Junichi Kawakubo

Nagasaki University Hospital, Nagasaki, Nagasaki, Japan

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Publications (9)8.27 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the relationship between preoperative analysis of platelet aggregability and perioperative complications, we analyzed 42 patients who underwent carotid endarterectomy or carotid artery stenting. The effect of antiplatelet drugs was tested by whole blood aggregometry. ADP (adenosine-diphosphoric acid) and collagen were used as agonists. According to platelet aggregability, patients were classified into 4 groups (class A: highly inhibited, class B: moderately inhibited, class C: normally inhibited, class D: non-inhibited). Seven (32%) of 22 patients were stratified as clopidogrel nonresponders, whereas four (10%) of 40 patients were aspirin nonresponders. Hemorrhagic complications were registered in four patients. All of them were classified as class A. Ischemic complications occurred in two patients, one was classified as class C, the other was class D. Preoperative analysis of platelet aggregability could be useful to reduce the risk of perioperative complications after carotid surgery.
    No shinkei geka. Neurological surgery 05/2011; 39(5):459-63. · 0.13 Impact Factor
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    ABSTRACT: As endovascular treatment becomes more prevalent, aneurysm recurrence from neck remnants, recanalization, incomplete obliteration and bleeding remain major concerns. In the current analysis, we attempted to identify factors related to disease progression and clinical outcome in patients treated with coil embolization. This study included 58 patients who underwent endovascular coil embolization for treatment of intracranial aneurysm. The result of embolization was evaluated with three-dimensional time-of-flight magnetic resonance angiography (TOF MRA) and classified as a complete occlusion, a residual neck (minor, central and marginal types), a residual dome (central and marginal types). Patients were followed up clinically and radiologically. Statistical analyses were performed to establish factors that influenced the occurrence of adverse events such as recurrence of aneurysm. Overall, the complete occlusion rate was 18.8%, the occurrence of a residual neck was 67.2%, and the residual dome rate was 14.1%. The mean clinical follow-up was 31.2 months. Recurrences were found in 18 aneurysms, and major recurrences were retreated with coiling or surgery. The post-treatment study revealed that the marginal-type aneurysm filling has a significant impact on outcome. Thus, perianeurysmal edema was correlated with recurrence of the aneurysm. Three-dimensional TOF MRA was a sensitive tool for visualizing residual filling of embolized aneurysm and is useful for long-term follow-up of patients.
    Neurological Research 01/2009; 31(7):674-80. · 1.18 Impact Factor
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    ABSTRACT: Hemorrhagic transformation is a major complication associated with tissue plasminogen activator (tPA) therapy for ischemic stroke. We studied the effect of tPA on the blood-brain barrier (BBB) function with our in vitro monolayer model generated using rat brain microvascular endothelial cells subjected either to normoxia or to hypoxia/reoxygenation (H/R) with or without the administration of tPA. The barrier function was evaluated by the transendothelial electrical resistance (TEER), the permeability of sodium fluorescein and Evans' blue-albumin (EBA), and the uptake of lucifer yellow (LY). The permeability of sodium fluorescein and EBA was used as an index of paracellular and transcellular transport, respectively. The administration of tPA increased the permeability of EBA and the uptake of LY under normoxia. It enhanced the increase in the permeability of both sodium fluorescein and EBA, the decrease in the TEER, and the disruption in the expression of ZO-1 under H/R conditions. Administration of tPA could cause an increase in the transcellular transport under normoxia, and both the transcellular and paracellular transport of the BBB under H/R conditions in vitro. Even in humans, tPA may lead to an opening of the BBB under non-ischemic conditions and have an additional effect on the ischemia-induced BBB disruption.
    Cellular and Molecular Neurobiology 12/2008; 28(8):1139-46. · 2.29 Impact Factor
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    ABSTRACT: We present a unique case of a cavernous sinus (CS) dural arteriovenous fistula (DAVF), which recurred at adjacent sinuses following repeated transvenous embolizations (TVEs). A 68-year-old woman presented with progressive left conjunctival chemosis and diplopia. Cerebral angiography revealed a left CS DAVF, which was completely obliterated by TVE via the left inferior petrosal sinus (IPS). Two years later, the DAVF recurred in the left IPS, and again in the left sigmoid sinus (SS) 3 years after the initial treatment in spite of a second TVE. Moreover, the left SS and the left internal jugular vein, which had been previously stenotic, had been occluded. The third TVE resulted in the complete obliteration of the SS DAVF. CS DAVFs may recur at adjacent sinuses even after complete obliteration by TVE. Careful follow-up is necessary to check for the recurrence of DAVFs, especially in cases with venous flow changes, such as sinus occlusion, following endovascular treatment.
    Radiation Medicine 09/2008; 26(7):431-7.
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    ABSTRACT: We described a case of endoluminal stent placement for cervical internal carotid artery stenosis in which access was obtained via the proximal portion of the right radial artery. A 70-year-old man with a history of arteriosclerosis obliterans presented for endoluminal revascularization of a stenosed left internal carotid artery. The transfemoral approach was not possible because of severe atherosclerosis of the bilateral common iliac arteries. An approach was attempted via the right radial artery. After placement of a 6F short sheath in the proximal portion of the right radial artery, the guiding catheter was positioned in the left common carotid artery using the coaxial catheter system. Stenting was successfully performed under distal protection. This novel approach should be considered for endovascular procedures for which access to the carotid artery is limited.
    No shinkei geka. Neurological surgery 04/2008; 36(3):233-7. · 0.13 Impact Factor
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    ABSTRACT: Giant fusiform aneurysms at the basilar trunk tend to have a poor natural history, and the surgical management for these aneurysms remains controversial. For these aneurysms, basilar trunk occlusion may offer a potentially long-lasting cure. However, the strategy for these aneurysms is difficult when the collateral supply from the carotid circulation is poor. The authors herein present a successful case of a thrombosed giant fusiform aneurysm at the basilar trunk with a poor collateral supply using repeated balloon test occlusion (BTO) and a second bypass surgery. A 46-year-old female was admitted to our institute because of progressing double vision. A radiologic examination revealed a thrombosed giant fusiform aneurysm at the upper basilar trunk, and the collateral supply from carotid circulation was poor. We attempted to perform a second bypass surgery before the basilar trunk coil occlusion due to intolerance after the repeated BTO. After confirmation of her tolerance against the third BTO, the aneurysm was successfully trapped using the endovascular technique. Various kind of bypass surgery should be tried for endovascular trapping of giant fusiform basilar trunk aneurysms, and repeated BTO is necessary to confirm the tolerance after bypass surgery especially for the complex aneurysms without a sufficient collateral supply.
    Neurological Research 01/2008; 29(8):842-6. · 1.18 Impact Factor
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    ABSTRACT: Carotid artery stenting has emerged as an acceptable treatment alternative in patient with occlusive carotid bifurcation disease. High-risk surgical candidates have a lower rate of morbidity after carotid artery stenting with distal embolic protection. Among distal protection devices, a Guardwire balloon occlusion is the most frequently employed in Japan. A 79-year-old male who had severe stenosis at the origin of left carotid artery was treated with stenting under Guardwire balloon protection. He was intolerant to carotid artery occlusion and endovascular procedures were performed under intravenous anesthesia or general anesthesia. In addition, he suffered recurrent stenosis seven months after the first procedure and 16 months after second procedure, and underwent repeated intervention. It was considered that the long tortuous lesion was a cause of the recurrent stenosis.
    No shinkei geka. Neurological surgery 01/2007; 34(12):1249-54. · 0.13 Impact Factor
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    ABSTRACT: Basilar artery occlusion usually has a very poor outcome and is associated with a high mortality rate. Local intra-arterial thrombolysis may improve the clinical outcome and reduce mortality in the treatment of acute basilar artery occlusion. We evaluated the possible variables affecting recanalization and clinical outcome in patients with basilar artery occlusions undergoing thrombolytic therapy. We analyzed retrospectively the clinical course and outcome of a series of 26 patients between 1998 and 2001. All patients who were examined within 24 hours after onset of symptoms underwent emergency cerebral angiography and subsequent intra-arterial thrombolysis. Three patients additionally received percutaneous transluminal angioplasty of underlying stenosis at the site of thrombosis. Outcome was good in 9 patients (34.6%) and poor in 17 (65.4%). Recanalization could be achieved in 24 patients (92.3%) and was not affected by age, sex, site of occlusion, etiology, thrombolytic drugs, or time interval. Good outcome was associated with younger age, good initial clinical condition, and no evidence of brain stem infarction. There was no association between the interval (greater or less than 6 hours) from the onset of symptoms until the end of thrombolysis and survival. We confirm that intra-arterial thrombolysis reduces mortality in basilar artery occlusion. Young patients (<75 years) without any infarct in brain stem before the start of treatment seem to be the ideal candidates for thrombolysis. Basilar artery thrombosis could and should be reopened, even late (after 6 hours) after symptom onset.
    Surgical Neurology 11/2003; 60(5):423-9; discussion 429-30. · 1.67 Impact Factor
  • Acta Neurochirurgica 10/2003; 145(9):807-8; discussion 808-9. · 1.55 Impact Factor

Publication Stats

68 Citations
8.27 Total Impact Points

Institutions

  • 2008–2011
    • Nagasaki University Hospital
      Nagasaki, Nagasaki, Japan
    • University Hospital Medical Information Network
      • Department of Neurosurgery
      Tokyo, Tokyo-to, Japan
  • 2007
    • Nagasaki University
      Nagasaki, Nagasaki, Japan