Education 【 display / non-display 】

Education 【 display / non-display 】

• 2006

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  2012

  Sapporo Medical University   医学部  

Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2023.04

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  Now

  札幌医科大学附属病院   脳神経外科   助教

• 2017.04

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  2018.03

  札幌医科大学附属病院   高度救命救急センター   助教

• 2022.04

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  2023.03

  市立函館病院   脳神経外科   医長

• 2020.10

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  2022.03

  帯広厚生病院   脳神経外科   医長

• 2019.10

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  2020.09

  砂川市立病院   脳神経外科   副医長

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Professional Memberships 【 display / non-display 】

Professional Memberships 【 display / non-display 】

• 2020

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  Now

  日本脳卒中の外科学会

• 2016

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  Now

  日本脳神経外傷学会

• 2015

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  Now

  日本脳神経外科学会

• 2016

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  Now

  日本脳神経血管内治療学会

• 2015

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  Now

  日本脳卒中学会

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Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• Sapporo Medical University   Department of Neurosurgery   助教  

Papers 【 display / non-display 】

Papers 【 display / non-display 】

• A Case of Subdural Hygroma due to a Ruptured Arachnoid Cyst in the Middle Cranial Fossa That Improved after Long-term Subdural Drainage: A Case Report and Review of the Literature.

  Ayumu Yamaoka, Shouhei Noshiro, Hiroki Akiyama, Ryota Sato, Ayaka Sasagawa, Terumasa Kuroiwa, Masafumi Ohtaki, Nobuhiro Mikuni

  NMC case report journal   11   313 - 319  2024  [Refereed]  [Domestic journal]

  Authorship：   Lead author  , Corresponding author

  　View Summary

  Arachnoid cysts have the potential to rupture, leading to the development of a subdural hygroma following minor trauma. Although surgery may be considered in cases of increased intracranial pressure (ICP) or regional neurological symptoms, the optimal approach remains unclear. We report a case of subdural hygroma due to a ruptured arachnoid cyst (SHrAC) with elevated ICP successfully treated with long-term subdural drainage for over 1 month. A 26-year-old man with persistent headache was admitted to our hospital. Magnetic resonance imaging revealed an arachnoid cyst within the left middle cranial fossa and a subdural hygroma in the left frontotemporal region. He was referred to our neurosurgery department for surgical intervention due to elevated ICP. Although burr hole surgery was initially performed, subsequent recurrence of elevated ICP necessitated the insertion of a subdural peritoneal shunt. However, the shunt was then removed following the development of postoperative meningitis, and a subdural drain was placed to control ICP. Cerebrospinal fluid (CSF) drainage gradually decreased, and the elevated ICP improved. The subdural drain was removed approximately one and a half months after drain placement. The subdural hygroma progressively reduced and completely disappeared 4 months after drain removal. The gradual reduction in the pressure difference between the arachnoid cyst and the subdural hygroma due to long-term CSF drainage and inflammation caused by meningitis may have contributed to close arachnoid membrane laceration. Although alternative approaches, such as shunt insertion and basal fenestration, should always be considered in SHrAC treatment, long-term subdural drainage can be an option.

  DOI PubMed

• Endovascular treatment of asymptomatic free-floating thrombus in the carotid artery bifurcation: a direct aspiration first-pass technique under double balloon protection.

  Ayumu Yamaoka, Kei Miyata, Satoshi Iihoshi, Nobuhiro Mikuni

  BMJ case reports   12 ( 8 )  2019.08  [Refereed]  [International journal]

  Authorship：   Lead author

  　View Summary

  Free-floating thrombus (FFT) in the carotid artery has been reported as a rare cause of acute ischaemic stroke. There are various treatment strategies, but higher risk of distal embolism may limit their applicability. A 77-year-old woman noticed right upper arm weakness. A CT angiogram revealed that a large floating thrombus had strayed across the carotid bifurcation, while another thrombus was present in the right axillary artery. As for the carotid FFT, in spite of anticoagulation therapy, the number of asymptomatic microthrombuses gradually increased on diffusion-weighted MRI. We performed endovascular therapy utilising two temporary occlusion balloon catheters and performed direct aspiration with a reperfusion catheter. The procedure was uneventful. We successfully performed a new endovascular technique for FFT in the carotid bifurcation. Our method is effective, minimally invasive and safe.

  DOI PubMed

• Traumatic Basilar Artery Entrapment without Longitudinal Clivus Fracture: A Case Report and Review of the Literature.

  Ayumu Yamaoka, Kei Miyata, Naofumi Bunya, Hirotoshi Mizuno, Hideto Irifune, Naoya Yama, Yukinori Akiyama, Takeshi Mikami, Masahiko Wanibuchi, Nobuhiro Mikuni

  Neurologia medico-chirurgica   58 ( 8 ) 362 - 367  2018.08  [Refereed]  [Domestic journal]

  Authorship：   Lead author  , Corresponding author

  　View Summary

  In blunt cerebrovascular injury, reported traumatic basilar artery occlusions have involved dissection of the basilar artery, distal embolization due to traumatic vertebral artery dissection, or entrapment of the basilar artery into the clivus fracture. To date, however, there are no reports of traumatic basilar artery entrapment without a clivus fracture. Here, we report the first case of traumatic basilar artery occlusion caused by entrapment into an originally existing bone defect. A 67-year-old man with a history of treatment for intracranial aneurysm suffered multiple traumatic injuries in a fall. On arrival at our hospital, he presented with neurogenic shock with quadriplegia. Computed tomography (CT) showed small epidural hematoma, C4-6 cervical spinous process fracture, and Th2-3 vertebral body fracture. CT angiography revealed occlusion of the basilar artery trunk. As vertebrobasilar artery dissections and clivus fracture were not observed; however, we could not elucidate the pathology of the basilar artery occlusion. On day 4, after surgery for the cervical and thoracic lesions, he exhibited consciousness disturbance. Diffusion-weighted imaging on day 5 showed hyperintensities in the brainstem and cerebellum. Basi-parallel anatomic scanning magnetic resonance imaging showed that the basilar artery, while lacking vascular wall injuries, was tethered into the clivus. Antithrombotic therapy was performed, but the patient progressed to a locked-in state. Previous head CT before the trauma revealed a bone defect already present in the clivus. We speculated basilar artery entrapment into this preexisting bone defect. We must look for basilar artery injury in trauma patients even in the absence of clivus fracture.

  DOI PubMed

• Cerebral air embolism associated with penetrating lung injury: a case report and review of the literature.

  Ayumu Yamaoka, Kei Miyata, Eichi Narimatsu, Eiji Sakawaki, Sonoko Sakawaki, Suguru Hirayama, Shuji Uemura, Naoya Yama

  Acute medicine & surgery   4 ( 2 ) 213 - 216  2017.04  [Refereed]  [International journal]

  Authorship：   Lead author  , Corresponding author

  　View Summary

  CASE: A 44-year-old man intentionally stabbed himself in the anterior neck and left thorax with a fruit knife. Physical examination revealed two open wounds entering the thoracic cavity in the front chest, and a stab wound entering the trachea at the neck. Two chest tubes were initially inserted for the left lung injury with open hemopneumothorax. Nevertheless, the worsening oxygenation required positive pressure ventilation (PPV) with endotracheal intubation. OUTCOME: Right hemiparesis was found during weaning from PPV. Magnetic resonance imaging revealed multiple infarctions in the area of the bifrontal and right temporal lobes. Cerebral air embolism (CAE) was strongly suspected from the imaging findings and clinical course. CONCLUSION: We concluded that mechanical ventilation was strongly involved in the occurrence of CAE. If delayed abnormal neurological findings are observed in patients with penetrating lung injuries receiving PPV management, CAE should be considered.

  DOI PubMed

• Deep learning from head CT scans to predict elevated intracranial pressure.

  Ryota Sato, Yukinori Akiyama, Takeshi Mikami, Ayumu Yamaoka, Chie Kamada, Kyoya Sakashita, Yasuhiro Takahashi, Yusuke Kimura, Katsuya Komatsu, Nobuhiro Mikuni

  Journal of neuroimaging : official journal of the American Society of Neuroimaging    2024.10  [Refereed]  [International journal]

  　View Summary

  BACKGROUND AND PURPOSE: Elevated intracranial pressure (ICP) resulting from severe head injury or stroke poses a risk of secondary brain injury that requires neurosurgical intervention. However, currently available noninvasive monitoring techniques for predicting ICP are not sufficiently advanced. We aimed to develop a minimally invasive ICP prediction model using simple CT images to prevent secondary brain injury caused by elevated ICP. METHODS: We used the following three methods to determine the presence or absence of elevated ICP using midbrain-level CT images: (1) a deep learning model created using the Python (PY) programming language; (2) a model based on cistern narrowing and scaling of brainstem deformities and presence of hydrocephalus, analyzed using the statistical tool Prediction One (PO); and (3) identification of ICP by senior residents (SRs). We compared the accuracy of the validation and test data using fivefold cross-validation and visualized or quantified the areas of interest in the models. RESULTS: The accuracy of the validation data for the PY, PO, and SR methods was 83.68% (83.42%-85.13%), 85.71% (73.81%-88.10%), and 66.67% (55.96%-72.62%), respectively. Significant differences in accuracy were observed between the PY and SR methods. Test data accuracy was 77.27% (70.45%-77.2%), 84.09% (75.00%-85.23%), and 61.36% (56.82%-68.18%), respectively. CONCLUSIONS: Overall, the outcomes suggest that these newly developed models may be valuable tools for the rapid and accurate detection of elevated ICP in clinical practice. These models can easily be applied to other sites, as a single CT image at the midbrain level can provide a highly accurate diagnosis.

  DOI PubMed

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Books and Other Publications 【 display / non-display 】

Books and Other Publications 【 display / non-display 】

• 脳神経外科臨床マニュアル

  端 和夫, 三國 信啓( Part： Contributor, 14節 呼吸管理―呼吸不全とその対策)

  丸善出版  2018.12 ISBN: 9784621303481

• 脳神経外科臨床マニュアル

  端 和夫, 三國 信啓( Part： Contributor, 50節 頭部外傷（traumatic brain injury：TBI）診療のポイント)

  丸善出版  2018.12 ISBN: 9784621303481

Awards 【 display / non-display 】

Awards 【 display / non-display 】

• 2nd

  2021.04   Conference on Neurosurgical Techniques and Tools   CNTT2021 顕微鏡下手術 端側吻合手技コンテスト

• 令和5年度札幌医科大学脳神経外科同門会優秀論文賞（症例報告部門）

  2024.11  

Presentations 【 display / non-display 】

Presentations 【 display / non-display 】

• もやもや病に対するSTA-MCA bypass術を成功させるためのoff the job trainingの工夫

  山岡 歩, 小松 克也, 西野 豪, 金 相年, 秋山 幸功, 松永 渉, 三上 毅, 三國 信啓

  日本脳神経外科学会 第83回学術集会 

  Presentation date： 2024.10

  Event date：

  2024.10

  　

  　

• Promoting the acquisition of surgical skills through off-the-job training of bypass surgery

  山岡 歩, 三上 毅, 小松 克也, 金 相年, 秋山 幸功, 能代 将平, 對馬 州一, 古明地 孝宏, 三國 信啓

  第53回 日本脳卒中の外科学会学術集会 

  Presentation date： 2024.03

  Event date：

  2024.03

  　

  　

• Analysis of the training of anastomosis in a deep corridor and learning curve

  山岡 歩, 三上 毅, 小松 克也, 秋山 幸功, 三國 信啓

  日本脳神経外科学会 第82回学術総会 

  Presentation date： 2023.10

  Event date：

  2023.10

  　

  　

• 救急科専門医が脳神経外科の手術手技を習得するためのルーチンワーク

  山岡 歩, 小松 克也, 金 相年, 秋山 幸功, 三上 毅, 三國 信啓

  第52回 日本救急医学会総会・学術集会 

  Presentation date： 2024.10

  Event date：

  2024.10

  　

  　

• 長期の硬膜下ドレーン留置後に改善を得た中頭蓋窩くも膜嚢胞破裂による硬膜下水腫の1例

  山岡 歩, 能代 将平, 笹川 彩佳, 黒岩 輝壮, 大瀧 雅文, 三國 信啓

  第46回 日本脳神経外傷学会 

  Presentation date： 2024.03

  Event date：

  2024.03

  　

  　

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