Publications by authors named "Kohei Shibuya"

5 Publications

  • Page 1 of 1

Hemodynamic features of an intracranial aneurysm rupture predicted by perianeurysmal edema: A case report.

Surg Neurol Int 2021 10;12:49. Epub 2021 Feb 10.

Department of Neurosurgery, Niigata University, Brain Research Institute, Niigata, Japan.

Background: Perianeurysmal edema (PAE) has been suggested as an indicator of potential aneurysm rupture; however, the hemodynamic features of these aneurysms are still unknown. A computational fluid dynamic (CFD) analysis was performed to evaluate the hemodynamic features of a very rare case of a ruptured middle cerebral artery (MCA) aneurysm with PAE.

Case Description: A 65-year-old woman presented with disturbed consciousness. A subarachnoid hemorrhage due to an azygos anterior cerebral artery (ACA) aneurysm rupture was suspected. An unruptured MCA aneurysm with PAE was identified in the left temporal lobe. Although the ACA aneurysm was clipped to prevent re-bleeding, the MCA aneurysm subsequently ruptured 6 days later. Clipping of the MCA aneurysm was performed, and hemosiderin deposits suggestive of sentinel bleeding were found on the surface of the aneurysm dome. CFD analysis revealed unstable hemodynamic stress at the expanded bleb area after rupture, localized to the rupture site. Moreover, this analysis revealed flow impingement with pressure elevation and low wall shear stress, which indicated increased inflammation and aneurysm wall thinning that likely led to rupture.

Conclusion: Hemosiderin deposits at the aneurysm wall and PAE indicates leakage from a cerebral aneurysm. Hemodynamic stress at the aneurysm may promote an inflammatory response and lead to wall weakening accompanied by PAE. Based on our findings, we recommend that surgical intervention should be considered as the first line of treatment for such aneurysms to prevent rupture.
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http://dx.doi.org/10.25259/SNI_780_2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7911146PMC
February 2021

Delayed Bleeding of Unruptured Intracranial Aneurysms After Coil Embolization: A Retrospective Case Series.

World Neurosurg 2021 Feb 20. Epub 2021 Feb 20.

Department of Neurosurgery, Brain Research Institute, Niigata University, Niigata, Japan.

Objective: Delayed bleeding of unruptured intracranial aneurysms (UIAs) after coil embolization is rare; this study aimed to analyze the occurrence of delayed bleeding of UIAs after coil embolization.

Methods: We retrospectively analyzed patients with UIAs after coil embolization between January 2002 and December 2018 and assessed the features of UIAs with delayed bleeding after coil embolization.

Results: Analysis included 307 patients with 335 UIAs. Mean follow-up was 7.1 ± 4.9 years, and total follow-up was 2365 aneurysm-years. There were 271 (80.9%) aneurysms located in the anterior circulation and 64 (19.1%) aneurysms located in the posterior circulation. Significant differences were observed between the 2 groups in terms of maximum size of the aneurysm (P < 0.01), width of the aneurysm neck (P < 0.01), and number of retreatment cases (P < 0.01). During the follow-up period, delayed bleeding occurred in 4 aneurysms (annual bleeding rate of 0.17%); all were located in the posterior circulation. The original size was not relatively large (mean 8.6 ± 2.4 mm). All aneurysms bled within 5 years (mean 35 ± 9.6 months) after the initial treatment. Two were de novo aneurysms that developed adjacent to the coiled aneurysms and were not detected on follow-up magnetic resonance angiography.

Conclusions: Cautious follow-up of UIAs with digital subtraction angiography is important, articularly within the first 5 years after the procedure. If there are changes in the anatomic outcomes, short-term reassessment or additional treatment should be actively considered, particularly for aneurysms in the posterior circulation.
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http://dx.doi.org/10.1016/j.wneu.2021.02.061DOI Listing
February 2021

Unilateral oculomotor nerve palsy caused by arterial compression accompanying subarachnoid hemorrhage: a case report.

Acta Neurochir (Wien) 2021 03 5;163(3):813-816. Epub 2020 Nov 5.

Department of Neurosurgery, Brain Research Institute, Niigata University, 1-757 Asahimachidori, Chuo-ku, Niigata, Niigata, 951-8585, Japan.

Unilateral oculomotor nerve palsy, often caused by aneurysmal compression, is one of the decisive findings for confirming the site of a ruptured aneurysm. However, arterial compression can also cause unilateral oculomotor nerve palsy. Here, we present the case of a 59-year-old woman with a ruptured right internal carotid-posterior communicating artery aneurysm accompanied by contralateral oculomotor nerve palsy. The nerve was found to be compressed by the posterior cerebral artery and was isolated from the ruptured aneurysm. When confirming a ruptured aneurysm based on the evidence of unilateral oculomotor palsy, the arteries surrounding the nerve must be thoroughly assessed.
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http://dx.doi.org/10.1007/s00701-020-04633-xDOI Listing
March 2021

Safety and feasibility of the distal transradial approach: A novel technique for diagnostic cerebral angiography.

Interv Neuroradiol 2020 Dec 13;26(6):713-718. Epub 2020 May 13.

Department of Neurosurgery, Brain Research Institute, Niigata University, Niigata, Japan.

Purpose: We aimed to evaluate the safety and feasibility of the distal transradial approach (DTRA) as a novel technique for cerebral angiography based on our institutional initial experience.

Methods: We retrospectively analyzed our institutional database of consecutive diagnostic cerebral angiographies performed with DTRA from December 2018 to August 2019. Patient demographics and clinical and procedural data were recorded.

Results: In total, 51 diagnostic cerebral angiographies in 51 patients (age, 15-83 years; mean age, 59.4 years, SD 13.5; 35 (69%) females) were performed or attempted with DTRA. Ultrasound evaluation showed that the mean inner distal radial artery diameter was significantly smaller than the mean inner forearm radial artery diameter (2.19 mm vs. 2.56 mm, P < 0.001). Cannulation via the distal radial artery was successful in 47 (92%) procedures. In the four procedures that failed, operators converted to the ipsilateral transradial approach without repositioning or redraping. Selective catheterization of the intended vessel was achieved in 64 (91%) of 70 vessels. In the remaining six, operators achieved the objective of the examination with angiography injecting from proximal and conversion to another approach was not required. One patient experienced temporary numbness around the puncture site after the procedure. No radial artery occlusion was identified in the patients who underwent ultrasound evaluation.

Conclusion: Our results demonstrate that DTRA could become a standard approach for diagnostic cerebral angiography owing to the low complication rate and the high cannulation success rate.
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http://dx.doi.org/10.1177/1591019920925709DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724605PMC
December 2020

Treatment Strategies for Infectious Intracranial Aneurysms: Report of Three Cases and Review of the Literature.

Neurol Med Chir (Tokyo) 2019 Sep 4;59(9):344-350. Epub 2019 Jul 4.

Department of Neurosurgery, Brain Research Institute, Niigata University.

We retrospectively reviewed the cases of three patients with infectious intracranial aneurysms (IIAs), and discuss the indications for surgical and endovascular treatments. We treated two men and one woman with a total of six aneurysms. The mean age was 43.3 years, ranging from 36 to 51 years. One patient presented initially with an intraparenchymal hemorrhage, one with mass effect, and the other one had four aneurysms (one causing subarachnoid hemorrhages and the other causing delayed intraparenchymal hemorrhages). The average size of all aneurysms was 12.2 mm (range, 2-50 mm). They were preferentially located in the distal posterior cerebral artery, and then, in the middle cerebral artery. All cases were caused by infective endocarditis. We selected endovascular treatments for five aneurysms and treated all but one within 24 h from detection. One aneurysm was treated by combined therapy with endovascular intervention and surgery. After treatment, none of the IIAs presented angiographical recurrence or re-bleeding. If feasible, endovascular treatment is probably the first choice, but a combined surgical and endovascular approach should be considered if surgery or endovascular treatment alone are not feasible. The method of treatment should be individualized. For cases with high risk of aneurysm rupture, treatment should be performed as soon as possible.
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http://dx.doi.org/10.2176/nmc.oa.2019-0051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6753255PMC
September 2019