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Dive into the research topics where Hisatsugu Yagura is active.

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Featured researches published by Hisatsugu Yagura.


Neurosurgery | 1993

Aneurysmal rupture during angiography.

Masaki Komiyama; Katsuhiko Tamura; Yasunori Nagata; Yoshihiko Fu; Hisatsugu Yagura; Toshihiro Yasui

The aim of the present study was to analyze the clinical data on rebleeding in cerebral aneurysms during angiography and to evaluate the importance of the time interval between the latest rupture and angiography. Fourteen personal cases and 202 patients reported in the literature are reviewed. Rebleeding during angiography occurred most often (78%) on Day O; 89% bled when angiography was performed within 6 hours of the latest rupture. The prognosis in such ruptures was poor, with a mortality of 79%. Intentional delay in angiography of at least 6 hours from the latest rupture is recommended if the associated hematoma is not large.


Neuroradiology | 1995

Simultaneous bleeding from multiple lenticulostriate arteries in hypertensive intracerebral haemorrhage

Masaki Komiyama; T. Yasui; K. Tamura; Yasunori Nagata; Yoshihiko Fu; Hisatsugu Yagura

Angiography within 1 h of the onset of an intracerebral haematoma in a hypertension man showed active bleeding from at least two lenticulostriate arteries. We discuss the pathophysiological significance of this finding.


Surgical Neurology | 1991

Traumatic carotid-cavernous sinus fistula associated with an intradural pseudoaneurysm: a case report.

Masaki Komiyama; Toshihiro Yasui; Hisatsugu Yagura; Yoshihiko Fu; Yasunori Nagata

A case of traumatic carotid-cavernous sinus fistula (CCF) associated with an intradural pseudoaneurysm is reported. A 42-year-old man developed traumatic CCF after severe head trauma. Cerebral angiography demonstrated a direct CCF associated with an intradural pseudoaneurysm at the C2 portion. Transarterial balloon embolization of the CCF caused severe subarachnoid hemorrhage. A CCF with an intradural pseudoaneurysm is life-threatening and requires emergency treatment. However, balloon occlusion in such cases is contraindicated because of possible rupture of a pseudoaneurysm. Trapping or a direct surgical approach is the treatment of choice.


Surgical Neurology | 1990

Indirect carotid-cavernous sinus fistula: Transvenous embolization from the external jugular vein using a superior ophthalmic vein approach. A case report

Masaki Komiyama; Kazutoshi Morikawa; Yoshihiko Fu; Hisatsugu Yagura; Toshihiro Yasui; Mitsuru Baba

A case of indirect carotid-cavernous sinus fistula treated by combined transarterial and transvenous embolization is described. A 49-year-old woman with a right indirect carotid-cavernous sinus fistula draining solely to the right superior ophthalmic vein was treated first by transarterial embolization with polyvinyl alcohol particles. Then, by approaching through the superior ophthalmic vein from the right external jugular vein, the cavernous sinus was embolized with platinum wire using a tracker microcatheter, which resulted in marked clinical improvement. Transvenous embolization by approaching from the external jugular vein through the superior ophthalmic vein represents a promising alternative when shunted blood drains anteriorly to the superior ophthalmic vein.


Journal of Computer Assisted Tomography | 1990

MR imaging of dural AV fistulas at the cavernous sinus.

Masaki Komiyama; Yoshihiko Fu; Hisatsugu Yagura; Toshihiro Yasui; Akira Hakuba

The magnetic resonance appearance of dural arteriovenous fistulas (AVFs) at the cavernous sinus (CS) was studied in six angiographically verified cases. Magnetic resonance clearly demonstrated shunted blood as an area of signal void both in the CS and in the superior ophthalmic vein. The relationship between shunted blood, internal carotid artery, and extraocular nerves, as well as proptosis, enlargement of the extraocular muscles, and bulging of the lateral wall of the CS were also depicted in the images. Normal venous flow in the involved CS was shown as a low signal area that enhanced after gadolinium administration. Magnetic resonance is useful for screening and follow-up examinations of dural AVFs at the CS. It is essentially a noninvasive procedure that may be repeated and obviates the need for follow-up angiography. However, it should be noted that a signal void in the CS sometimes represents normal venous flow. A definite diagnosis should rely on angiography, which is essential for therapeutic planning.


Surgical Neurology | 1995

Angiographic extravasation of contrast medium in acute “spontaneous” subdural hematoma

Toshihiro Yasui; Masaki Komiyama; Hiroshige Kishi; Hisatsugu Yagura; Yoshihiko Fu; Yasunori Nagata; Katsuhiko Tamura

Acute spontaneous subdural hematoma is very rare. We have encountered four such cases and verified the arterial origin of the bleeding at operation. None of the patients had a history of head trauma, and each had developed sudden onset of headache and other neurologic deficits, which simulate other cerebrovascular diseases. CT directly revealed subdural hematoma but gave no indication as to the source of the bleeding. Cerebral angiography was performed in all cases, with three of them showing localized extravasation of the contrast material into the subdural space. The extravasation was noted usually in the late arterial phase. This is a useful finding for diagnosing this disease and localizing the bleeding point. It is expected that with more routine use of cerebral angiography in cases of acute spontaneous subdural hematoma, extravasation of the contrast medium will be seen more frequently.


Surgical Neurology | 1994

Chronic subdural hematoma associated with middle meningeal arteriovenous fistula treated by a combination of embolization and burr hole drainage

Masaki Komiyama; Toshihiro Yasui; Katsuhiko Tamura; Yasunori Nagata; Yoshihiko Fu; Hisatsugu Yagura

A rare case of chronic subdural hematoma associated with a middle meningeal arteriovenous fistula was treated by a combination of embolization and burr hole drainage. This clinical situation might be missed in this era of computed tomography, when cerebral angiography is seldom indicated for the diagnosis of neuro-traumatic diseases. We should bear in mind the possibility of this clinical situation of a chronic subdural hematoma associated with a linear skull fracture crossing the middle meningeal groove in order to avoid possible hemorrhagic complications during surgery for chronic subdural hematoma.


Surgical Neurology | 1987

Magnetic resonance imaging: lumbosacral lipoma.

Masaki Komiyama; Akira Hakuba; Yuichi Inoue; Toshihiro Yasui; Hisatsugu Yagura; Mitsuru Baba

To evaluate the clinical efficacy of magnetic resonance imaging (MRI) of lumbosacral lipomas, the magnetic resonance images of nine patients were reviewed. T1- and T2-weighted spin echo sequences were used with a 0.5-T magnetic resonance system. The tethered or low-positioned conus medullaris, the lipoma itself, the lipoma--cord interface, the subarachnoid space, and hydromyelia were clearly disclosed. The nerve rootlets were not as clear. These results indicate the possible discontinuance of myelography and metrizamide computed tomography (CT) cisternography for such imaging. The diagnostic modalities of choice for lumbosacral lipoma imaging are plain spine films, plain CT scan, and MRI.


Surgical Neurology | 1993

Mechanism of acute deterioration of the neurological status following rapid and massive intraluminal thrombosis in case of a giant intracavernous carotid artery aneurysm: Demonstration by mr imaging

Toshihiro Yasui; Hisatsugu Yagura; Masaki Komiyama; Yoshihiko Fu; Yasunori Nagata; Katsuhiko Tamura; Yuichi Inoue

A case is reported of a thrombosed giant aneurysm of the intracavernous carotid artery. Transient neurological deterioration was attributable to the acute swelling of the aneurysmal mass after rapid and massive intraluminal thrombosis. Characteristics on the magnetic resonance imaging of this case are reported and discussed.


Surgical Neurology | 1989

A new microcatheter system for endovascular treatment of cerebral arteriovenous malformations

Masaki Komiyama; Toshihiro Yasui; Yoshihiko Fu; Hisatsugu Yagura; Mitsuru Baba; Akira Hakuba

A new microcatheter system was used for diagnostic and therapeutic purposes in three cases of arteriovenous malformation. This microcatheter is used with a steerable guidewire and provides high selectivity of the target vessels and greater catheter maneuverability than does balloon catheters. Tissue adhesive was safely injected for the therapeutic embolization in two of the cases. With this system, however, the utmost attention is necessary to prevent reflux of the tissue adhesive and to avoid lacerating the feeding vessels with the guidewire. This microcatheter system was found to be very useful for diagnostic and therapeutic procedures in endovascular treatment of cerebral arteriovenous malformations.

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Masaki Komiyama

Memorial Hospital of South Bend

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Toshihiro Yasui

Memorial Hospital of South Bend

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Yoshihiko Fu

Memorial Hospital of South Bend

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Mitsuru Baba

Memorial Hospital of South Bend

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Yasunori Nagata

Memorial Hospital of South Bend

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Katsuhiko Tamura

Memorial Hospital of South Bend

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Hajime Sugata

Memorial Hospital of South Bend

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