- 著者
- Shin Hirota Satoru Takahashi Masataka Yoshimura Sakyo Hirai Takamaro Takei Asumi Orihara Hirotaka Sagawa Hikaru Wakabayashi Shoko Fuji Shinji Yamamoto Kazutaka Sumita
- 出版者
- The Japanese Society for Neuroendovascular Therapy
- 雑誌
- Journal of Neuroendovascular Therapy (ISSN:18824072)
- 巻号頁・発行日
- pp.cr.2023-0041, (Released:2023-09-01)
- 参考文献数
- 20
Objective: Basilar artery occlusion (BAO) secondary to traumatic vertebral artery (VA) dissection caused by vertebral fracture is a rare cause of acute ischemic stroke, and optimal management, such as antithrombotic agents, surgical fixation, and parent artery occlusion (PAO), has been controversial. We report a case in which mechanical thrombectomy and PAO were performed for a BAO due to right VA dissection caused by a transverse foramen fracture of the axis vertebra.Case Presentation: A patient in her 80s suffered from a backward fall, and a neck CT revealed a fracture and dislocation of the right lateral mass of the axis and a compressed transverse foramen. The patient was instructed to admit and to remain in bed rest; however, she suddenly lost consciousness the following day. The CTA revealed right VA occlusion and BAO; therefore, the patient underwent mechanical thrombectomy and the BAO was successfully reperfused but the VA stenotic dissection remained. PAO of the right VA was performed on the fifth day after the accident to prevent BAO recurrence.Conclusion: Mechanical thrombectomy is an effective treatment for BAO caused by VA dissection, and PAO may contribute to the prevention of stroke recurrence.
- 著者
- Takayuki YAMADA Shinji NISHIWAKI Kazuhiro IZUI Masataka YOSHIMURA Akihiro TAKEZAWA
- 出版者
- The Japan Society of Mechanical Engineers
- 雑誌
- Journal of Environment and Engineering (ISSN:1880988X)
- 巻号頁・発行日
- vol.6, no.3, pp.567-578, 2011 (Released:2011-04-15)
- 参考文献数
- 18
- 被引用文献数
- 2 4
Topology optimization has been successfully used in many industries, especially those engaged in the design and manufacturing of mechanical devices, but numerical problems are often encountered, such as grayscale representations of obtained composites. A type of structural optimization method using the level set theory for boundary expressions has been proposed, in which the outlines of target structures are implicitly represented using the level set function, and optimal configurations are obtained by updating this function based on the shape sensitivities. Level set-based methods typically have a drawback, however, in that topological changes that increase the number of holes in the material domain are not allowed. To overcome the above numerical and topological problems, this paper proposes a new topology optimization method incorporating level set boundary expressions based on the concept of the phase field method, which we apply to a minimum mean compliance problem. First, a structural optimization problem is formulated based on a boundary expression, using the level set function. Next, a time evolutionary equation for updating the level set function is formulated based on the concept of the phase field method, and the minimum mean compliance problem is formulated using a level set boundary expression. An optimization algorithm for the topology optimization incorporating the level set boundary expression based on the concept of the phase field method is then derived. Several examples are provided to confirm the usefulness of the proposed structural topology optimization method.