Reversed-Image Mechanical Thrombectomy for Acute Ischemic Stroke in a Situs Inversus Totalis Patient.

An 85-year-old female with situs inversus totalis presented with right hemiplegia, right facial nerve palsy, eye deviation to the left, and aphasia. Magnetic resonance imaging revealed acute ischemic lesions in the left insular cortex and the frontal lobe. Magnetic resonance angiography revealed an occlusion of the left internal carotid artery. Reversed-image mechanical thrombectomy achieved complete reperfusion in three passes within 54 minutes. Six months post-intervention, the patient could walk indoors independently. Our technique, which replicates the normal arterial anatomy by inversion and angulation, was adapted to situs inversus totalis.

A Study of Factors Affecting Functional Outcomes in Patients With Successful Recanalization by Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: Reperfusion therapy is typically performed in cases with acute cerebral infarction. Mechanical thrombectomy (MT) achieves superior recanalization and favorable outcomes. However, some patients have poor functional prognosis despite successful recanalization. We investigated factors affecting functional prognosis after MT with good reperfusion. METHODS: Among the 205 consecutive cases with ischemic stroke treated with MT at our center from January 1, 2019 to March 31, 2021, 168 with successful recanalization were included. Factors affecting early neurological improvement (ENI) and modified Rankin Scale (mRS) scores were reviewed retrospectively. RESULTS: There were 93 (55%) cases with ENI and 75 (45%) without ENI. The times from onset to recombinant tissue-type plasminogen activator administration and recanalization in ENI cases were shorter than those in non-ENI cases. However, non-ENI cases had significantly higher Fazekas grades for white matter lesions. In multivariate analysis, the Fazekas grade was related to ENI (odds ratio [OR]=0.572, 95% confidence interval [CI]=0.345-0.948). The mRS score at discharge was 0-2 in 64 cases (good outcome) and 3-6 in 104 cases (poor outcome). Patients with a poor outcome had a significantly higher age, National Institutes of Health Stroke Scale (NIHSS) score, and Fazekas grade. Multivariate analysis revealed that the NIHSS score (OR=1.073, 95% CI=1.020-1.129) and Fazekas grade (OR=2.162, 95% CI=1.458-3.205) at hospitalization affected the mRS score at discharge. CONCLUSION: There is a correlation of greater severity of white matter lesions with poorer ENI and clinical outcomes at discharge post-MT.

Mechanical thrombectomy in acute in-stent thromboembolism.

Following the implantation of a carotid artery stent (CAS), the aetiology of in-stent occlusion typically shifts from embolic events in the acute phase to intimal hyperplasia in the chronic phase. A man in his 70s with a history of CAS implantation (performed 5 years ago) for left internal carotid artery (ICA) stenosis was admitted to our hospital with a chief complaint of left-sided transient scotoma. MRI revealed an acute occlusion of the left ICA, and an urgent digital subtraction angiography (DSA) was performed. The DSA results suggested the presence of an in-stent thrombus instead of in-stent stenosis. An urgent endovascular thrombectomy was performed, and the thrombus was successfully retrieved from the carotid stent. Full reperfusion was achieved, and no damage occurred to the carotid stent. This case highlights the importance of thorough examination of MRI and DSA findings for accurate differentiation between the causes of vessel occlusion.

Fenestration of the superior cerebellar artery diagnosed by magnetic resonance angiography.

We herein report a case of fenestration of the superior cerebellar artery (SCA), which was incidentally diagnosed by magnetic resonance (MR) angiography. A 65-year-old woman was referred to our hospital for unruptured cerebral aneurysms. MR angiography revealed 2 unruptured aneurysms. It also showed fenestration of the left SCA near its origin from the basilar artery, as well as several other vascular variations: a left common carotid artery arising from the brachiocephalic trunk, and a right vertebral artery terminating to the right posterior inferior cerebellar artery. Yearly observation was chosen as a treatment strategy due to the small size of the cerebral aneurysms. According to previous reports, SCA fenestration is an extremely rare variation. This is the second case of SCA fenestration diagnosed by MR angiography in the relevant English-language literature.

Simplified Transradial Access for Aneurysms Treatment: A Guiding System Using Solo Distal Access Catheter and Anatomical Considerations.

OBJECTIVE: The recent shift from transfemoral access to transradial access in neurointervention has led to gaps in guiding systems. We propose a useful guiding system, the solo distal access catheter system without a conventional guiding catheter or a sheath in transradial access for aneurysms treatment. We also assessed the anatomical features required for suitable patient selection. METHODS: We retrospectively collected data from consecutive patients with aneurysms treated with the solo distal access catheter system at our institution between April 2022 and April 2023, and evaluated the anatomical factors that appeared to affect the procedure. RESULTS: Of the 20 patients who underwent transradial access, 11 were treated using the solo distal access catheter system, and 10 (90.9%) completed the procedure. No radial artery occlusion was detected. The entry angle of the target vessel ranged from 37° to 139°, and the mean proximal parent artery diameter was 9.34 ± 1.48 mm. A double subclavian innominate curve was observed in 3 of 5 patients whose target vessels were the right common carotid artery. CONCLUSIONS: Using a solo distal access catheter as a guiding system for treating aneurysm proved effective and feasible with appropriate patient selection. Anatomical assessment of the entry angle of the target vessel, proximal parent artery diameter, and tortuosity may be important factors for the success of this method.

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.

Recurrent Stroke with Rapid Development of Intracranial Artery Stenosis and Subsequent Successful Mechanical Thrombectomy in Essential Thrombocythemia.

Essential thrombocythemia is a myeloproliferative neoplasm. Ischemic stroke is frequently the first manifestation of essential thrombocythemia. We herein report a patient with JAK2V617 mutation-positive essential thrombocythemia who developed recurrent ischemic stroke with rapid development of intracranial artery stenosis and subsequently underwent successful mechanical thrombectomy. The high JAK2V617F allele burden in our patient (58.4%) may have affected the patient's condition. We discuss similar reports in the literature and the possible pathophysiologic mechanism of large artery involvement in these patients.

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.

Intra-aneurysmal embolization for subarachnoid hemorrhage due to rupture of an aneurysm located at the anterior spinal artery and vertebral artery: illustrative case.

BACKGROUND: A vertebral artery-anterior spinal artery (VA-ASA) aneurysm is very rare. The authors report a case of successful coil embolization of a ruptured aneurysm of the VA-ASA. OBSERVATIONS: A 54-year-old man with World Federation of Neurosurgical Societies grade II subarachnoid hemorrhage presented with an aneurysm located at the region involving the origin of ASA on the VA. Endovascular treatment was chosen to prevent rerupture and preserve the perforating branches. The catheter shape was modified with steam forming to allow access to the aneurysm. Partial embolization was performed to preserve the ASA. The authors also prevented further rupture. On day 16, angiography showed thrombosis within the aneurysm and preserved blood flow in the ASA despite a neck remnant. The patient was discharged home with a modified Rankin Scale score of 0. Careful follow-up has been continued. LESSONS: Endovascular coiling in the acute phase of rupture of a VA-ASA aneurysm achieved favorable results. The aneurysm could be safely treated by selecting the appropriate device and catheter geometry.

The optimal management of ruptured basilar artery dissecting aneurysms: a case series and scoping review.

The natural history of ruptured basilar artery dissecting aneurysms (BADAs) remains unclear compared to that of ruptured vertebral artery dissecting aneurysms (VADAs). In this study, we investigated the natural history and optimal management of ruptured BADAs. We identified 17 patients with ruptured BADA among 4586 patients with aneurysmal subarachnoid hemorrhage (SAH) treated in seven participating hospitals. A scoping literature review was undertaken to investigate prognostic factors. Six patients among the profiled patients (35.3%) died, all with poor SAH grades (World Federation of Neurological Societies Grade IV and V). Rebleeding after admission was observed in three patients (17.6%) with poor SAH grades. Aggressive treatment and conservative management were initiated in seven and ten patients, respectively. Patients with good SAH grades had significantly higher favorable treatment outcomes than those with poor grades (83.3% vs. 9.1%, P = 0.005). Moreover, based on a scoping review of 158 cases with ruptured BADA, including the patients from our series, approximately 90% of patients with good SAH grades had favorable outcomes. A good SAH grade and no rebleeding after admission were favorable prognostic factors (P < 0.0001 and P = 0.002, respectively). The rebleeding rates were 20.2%, 13.3%, and 6.3% for dilated, pearl and string, and stenotic lesions, respectively. We concluded that the natural history of isolated ruptured BADAs may be better than that of VADAs. Although definitive treatment, if possible, is undoubtedly important, conservative management with careful radiological follow-up for morphological changes might be a viable option for patients in good clinical condition and with non-dilated lesions.

Status of neurological deficits after mechanical thrombectomy in elderly patients with ischemia.

BACKGROUND: Numerous studies report poorer outcomes after mechanical thrombectomy (MT) in elderly patients than in non-elderly patients. We aimed to investigate the changes in neurological symptoms after MT in elderly patients. METHODS: We included 151 patients with acute stroke who independently performed activities of daily living before admission, underwent MT at our hospital between January 1, 2019 and December 31, 2021, and had successful recanalization (thrombolysis in cerebral infarction grade >2b). The subjects were divided into two groups according to whether they were aged ≥80 years (elderly group) or <80 years (non-elderly group), and the National Institutes of Health Stroke Scale (NIHSS) scores and deep and subcortical white matter hyperintensity (DSWMH) grades were compared between both groups. RESULTS: There were 57 (38 %) and 94 (62 %) patients in the elderly and non-elderly groups, respectively. After propensity score matching, the median (interquartile range) NIHSS scores were significantly higher in the elderly group than in the non-elderly group at both 24 h (12 [5.5-19] vs 8; [2-14] P = 0.040) and 1 week (8 [3-12] vs 2.5 [0-13.5]; P = 0.041) after MT but not before MT (18 [13.5-22.5] vs 20 [14.5-24]; P = 0.549). DSWMH grades were significantly higher in the elderly group than in the non-elderly group (2 [1-3] vs 1 [0-2]; P = 0.018). CONCLUSIONS: MT in the elderly group was associated with poorer improvement in neurological symptoms from the early period after MT than in the non-elderly group, even when successful recanalization was achieved. White matter lesions may contribute to the poor neurological improvement after recanalization in the elderly group.

Predictors of Ischemic Complication in Anterior Choroidal Artery Aneurysm Repair.

BACKGROUND: Treatment of anterior choroidal artery (AchoA) aneurysms is challenging because of the risk of artery injury. The objective of the study was to evaluate the incidence and predictors of AchoA infarction in patients who underwent surgical or endovascular procedure. METHODS: We included 123 patients with AchoA aneurysms treated by surgical clipping (n = 62; 50.4%) or endovascular coiling, including flow diverter placement (n = 61; 49.6%). The clinical and radiological data were retrospectively analyzed. AchoA infarction was defined as the presence of a hyperintense signal on diffusion-weighted imaging in the area of AchoA, including the posterior limb of the internal capsule. RESULTS: AchoA infarction was detected in 8 cases (6.5%), with similar incidence in both groups (6.5% [4/62] vs. 6.6% [4/61]). It occurred in ruptured aneurysms more frequently than in unruptured aneurysms (14.3% [6/42] vs. 2.5% [2/81], P = 0.019). In the surgical group, all 4 affected patients had a non-proximal type AchoA, whereas in the non-infarction group, 9 patients (15.5%) had a non-proximal type AchoA (P = 0.001). In the endovascular group, the incidence was higher in patients with ruptured aneurysms (17.3% [4/23] vs. 0% [0/38], P = 0.017) and lower in patients with pre-admission antiplatelet therapy (0% [0/39] vs. 18.8% [4/22], P = 0.014). CONCLUSIONS: Repair of an AchoA aneurysm is associated with the risk of incurring post-procedural AchoA infarction. Surgical clipping and endovascular coiling have similar complication rates, but risk factors specific to each intervention exist. Careful surgical planning to avoid these risk factors in each therapeutic modality may improve patient outcomes.

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.

Clinical Features of Ruptured Very Small Intracranial Aneurysms (<3 mm) in Patients with Subarachnoid Hemorrhage.

OBJECTIVE: Although small unruptured aneurysms rarely rupture, many patients with subarachnoid hemorrhage (SAH) have ruptured small, especially very small intracranial aneurysms (VSIAs; <3 mm) in clinical practice. We aimed to clarify the proportion and clinical features of patients with SAH with ruptured VSIAs. METHODS: 609 patients with ruptured intracranial aneurysms diagnosed at our institution from January 2012 to December 2018 were retrospectively analyzed. We classified patients into 2 groups based on ruptured aneurysm size: VSIAs or non-VSIAs (≥3 mm). We analyzed age, sex, location of aneurysms, World Federation of Neurological Surgeons grade on admission, treatment modality, and outcome at discharge. RESULTS: Among 609 patients, 103 had ruptured VSIAs. The proportion of young patients (age <40 years) was greater in the VSIA group than the non-VSIA group (10.7% vs. 3.6%, P = 0.002). The proportions of VSIAs located in the middle cerebral and vertebrobasilar arteries were relatively low and high, respectively (P = 0.002, 0.005). Significantly more patients with VSIAs than those with non-VSIAs were classified under World Federation of Neurological Surgeons grade I-III (70.9% vs. 56.3%, P = 0.006). Coil embolization was preferred for VSIAs (68.0% vs. 32.0%, P = 0.006). Outcomes were more favorable in the VSIA group than in the non-VSIA group. CONCLUSIONS: Small unruptured aneurysms rarely rupture; however, many patients with SAH have ruptured VSIAs in clinical practice. We observed that VSIA rates among ruptured aneurysms were fairly high. Age, posterior circulation location, and preferable outcome may be important clinical characteristics of ruptured VSIAs.

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.

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.

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.