Naoki Kitagawa

Nagasaki University Hospital, Nagasaki, Nagasaki, Japan

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Publications (84)104.97 Total impact

  • Neurologia medico-chirurgica 01/2012; 52(9):686-690. · 0.49 Impact Factor
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    ABSTRACT: Abstract We report a case of a dural arteriovenous fistula (DAVF) at the tentorium cerebelli, which presented progressive myelopathy. A 68-year-old man with neurological deterioration of the cervical myelopathy visited our hospital. T<sub>2</sub> weighted magnetic resonance (MR) imaging showed high signal area and edema from the medulla to the upper thoracic spinal cord with flow voids on the dorsal surface of the cord. Angiography showed right tentorial DAVF, which was supplied by the right meningohypophyseal trunk, the middle meningeal artery, the accessory meningeal artery, and was drained into the posterior spinal veins. The patient underwent right retrosigmoid suboccipital craniotomy, then disruption of the fistula was performed by using micro Doppler sonography following endovascular obliteration of the main feeders. Postoperative angiography showed complete obliteration of the fistula. His daily functioning gradually improved up to 6 months after the surgery. Tentorial DAVFs with clinical manifestation of myelopathy are rare. Considering its aggressive nature, early surgical treatment could be necessary. (Received: November 17, 2010, Accepted: December 18, 2010).
    Brain and nerve = Shinkei kenkyū no shinpo 06/2011; 63(6):611-5.
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    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
  • Acta Neurochirurgica 12/2010; 153(5):1143-4. · 1.55 Impact Factor
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    ABSTRACT: The Rubinstein-Taybi syndrome (RTS) is defined congenital anomalies and is characterized by postnatal growth deficiency, microcephaly, specific facial characteristics, broad thumbs and big toes, and mental retardation. RTS displays an autosomal dominant inheritance pattern and is typically caused by cAMP response element-binding (CREB)-binding protein deficiency. Various complications such as eye anomalies and a variety of congenital heart defects are reported in such cases. We treated an RTS patient who had a dissecting aneurysm of the anterior cerebral artery. The patient was a 44-year-old man who was brought to our hospital because of sudden left hemiplegia. Magnetic resonance images showed a cerebral infarction caused by anterior cerebral artery dissection. Coil embolization was performed on enlargement of the dissecting aneurysm, and the procedure was successful. Conclusion: RTS may be accompanied by cerebrovascular disease.
    Brain and nerve = Shinkei kenkyū no shinpo 10/2010; 62(10):1083-8.
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    ABSTRACT: Although aneurysm formation accompanying parenchymal hemorrhage is one of devastating complications in the central nerves system (CNS), imaging studies of the brain are not routinely warranted in patients with infective endocarditis (IE). To assess the clinical importance for detecting silent lesions in the central nervous system, we investigated hypointense signal spots detected on the brain T2*-weighted MR imaging in patients with IE. Eleven patients with IE were retrospectively reviewed. Seven patients (63.6%) showed hypointense signal spots on T2*-weighted MR images. The number of hypointense signal spots increased within only a few weeks in five patients. The brain T2*-weighted MR imaging in patients with IE may have a potential role to detect CNS lesions with clinical significance of potentially high risk of intracranial hemorrhage. T2*-weighted hypointense signal spots may be specific to brain involvement, and be quite useful in monitoring CNS lesions associated with IE, even if they are asymptomatic.
    Clinical neurology and neurosurgery 04/2010; 112(5):436-40. · 1.30 Impact Factor
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    ABSTRACT: A 32-year-old man presented with malignant craniopharyngioma associated with moyamoya syndrome manifesting as right visual disturbance. Magnetic resonance (MR) imaging revealed a parasellar mass lesion diagnosed as adamantinomatous craniopharyngioma. He underwent three surgical procedures and repeated courses of radiotherapy, and was able to resume his daily life. MR imaging demonstrated tumor regrowth and bilateral occlusions of the internal carotid arteries (ICAs) with basal moyamoya phenomenon, which might have been induced by irradiation and/or tumor compression, 10 years after the initial manifestations. Sufficient debulking was safely achieved via the transsphenoidal route and histological examination revealed squamous cell carcinoma, indicating malignant transformation of craniopharyngioma. The tumor relapsed after only one month, so transsphenoidal tumor debulking was tried again. However, the postoperative course was unfavorable because of intraoperative bleeding from the right ICA. Malignant transformation of craniopharyngioma may be included in moyamoya syndrome. The treatment strategy should be carefully considered in such a complicated situation.
    Neurologia medico-chirurgica 01/2010; 50(7):599-603. · 0.49 Impact Factor
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    ABSTRACT: We report a case of dural arteriovenous fistulas (DAVFs) at the craniocervical junction, which are supplied by the radicular arteries from bilateral vertebral arteries separately, and drainaged into intracranial sinuses. A 58-year-old man with intermittent neck pain visited our hospital. T2-weighted magnetic resonance (MR) imaging showed flow voids on the dorsal surface of the medulla and upper cervical cord without any signal changes suggesting ischemia. Postcontrast MR digital subtraction angiography (MRDSA) showed early venous filling at the craniocervical junction. Angiography demonstrated bilateral fistulas near each vertebral artery penetration point of the dura matter, which were drainaged into the superior and inferior petrosal sinuses. The patient underwent suboccipital craniotomy and laminectomy of the C1, then disruption of the bilateral fistulas was performed by using micro Doppler sonography after intradural exposure of the shunt points. His symptom subsided post operatively, and MRDSA showed no abnormal vessels. Angiography performed 1 week after surgery confirmed complete obliteration of the fistulas. DAVFs at the craniocervical junction fed by bilateral vertebral arteries is extremely rare. Even in such a case, direct interruption of the fistulas using micro Doppler sonography is the most effective treatment. In addition. MRDSA could be useful for screening and perioperative studies.
    No shinkei geka. Neurological surgery 12/2009; 37(12):1229-33. · 0.13 Impact Factor
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    ABSTRACT: NAGASAKI IS LOCATED on the western edge of Japan, closer to the Asian continent. Because of this geographical proximity, Nagasaki became a gateway for the introduction of continental culture and civilization to Japan. After the port of Nagasaki was opened for trade with the Portuguese in 1571, Nagasaki had a central role in cultural exchange with the West and China until the latter half of the 19th century. As a result of the political situation, students came to Nagasaki from all over Japan to obtain information on Western science, especially in medicine, turning Nagasaki into a hub for modern academic studies. The first medical facility in Japan educating doctors in the Western style was founded in Nagasaki in 1857. Despite the tragedy of World War II, the medical school arose again. More than 10 000 physicians have completed their studies at the medical school since its founding. The Department of Neurosurgery at Nagasaki University had its origins within the Second Department of Surgery and became an independent department in 1973. The post of professor was assumed by Kazuo Mori and succeeded in 1991 by Shobu Shibata and in 2003 by Izumi Nagata, who holds the post at the time of this writing. Neurosurgery is dynamic and constantly changing at Nagasaki University with work in progress on technological, diagnostic, and surgical innovations that permit the treatment of highly complex cases. In 2007, the 150th anniversary of the founding of Nagasaki University School of Medicine was celebrated with a number of commemorative events.
    Neurosurgery 10/2009; 65(3):595-9; discussion 599-600. · 2.53 Impact Factor
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    ABSTRACT: The authors report a case of vertebrobasilar insufficiency caused by vertebral artery (VA) compression due to a herniated cervical disc, which was surgically treated with the aid of intraoperative angiography. This 78-year-old man visited the hospital because of syncope following head rotation. Admission CT scans revealed a calcified mass adjacent to the right lateral process of the C-4 spine. Cervical angiography demonstrated an obstruction of the right VA at this region on rotation of the head to the right. The operation revealed a cervical disc protruding toward the right VA. The disc was surgically removed, and then the decompression of the right VA was confirmed on intraoperative angiography studies. A histopathological examination showed fibrohyaline cartilage, indicating an ossified intervertebral disc. The postoperative course was uneventful, and he has not experienced any syncope since treatment. A cervical disc herniation could be a cause of vertebrobasilar insufficiency by exerting positional compression of the VA. Intraoperative angiography could be quite useful to confirm this condition during decompression surgery for a cervical VA.
    Journal of Neurosurgery Spine 09/2009; 11(3):326-9. · 1.98 Impact Factor
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    ABSTRACT: We report a rare case of a vertebral arteriovenous fistula presenting with subarachnoid hemorrhage (SAH). A 60-year-old man was admitted to our hospital with a sudden onset of headache and neck pain. A neurological examination showed no abnormalities. Computed tomography scans revealed SAH in the pontine cistern and cistern magna. Although the first cerebral angiogram failed to depict the cause of bleeding, the second angiogram on day 15 demonstrated an arteriovenous fistula in the left vertebral artery at C4-5, which was draining into the internal vertebral venous plexus and forming a venous pouch. The fistula was successfully obliterated by transarterial embolization using detachable platinum coils. In patients with SAH with predominance in the posterior fossa, attention should also be paid to spinal vascular lesions. Three-dimensional digital angiography and digital subtraction angiography allow a reliable visualization of such lesions.
    No shinkei geka. Neurological surgery 08/2009; 37(7):667-71. · 0.13 Impact Factor
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    ABSTRACT: Preoperative embolization of cranio-cervical tumors is commonly used to reduce intraoperative blood loss. Gelpart is a new collagen embolic agent. Because of its porous structure, it is deformable and tends not to aggregate. The purpose of this study is to evaluate the efficacy of the Gelpart embolization for cranio-cervical tumors. The shape and size of Gelpart was observed under high-resolution microscope. Eight cases of cranio-cervical tumors were treated with Gelpart embolization. A microcatheter was introduced to the feeding artery and Gelpart, mixed with contrast medium, was injected manually. The effect of the Gelpart embolization was evaluated with MRI and operative specimen. The shape of Gelpart was not spherical, but the surface became smooth after mixture with contrast medium. Gelpart injection proceeded smoothly and it resulted in excellent angiographical devascularization. No complications occurred related to the Gelpart embolization. At surgery, the tumor was soft and was removed easily. Intraoperative blood loss was relatively less than that using often method. Gelpart embolized peritumoral small arteries and induced tumor necrosis. We reported our preliminary experience of Gelpart for preoperative embolization of cranio-cervical tumors. Gelpart was effective for tumor embolization.
    No shinkei geka. Neurological surgery 08/2009; 37(7):651-6. · 0.13 Impact Factor
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    ABSTRACT: Endovascular embolization for a cerebrovascular lesion has been increasingly performed. We experienced disruption of the microcatheter during a cerebral aneurysm embolization and removed the catheter fragment with retrieval forceps. A 56-year-old woman was brought to our hospital because of consciousness disturbance. Radiological examination revealed subarachnoid hemorrhage due to the rupture of an anterior communicating artery aneurysm. Despite endovascular embolization and neck clipping of the aneurysm, the aneurysm recurred. Then, endovascular embolization was performed. During introduction of the microcatheter to the cerebral aneurysm, the microcatheter disrupted spontaneously at the center of the catheter and the distal end of the catheter migrated into the right middle cerebral artery. The proximal part of the catheter fragment was located at the common carotid artery bifurcation. An attempt to retrieve the catheter by snare failed. Then, retrieval forceps were navigated. The catheter fragment was caught at the common carotid artery bifurcation and successfully removed. Subsequently, the cerebral aneurysm was embolized with detachable coils. No additional complication occured. Microscopical observation of the catheter end revealed relatively sharp disruption and extension of the stainless steel blade. Microcatheter disruption and migration is a rare but significant complication of endovascular embolization. Percutaneous technique with retrieval forceps for the extraction of intravascular foreign objects was useful.
    No shinkei geka. Neurological surgery 06/2009; 37(5):485-90. · 0.13 Impact Factor
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    ABSTRACT: Carotid artery stenting in patients with high surgical risk is considered as an effective alternative to carotid endarterectomy. Because the occurrence of distal embolization with CAS is still a major concern, an embolus protection device is usually used during the procedure. We developed a technique for observation of embolus protection filter and evaluated the debris or thrombus microscopically, and the pathologic findings were compared with preoperative imaging studies. After completing CAS, the filter membrane was stained with HE solution and removed from filter strut. Mounting onto a glass slide, the filter was evaluated under a microscope. Plaque debris and appearance of filter membrane were evaluated, and the covered area was measured. The pathologic findings were compared with preoperative imaging studies. Microscopic observation of the slide revealed atheromatous debris as well as thrombotic material to the filter membrane. Hematoxylin-eosin stain facilitates the characterization of the debris composition, namely, thrombotic debris, calcified debris, organized debris, fibrous debris, and lipid-rich debris. The subtypes of debris were consistent with preoperative imaging studies. Thus, in cases of intraprocedural flow impairment, more than 50% of the filter area was covered with debris or thrombotic material. Carotid plaque debris captured during carotid stenting with protection filter can be visualized with HE stain on the glass side. This simple method allows us to better understand the plaque debris and appearance of embolus protection filter.
    Surgical Neurology 04/2009; 72(5):532-7; discussion 537. · 1.67 Impact Factor
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    ABSTRACT: A 51-year-old man underwent surgery for ossification of the ligamentum flavum at the T9-T10 levels. Intraoperatively, the dura was opened unintentionally and a subcutaneous suction drain was placed. The patient complained of severe headache and nausea postoperatively. Brain computed tomography obtained 3 days after the surgery demonstrated remote cerebellar hemorrhage and hydrocephalus. Suboccipital decompression, C1 laminectomy, and ventriculostomy were performed and his symptoms subsided 2 months later. Remote cerebellar hemorrhage following spinal surgery is extremely rare, but may occur after any type of spinal surgery resulting in dural tear or intradural manipulation. Early diagnosis is particularly important for the treatment of remote cerebellar hemorrhage following spinal surgery.
    Neurologia medico-chirurgica 04/2009; 49(3):117-9. · 0.49 Impact Factor
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    ABSTRACT: Identifying the precise hemodynamic features, including the fistulous point, is essential for treatments of dural arteriovenous fistulas (DAVFs). This study illustrates the efficacy of DynaCT digital angiograms obtained from a 3D C-arm CT to directly visualize the location of the fistulous points in DAVFs. This retrospective study observed 14 consecutive patients with DAVFs, which included 7 cavernous sinuses, 4 transverse-sigmoid sinuses, 2 convexity-superior sagittal sinuses, and 1 tentorial sinus. In the assessment of the practical applicability for the diagnosis of DAVFs, images obtained from 2D digital subtraction angiography (DSA) and DynaCT were comparatively evaluated. In all patients, DynaCT digital angiography could clearly demonstrate the feeding arteries, the fistulous points, and the draining veins. Significant anatomic landmarks for the fistulous points with relationships to osseous structures were also provided. Compared with 2D DSA, DynaCT digital angiograms demonstrated 12 additional findings in 8 patients (57%), including the detection of the fistulous points (n = 7), the feeders (n = 1), the retrograde leptomeningeal drainage (n = 1), the draining veins (n = 1), and the venous anomaly (n = 2). In comparison with 2D DSA, DynaCT may provide more detailed information to evaluate DAVFs. DynaCT digital angiograms have a high contrast and isotropic spatial resolution, allowing a reliable visualization of small vessels and fine osseous structures. Such detailed information, especially for the location of the fistulous points, could be very useful for either the endovascular or the surgical treatments of DAVFs.
    American Journal of Neuroradiology 03/2009; 30(3):487-91. · 3.17 Impact Factor
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    ABSTRACT: Recently, carotid artery stenting (CAS) has gained a lot of interest as a potentially valuable minimally invasive alternative to carotid endarterectomy. Since the occurrence of distal embolization as a result of CAS is still a major concern, an embolus protection device is usually employed during the procedure. Here, we report a case of internal carotid artery (ICA) stenosis complicated with shower embolism during CAS with an embolus protection filter. A 77-year-old man who had a history of coronary bypass surgery was referred to our department for the treatment of carotid artery stenosis. Angiography showed high-grade stenosis at the origin of the right ICA. Plaque magnetic resonance imaging (MRI) showed a hyperintense lesion at the right ICA stenosis, indicating the presence of a lipid-rich plaque. Since cerebral circulation was impaired significantly in the right cerebral hemisphere, CAS was performed for the right ICA stenosis, with an embolus protection filter. A self-expandable stent was placed in the right ICA following predilation. During stenting, plaque protrusion was identified and treated with balloon angioplasty. The patient developed right hemiparesis postoperatively. MRI showed multiple infarction in the right cerebral hemisphere. The symptom resoeved 7 days later. A potential disadvantage of the filter device is incomplete protection from emboli or failure to protect against soluble mediators. An embolus protection filter is not suitable for capturing the debris from lipid-rich plaques.
    Brain and nerve = Shinkei kenkyū no shinpo 02/2009; 61(1):83-7.
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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: The SAPPHIRE trial has established carotid artery stenting (CAS) in high-surgical-risk patients as an effective alternative to carotid endarterectomy. Since the occurrence of distal embolization with CAS is still a major concern, an embolus protection device is usually employed during the procedure. Although the advantage of the filter device is continuation of blood flow during the procedure, blood flow is occasionally reduced due to plaque debris or thrombus. Here, we report a case of internal carotid artery (ICA) stenosis complicated with filter obstruction during CAS. A 74-year-old woman who had a history of coronary artery stenting was referred to our hospital for the treatment of carotid artery stenosis. Angiography showed occlusion of the right ICA and high-grade stenosis at the origin of the left ICA. Since cerebral circulation was impaired significantly in the left cerebral hemisphere, CAS was performed for the left ICA stenosis using an embolus protection filter. Self-expandable stent was placed into the left ICA following predilation. The patient developed consciousness disturbance and right hemiparesis during postdilation. Angiography showed impairment of blood flow, indicating filter obstruction. The debris containing blood stasis was removed with an aspiration catheter and the flow was restarted retrieving the filter. The symptom recovered within one hour. Appropriate antithrombotic therapy and preparation for filter obstruction such as the provision of an aspiration catheter are important in CAS using an embolus protection filter.
    No shinkei geka. Neurological surgery 01/2009; 36(12):1133-8. · 0.13 Impact Factor
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    ABSTRACT: We herein report the first case of progressive perianeurysmal edema preceding the rupture of a small saccular aneurysm, without any intervention or intraluminal thrombosis. A 71-year-old woman was incidentally noted to have a cerebral aneurysm (5mm in diameter) at the lower basilar artery. Twelve months later, magnetic resonance (MR) imaging showed a T2-elongated area around a dome of the aneurysm buried in the brain stem, suggesting perianeurysmal edema formation. Interestingly, the edema progressed with the formation of a bleb, in addition to an increase in size of the aneurysm over the following 3-year period. The aneurysm eventually ruptured as a brain stem hemorrhage without any subarachnoid clots 3 days after the final check-up with MR imaging, by which a significant increase of edema formation with an increase in size of the aneurysm and a marked expansion of the bleb was observed. These findings raise the possibility that bleb formation and an enlargement of a small cerebral aneurysm might also be associated with perianeurysmal edema and a subsequent aneurysmal rupture. In addition to the pulsatile flow and/or compression from the expanded aneurysm, local inflammation in the aneurysm wall may play an important role in such edema formation.
    Clinical neurology and neurosurgery 01/2009; 111(2):216-9. · 1.30 Impact Factor

Publication Stats

443 Citations
104.97 Total Impact Points

Institutions

  • 1994–2011
    • Nagasaki University Hospital
      Nagasaki, Nagasaki, Japan
  • 2007–2009
    • University Hospital Medical Information Network
      • Department of Neurosurgery
      Tokyo, Tokyo-to, Japan
  • 2001–2007
    • Nagasaki University
      • • Department of Neurobiology and Behavior
      • • School of Medicine
      Nagasaki, Nagasaki, Japan
    • Sasebo City General Hospital
      Nagasaki, Nagasaki, Japan