Hiroki Sakamoto

The Jikei University School of Medicine, Edo, Tōkyō, Japan

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Publications (5)4.64 Total impact

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    ABSTRACT: Recently, intraoperative indocyanine green (ICG) videoangiography has become a common technique for treating cerebrovascular diseases. We report a case of dural arteriovenous fistula (AVF) treated with direct surgery using intraoperative ICG videoangiography. A 41-year-old man with right hemiplegia caused by a left subcortical hemorrhage was transferred to our hospital. Digital subtraction angiography (DSA) revealed a left convexity parasagittal dural AVF. Surgical resection of the dural AVF was performed using step-by-step ICG videoangiography 4 times in each dissection procedure, which precisely delineated the structure of the dural AVF. After a circular incision of the dura around the fistular point, repeated ICG videoangiography identified the residual fistula between the pial artery from the middle cerebral artery and the draining vein. Complete disappearance of the AVF was confirmed by ICG videoangiography after this pial fistula was removed. Postoperative DSA revealed no residual AVF. Accurate detection of all fistular points and complete resection, including the dura mater and pial vessels, are necessary to avoid rebleeding caused by the residual dural AVF due to incomplete obliteration of the fistular points. Intraoperative ICG videoangiography could provide information on angiographically occult vascular malformation, such as pial fistulas, that cannot be detected by preoperative DSA. Our findings suggest that multistage intraoperative ICG videoangiography can be quite useful for complete resection of a dural AVF with angiographically occult pial fistula.
    No preview · Article · Jun 2012 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association
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    ABSTRACT: A patient who presented with trigeminal neuralgia associated with a persistent primitive trigeminal artery (PPTA) is presented. A 62-year-old woman suffering from right orbital pain was admitted to the hospital. Medical treatment for three months was ineffective, and her neuralgia had deteriorated and gradually spread in the maxillary division. Magnetic resonance imaging demonstrated the flow void signal attached to the right trigeminal nerve. Thus, microvascular decompression was performed. The superior cerebellar artery was the responsible artery, and it was transposed to decompress the trigeminal nerve. After this manoeuvre, an artery was identified running parallel to the trigeminal nerve toward Meckel's cave. The artery, which turned out to be a PPTA, communicated with the basilar artery. The PPTA was carefully observed, and it was found not to be the artery causing the neuralgia because it did not compress the nerve at surgical observation. No additional procedure between the PPTA and the trigeminal nerve was performed. The patient's symptom improved dramatically following surgery, and her postoperative course was uneventful. Postoperative three-dimensional computed tomography showed the PPTA. The findings in the present case suggest that transposition of the responsible artery effectively decompresses the root entry zone and assists in determining whether the PPTA is affecting the trigeminal nerve.
    Full-text · Article · Sep 2011 · Pain research & management: the journal of the Canadian Pain Society = journal de la societe canadienne pour le traitement de la douleur
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    ABSTRACT: A 70-year-old man presented with a rare case of paranasal osteoma with secondary mucocele extending intracranially, manifesting as a generalized convulsion. Computed tomography showed a large calcified tumor adjacent to the cystic mass in the left frontal lobe. He underwent left frontal craniotomy, and the cystic lesion was totally removed. Histological examination confirmed the diagnosis of osteoma and mucocele. The giant paranasal sinus osteoma prevented growth of the mucocele into orbital recess and extension into the orbital space and paranasal sinus. The mucocele disrupted the dura in the anterior cranial fossa, resulting in a giant cystic intracranial lesion. Frontal osteoplastic craniotomy was effective for exposing both lesions and plastic repair of the dural perforation to prevent cerebrospinal fluid leakage and secondary infection.
    No preview · Article · Aug 2011 · Neurologia medico-chirurgica
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    ABSTRACT: The incidence of brain abscess remains high, despite the development of novel antibiotics. Vancomycin or carbapenems, which are third-generation cephems, are recommended as standard therapy for bacterial meningitis or brain abscess. The effectiveness of the high-dose meropenem therapy on brain abscess has occasionally been reported. We experienced 2 consecutive cases of brain abscess in adults. The first patient was a 67-year-old man with diplopia, dizziness, and dysesthesia on the left upper and lower extremities. Images of T1-weighted magnetic resonance imaging (MRI) with contrast medium and diffusion-weighted MRI showed a ring enhancing cystic lesion and a high intensity lesion, respectively, in the right pons. The second patient was a 37-year-old man who complained of right hemiparesis. MRI revealed a ring-enhancing cystic mass in the left thalamus. On the basis of MRI findings, patients were diagnosed with brain abscess and were given high-dose meropenem (6g/day) continuously for 2 months. The abscess resolved completely after treatment with meropenem administered intravenously. Further, neurological deficits caused by abscess successfully improved. High-dose meropenem therapy should be considered as an effective treatment for brain abscess, even in the brain stem and basal ganglia, where it is quite difficult to achieve surgical access.
    No preview · Article · Aug 2011 · Brain and nerve = Shinkei kenkyū no shinpo
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    ABSTRACT: A 34-year-old male presented with a rare case of Rathke's cleft cyst (RCC) with calcification manifesting as persistent high fever and impaired consciousness. Physical findings revealed panhypopituitarism and bitemporal hemianopsia. Computed tomography showed mass lesions with marked calcification within the sella turcica and the suprasellar region. Magnetic resonance imaging showed solid and cystic components compressing the optic nerve. The preoperative diagnosis was craniopharyngioma. Initial endonasal transsphenoidal surgery (TSS) was performed with a surgical microscope, but the mass was extremely hard, so only partial removal was possible. Second endonasal extended TSS was performed with a neuroendoscope. The solid components were totally removed, but calcifications adhering to the optic nerve could not be removed completely. The histological diagnosis was RCC with marked granulation reaction. RCC with calcification is rare and difficult to differentiate from craniopharyngioma on neuroimages. Extremely thick calcification of the sella turcica enclosing granulation tissue and the cyst similar to armor, here called "armor-like calcification," is a characteristic imaging finding of RCC with calcification. The most important aspect is choosing a surgical approach to carefully and effectively relieve pressure upon the optic nerve. Endonasal extended TSS with an endoscope was effective in the present case.
    No preview · Article · Jul 2011 · Neurologia medico-chirurgica