 60 patients, 29 were symptomatic(transient ischemic attack (TIA) in 8 patients; infarction in 20;and amaurosis in 1). Symptoms were less common as patient age increased. The incidence of TIA also tended to decrease with an increase in age, although the opposite trend was seen with infarction. In plaque morphology, the presence of active plaque, macrophage, inflammatory infiltration, and capillary angiogenesis decreased as age increased, while the presence of degenerative plaques, decrease in smooth muscle cell number, and calcification inversely increased. Active, degenerative, and combined (active/degenerative) lesions are statistically unrelated to symptoms as well as systolic velocity (cm/sec) at the carotid stenosis. The rates of hemorrhagic lesions were similar among decades, but the lesion statistically contributed to increasing symptoms (p=0.0045) and increasing systolic velocity (p=0.031). Conclusion: Increasing age contributes to morphological changes in carotid plaques and symptoms. When hemorrhagic lesions are suspected in carotid plaques, patients will be symptomatic and may require surgery.
    No preview · Article · Sep 2014 · No shinkei geka. Neurological surgery
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    ABSTRACT: IntroductionTakotsubo cardiomyopathy (TCM) is a life-threatening systemic consequence early after subarachnoid hemorrhage (SAH), but precise hemodynamics and related outcome have not been studied. The purpose of this study was to investigate the TCM-induced cardiac function by transpulmonary thermodilution and its impact on clinical outcome of SAH.Methods We retrospectively analyzed 46 consecutive postoperative SAH patients who developed TCM. Patients were divided into two groups of echocardiographic left ventricular ejection fraction (LVEF)¿<¿40% (TCM with left ventricular (LV) dysfunction) and LVEF ¿40% (TCM without LV dysfunction). Cardiac function index (CFI) and extravascular lung water index (ELWI) were monitored by transpulmonary thermodilution, in parallel with serial measurements of echocardiographic parameters and blood biochemical markers.ResultsTranspulmonary thermodilution-derived cardiac function index (CFI) was significantly correlated with (LVEF) (r¿=¿0.82, P¿<¿0.0001). The CFI between day 0 to day 7 was significantly lower in patients with LV dysfunction (LVEF <40%) than in patients with LVEF ¿40% (P¿<¿0.05). CFI had a better ability than cardiac output to detect cardiac dysfunction (LVEF¿<¿40%) (area under the curve: 0.85¿±¿0.02; P¿<¿0.001). A CFI value of¿<¿4.2 min¿1 had a sensitivity of 82% and specificity of 84% for detecting LVEF <40%. The CFI¿<¿4.2 min¿1 was associated with delayed cerebral ischemia (DCI) (odds ratio (OR), 2.14; 95% confidence interval (CI), 1.33¿2.86; P¿=¿0.004) and poor 3-month functional outcome on modified Rankin Scale of 4¿6 (OR, 1.87; 95% CI, 1.06¿3.29; P¿=¿0.02). An extravascular lung water index (ELWI)¿>¿14 mL/kg after day 4 increased the risk of poor functional outcome at 3-month follow-up (OR, 2.10; 95% CI, 1.11¿3.97; P¿=¿0.04).Conclusions Prolonged cardiac dysfunction and pulmonary edema increased the risk of DCI and poor 3-month functional outcome in patients with SAH suffering from TCM. Serial measurements of CFI and ELWI by transpulmonary thermodilution may provide an easy bedside method of detecting early changes of the cardiopulmonary function in directing proper post-SAH treatment.
    Preview · Article · Aug 2014 · Critical care (London, England)
  • Takeshi Okada · Taizen Nakase · Masahiro Sasaki · Tatsuya Ishikawa
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    ABSTRACT: Background: It is controversial whether taking antiplatelet agents (APs) or anticoagulant agents (ACs) could influence clinical outcome after intracerebral hemorrhage (ICH). Methods: We retrospectively investigated 557 ICH patients between September 2008 and August 2013. We reviewed patients' characteristics, hematoma volume, deterioration (hematoma expansion, surgical hematoma evacuation, or death), and clinical outcome in modified Rankin Scale. Results: A total of 397 were classified as neither AP nor AC ("Nothing"), 81 as single AP (44 as aspirin [ASA], 22 as clopidogrel or ticlopidine [CLP/TIC], 7 as cilostazol, 8 as dual antiplatelet therapy), 43 as single AC (40 as warfarin, 2 as rivaroxaban, 1 as dabigatran), and 36 as both AP and AC (AP + AC). The clinical outcome was worse in APs than in "Nothing" (P = .021). Among APs, CLP/TIC showed poorer clinical outcome than ASA (P = .020). Deterioration was observed more frequently in AC than in "Nothing" (P < .001) and the clinical outcome was also worse in AC than in "Nothing" (P < .001). AP + AC use resulted in deterioration more frequently than "Nothing" (P < .001) and in poorer outcome than in "Nothing" (P < .001). Conclusions: The use of antithrombotic agents could be associated with the deterioration after admission and the poor clinical outcome. CLP/TIC use may affect the poor outcome compared with ASA use.
    No preview · Article · Jun 2014 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association
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    Jun Tanabe · Tatsuya Ishikawa · Junta Moroi · Akifumi Suzuki
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    ABSTRACT: The study aims were to clarify safe duration for temporary vessel occlusion of the internal carotid artery (ICA) during aneurysm surgery as exactly as possible. We examined safe time duration (STD), where brain tissue exposed to ischemia will never fall into even the ischemic penumbra using intraoperative motor-evoked potential (MEP). In 45 patients, temporary occlusion of the ICA was performed with MEP. We measured STD as the duration of temporary vessel occlusion during which MEP changes did not occur. To estimate average STD, we calculated the 95% confidence interval for the population mean from sample data for STD in patients with MEP changes and in patients without changes. In the proximal-control group, 4 of 38 patients (10.5%) developed intraoperative MEP changes. In 4 patients, the time to MEP change (i.e. STD) was 6.0 ± 2.5 min. STD was 3.8 ± 1.6 min in the 34 patients without changes. The average STD was 4.0 ± 0.6 min. In the trap group (proximal and distal flow control), five of seven patients (60.0%) experienced intraoperative MEP changes (STD, 2.3 ± 1.0 min). All patients in the trap group who developed MEP changes showed involvement of the anterior choroidal artery (AchA) in the trapped segment. Average STD was 2.3 ± 1.1 min when trapping involving the AchA. Although the study is preliminary based on the limited number of the patients, the 95% upper confidence limit for average STD was 4.6 min when the ICA was occluded proximal to the aneurysm, 3.4 min when the ICA was trapped involving the AchA.
    Full-text · Article · Apr 2014 · Surgical Neurology International
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    ABSTRACT: Recent clinical data suggest that postoperative hemodynamic profile and fluid management may differ in aneurysmal subarachnoid hemorrhage patients depending on the treatment option: surgical clipping or endovascular coiling. Our aim was to determine the differences in hemodynamic parameters between the 2 modalities using an advanced transpulmonary thermodilution technique. We studied 73 consecutive aneurysmal subarachnoid hemorrhage patients treated with either clipping or coiling. Transpulmonary thermodilution was established for monitoring cardiac index, global end-diastolic volume index (GEDI), and extravascular lung water index (ELWI). Blood biochemical markers were sampled in parallel. Hypovolemia (GEDI: 656±72 vs. 713±40 mL/m; P=0.0001) and elevated plasma brain natriuretic peptide (114.0±56.7 vs. 68.6±47.4 pg/mL; P=0.0004) were evident on initial measurements in the clipping group. The number of fluid challenges until normalization of GEDI and ROC-based prediction of the responders (GEDI≥10%) during vasospasm risk period (day 4 to 14 of ictus) were less with coiling than with clipping (P<0.05). Therapy-related pulmonary edema was detected only in the clipping group (8%, n=3). Although length of intensive care unit stay was shorter in the coiling group (P=0.016), incidences of delayed ischemia (13% vs. 11%; P=0.50) and poor functional outcome on modified Rankin Scale score 4 to 6 at 1 month (37% vs. 46%; P=0.30) were not statistically different. Surgical clipping is associated with higher cardiac output and hypovolemia in the early postoperative stage and poorer preload responsiveness to volume therapy during the vasospasm risk period compared with endovascular coiling.
    No preview · Article · Apr 2014 · Journal of neurosurgical anesthesiology
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    ABSTRACT: Strategic cervical internal carotid occlusion is employed either temporarily or permanently in various neurosurgical procedures. The aim of the present study was to assess changes in cortical arterial pressure during cervical internal carotid cross-clamping before and after the placement of radial artery (RA) graft bypass in the treatment of complex carotid artery aneurysms. Perfusion pressure of the middle cerebral artery (MCA) was assessed in 22 patients with complex carotid aneurysm treated with RA graft bypass. Regional cerebral blood flow was assessed postoperatively using single-photon computed tomography. Mean cortical blood pressure (mcBP) was found to be 48.2 ± 24.2 and 97.0 ± 24.0 % of baseline after clamping the cervical internal carotid artery and opening the RA graft bypass, respectively. Cerebral perfusion pressure estimated by the mcBP failed to sustain a critical limit of greater than 70 mmHg under craniotomy in 16 out of 20 (80 %) patients. There was an inverse correlation in mcBP between the baseline and after the placement of the RA graft bypass (r = 0.66, P < 0.005). Postoperative regional cerebral blood flow in the MCA territory on the ipsilateral side of the aneurysm was 97 ± 7 % of that of the contralateral side after internal carotid artery (ICA) ligation combined with RA graft bypass. Substantial pressure reductions in cerebral cortical arteries were observed during the cervical internal carotid cross-clamping. Perfusion pressure in peripheral cortical arteries after the placement of the RA graft bypass was comparable to the state before ICA clamping.
    No preview · Article · Apr 2014 · Neurosurgical Review
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    ABSTRACT: The results of previous studies suggest that early goal-directed fluid therapy (EGDT) reduces delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage, but the effects of EGDT on clinical outcomes are still unclear. This study aimed to determine whether EGDT improves outcomes compared with standard less-invasive hemodynamic therapy. This study included 160 patients treated within 24 hours after subarachnoid hemorrhage, randomized to receive either (1) EGDT guided by preload volume and cardiac output monitored by transpulmonary thermodilution (treatment group) or (2) standard therapy guided by fluid balance or central venous pressure, assisted by uncalibrated less-invasive cardiac output monitoring during hyperdynamic therapy in patients with clinical or radiological indications of DCI (control group). DCI determined by clinical or radiological findings and functional outcome determined by the modified Rankin Scale score at 3 months were compared between groups. For all clinical grades combined, there were no significant differences in the rates of DCI (33% versus 42%; P=0.33) or modified Rankin Scale score of 0 to 3 at 3 months (67% versus 57%; P=0.22) between the 2 groups. For patients with poor clinical grade, those who received EGDT had a significantly lower rate of DCI (5% versus 14%; P=0.036), modified Rankin Scale score of 0 to 3 at 3 months (52% versus 36%; P=0.026), and shorter length of intensive care unit stay (14 versus 17 days; P=0.043) than those who received standard therapy. EGDT is beneficial for reducing DCI and improving postoperative functional outcome in patients with poor clinical grade. http://www.clinicaltrials.gov. Unique identifier: UMIN000007509.
    No preview · Article · Apr 2014 · Stroke
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    ABSTRACT: Object: Although combined direct and indirect anastomosis in patients with moyamoya disease immediately increases cerebral blood flow, the surgical procedure is more complex. Data pertinent to the postoperative complications associated with combined bypass are relatively scarce compared with those associated with indirect bypass. This study investigated the incidence and characteristics of postoperative stroke in combined bypass and compared them with those determined from a literature review to obtain data from a large population. Methods: A total of 358 revascularization procedures in 236 patients were retrospectively assessed by reviewing clinical charts and radiological data. PubMed was searched for published studies on surgical treatment to determine the incidence of postoperative complications in a larger population. Results: Seventeen instances of postoperative stroke were observed in 16 patients (4.7% per surgery, 95% CI 2.8%-7.5%). Postoperative stroke was more frequent (7.9% per surgery) in adults than in pediatric patients (1.7% per surgery, OR 4.07, 95% CI 1.12-14.7; p < 0.05). Acute progression of stenoocclusive changes were identified in the major cerebral arteries (anterior cerebral artery, n = 3; middle cerebral artery, n = 1; posterior cerebral artery, n = 2). The postoperative stroke rate was comparable with that (5.4%) determined from a literature search that included studies reporting more than 2000 direct/combined procedures. No differences in the stroke rates between the direct/combined and indirect procedures were found. In the literature review, direct/combined bypass was more often associated with excellent revascularization (angiographic opacification greater than two-thirds) than indirect bypass (p < 0.05). Conclusions: This experience of 358 consecutive procedures is one of the largest series for which the postoperative stoke rate for direct/combined bypass performed with a unified strategy has been reported. A systematic review confirmed that the postoperative stroke rate for the direct/combined procedure was comparable to that for the indirect procedure.
    Full-text · Article · Mar 2014 · Journal of Neurosurgery
  • Kentaro Hikichi · Tatsuya Ishikawa · Junta Moroi · Hajime Miyata
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    ABSTRACT: Distal anterior inferior cerebellar artery(AICA)aneurysms are rare, so its pathogenesis and treatment remain controversial. Here, we report the unique pathogenesis of a ruptured aneurysm in this area that was based on anomalous components as well as partial dissection of the arterial wall. A 61-year-old woman presented to our hospital with sudden headache and nausea. On admission, neurological examination revealed slight consciousness disturbance. Computed tomography(CT)of the head showed a clotted subarachnoid hemorrhage(SAH)that was dominant in the right cerebellopontine and prepontine cistern. Three-dimensional CT angiography detected an irregular fusiform aneurysm 4.5×3.2mm in size in the distal portion of the AICA. The patient underwent trapping without distal vascular reconstruction by the lateral suboccipital approach. After surgery, she experienced right hearing disturbance and ipsilateral facial palsy that were considered to be caused by vasogenic edema at the cerebellar peduncle that resulted from the initial SAH damage. Pathology revealed an aneurysmal wall with anomalous components and arterial dissection in the arterial wall. To our knowledge, only one article has reported the histological findings of a distal AICA aneurysm. Based on the pathology of this case, these findings may suggest a useful treatment strategy for this rare aneurysm.
    No preview · Article · Jan 2014 · No shinkei geka. Neurological surgery
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    ABSTRACT: We introduce our program for training microsurgical operators in aneurysm clipping. We also discuss risk management of senior operators in surgical training courses for aneurysm clipping. In this program, the neurosurgical resident is assigned to perform clipping for 20 cases of cerebral aneurysm with relatively low surgical risk. The resident must make a detailed preoperative report on head position, skin incision, craniotomy, dissection of fissure and aneurysm, clip type and assumed risks associated with each procedure. A senior operator then examines and approves the report. Intraoperatively, the resident is required by the senior operator to maintain a bloodless operative field and operate under high magnification to confirm safety. The senior operator confirms in a timely manner that the resident is operating according to the operation plan and also is prepared to deal with unexpected situations such as premature rupture of the aneurysm. The senior operator evaluates each technique of the resident, and takes over temporarily when the resident performs a procedure associated with an increased risk of complications. Between 2007 and 2012, this program had 10 resident participants, five of whom completed it. In this program, temporary deficits were observed in four cases (4.2%); however, no permanent deficits were noted. This program for aneurysm clipping allows safe, effective training of microsurgical operators.
    Preview · Article · Jan 2014 · Surgery for Cerebral Stroke

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  • No preview · Article · Aug 2013 · No shinkei geka. Neurological surgery
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    ABSTRACT: Background and importance: The falcine sinus is an embryonic vessel that connects the superior and inferior sagittal sinuses and mostly closes after birth. Although some cases of persistent falcine sinus have been reported, dural arteriovenous fistula (dAVF) associated with the falcine sinus has not previously been reported. Clinical presentation: A 60-year-old man presented with asymptomatic dAVFs on digital subtraction angiography. The dAVFs were fed mainly by the cortical branch of the left anterior cerebral artery and drained into the falcine sinus. Intraoperatively, all veins draining in a retrograde manner into cortical veins were obstructed. However, cortical venous reflux did not disappear before removal of the falx cerebri, including the falcine sinus and inferior sagittal sinus. In this case, we considered falcine sinus dAVF as equivalent to olfactory groove dAVF because the medial olfactory artery, in its role as a common feeding artery in olfactory groove dAVF, is a rudiment of the anterior cerebral artery as the main feeding artery in this case. Intraoperative findings and the surgical specimen revealed a small vessel network in the falx cerebri communicating with the falcine and inferior sagittal sinuses, which was considered to represent a falcine venous plexus, not a vessel anomaly. Conclusion: Extensive removal of the falx cerebri including the falcine sinus or complete endovascular obliteration of the whole falcine sinus as early as possible represents an important strategy in the surgical treatment of falcine sinus dAVF.
    No preview · Article · Apr 2013 · Neurosurgery
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    ABSTRACT: We retrospectively investigated surgical immediate and long-term overall results after clipping of the unruptured aneurysms. Between 1991 and 2008, 166 patients underwent neck clipping of unruptured saccular aneurysms at our institute. Patients were subsequently followed to clarify the occurrence of subarachnoid hemorrhage (SAH), and stroke other than SAH, aneurysm recurrence, cerebrovascular death, all-cause death, and risk factors. Surgical complication was noted in 14 patients (8.4 %) and surgical morbidity in two patients (1.2 %). Of 164 patients except for these two patients who suffered surgical morbidity, we could obtain more than 3 years follow-up information for 144 patients (87.8 %). There were 49 men and 95 women. The mean age was 58.5 years, and mean follow-up period was 7.9 years. Eight cases had died during follow-up (hepatic insufficiency in one, renal insufficiency in one, suicide in one, intracerebral hemorrhage (ICH) in two, SAH in one, and pneumonia after stroke in two). Therefore, the cause of death was stroke and late effects of stroke. Twelve symptomatic cerebrovascular events (cerebral infarction in seven, ICH in four, and SAH in one) occurred in ten patients. Consequently, annual risk of SAH after clipping of unruptured aneurysms was 0.085 %. Besides, annual risk of stroke in those patients was 1.06 %, and this incidence was higher than that in the general population. Although this study confirmed the good surgical result, annual risk of stroke after clipping of unruptured aneurysms was much higher than that in the general population. The long-term periodic examination to detect recurrent aneurysms and appropriate management to prevent stroke should be performed for patients with surgically treated unruptured aneurysm.
    No preview · Article · Apr 2013 · Neurosurgical Review

Publication Stats

1k Citations
187.92 Total Impact Points


  • 1992-2015
    • Research Institute for Brain and Blood Vessels-Akita
      Akita, Akita, Japan
    • Japan Red Cross Fukuoka Hospital
      Hukuoka, Fukuoka, Japan
  • 2012
    • University of Toyama
      • Department of Neurosurgery
      Тояма, Toyama, Japan
  • 1999-2007
    • Hokkaido University Hospital
      • Division of Neurosurgery
      Sapporo, Hokkaidō, Japan
  • 1990-2006
    • Hokkaido University
      • Department of Neurosurgery
      Sapporo, Hokkaido, Japan
  • 2003
    • Sapporo Medical University
      • Division of Neurosurgery
      Sapporo, Hokkaidō, Japan