Purpose Thrombectomy has been the gold standard therapy for anterior circulation occlusion; however, studies regarding thrombectomy in posterior circulation are lacking. In this study, we compared the efficiency of thrombectomy for acute large vessel occlusion between the posterior and anterior circulation at a single institution. Methods We retrospectively analyzed consecutive patients who underwent thrombectomy for acute large vessel occlusion at our institution between August 2014 and April 2021. Differences in the clinical background, time course, and treatment technique and outcomes were evaluated between anterior and posterior circulation occlusions. Results Overall, 353 patients (225 men and 128 women) were included: 314 patients had anterior circulation occlusion and 39 patients had posterior circulation occlusion. Between the patients with anterior and posterior circulation occlusions, the National Institutes of Health Stroke Scale (NIHSS) score (16 [12–21] vs. 29 [19–34], respectively, p < 0.001), door-to-puncture time (65 [45–99] vs. 99 [51–121] min, respectively, p = 0.018), and mortality (22 [7%] vs. 8 [20.5%] patients, respectively, p = 0.010) were significantly different; however, favorable outcome was not significantly different. Conclusion Higher NIHSS score, delayed treatment, and higher mortality were observed in posterior circulation occlusion than in anterior circulation occlusion; successful reperfusion and favorable outcomes were similar between them. Similar favorable outcomes and reperfusion ratio to the anterior circulation might be achieved also in the posterior circulation; however, delayed treatment and the optimal first-pass strategy might need further improvement.

Mechanical thrombectomy using a standard device has been effective for acute cerebral large-vessel occlusions, particularly those due to cardiogenic embolism. However, evidence for those with underlying atherosclerotic lesions is lacking. In this study, we evaluated the predictive factors, treatment details, and outcomes of acute cerebral large-vessel occlusions with underlying atherosclerotic lesions in patients who underwent mechanical thrombectomy. Methods:We retrospectively analyzed consecutive patients with acute large-vessel occlusions who underwent mechanical thrombectomy at our institution between August 2014 and May 2021. Predictive factors of underlying atherosclerotic lesions were evaluated using univariate and multivariate analyses. In addition, treatment details and outcomes were evaluated and compared with those of other etiologies.Results: Among 322 included patients, 202 (62.7%) were males and 65 (20.2%) had underlying atherosclerotic lesions. Multivariate analysis identified dyslipidemia, lack of arterial fibrillation documented on admission, smoking, internal carotid artery lesions, and stenosis ≥ 25% in non-occluded large vessels as predictive factors of underlying atherosclerotic lesions. Regarding treatment for underlying atherosclerotic lesions, the need for percutaneous transluminal angioplasty, stent placement, medical therapy, and longer procedure time were observed, while successful reperfusion rates, favorable outcomes, and mortality rates showed no significant differences with those of other etiologies. Conclusion:Coexisting diseases and radiological findings were useful for predicting underlying atherosclerotic lesions. Further understanding these characteristics may lead to the early detection of underlying atherosclerotic lesions, optimal treatment strategies, and better outcomes.have shifted toward eligibility criteria expansion and revascularization rate improvement. The aforementioned randomized studies have indicated the effectiveness of the procedure at ＜6 hours from onset; however, clinical-imaging mismatch has also been observed at ＞6 hours from onset in two subsequent randomized

Small cerebral aneurysms that occur at non-branching sites are generally considered to have extremely weak aneurysm walls or a pseudoaneurysm formed by a thrombus. Since conventional clipping and coil embolization are difficult and high-risk, trapping with bypass has been considered the preferred treatment method. The aim of this study is to investigate a case of trapping with high-flow bypass for a ruptured aneurysm at non-branching sites of the middle cerebral artery (MCA). In this study, the CT results indicated subarachnoid hemorrhage, while the CT angiography (CTA) results showed a small aneurysm at the nonbranching site of the MCA M1 segment. Moreover, the intraoperative digital subtraction angiography (DSA) results strongly suggested a pseudoaneurysm. The aneurysm was judged to be a pseudoaneurysm over the rupture site of the true aneurysm sac. Coil embolization was performed, but the treatment was interrupted as the aneurysm completely disappeared during the procedure. However, based on the magnetic resonance angiography findings, the aneurysm reappeared on day five and became enlarged. Thus, trapping with highflow bypass was performed on day 15 and the patient was cured. Owing to the unusual and noteworthy course of this case, trapping with high-flow bypass was considered to be the safest and most reliable firstchoice treatment procedure for pseudoaneurysm at non-branching sites of the MCA.

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The increase in the rate of mRNA vaccination against coronavirus disease 2019 (COVID-19) worldwide has been accompanied by reports of an increase in the side effects of the vaccine. In the field of neurosurgery, several cases of venous thrombosis have been reported as possible complications after COVID-19 vaccination. However, no such side effects have been reported in patients with brain tumors, and COVID-19 vaccination is considered safe for this patient population. In this report, we present the cases of two patients with brain tumors who experienced intratumoral hemorrhage as a possible side effect of the COVID-19 vaccine. In the first case, a 54-year-old man who had received CyberKnife treatment for a vestibular schwannoma eight years prior presented with tongue discomfort, right-side facial numbness, and dizziness since the day after his COVID-19 vaccination. MRI revealed intratumoral hemorrhage of the vestibular schwannoma. The second patient was a 60-year-old woman who presented with a sudden-onset headache and vomiting that had started three days after her COVID-19 vaccination. CT revealed a meningioma with intratumoral hemorrhage. Both patients had undergone surgery prior to this presentation, and their symptoms had improved. They had no risk factors for intratumoral hemorrhage, suggesting that it may be a side effect of the mRNA vaccine against COVID-19. Although the causal relationship is unclear, acute inflammation with predominantly lymphocytic infiltration and thrombogenicity after COVID-19 vaccination may damage the fragile microcirculation of the tumor.