Hiroyuki Masaoka

Nippon Medical School, Edo, Tōkyō, Japan

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Publications (66)35.89 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Arteriovenous malformation (AVM)-related intracerebral hemorrhage (ICH) is the cause of approximately 2–3% of ICH and is an important factor in the significant morbidity and mortality in patients with AVM. Decompressive craniectomy (DC) is a surgical procedure to relieve malignant elevation of intracranial pressure. The use of DC to treat patients with AVM-ICH has been much less common. The present study describes our experience with DC for AVM-ICH and discusses the safety of this procedure. The present retrospective analysis compared 12 consecutive patients treated with DC for AVM-ICH with 23 patients treated with DC for hypertensive ICH. Nine patients were male and three were female, aged from 11 to 53 years (mean, 31.7 years). Hematoma volumes ranged from 50 to 106 ml (mean, 75.8 ml). The outcomes were good recovery in one patient, moderate disability in three, severe disability in seven, and vegetative state in one. Complications after DC included subdural hygroma in four patients, hydrocephalus in one, intracranial infection in two, and intracranial hemorrhage in one. No significant difference was found in the incidence of complications between DC for large AVM-ICH and DC for hypertensive ICH. In conclusion, the present study found no significant difference in the incidence of complications between DC for large AVM-ICH and DC for hypertensive ICH. Further investigations including a prospective randomized trial are needed to confirm the safety and efficacy of DC for the treatment of large AVM-ICH.
    No preview · Article · Jan 2015 · Journal of Clinical Neuroscience
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    ABSTRACT: Posterior fossa injury is rare, occurring in less than 3 % of head injuries. We retrospectively reviewed patients' clinical and radiological findings, management, and outcomes. The aim of the present study was to investigate the features of posterior fossa hematoma, including posterior fossa epidural hematoma (EDH), posterior fossa subdural hematoma (SDH), and intracerebellar hematoma. From January 1995 to January 2009, 4,315 patients with head trauma were hospitalized at our institution. The -present study focused on 41 patients (1.0 %) with traumatic hematomas of the posterior fossa. Eighteen patients had EDH, 10 patients had SDH, and 17 patients had intracerebellar hematomas. In each type of injury, occipital bone fractures were seen in many patients, and hematoma enlargement was often observed within a few days of the injury. In addition, a high frequency of associated lesions and a high poor outcome rate were features of intracerebellar hematomas and -posterior fossa SDH. The present study suggests that repeat CT imaging and careful management are necessary until the lesion is stabilized, and patients showing lesions with mass effects should therefore be immediately treated with surgery.
    No preview · Article · Apr 2013 · Acta neurochirurgica. Supplement
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    ABSTRACT: Numerous studies on hydrocephalus after decompressive craniectomy (DC) for severe traumatic brain injury have been reported, whereas there have been only two reports on DC for hemispheric cerebral infarction. Here, we present the clinical details of 23 patients who underwent DC for hemispheric cerebral infarction and the incidence of hydrocephalus following DC. Of the 23 patients, 13 were male and 10 were female, with an age range from 34 to 75 years (mean, 60.8 years). The areas of hemispheric infarctions were those of the middle cerebral arteries in 12 patients and of the internal carotid arteries in 11 patients. The mean preoperative GCS score was 6. Nineteen patients (82.6 %) underwent cranioplasty. Pre-cranioplasty hydrocephalus was observed in 11 (47.8 %) patients. Four patients who had precranioplasty hydrocephalus were transferred or died without cranioplasty, and post-cranioplasty hydrocephalus occurred in 7 (36.8 %). Only one patient underwent a shunt procedure after cranioplasty. We consider that the explanation for the discrepancies between our study and the previous studies might lie in the definition of hydrocephalus and the indications for shunting.
    No preview · Article · Apr 2013 · Acta neurochirurgica. Supplement
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    ABSTRACT: Subacute subdural hematoma (SASDH) is a rare entity. We retrospectively reviewed 8 patients with SASDH. Four patients were male and 4 were female, with an age range of 45-87 years (mean, 67.8 years). The minimal level of deterioration ranged from 8 to 14 (mean, 10.5). The deterioration of neurological symptoms was confirmed 4-20 days after injury (mean, 12.9). The hematoma volume was increased in 6 patients. Seven patients underwent surgeries (burr-hole irrigation in 6, craniotomy in 1). The Glasgow Outcome Scale indicated a good recovery in 4 patients and moderate disability in 4 patients. Increased cerebral blood flow was observed just below the SDH in 1 patient. We consider that the hypoperfused tissue in the acute phase might become hyperperfused during the subacute phase owing to impaired autoregulation, and the hyperperfusion may be responsible for the development of the SASDH, leading to deterioration. Further investigations in a larger series are needed to elucidate the mechanism underlying the development of SASDH.
    No preview · Article · Apr 2013 · Acta neurochirurgica. Supplement
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    ABSTRACT: New findings (NF) on postoperative CTs are -occasionally found in patients who undergo surgery for traumatic brain injury (TBI). We conducted a retrospective -registry-based review of the care of 102 patients who underwent decompressive craniectomy (DC) for TBI to investigate the prognostic factors of new findings on CT early after -surgery. Of the 102 patients, the mean age was 50 years and 69.6 % were male. The overall survival was 72.5 %. The primary indication for DC included subdural hematoma in 72 (70.6 %), epidural hematoma in 17 (16.7 %), and intraparenchymal contusion in 13 (12.7 %). New findings on postoperative CTs were observed in 26 patients (25.5 %). The univariate analysis showed that a GCS score ≤8 (P = 0.012) and the absence of a basal cistern (P = 0.012) were significantly associated with NF on postoperative CT. The logistic regression analysis demonstrated that the GCS score ≤8 (P = 0.041; OR, 3.0; 95 % CI, 1.048-8.517) was the only significant factor. TBI patients with a low GCS score who underwent DC should undergo additional CT evaluations immediately after surgery.
    No preview · Article · Apr 2013 · Acta neurochirurgica. Supplement
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    ABSTRACT: Twenty patients with traumatic basal ganglia hematoma (TBGH) were studied. Of the 20 patients, 16 were male and 4 were female, with an age range of 4-89 years (mean, 54.4 years). The causes of injury were traffic accidents in 12 patients and falls in 8. The mean admission GCS score was 7.5. Skull fractures were revealed in five patients (25 %). The hematoma was found in the putamen in 15 patients (80 %), the thalamus in 4, and the caudate in 1. The mean hematoma volume was 10.7 mL. The CT findings indicated focal contusions in 9 patients, subdural hematoma in 5, intraventricular hemorrhage in 4, subarachnoid hemorrhage in 10, and diffuse axonal injury in 5. Six patients (30 %) underwent surgery. The final outcomes were poor: 7 patients (35 %) died, 1 was in a vegetative state, 4 experienced severe disabilities, and 8 patients (40 %) made a favorable recovery. The statistical analysis identified the GCS score and midline shift as prognostic factors.Our study revealed interesting characteristics of TBGH, including a high frequency of putaminal involvement, a low frequency of skull fractures, a high frequency of associated intracranial lesions, and a high poor outcome and mortality rate.
    No preview · Article · Apr 2013 · Acta neurochirurgica. Supplement
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    ABSTRACT: The aim of the present study was to investigate the risk factors for hydrocephalus after decompressive craniectomy (DC) for hemispheric cerebral infarction. This study selected 28 patients who underwent DC for malignant hemispheric cerebral infarction. The patients' clinical and radiologic findings were retrospectively reviewed. Fourteen of the 28 patients were male and 14 were female, with an age range from 34 to 80years (mean, 63.5years). Eighteen patients (64.3%) underwent DC within 48hours of stroke onset. The superior limit of DC was <25mm from the midline in 16 patients (57.1%). Twenty-two patients underwent cranioplasty, and the interval from DC to cranioplasty was within 60days in 14 patients. Pre- and post-cranioplasty hydrocephalus were observed in 13 and nine patients, respectively. Two patients required shunt procedures for post-cranioplasty hydrocephalus. Patients with DC whose superior limit was <25mm from the midline had a significantly increased risk of developing not only pre-cranioplasty but also post-cranioplasty hydrocephalus (p=0.008, p=0.010, respectively). In addition, the presence of pre-cranioplasty hydrocephalus was significantly associated with the development of post-cranioplasty hydrocephalus (p=0.001). The presence of pre- and post-cranioplasty hydrocephalus was significantly associated with a poor outcome (p=0.031, p=0.049, respectively). DC with a superior limit <25mm from the midline should be avoided to prevent the development of hydrocephalus.
    No preview · Article · Dec 2012 · Journal of Clinical Neuroscience
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    ABSTRACT: Objective: Primary brainstem hemorrhage (PBH) frequently causes severe disturbances of consciousness, papillary abnormalities, as well as respiratory and motor disturbances. The prognosis has been reported to be highly dependent on the clinical severity at presentation and the presence of certain radiological markers. However, the number of PBH patients enrolled in previous reports tended to be small, and precise statistical analyses were also lacking. The aim of this study was to analyze the impact of clinical or radiologic parameters on the outcome of patients with PBH. Methods: We retrospectively reviewed 212 consecutive patients with PBH and analyzed the impact of the clinical or radiological parameters on the outcome of patients with PBH. Results: Of the 212 patients, 134 (63.2%) were male and 78 (36.8%) were female, with an age range of 17-97 years (mean, 60.3 years). The median admission GCS score was 4. The outcomes included a good recovery in 13 patients (6.1%), moderate disability in 27 (12.7%), severe disability in 27 (12.7%), a vegetative state in 23 (10.8%), and death in 122 (57.5%). A multivariate analysis demonstrated bilateral hematoma extension, a GCS score ≤8, the presence of hydrocephalus, gender, and the hematoma volume to all be significantly associated with the 3-month mortality, while the GCS score ≤8, the presence of a pupillary abnormality, and the hematoma volume were found to be associated with the 3-month poor outcome. Conclusion: The identification of these factors is therefore considered to be useful for managing patients with PBH.
    No preview · Article · Aug 2012 · Clinical neurology and neurosurgery
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    ABSTRACT: BACKGROUND: It is well known that intracranial lesions, which are already diagnosed on preoperative computed tomography, often expand after surgery, and the risk factors have been investigated. On the other hand, we have experienced cases in which new lesions, which were not detected on preoperative computed tomography, were found on postoperative computed tomography. However, little is known about the factors associated with such new postoperative lesions. Here, we investigated the predictive factors of new findings (NFs) on computed tomography early after surgery. METHODS: We conducted a retrospective registry-based review of 186 consecutive patients who underwent surgery for traumatic brain injury and investigated the prognostic factors of NFs on computed tomography early after surgery. RESULTS: Mean age was 51 years, and 67.2% were males among the 186 patients. NFs on postoperative computed tomography were observed in 29 patients (15.6%). A univariate analysis showed that Glasgow Coma Scale (GCS) score of 8 or less (p < 0.001), subdural hematoma as the primary indication for surgery (p = 0.012), midline shift (p < 0.001), absence of basal cistern (p < 0.001), and decompressive craniectomy and craniotomy as the surgical procedures (p < 0.001, p = 0.004, respectively) were significantly associated with NFs on postoperative computed tomography. A logistic regression analysis demonstrated that decompressive craniectomy as the surgical procedure (p = 0.001; odds ratio [OR], 8.1; 95% confidence interval [CI], 2.23-28.82), GCS score of 8 or less (p = 0.019; OR, 3.4; 95% CI, 1.23-9.52), and absence of basal cistern (p = 0.023; OR, 3.5; 95% CI, 1.19-10.35) were significant factors. CONCLUSION: Early postoperative computed tomography after surgery for head trauma seems to be warranted in patients presenting with the indicated predictive factors of NFs. LEVEL OF EVIDENCE: Prognostic/therapeutic study, level IV.
    No preview · Article · Aug 2012
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    ABSTRACT: Objective: The aim of the present study was to investigate factors associated with the development of ventriculomegaly suggestive of hydrocephalus (VSOH) after decompressive craniectomy with hematoma evacuation for hemispheric hypertensive intracerebral hemorrhage. Methods: This study focused on 21 patients who underwent decompressive craniectomy with hematoma evacuation for hemispheric hypertensive intracerebral hemorrhage. The patients' clinical and radiological findings were retrospectively reviewed. Results: Eleven patients were male and ten were female, with an age range from 22 to 75 years (mean, 56.6 years). The preoperative Glasgow Coma Scale score ranged from 3 to 13 (mean, 6.9). Hematoma volumes ranged from 33.4 to 98.1 ml (mean, 74.2 ml). Hematoma locations were the basal ganglia in 10 patients and the subcortex in 11 patients. The presence of intraventricular hemorrhage was significantly associated with the development of VSOH (P=0.023). The distance of the decompressive defect to the midline and the presence of meningitis showed a strong trend for association with VSOH (P=0.051, P=0.090, respectively). Conclusion: Careful attention should be paid to the occurrence of VSOH after decompressive craniectomy with hematoma evacuation in intracerebral hemorrhage patients with intraventricular extension, meningitis, and/or a short distance of the decompressive defect to the midline.
    No preview · Article · Jun 2012 · Clinical neurology and neurosurgery
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    ABSTRACT: This study aimed to investigate the clinicoradiological features in patients with traumatic peritentorial subdural hematomas (SDHs). We retrospectively reviewed the clinical and radiological findings, management criteria, and outcomes in 32 patients with peritentorial SDHs. The outcomes were classified as favorable (good recovery or moderate disability) or poor (severe disability, vegetative state, or death). Of the 32 patients, 19 were male and 13 were female. The patients' ages ranged from 10-92 years (mean age, 60.9 years). Coagulopathies were observed in 23 patients. Twenty-four patients presented with associated intracranial lesions. Eighteen patients had favorable outcomes and 14 had poor outcomes. All patients were treated conservatively. The presence of coagulopathy (p = 0.024) and presence of convexity SDH (p = 0.008) correlated with the outcome. The patients with traumatic peritentorial SDHs were predominantly male and relatively elderly, and had a high incidence of coagulopathy, associated intracranial lesions (especially falx SDHs), a high rate of impact in the occipital or frontal regions, and a low incidence of skull fractures. The factors that were correlated with outcome in patients receiving conservative therapy were the presence of coagulopathy and the presence of convexity SDH.
    Full-text · Article · May 2012 · Turkish neurosurgery
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    ABSTRACT: OBJECTIVE: Intravenous tissue plasminogen activator (IV tPA) is an approved treatment for acute ischemic stroke. However, the effects of decompressive craniectomy (DC) after IV tPA administration for ischemic stroke are still largely unknown. The aim of this study was to investigate the safety and outcomes of DC after IV tPA administration. METHODS: We retrospectively reviewed patients who underwent DC for malignant hemispheric infarction. We compared 20 patients who underwent DC after IV tPA administration with another 20 patients who underwent DC without prior IV tPA administration. RESULTS: The patient characteristics did not differ between the DC patients with and without prior IV tPA administration. New intracranial bleeding or worsening of pre-existing ICH occurred in two patients (10%) in each group. Furthermore, the rates of an mRS score of 4-6, 5 or 6, and 6 did not differ significantly between the two groups. CONCLUSION: DC may be a safe and useful surgical procedure for space-occupying edema after IV tPA administration for acute stroke.
    No preview · Article · Apr 2012 · Clinical neurology and neurosurgery
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    ABSTRACT: A 60-year-old man was admitted with slowly progressive dizziness. Cranial nerve evaluation found no abnormalities. Magnetic resonance imaging revealed a well-circumscribed mass with homogeneous enhancement located in the fourth ventricle. The patient underwent surgery for the removal of the tumor via the bilateral suboccipital approach. Subtotal removal of the tumor was achieved in a piecemeal fashion. Histological diagnosis was meningothelial meningioma. Fourth ventricular meningiomas are extremely rare. We reviewed the literature and discussed the features of fourth ventricular meningiomas.
    No preview · Article · Mar 2012 · Acta neurologica Belgica
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    ABSTRACT: Traumatic hematomas in the posterior fossa are rare, especially traumatic posterior fossa subdural hematomas (SDHs), which account for <1% of head injured patients. The aim of this study was to investigate the features of traumatic posterior fossa SDHs. We retrospectively reviewed clinical and radiologic findings, management, and outcomes of patients with traumatic posterior fossa SDH. Ten patients with traumatic posterior fossa SDHs were admitted to our hospital. There were seven males and three females, with an age range of 3 years to 97 years (mean, 57.5 years). Coagulopathies were observed in five patients. The causes of injury were motor vehicle crash in three patients, falls in six patients, and being hit by an iron plate in one patient. The mean admission Glasgow Coma Scale score was 8.3. Skull fractures were revealed in six patients. Hematoma sizes ranged from 5 mm to 20 mm (mean, 7.7 mm). Two patients presented with isolated posterior fossa SDHs, and eight patients presented with associated intracranial lesions. Only one patient was treated surgically for posterior fossa SDHs associated with intracerebellar hematomas. The poor outcome rate was 90% and the mortality was 50%. A review of the literature revealed the following characteristics of posterior fossa SDHs: (1) a relatively high frequency of occipital impacts and fractures, (2) a low Glasgow Coma Scale score, (3) a high frequency of associated intracranial lesions, especially supratentorial lesions and intracerebellar hematomas, (4) a potential for lesion evolution, especially within 2 days, and (5) a high poor outcome rate and mortality. IV.
    No preview · Article · Feb 2012
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    ABSTRACT: In order to rapidly judge the response to intravenous tissue plasminogen activator (Ⅳ tPA) treatment, we retrospectively analyzed clinical data, such as MRI diffusion-weighted images (DWI), and treatment outcomes in 73 patients who developed anterior circulation disorders. The patients with favorable outcomes (modified Rankin Scale [mRS]: 2 or less) at discharge accounted for 32.9%. In these patients, the National Institutes of Health Stroke Scale (NIHSS) value, DWI Alberta Stroke Programme Early CT Score (ASPECTS), and the incidence of large artery (internal carotid artery [ICA]/sphenoidal segment of the middle cerebral artery [M1]) occlusion at their hospital visit were lower, higher, and lower, respectively (all P < 0.05 in univariate analysis). Multivariate analysis showed significant differences in DWI ASPECTS and the incidence of large artery occlusion. A DWI ASPECTS of at least 8 was found to be predictive of favorable outcomes. However, subclass analysis in the group with a DWI ASPECTS of 8 or higher predicting favorable outcome revealed 13 patients (41.9%) with unfavorable (mRS, 3-6) outcome. The factor associated with unfavorable outcomes is ICA occlusion. The combination of DWI ASPECTS and MRA appeared to be useful for predicting outcomes of Ⅳ tPA.
    No preview · Article · Jan 2012 · Journal of medical and dental sciences
  • Satoru Takeuchi · Yoshio Takasato · Hiroyuki Masaoka

    No preview · Article · Jan 2012 · Internal Medicine
  • Satoru Takeuchi · Yoshio Takasato · Hiroyuki Masaoka

    No preview · Article · Jan 2012 · Internal Medicine
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    ABSTRACT: We retrospectively reviewed the clinical and radiological findings, management, and factors correlated with outcomes in 20 patients with simultaneous multiple hypertensive intracranial hemorrhages (ICH). The mean admission Glasgow Coma Scale score was 7.8. The most common hematoma location was the putamen, while putamen-brainstem hematomas were the most common combination. The mean hematoma volume was 27.5 mL. Eight patients had favorable outcomes and 12 had poor outcomes. Statistical analysis identified that the GCS score on admission, hematoma distribution (unilateral supratentorial hematomas were the most favorable), and total hematoma volume were prognostic factors. This study provides important information on the clinicoradiological findings and prognosis in patients with simultaneous multiple hypertensive ICH.
    No preview · Article · Sep 2011 · Journal of Clinical Neuroscience
  • Satoru Takeuchi · Yoshio Takasato · Hiroyuki Masaoka
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    ABSTRACT: We report a rare case of chronic encapsulated intracerebral hematoma (CEIH) after radiosurgery for a cerebral arteriovenous malformation (AVM). A 49-year-old male underwent transarterial embolization and surgical excision of a cerebral AVM presenting with cerebral hemorrhage in the left temporal lobe. Stereotactic radiosurgery (SRS) was done after 12 months. Magnetic resonance imaging (MRI) 14 months after SRS showed a small-enhancing lesion close to the left lateral ventricle and marked white matter edema. At that time a diagnosis of radiation-induced necrosis was made and steroids administered. At 43 months after SRS, MRI showed a small-enhancing mass close to the lateral ventricle with a hematoma cavity. Surgical excision was performed and histological examination revealed that the capsule consisted of an outer collagenous layer and an inner granulated layer with deposits of hemosiderin, which was compatible with CEIH. CEIH should be considered after SRS for AVM.
    No preview · Article · Jul 2011 · Neurology India
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    ABSTRACT: We report on 17 patients with traumatic intra-cerebellar haematomas. We retrospectively reviewed patients' clinical and radiological findings, management criteria and outcomes. Ten patients had poor outcomes. Glasgow Coma Scale (GCS) score at admission was significantly higher in the favourable outcome group than in the poor outcome group (p = 0.010). The haematoma volume was significantly smaller in the favourable outcome group than in the poor outcome group (p = 0.025). There were also significant differences between the two groups in terms of types of haematoma location, the status of the brainstem cisterns, the status of the fourth ventricle, and the presence of associated subarachnoid haemorrhage (SAH) (p = 0.035, 0.002, 0.010, 0.003, respectively). The factors correlated with outcome were GCS score, the status of the brainstem cisterns and the fourth ventricle, the presence of associated SAH, haematoma volume and haematoma location. Further studies are needed to investigate the factors relevant to the management of traumatic intra-cerebellar haematomas.
    No preview · Article · Feb 2011 · British Journal of Neurosurgery