Article
Clinical Neurology
Mohamed M. M. Salem, Svetlana Kvint, Philipp Hendrix, Fadi Al Saiegh, Avi A. A. Gajjar, Omar Choudhri, Brian T. T. Jankowitz, Oded Goren, Bradley A. A. Gross, Pascal Jabbour, Michael Lang, Clemens M. M. Schirmer, Stavropoula I. I. Tjoumakaris, Christoph J. J. Griessenauer, Jan-Karl Burkhardt
Summary: This study reports on the short-term multicenter experience with FRED treatment for intracranial aneurysms.
Article
Clinical Neurology
Jaims Lim, Andre Monteiro, Gustavo M. Cortez, Victor H. Benalia, Ammad A. Baig, Wady T. Jacoby, Brianna M. Donnelly, Bennett R. Levy, Vinay Jaikumar, Jason M. Davies, Kenneth V. Snyder, Adnan H. Siddiqui, Ricardo A. Hanel, Elad I. Levy, Kunal Vakharia
Summary: Through studying the early termination of DAPT after PED-Shield treatment for intracranial aneurysms, we found that early termination of DAPT is safe and has comparable complete occlusion rates to standard duration DAPT.
WORLD NEUROSURGERY
(2023)
Article
Clinical Neurology
Mohamed M. Salem, Aryan Ali, Howard A. Riina, Jan-Karl Burkhardt
Summary: This article reports technical complications encountered with the use of the WEB 17 system for aneurysm treatment and discusses potential reasons for failure and management plans. The results indicate that WEB 17 embolization may pose technical challenges in smaller wide-necked aneurysms, requiring rescue stenting for device migration and prolapse.
WORLD NEUROSURGERY
(2022)
Article
Clinical Neurology
Kristina Sirakova, Marin Penkov, Svetozar Matanov, Krasimir Minkin, Kristian Ninov, Asen Hadzhiyanev, Vasil Karakostov, Irena Ivanova, Stanimir Sirakov
Summary: This study analyzed the treatment outcomes of using flow diverter stents for large symptomatic aneurysms and found that it effectively reduced aneurysmal volume and resolved associated symptoms. The complication rate was low in this study.
FRONTIERS IN NEUROLOGY
(2022)
Article
Clinical Neurology
Chao Ma, Haoyu Zhu, Shikai Liang, Fei Liang, Jidian Sun, Yupeng Zhang, Chuhan Jiang
Summary: This study compared the efficacy of traditional endovascular therapeutic approaches and the pipeline embolization device (PED) in treating distal cerebral circulation aneurysms. The study found that PED can provide similar rates of occlusion and complications compared to traditional endovascular therapeutic approaches. Rigorous patient selection and proper planning should be undertaken to reduce treatment-related complications.
FRONTIERS IN NEUROLOGY
(2022)
Article
Clinical Neurology
Tae Keun Jee, Je Young Yeon, Keon Ha Kim, Jong-Soo Kim, Seung-Chyul Hong, Pyoung Jeon
Summary: This study evaluated the efficacy and safety of single-device flow diversion in patients with aneurysms measuring more than 15 mm in diameter, and found that it was ineffective for large or giant intracranial aneurysms with a high parent vessel angle.
WORLD NEUROSURGERY
(2021)
Review
Clinical Neurology
Nisha Dabhi, Danyas Sarathy, M. Harrison Snyder, Ryan T. Kellogg, Min S. Park
Summary: This review summarized the clinical and angiographic outcomes of flow diverting stents (FDSs) for the treatment of intracranial aneurysms in small caliber parent arteries. The results showed that FDS treatment in these arteries had comparable rates of long-term complete aneurysm occlusion, mortality, and permanent neurologic deficit compared to FDS-treated aneurysms in larger parent arteries. However, the relatively increased risk of symptomatic stroke for these FDS-treated aneurysms should be considered.
WORLD NEUROSURGERY
(2022)
Review
Clinical Neurology
Cem Bilgin, Sherief Ghozy, Mostafa Shehata, Mohamed Ibrahim, Mohamed Sobhi Jabal, Hassan Kobeissi, Danielle J. Gerberi, Ramanathan Kadirvel, David F. Kallmes
Summary: This review assessed the safety and efficacy of prophylactic GP2B3A inhibitor use in intracranial aneurysm patients treated with stent-assisted coil embolization or flow diversion. The results showed that GP2B3A inhibitors are safe and effective in preventing ischemic complications associated with endoluminal devices, regardless of aneurysm rupture status.
WORLD NEUROSURGERY
(2022)
Review
Clinical Neurology
David C. Lauzier, Anna L. Huguenard, Anja I. Srienc, Samuel J. Cler, Joshua W. Osbun, Arindam R. Chatterjee, Ananth K. Vellimana, Akash P. Kansagra, Colin P. Derdeyn, Dewitte T. Cross, Christopher J. Moran
Summary: The tools and techniques used in endovascular brain aneurysm treatment have rapidly evolved in recent decades, leading to improved outcomes for patients with complex intracranial aneurysms. This review highlights the major innovations in neurointervention that have contributed to the current state of brain aneurysm treatment.
FRONTIERS IN NEUROLOGY
(2023)
Article
Clinical Neurology
Thomas Liebig, Monika Killer-Oberpfalzer, Gyula Gal, Peter Schramm, Ansgar Berlis, Franziska Dorn, Olav Jansen, Jens Fiehler, Fritz Wodarg
Summary: The study evaluated the safety and effectiveness of the Contour device for treating nonruptured bifurcation aneurysms. The results showed that the Contour device is both safe and effective in treating these aneurysms.
Article
Clinical Neurology
Victoria Hellstern, Marta Aguilar-Perez, Elina Henkes, Carmen Serna-Candel, Christina Wendl, Hansjoerg Baezner, Oliver Ganslandt, Hans Henkes
Summary: The study evaluated the safety and effectiveness of p64 FD for treating saccular, unruptured aneurysms in the posterior circulation. The results showed that p64 FD implantation is a safe and effective device with a high success rate and low complication rate.
FRONTIERS IN NEUROLOGY
(2021)
Article
Clinical Neurology
Sandeep Muram, Muneer Eesa, Brooke L. Belanger, Mohammed Almekhlafi, Mayank Goyal, William Morrish, John H. Wong, Santiago Gomez-Paz, Yosuke Akamatsu, Mohamed M. Salem, Timothy M. Robinson, Justin M. Moore, Ajith J. Thomas, Christopher S. Ogilvy, Alim P. Mitha
Summary: The study revealed that oversizing the stent and poor wall apposition can lead to aneurysm recurrence after PED placement due to elongation. A novel parameter based on two-dimensional imaging, the ML/NL ratio, was found to be significantly larger in nonoccluded aneurysms, suggesting it could predict aneurysm occlusion after PED placement.
WORLD NEUROSURGERY
(2021)
Article
Clinical Neurology
Joshua H. Weinberg, Ahmad Sweid, Batoul Hammoud, Ashlee Asada, Cannon Greco-Hiranaka, Keenan Piper, Michael Reid Gooch, Stavropoula Tjoumakaris, Nabeel Herial, David Hasan, Hekmat Zarzour, Robert H. Rosenwasser, Pascal Jabbour
Summary: This study compared the safety and efficacy of treating intracranial aneurysms using the Pipeline Embolization Device via transradial access (TRA) versus transfemoral access (TFA). The results showed that TRA was comparable to TFA in terms of safety and efficacy, but TFA was associated with significantly higher overall complication rate and longer procedure duration.
Article
Clinical Neurology
David C. Lauzier, Brandon K. Root, Yasha Kayan, Josser E. Delgado Almandoz, Joshua W. Osbun, Arindam R. Chatterjee, Kayla L. Whaley, Megan E. Tipps, Christopher J. Moran, Akash P. Kansagra
Summary: This study aimed to evaluate the safety and efficacy of Pipeline embolization for distal MCA aneurysms in the M2-M4 segments. The results showed that Pipeline embolization achieved a high rate of aneurysm occlusion (88%) with no clinical complications in our dual-center cohort. The meta-analysis demonstrated an overall aneurysm occlusion rate of 80% and a clinical complication rate of 9%.
CLINICAL NEUROLOGY AND NEUROSURGERY
(2022)
Article
Physiology
Sara Hadad, Aseem Pradhan, Ramanathan Kadirvel, David Kallmes, Juan R. Cebral, Fernando Mut
Summary: This study analyzes the impact of flow diverters treatment for intracranial aneurysms on distal blood flow, and finds that the treatment may cause significant flow reversals, which could have detrimental effects on collateral vessels. These findings are of great importance in understanding the causes of delayed intraparenchymal hemorrhages (DIPHs).
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Engineering, Biomedical
Mingzi Zhang, Yujie Li, Shin-ichiro Sugiyama, David I. Verrelli, Yasushi Matsumoto, Teiji Tominaga, Yi Qian, Simon Tupin, Hitomi Anzai, Makoto Ohta
Summary: Incomplete stent expansion (IncSE) in flow-diversion (FD) treatment of intracranial aneurysms may lead to variable haemodynamic consequences, with significant reductions in aneurysm flow-reduction performance observed when central or distal IncSE occurs, while a slight reduction in aneurysm inflow was associated with proximal IncSE. The effects of IncSE vary greatly with the location of occurrence, emphasizing the importance of individualized, patient-specific risk assessment before treatment.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2021)
Article
Mechanics
A. Yakeno, S. Obayashi
Summary: The study investigated the transition characteristics around the leading edge of a swept-back wing shape using direct numerical simulations. It was found that applying impulsive local body forces can induce coherent waves in both an attachment line and a three-dimensional boundary layer. Increasing roughness forcing can lead to the generation of stationary waves, rather than traveling waves, due to the attachment-line boundary layer being more receptive to disturbances.
Article
Physics, Fluids & Plasmas
Masahide Kuwata, Yoshiaki Abe, Sho Yokota, Taku Nonomura, Hideo Sawada, Aiko Yakeno, Keisuke Asai, Shigeru Obayashi
Summary: This study focused on a freestream-aligned circular cylinder with a low fineness ratio and used a magnetic suspension and balance system to eliminate interference from a mechanical model support. The results showed that as the fineness ratio decreases below 1.50, the size of the recirculation bubble increases and the velocity distribution gradually converges to that of a circular disk. Large-eddy simulations also revealed that the drag coefficient of the cylinder monotonically converges to that of a circular disk without a local maximum in the low-fineness-ratio regime.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Mechanics
Chenguang Lai, Liangkui Tan, Yujie Zhu, Shengji Zhu, Shigeru Obayashi
Summary: This study numerically examines the aeroacoustic characteristics of a multi-directional wing under the wing-in-ground effect. The results show that different intensities of the wing-in-ground effect led to remarkable differences in the characteristic frequency of aerodynamic noise induced by the multi-directional wing.
Article
Nanoscience & Nanotechnology
Hikaru Takami, Shigeru Obayashi
Summary: This paper proposes a comparator-based constraint handling technique, MLVM, for solving constrained optimization problems in industrial design. The MLVM structure is simple and can be easily integrated into evolutionary algorithms. The method utilizes constraint weights and tolerances to improve optimization performance and preserve diverse solutions.
Article
Mechanics
Shun Takahashi, Takayuki Nagata, Yusuke Mizuno, Taku Nonomura, Shigeru Obayashi
Summary: This study investigates the unsteady drag, unsteady lift, and particle motion caused by a planar shock wave using particle-resolved simulations of viscous flows. The analysis reveals that interference by the shock wave, Mach stem convergence, and the reflection of shock waves from other particles influence the time evolution of drag and lift. The arrangement of particles also affects their relative positions after the shock wave passes.
Article
Mechanics
Chenguang Lai, Shengji Zhu, Shuai Feng, Guangtao Zhai, Liangkui Tan, Shigeru Obayashi
Summary: This study investigates the flow characteristics and wake structure of convertible vehicles. Numerical simulations and experimental results validate the numerical model used. The wake topology and vortical generating mechanism provide insights into reducing drag and aeroacoustic noise in convertibles.
Article
Mechanics
Chenguang Lai, Liangkui Tan, Shigeru Obayashi
Summary: This study investigates the aeroacoustic control mechanism of a plasma jet on a high-speed moving wing under a wing-in-ground effect. The results show that different plasma excitation modes interfere with the vortex generation and development in different ways to achieve aeroacoustic reduction. The modal analysis reveals that the change in each order of the modal corresponds to the energy decrease at the peak frequency and the energy increase at high frequencies.
Article
Instruments & Instrumentation
Chiharu Inomata, Masahide Kuwata, Sho Yokota, Yoshiaki Abe, Hideo Sawada, Shigeru Obayashi, Keisuke Asai, Taku Nonomura
Summary: A new model-position-sensing method is proposed for magnetic suspension of low fineness ratio models. The method utilizes two line sensors parallel to the central axis of the model image and achieves high-resolution position measurements. Experimental results demonstrate the effectiveness of the method in levitating low fineness ratio circular cylinder and reentry capsule models.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Acoustics
Muhammad Shiddiq Sayyid Hashuro, Simon Tupin, Narendra Kurnia Putra, Kotaro Daibo, Kosuke Inoue, Takuro Ishii, Hiroyuki Kosukegawa, Kenichi Funamoto, Toshiyuki Hayase, Makoto Ohta
Summary: A transparent ultrasound flow phantom material composed of poly(vinyl alcohol) hydrogel (PVA-H) with dimethyl sulfoxide (DMSO) and water solution was proposed for visualizing and measuring flow inside ultrasound systems. The material's refractive index was modified to match that of glass for transparency. Feasibility tests were conducted, and an ultrasound flow phantom was fabricated for B-mode visualization and Doppler-PIV comparison. The results showed promising accuracy in velocity measurement and similarity to real tissue visualization, with some limitations regarding sound velocity and Doppler measurements.
ULTRASOUND IN MEDICINE AND BIOLOGY
(2023)
Article
Computer Science, Artificial Intelligence
Meghane Decroocq, Carole Frindel, Pierre Rouge, Makoto Ohta, Guillaume Lavoue
Summary: This paper proposes an automatic method to generate a structured hexahedral mesh suitable for CFD directly from centerlines, which offers better robustness and mesh quality compared to existing methods. It allows for easy editing of vascular models to study the impact of vascular geometry and topology on hemodynamics.
MEDICAL IMAGE ANALYSIS
(2023)
Review
Engineering, Biomedical
Makoto Ohta, Naoya Sakamoto, Kenichi Funamoto, Zi Wang, Yukiko Kojima, Hitomi Anzai
Summary: Vascular endothelial cells are exposed to mechanical stress from blood flow and their functions can be studied using specific chamber designs. The functions of these cells are closely connected to the outer layers of arteries and organs, and the interaction between smooth muscle cells in the middle layer and endothelial cells can be investigated using coculture chambers. Additionally, microfabrication technology in microfluidic devices allows for mechanical and chemical stimulation of cells to study their dynamics in vivo microenvironments.
JOURNAL OF FUNCTIONAL BIOMATERIALS
(2022)
Article
Engineering, Aerospace
Hikaru Takami, Shigeru Obayashi
Summary: This study formulates a realistic industrial conceptual design optimization problem for commercial transport airplanes, providing a baseline for research on robust and efficient optimization methods. The results demonstrate the feasibility of applying this method to the conceptual design optimization of commercial transport airplanes, including simultaneous optimization of family airplanes.
Article
Physics, Fluids & Plasmas
Simon Tupin, Kei Takase, Makoto Ohta
Summary: This study investigated the ability of a porous stent called the Multilayer Flow Modulator (MFM) to maintain renal perfusion in vascular surgery. The results showed that the MFM device was able to preserve renal perfusion thanks to its highly porous microstructure. However, overlapping MFM devices led to a decrease in certain 2D metrics, but did not affect branch perfusion.
Article
Engineering, Biomedical
Kohei Mitsuzuka, Yujie Li, Toshio Nakayama, Hitomi Anzai, Daisuke Goanno, Simon Tupin, Mingzi Zhang, Haoran Wang, Kazunori Horie, Makoto Ohta
Summary: This study aimed to improve the visibility of angioscopy operations. Through computational fluid dynamics simulations under different values for the parameters of the injection waveform, endoscope position, and catheter angle, the study found that using a stepped waveform, bottom endoscope, and three-degree-angle catheter resulted in the highest visibility, improving the success rate of angioscopy operations.
JOURNAL OF FUNCTIONAL BIOMATERIALS
(2022)
