Japan Trevo Registry: Real-world Registry of Stent Retriever Alone or in Combined Therapy with Aspiration Catheter for Acute Ischemic Stroke in Japan.

Endovascular therapy (EVT) for real-world patients after extended time frames is associated with concerns about its efficacy and safety. We conducted a prospective registry at 77 centers between November 2019 and October 2020. The registry criteria included patients treated with Trevo Retriever alone or in combined therapy with an aspiration catheter. The primary outcome was effective reperfusion (thrombolysis in cerebral infarction grade ≥ 2b), the secondary outcome was a modified Rankin scale 0-2 at 90 days, and the safety outcomes were worsening of neurologic symptoms within 24 h postoperatively, intracranial hemorrhage (ICH) within 24 h after EVT and mortality. We also exlpored the difference between patients whose last known well time (LKWT) to a puncture was less than 6 h (0-6 h) and those whose LKWT was 6 h or more but less than 24 h (6-24 h). Among the 1041 patients registered, 1025 patients were analyzed. The mean age was 76.9 years, and 53.6% of the participants were males. The 6-24 h group was 206/998 (20.6%), the median National Institute of Health Stroke Scale (NIHSS) score at admission was 18, and the median Alberta Stroke Program Early CT score was 8. Combined technique as the first pass was used on 817 (79.7%) patients. The primary outcome was 934 (91.1%). The secondary outcome was 433/1021 (42.4%). Symptomatic ICH, any ICH, and mortality were 10/1019 (1.0%), 311/1019 (30.5%), and 75 (7.3%). In the subanalysis, the 6-24 h group was lower in NIHSS (median;18 vs 16), and the secondary outcome was not significantly different in the <6 h group. Even after treatment time expansion, this result was comparable to other Trevo-based trials and nationwide registries.

Ischemic stroke in a young adult with a known epileptogenic arteriovenous malformation: illustrative case.

BACKGROUND: Brain arteriovenous malformations (AVMs) usually manifest as hemorrhages or seizures. They rarely present with ischemic symptoms, especially in young patients. We present a case of an epileptogenic AVM that led to cerebral infarction due to paradoxical embolic occlusion of the middle cerebral artery (MCA) involving the main feeder of the lesion. OBSERVATIONS: A 35-year-old male had been suffering from AVM-associated epilepsy for 10 years and was scheduled for surgery. He suddenly developed right-sided hemiconvulsions followed by hemiparalysis and impaired consciousness. Computed tomography revealed no intracerebral hemorrhage, and symptoms were initially thought to indicate epilepsy and Todd's palsy. Because of his prolonged symptoms, he underwent magnetic resonance imaging, which revealed a large cerebral infarction due to occlusion of the MCA involving the main feeder of the AVM. The patient underwent AVM resection, and the partially thrombosed nidus was completely removed. Histopathological investigation revealed a fresh thrombus in totally occluded nonarteriosclerotic feeders. He had no atrial fibrillation; however, subsequent transesophageal echocardiography revealed a patent foramen ovale, suggesting a paradoxical embolism. LESSONS: This case serves as a reminder that AVMs can present with considerable variability. Acute cerebral infarction should be considered a possible mechanism of seizures, even in patients with epileptogenic AVM.

Delayed aneurysm rupture in a patient treated with flow redirection endoluminal device: A case report and literature review.

Background: Delayed aneurysm rupture after flow-redirection endoluminal device (FRED) implantation is rare. We report a case of internal carotid-cavernous fistula (CCF) caused by a delayed aneurysm rupture of the cavernous portion of the internal carotid artery (ICA) after FRED implantation. Case Description: A 75-year-old woman had a gradually enlarging aneurysm at the C4 portion of the left ICA. We performed FRED implantation for the same. The FRED implantation procedure was smooth and the FRED expanded well and attached to the vessel wall. Five days after surgery, the patient developed a strong headache, hyperemia of the left eye, and disturbance of the left eye movement. Magnetic resonance imaging and angiography revealed a left CCF with cortical venous reflux. We performed transarterial aneurysmal and transvenous cavernous sinus embolization. Postoperatively, angiography showed no fistula and complete occlusion of the aneurysm; however, minor eye movement disorder persisted. Conclusion: To prevent the development of delayed aneurysm rupture in patients treated with FRED, preoperative consideration of whether to add coil embolization is important, even if the aneurysm is located in the C4 portion of the ICA and there is no risk of subarachnoid hemorrhage, including the size of aneurysm. In this report, we have tried to alert surgeons regarding the risk of delayed aneurysm rupture due to FRED implantation.

Stent-assisted Coil Embolization Using a Transcirculation Technique for Superior Cerebellar Artery Aneurysm: A Report of Two Cases.

Stent-assisted coil embolization (SACE) is useful for treating wide-necked aneurysms. Most superior cerebellar artery (SCA) aneurysms have a wide neck, but there are few reports of SCA aneurysms treated with SACE. One reason is that the anatomical characteristic of SCA aneurysm is not suitable for standard SACE. It is often challenging to deliver a stent to SCA via the basilar artery in an anterograde manner. In contrast, it is not difficult to deliver a stent to SCA from the anterior circulation via the posterior communicating artery. This method, in which a catheter is navigated from the anterior to the posterior circulation, is called a transcirculation technique. We report two cases of SCA aneurysm successfully treated with SACE using transcirculation technique. This approach is helpful for wide-necked SCA aneurysms.

Thrombectomy for acute large vessel occlusion in posterior and anterior circulation: a single institutional retrospective observational study.

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.

Preprocedural Prediction of Underlying Atherosclerotic Lesions in Cerebral Large-Vessel Occlusions: Clinical Backgrounds, Radiological Findings, and Treatment Outcomes.

AIMS: 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.

A case of subdural hemorrhage due to ruptured cerebral aneurysm presenting with atypical imaging features.

Acute subdural hemorrhage caused by ruptured cerebral aneurysms is rare. Herein, we report an atypical case of subdural hemorrhage caused by ruptured anterior communicating artery aneurysm in a 49-year-old woman. Computed tomography revealed subarachnoid, intracerebral, and subdural hemorrhages. After the treatment with endovascular coiling significantly decreased the patient's subdural hemorrhage. However, the subdural hemorrhage revealed and became iso-attenuation compared with the white matter on the 11th day, and hypo-attenuation on the 19th day. On the 33rd day, this subdural hemorrhage completely resolved after discontinuation of dual antiplatelet therapy. Due to rapid changes in the radiologic features of SDH, frequent computed tomography scans at least once a week may be needed especially in patients who receive antiplatelet therapy during the vasospasm phase.

A rare brainstem hemorrhage due to incomplete transvenous embolization of the cavernous sinus dural arteriovenous fistula: A case report.

Endovascular embolization is generally thought to be safe and effective for the cavernous sinus dural arteriovenous fistula (CS DAVF); however, some complications have been reported. We report an extremely rare brainstem hemorrhage associated with transvenous embolization (TVE) of CS DAVF. A 66-year-old man presented with right-sided conjunctival chemosis and exophthalmos. His brain magnetic resonance image showed right CS DAVF. Thus, emergent TVE was performed. Although his symptoms improved after the first TVE, magnetic resonance image showed brainstem edema, and venous congestion was suspected because of incomplete TVE. Second TVE was performed. Thereafter, computed tomography showed brainstem hemorrhage, resulting in the occurrence of right abducent nerve palsy, right-sided facial palsy, and ataxia. The patient's condition gradually improved, and a year has passed without recurrence. Incomplete TVE of CS DAVF can result in life-threatening complications, such as cerebral hemorrhage. To avoid these complications, the anatomical structure of the cavernous sinus should be understood accurately, and important drainage veins should be determined.

Clinical and Morphological Characteristics of Ruptured Small (<5 mm) Posterior Communicating Artery Aneurysms.

CONTEXT: Small intracranial aneurysms (IAs) are considered to have a low risk of rupture; however, in clinical practice, we often encounter patients with subarachnoid hemorrhage (SAH) due to rupture of small IAs. AIMS: This study aims to clarify the clinical and morphological characteristics of ruptured small IA, focusing on posterior communicating artery (PCoA) aneurysms as a prone site. SETTINGS AND DESIGN: We retrospectively reviewed 102 consecutive patients with SAH due to ruptured PCoA aneurysm who underwent microsurgical or endovascular aneurysm repair between April 2013 and March 2018. SUBJECTS AND METHODS: All PCoA aneurysms were diagnosed using three-dimensional rotation angiography or three-dimensional computed tomography angiography. Information regarding the following clinical characteristics was collected: age, sex, past medical history, current smoking, antithrombotic therapy, multiplicity, hydrocephalus, intracerebral hemorrhage, intraventricular hemorrhage, and World Federation of Neurosurgical Societies (WFNS) Grade on admission. STATISTICAL ANALYSIS USED: We analyzed factors of ruptured small IA, focusing on PCoA aneurysms using univariate and multivariate regression analyses. RESULTS: Univariate and multivariate analyses revealed that low aspect ratio (AR) (odds ratio [OR] = 0.33, P = 0.01) and nonfetal type of PCoA (OR = 0.31, P = 0.02) might be independent characteristics of ruptured small PCoA aneurysms. However, age, sex, past medical history, WFNS grade, and treatment outcome were not different between the small and nonsmall PCoA aneurysms. The aneurysm size was not associated to the selection of treatment, proportion of complications, and treatment outcome. CONCLUSIONS: In cases of ruptured PCoA aneurysms, low AR and nonfetal type of PCoA might be associated with rupture of small aneurysms.

One-Way Valve Method for Achieving Effective Flow Reversal on Carotid Artery Stenting.

Objective: We report a simplified method of manual transfusion with a one-way valve during carotid artery stenting (CAS) with flow reversal. Case Presentation: A 77-year-old man with cervical internal carotid artery stenosis who developed vulnerable plaques was scheduled for CAS using flow reversal. Blood flow reversal was naturally caused by the arteriovenous pressure gradient, and a method with a one-way valve, which enables simplified manual transfusion using a syringe technique, was used for the patient. CAS was completed without distal embolization. Conclusion: Manual transfusion can be simplified using a one-way valve in cases of flow reversal during CAS, which often require complicated procedures.

[Usefulness of Bilateral rSO2 Monitoring for Predicting Cerebral Hyperperfusion Syndrome after Carotid Artery Stenting].

OBJECTIVE: Cerebral hyperperfusion syndrome(CHS)and cerebral hyperperfusion phenomenon(CHP)induce intracranial hemorrhage and can become critical complications after carotid artery stenting(CAS). The purpose of the present study was to predict and avoid CHS after CAS using bilateral rSO2 intraoperative monitoring. METHODS: We retrospectively analyzed 100 consecutive patients who underwent CAS between January 2012 and May 2014 in our institution. We performed continuous bilateral rSO2 monitoring from anesthetic induction to the day following CAS. CHS was defined as the deterioration of neurological conditions post-CAS, no ischemic changes on post-CAS head CT or brain MRI, an increase in cerebral blood flow(CBF)and cerebral blood volume(CBV), and shortening of the mean transit time(MTT)or time to peak(TTP)on CT perfusion. To compare the CHS/CHP group and non-CHS/CHP group, we defined four parameters:rSO2 difference(rSO2 at the endpoint of the procedure-baseline rSO2), ΔrSO2 difference(affected side rSO2 difference-unaffected side rSO2 difference), rSO2 ratio(rSO2 at the endpoint of the procedure/baseline rSO2), and ΔrSO2 ratio(affected side rSO2 ratio/unaffected side rSO2 ratio). RESULTS: There were 2 CHS cases(2.2%)and 3 CHP cases(3.3%). In the CHS/CHP group, the ΔrSO2 difference and ΔrSO2 ratio were significantly higher than those in the non-CHS/CHP group(p value<0.05);however, no significant differences were found in the affected side rSO2 difference(p value=0.063)and affected side rSO2 ratio(p value=0.054)between the groups. CONCLUSION: We could promptly detect CHS and CHP in all cases by using continuous bilateral rSO2 monitoring and analysis of the ΔrSO2 difference and ΔrSO2 ratio.