Characteristics of MRI Findings after Subarachnoid Hemorrhage and D-Dimer as a Predictive Value for Early Brain Injury.

BACKGROUND: The pathological mechanisms of early brain injury (EBI) have remained obscure. Several studies have reported on the neuroradiological findings of EBI. However, to our knowledge, no study has attempted to explore the mechanism of EBI after subarachnoid hemorrhage (SAH). Therefore, this study evaluates whether the initial plasma D-dimer levels were associated with EBI, classifies magnetic resonance imaging (MRI) findings, and speculates about the mechanism of EBI. METHODS: This study included 97 patients hospitalized within 24 h from the onset of nontraumatic SAH. The patients underwent MRI within 0-5 days from onset (before vasospasm) to detect EBI. EBI was radiologically defined as diffusion-weighted imaging (DWI)-positive lesions that appear dark on apparent diffusion coefficient maps, excluding procedure-related lesions. EBI, plasma D-dimer levels, and clinical features were retrospectively investigated. RESULTS: Elevated D-dimer levels were associated with poor outcomes. Patients with EBI had significantly higher D-dimer levels than those without EBI. EBI was detected in 24 patients (27.3%) of all, and in 22 (45%) of 49 patients with World Federation of Neurosurgical Societies (WFNS) grade 4-5 SAH. EBI was frequently observed in the paramedian frontal lobe. There were several types of the pathology in EBI, including widespread symmetrical cerebral cortex lesions, focal cortex lesions, periventricular injury, and other lesions impossible to classify due to unknown mechanisms such as thrombotic complication and microcirculatory disturbance, ultra-early spasm, and spreading depolarization. CONCLUSIONS: This study suggests that D-dimer levels predict poor outcomes in patients with SAH and that EBI was associated high D-dimer levels.

Impact of Antiplatelets and Anticoagulants on the Prognosis of Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) associated with antithrombotic therapy (AT) is becoming more common as the use of those medications increases in the aging population. METHODS: This study included 490 consecutive patients hospitalized for nontraumatic ICH in a single center during an 8-year period, which was subdivided into former (2008-2011) and latter (2012-2015). Patients were classified into those with no antithrombotic drugs (NATs) and those with AT. The AT group was divided into 4 subgroups according to medications: antiplatelet (AP1), multiple antiplatelets (AP2), anticoagulant (AC), and antiplatelet and anticoagulant (APC). We evaluated the clinical characteristics and prognosis and compared the number of patients on AT between the former and latter groups. RESULTS: There were 125 patients treated with AT (25.5%), including 50 (10.2%) on AP1, 14 (2.9%) on AP2, 32 (6.5%) on ACs, and 29 (5.9%) on APCs. Compared with the former group, the latter group had a higher number of patients on AT (19.3% versus 31.7%), AP1 (9.8% versus 10.6%), AP2 (1.6% versus 4.1%), ACs (4.9% versus 8.1%), and APCs (2.90% versus 8.9%). Compared with the NAT group, the patients in the AT group had a larger ICH volume, more frequent hematoma expansion, and higher rate of poor outcome, particularly for those on APCs. CONCLUSION: The number of ICH patients on AT has increased; these patients were more likely to have a poor prognosis than those who were not on AT. Care should be taken when giving a combination of antiplatelets and anticoagulants in ICH.

[Dural Arteriovenous Fistulae in the Tentorium Manifesting as Dementia].

BACKGROUND: Tentorial dural arteriovenous fistula(dAVF)is a relatively rare disease which accounts for about 4.8% of all types of dAVF reported in Japan. Approximately 12.5% of intracranial dAVFs manifest with dementia-like symptoms. However, a tentorial dAVF typically presents more aggressively and rarely manifests as dementia. Here, we report the case of a patient with a tentorial dAVF manifesting as dementia, who was successfully treated with surgical interruption of the draining vein using indocyanine green video angiography(ICG-VA). CASE PRESENTATION: A case of a 69-year-old man with a history of colon cancer, hypertension, and previous stroke presenting with cognitive impairment. CT showed multiple intracranial hemorrhages in the left parietal and occipital lobes, and MRI demonstrated flow void in the left cerebellopontine angle. DSA revealed left tentorial dAVF with venous reflux. We performed surgical interruption of the draining vein. The patient's mental status immediately returned to baseline. Serial MRIs showed decreasing edema in the left occipital lobe and thalamus. CONCLUSIONS: Cognitive impairment is an uncommon but curable symptom of tentorial dAVF. Surgical interruption of the draining vein using ICG-VA is a relatively simple and safe procedure to perform in such a case.

[Efficacy of Stent-Assisted Coil Embolization for a Dissecting Aneurysm of the Cervical Internal Carotid Artery Caused by a Systemic Vascular Disease: A Case Report].

Systemic vascular diseases such as fibromuscular dysplasia, Ehlers-Danlos syndrome, Marfan syndrome, and Behçet's disease are known to cause spontaneous dissecting aneurysms of the cervical internal carotid artery. These diseases are generally associated with vascular fragility; therefore, invasive treatments are avoided in many cases of dissecting aneurysms, and a conservative approach is used for the primary disease. Surgical or intravascular treatment may be chosen when aneurysms are progressive or are associated with a high risk of hemorrhage; however, there is no consensus on which treatment is better. We report a case of a dissecting aneurysm of the cervical internal carotid artery in a patient with suspected Behçet's disease, which was treated using stent-assisted coil embolization. A man in his 40's, with suspected Behçet's disease, presented with an enlarged dissecting aneurysm of the right cervical internal carotid artery. The lesion was present for approximately 10 years. We performed stent-assisted coil embolization for the lesion. Post-surgery, no aneurysms were detected with carotid artery echography. Our case report suggests that stent-assisted coil embolization is a promising treatment for dissecting aneurysms of the cervical internal carotid artery. In addition, the procedure demonstrates the utility of carotid artery echograms for examining recanalization after stent-assisted coil embolization.

Short-, middle- and long-term safety of superparamagnetic iron oxide-labeled allogeneic bone marrow stromal cell transplantation in rat model of lacunar infarction.

Recently, both basic and clinical studies demonstrated that bone marrow stromal cell (BMSC) transplantation therapy can promote functional recovery of patients with CNS disorders. A non-invasive method for cell tracking using MRI and superparamagnetic iron oxide (SPIO)-based labeling agents has been applied to elucidate the behavior of transplanted cells. However, the long-term safety of SPIO-labeled BMSCs still remains unclear. The aim of this study was to investigate the short-, middle- and long-term safety of the SPIO-labeled allogeneic BMSC transplantation. For this purpose, BMSCs were isolated from transgenic rats expressing green fluorescent protein (GFP) and were labeled with SPIO. The Na/K ATPase pump inhibitor ouabain or vehicle was stereotactically injected into the right striatum of wild-type rats to induce a lacunar lesion (n = 22). Seven days after the insult, either BMSCs or SPIO solution were stereotactically injected into the left striatum. A 7.0-Tesla MRI was performed to serially monitor the behavior of BMSCs in the host brain. The animals were sacrificed after 7 days (n = 7), 6 weeks (n = 6) or 10 months (n = 9) after the transplantation. MRI demonstrated that BMSCs migrated to the damage area through the corpus callosum. Histological analysis showed that activated microglia were present around the bolus of donor cells 7 days after the allogeneic cell transplantation, although an immunosuppressive drug was administered. The SPIO-labeled BMSCs resided and started to proliferate around the route of the cell transplantation. Within 6 weeks, large numbers of SPIO-labeled BMSCs reached the lacunar infarction area from the transplantation region through the corpus callosum. Some SPIO nanoparticles were phagocytized by microglia. After 10 months, the number of SPIO-positive cells was lower compared with the 7-day and 6-week groups. There was no tumorigenesis or severe injury observed in any of the animals. These findings suggest that BMSCs are safe after cell transplantation for the treatment of stroke.

Pathological findings of saccular cerebral aneurysms-impact of subintimal fibrin deposition on aneurysm rupture.

Although several studies have suggested that aneurysmal wall inflammation and laminar thrombus are associated with the rupture of saccular aneurysms, the mechanisms leading to the rupture remain obscure. We performed full exposure of aneurysms before clip application and attempted to keep the fibrin cap on the rupture point. Using these specimens in a nearly original state before surgery, we conducted a pathological analysis and studied the differences between ruptured and unruptured aneurysms to clarify the mechanism of aneurysmal wall degeneration. This study included ruptured (n = 28) and unruptured (n = 12) saccular aneurysms resected after clipping. All of the ruptured aneurysms were obtained within 24 h of onset. Immunostainings for markers of inflammatory cells (CD68) and classical histological staining techniques were performed. Clinical variables and pathological findings from ruptured and unruptured aneurysms were compared. Patients with ruptured or unruptured aneurysms did not differ by age, gender, size, location, and risk factors, such as hypertension, smoking, and hyperlipidemia. The absence or fragmentation of the internal elastica lamina, the myointimal hyperplasia, and the thinning of the aneurysmal wall were generally observed in both aneurysms. The existence of subintimal fibrin deposition, organized laminar thrombus, intramural hemorrhage, neovascularization, and monocyte infiltration are more frequently observed in ruptured aneurysms. Multivariate logistic regression analysis showed that ruptured aneurysm was associated with presence of subintimal fibrin deposition and monocyte infiltration. These findings suggest that subintimal fibrin deposition and chronic inflammation have a strong impact on degeneration of the aneurysmal wall leading to their rupture, and this finding may be caused by endothelial dysfunction.

Surgical Outcomes for Cervical Carotid Artery Stenosis: Treatment Strategy for Bilateral Cervical Carotid Artery Stenosis.

BACKGROUND: Carotid endarterectomy (CEA) and carotid stenting (CAS) are beneficial procedures for patients with high-grade cervical carotid stenosis. However, it is sometimes difficult to manage patients with bilateral carotid stenosis. To decide the treatment strategy, one of the most important questions is whether contralateral stenosis increases the risk of patients undergoing CEA. METHODS: This retrospective study included 201 patients with carotid stenosis who underwent a total of 219 consecutive procedures (CEA 189/CAS 30). We retrospectively analyzed outcomes in patients with carotid stenosis who were treated with either CEA or CAS and evaluated whether or not contralateral lesions increases the risk of patients undergoing CEA or CAS. Furthermore, we retrospectively verified our treatment strategy for bilateral carotid stenosis. RESULTS: The incidences of perioperative complications were 5.3% in the CEA patients and 6.7% in the CAS patients, respectively. There was no significant difference between these 2 groups. The existences of contralateral occlusion and/or contralateral stenosis were not associated with perioperative complications in both the groups. There were 32 patients with bilateral severe carotid stenosis (>50%). Of those, 13 patients underwent bilateral revascularizations; CEA followed by CEA in 8, CEA followed by CAS in 3, CAS followed by CEA + coronary artery bpass grafting in 1, and CAS followed by CAS in 1. CONCLUSIONS: Our date showed that the existence of contralateral carotid lesion was not associated with perioperative complications, and most of our cases with bilateral carotid stenosis initially underwent CEA.

The impact of atherosclerotic factors on cerebral aneurysm is location dependent: aneurysms in stroke patients and healthy controls.

Previous studies have indicated that cerebrovascular diseases (CVDs) seem to increase the occurrence of unruptured intracranial aneurysms (UIAs). However, this maybe explained by the fact that CVDs and UIAs share common risk factors, such as hypertension (HT) and smoking. To clarify the impact of atherosclerotic risk factors on cerebral aneurysmal formation, we explored the incidence of UIAs and their locations in healthy controls and patients with CVD, who frequently have atherosclerotic risk factors. This study included consecutive 283 asymptomatic healthy adults and 173 acute stroke patients, from patients diagnosed with acute cerebral hemorrhage or cerebral infarction and admitted to our hospital. The incidence, maximum diameter, and location of UIAs were evaluated, and we also investigated the following factors: age, gender, current smoking, HT, diabetes mellitus (DM), and dyslipidemia. UIAs were found in 19 of the total 456 subjects (4.2%), 11 of 283 healthy subjects (3.9%), and 8 of 173 stroke patients (4.6%). These differences are not statically significant. The incidence of middle cerebral artery (MCA) aneurysms was significantly higher in the CVD patients than in the healthy controls (P = .03), and the incidence of paraclinoid aneurysms was significantly higher in the healthy controls than in the CVD patients (P = .03). Moreover, higher incidences of HTs and CVDs in the MCA aneurysms than in the other locations of UIAs were observed. These results indicate that the impact of atherosclerotic factors on cerebral aneurysmal formation depends on their location and that there is a stronger impact on MCA aneurysms than on paraclinoid aneurysms.

Treatment strategy for bilateral carotid stenosis: 2 cases of carotid endarterectomy for the symptomatic side followed by carotid stenting.

Since the introduction of carotid stenting (CAS), a combined treatment for bilateral lesions using carotid endarterectomy (CEA) and CAS has been developed. However, there has been only 1 report about CEA then CAS. Herein we describe 2 patients with bilateral severe carotid stenosis who were treated by CEA for the symptomatic side and CAS for the contralateral asymptomatic side. A 71-year-old man underwent CEA for the symptomatic side. Although the patient suffered hyperperfusion syndrome after CEA, he recovered fully after 3 weeks of rehabilitation. Two months later, CAS was performed for the asymptomatic side, and he was discharged with no deficit. A 67-year-old man underwent CEA for the symptomatic side. The patient developed no postoperative neurologic deficits except for hoarseness. Four weeks later, CAS was performed for the contralateral asymptomatic side. After the procedure, however, severe hypotension occurred, and treatment by continuous injection of catecholamine was necessary to maintain systematic blood pressure. The patient was ultimately discharged with no deficit. The combined therapy of CAS for the asymptomatic side and then CEA for the symptomatic side has been recommended by several authors. However, one of the problems of this strategy is the higher incidence of postprocedural hemodynamic complications, and hypotension after CAS may be dangerous for the symptomatic hemisphere. We suggest a combined therapy using CEA for the symptomatic side and then CAS for the asymptomatic side can be 1 beneficial treatment option for patients with bilateral carotid stenosis without coronary artery disease.

Two illustrative cases of traumatic intracranial cerebral artery dissection in children.

Traumatic intracranial cerebral artery dissection (ICAD) in the pediatric population is relatively rare. We report two traumatic ICAD cases in children. Case 1: A 13-year-old boy presented with headache and left hemiparesis after body contact while playing basketball. We found a cerebral infarction in the middle cerebral artery territory and dissection at the bifurcation of the right internal carotid artery and posterior communicating artery. Six days after onset, his right hemiparesis deteriorated, and the infarction progressed. Therefore, bypass surgery was performed. Three months later, he regained the ability to walk without a cane and resumed school. Case 2: A 10-year-old boy fell while skiing and experienced a severe headache several hours later. Neuroradiological examination revealed a subarachnoid hemorrhage in the basal cistern without aneurysm. Six days after admission, magnetic resonance angiography revealed stenotic changes and an irregularly shaped basilar artery (BA). On day 7, an angiogram confirmed BA dissection. The patient's headache gradually improved, and the irregular shape of the BA normalized 3 weeks later. He was discharged without any neurological deficits. Determining whether vascular reconstruction should be performed is challenging. However, we believe that therapeutic intervention should be performed promptly when symptoms or brain images deteriorate.

Long-term prognosis in patients with clipped unruptured cerebral aneurysms--increased cerebrovascular events in patients with surgically treated unruptured aneurysms.

We retrospectively investigated surgical immediate and long-term overall results after clipping of the unruptured aneurysms. Between 1991 and 2008, 166 patients underwent neck clipping of unruptured saccular aneurysms at our institute. Patients were subsequently followed to clarify the occurrence of subarachnoid hemorrhage (SAH), and stroke other than SAH, aneurysm recurrence, cerebrovascular death, all-cause death, and risk factors. Surgical complication was noted in 14 patients (8.4%) and surgical morbidity in two patients (1.2%). Of 164 patients except for these two patients who suffered surgical morbidity, we could obtain more than 3 years follow-up information for 144 patients (87.8%). There were 49 men and 95 women. The mean age was 58.5 years, and mean follow-up period was 7.9 years. Eight cases had died during follow-up (hepatic insufficiency in one, renal insufficiency in one, suicide in one, intracerebral hemorrhage (ICH) in two, SAH in one, and pneumonia after stroke in two). Therefore, the cause of death was stroke and late effects of stroke. Twelve symptomatic cerebrovascular events (cerebral infarction in seven, ICH in four, and SAH in one) occurred in ten patients. Consequently, annual risk of SAH after clipping of unruptured aneurysms was 0.085%. Besides, annual risk of stroke in those patients was 1.06%, and this incidence was higher than that in the general population. Although this study confirmed the good surgical result, annual risk of stroke after clipping of unruptured aneurysms was much higher than that in the general population. The long-term periodic examination to detect recurrent aneurysms and appropriate management to prevent stroke should be performed for patients with surgically treated unruptured aneurysm.

Successful treatment with urgent revascularization and parent artery occlusion for a ruptured intratumoral aneurysm following prior meningioma surgery: illustrative case.

BACKGROUND: An intratumoral aneurysm encased within the associated intracranial tumor is rare, and hemorrhage caused by its rupture is even more rare. While urgent and adequate surgical treatment is important, the treatment can be difficult given the limited understanding of this rare condition. OBSERVATIONS: A 69-year-old man who had undergone meningioma surgery 30 years prior presented with a disturbance in consciousness. Magnetic resonance imaging revealed massive intracerebral and subarachnoid hemorrhage. A round, partially calcified mass, which was diagnosed as recurrent meningioma, was also observed. Subsequent cerebral angiography revealed that the source of the hemorrhage was an intratumoral aneurysm in the dorsal internal carotid artery (ICA) encased within the recurrent meningioma. Urgent surgical ICA trapping and high-flow graft bypass were conducted. The postoperative course was uneventful, and he was referred to another hospital for rehabilitation. LESSONS: This is the first case report of a ruptured intratumoral aneurysm being treated with urgent combined revascularization and parent artery trapping surgery. This surgical approach may be a feasible treatment option for such a challenging condition. Additionally, this case highlights the importance of diligent long-term follow-up after skull-base surgery, as minor intraoperative vascular wall injury may trigger the development and rupture of an intracerebral aneurysm.

Treatment of aneurysmal subarachnoid hemorrhage in subacute phase; retrospective comparison of treatment in sub- and hyper-acute phases.

OBJECTIVE: As soon as possible treatment initiation for aneurysmal subarachnoid hemorrhage (aSAH) is recommended. However, some patients require treatment in "subacute" phase of aSAH, defined in this study as "more than one day after the onset". To establish an optimal treatment strategy for these patients, we retrospectively analyzed the clinical experience of treating ruptured aneurysm with either clipping or coiling in subacute phase. METHODS: Patients treated for aSAH between 2015 and 2021were analyzed. Patients were divided into the hyperacute phase (within 24 h) and subacute phase (later than 24 h) groups. The subacute group was analyzed to determine whether the selected procedure and its timing affected postoperative course and clinical outcomes. In addition, we conducted a multivariate logistic regression analysis to determine the independent factors that affect clinical outcomes. RESULTS: Of 215 patients, 31 were treated in the subacute phase. While cerebral vasospasm at initial imaging was more frequently observed in subacute group, there was no difference in incidence of postoperative vasospasms. Patients in subacute group seemed to have better clinical outcomes due to the milder severity at the time of treatment initiation. Risk of angiographic vasospasm seemed to be higher in patients treated with clipping than coiling, while no difference was seen in clinical outcomes. Multivariate logistic regression analysis showed that the timing and selected treatment did not significantly affect the clinical outcome or the occurrence of delayed vasospasm. CONCLUSIONS: Treatment of aSAH in the subacute phase may also result in favorable clinical outcomes, similar to patients treated in the hyperacute phase with mild presentation. However, further investigations are required to establish the optimal treatment strategies for such patients.

Possible Delayed Foreign Body Reactions against Titanium Clips and Coating Materials after Unruptured Cerebral Aneurysm Surgery.

Delayed foreign body reactions to either or both clipping and coating materials have been reported in several small series; however, studies in the titanium clip era are scarce. This study aims to survey the contemporary status of such reactions to titanium clips and coating materials. Among patients who received a total of 2327 unruptured cerebral aneurysmal surgeries, 12 developed delayed intraparenchymal reactions during outpatient magnetic resonance imaging (MRI) follow-up. A retrospective investigation was conducted. The patients' average age was 58.6 (45-73) years, and 11 were women. The aneurysms were located in the middle cerebral artery (n = 7), internal carotid artery (n = 4), or anterior communicating artery (AComA, n = 1). In 10 patients, additional coating with tiny cotton fragments was applied to the residual neck after clipping with titanium clips; however, only the clipping with titanium clips was performed in the remaining two. The median time from surgery to diagnosis was 4.5 (0.3-60) months. Seven (58.3%) patients were asymptomatic, and three developed neurological deficits. MRI findings were characterized by a solid- or rim-enhancing lobulated mass adjacent to the clip with surrounding parenchymal edema. In 11 patients, the lesions reduced in size or disappeared; however, in one patient, an AComA aneurysm was exacerbated, necessitating its removal along with optic nerve decompression. In conclusion, cotton material is a strongly suspected cause of delayed foreign body reactions, and although extremely rare, titanium clips alone may also induce such a reaction. The prognosis is relatively good with steroid therapy; however, caution is required when the aneurysm is close to the optic nerve, as in AComA aneurysms.

Carotid Artery Stenting Using Stent-in-Stent Technique with a Closed-Cell Stent and a Dual-Layer Micromesh Stent: A Case Report.

Objective: Recent studies evaluating plaque protrusion at carotid artery stenting (CAS) using optical coherence tomography showed not a few cases of plaque protrusion when using double-layer micromesh stents. We report a case of symptomatic internal carotid artery (ICA) stenosis with at-risk unstable plaques in which CAS was successfully performed using a stent-in-stent technique by the combined use of a closed-cell stent and a dual-layer micromesh stent. Case Presentation: An 87-year-old Japanese man with dysarthria and right hemiparesis was diagnosed with atheromatous cerebral embolism caused by severe left ICA stenosis on MRI and DSA. MRI with T1-weighted black blood methods showed high intensities in the plaques of the left ICA, suggesting unstable plaque characteristics with intraplaque hemorrhage components. On day 20, CAS was performed. After the pre-stent dilation under proximal and distal protection, a Carotid WALLSTENT was placed to cover the stenotic lesion. Then, a CASPER Rx was placed from the proximal left ICA to the common carotid artery to cover the Carotid WALLSTENT. Although visible plaque debris was recognized in the aspirated blood, the debris became invisible after aspiration of 1300 mL. Postoperative angiography showed enough dilation of the left ICA, with no plaque protrusion or acute stent thrombosis. The patient had an uneventful postoperative course and was discharged without any neurological sequelae. Conclusion: The present case suggests that the combined stent-in-stent technique using a closed-cell stent and a micromesh stent can be considered as one of the treatment strategies for preventing plaque protrusion and procedural ischemic complications in patients with high-risk carotid plaques.

Current Treatment Results of Intracranial Carotid Artery Dissection Causing Cerebral Ischemia: A Japanese Nationwide Survey.

Intracranial carotid artery dissection causing cerebral ischemia is a rare but important cause of cerebral infarction in children and adolescents. Although endovascular therapy has been reported to be effective, questions regarding the indications for intervention are yet to be addressed. Therefore, this study aimed to evaluate factors related to clinical outcomes through a nationwide survey. Overall, 35 neurosurgical centers reported patients within 2 weeks after ischemic onset due to intracranial carotid artery dissection causing cerebral ischemia treated between January 2015 and December 2020. Data on clinical and radiological findings were statistically analyzed. Twenty-eight patients met the inclusion criteria. The median age was 36 years (range, 7-59 years), without sex differences. Headache at onset was documented in 60.7% of the patients. Dissection findings were categorized into stenosis (71.4%) or occlusion (28.6%). Initial treatments, including various antithrombotic agent combinations in 23 (82.1%) patients, effectively improved or prevented aggravation in half of the patients. The patients with stenotic dissection were significantly more likely to experience aggravation during the initial treatment than did those with occlusive dissection (P = 0.03). In addition, the patients with moderate to severe neurological deficits on admission had poorer outcomes at discharge more frequently than did those with mild neurological deficits on admission. Eight patients undergoing endovascular therapy had no procedural complications or further aggravation after intervention. In conclusion, patients with intracranial carotid dissection causing cerebral ischemia who had a stenotic dissection were at risk of further aggravation, and endovascular therapy effectively improved or prevented aggravation.

Clinical characteristics of endovascular treatment for acute ischemic stroke with atherosclerotic etiology: Factors associating its clinical outcome.

OBJECTIVE: Clinical characteristics of endovascular treatment (EVT) for acute ischemic stroke (AIS) secondary to atherosclerosis are not fully delineated. An optimal treatment strategy with considerations of stroke etiology has not yet been established. Here-in, we performed retrospective analysis of EVT for atherosclerotic AIS. METHODS: Data from patients with AIS who underwent EVT between 2017 and 2022 were analyzed. Clinical characteristics, procedural data, and outcomes were assessed. Further analysis was conducted to elucidate the factors associated with clinical outcomes. And data of patients with poor clinical outcomes (mRS, 5 or 6) were evaluated further to determine the primary cause. RESULTS: Among 194 patients who received EVT, 40 (20.6%) were diagnosed with AIS with an atherosclerotic etiology. The rates of successful reperfusion (TICI 2b or 3) and good clinical outcomes (mRS, 0-2) were 95.0% and 45.0%, respectively. No procedure-related complications were noted. Older age (p = 0.007), more severe baseline NIHSS score (p = 0.004), lesion in the posterior circulation (p = 0.025), and recanalization failure (p = 0.027) were more frequently observed in patients with poor clinical outcomes. Brainstem infarction and postprocedural intracerebral hemorrhage were the main reasons for poor clinical outcomes. CONCLUSION: The EVT for atherosclerotic AIS were effective and safe. Older age, more severe NIHSS score, lesions in the posterior circulation, and recanalization failure were the factors associated with poor clinical outcomes. It is important to recognize that these factors may aggravate the clinical response to this promising therapy, even in patient successful recanalization was attained.

[Surgery for unruptured anterior cerebral artery aneurysms].

In Japan, a large number of surgical treatments for unruptured intracranial aneurysms have been performed. On the other hands, it is known that surgical treatment for unruptured intracranial aneurysms is the most frequent source of lawsuits in the neurosurgical field. Neurosurgeons have the duty to disclose all risks and consequences of a proposed surgical procedure to each patient. Moreover, precise knowledge of surgical risks would be helpful in preventing complications from occurring. However, it is almost impossible that a single surgeon or an institute have experiences with all possible surgical complications because there is limitation of the number of surgery. In this review series, we attempted an exhaustive bibliographic survey of the possible surgical complications including exceptional ones, and then, determined the frequency of each complications as far as possible quantitatively. In this paper, we focused on the complications of surgical treatment for anterior cerebral artery aneurysms.

Induction of large cerebral aneurysms by intraperitoneal administration of ß-aminopropionitrile fumarate in male rats.

BACKGROUND: It is necessary and useful to obtain an experimental model which steadily and rapidly induces aneurysms for investigation of the pathogenesis of cerebral aneurysm. We attempted to examine whether intraperitoneal administration of ß-aminopropionitrile fumarate (BAPN-F) with additional treatments of induced hypertension and hemodynamic stress could steadily and rapidly induce aneurysms in male rats. METHODS: Seven-week-old male Sprague-Dawley rats pretreated with ligation of left common carotid and bilateral posterior renal arteries were administrated BAPN-F intraperitoneally. Induction rate and size of aneurysms was investigated with varying dose and duration of BAPN-F administration (low dose; 400 mg/kg/week for 4 or 8 weeks and high dose; 2800 mg/kg/week for 8 or 12 weeks). RESULTS: Induction rate in the high-dose groups was significantly higher (P<0.01) than that in the low-dose groups. Making comparisons between 8 and 12 weeks of the high-dose groups, while there was no difference in induction rate (8 weeks; 85.2% vs. 12 weeks; 76.9%), aneurysmal size was larger in 12 weeks (8 weeks; 127.5 µm, vs. 12 weeks; 181.7 µm in terms of median) but lethal intrathoracic hemorrhage was increased in 12 weeks (8 weeks; 7.4% vs. 12 weeks; 30.8%). Induction rate of large aneurysm was 22.2% and 30.8% in 8 and 12 weeks of the high-dose groups, respectively. CONCLUSIONS: High-dose BAPN-F administration can cause high-frequency aneurysmal induction. Although there was the difference in size and mortality rate based on administration duration, intraperitoneal administration of 2800 mg/kg/week BAPN-F for 8 weeks would be suitable for aneurysmal induction.

Clinical characteristics and outcomes in carotid endarterectomy for internal carotid artery stenosis in a Japanese population: 10-year microsurgical experience.

Few studies have explored the significance of carotid endarterectomy (CEA) in long-term prognosis in Japanese patients. In the present study, we precisely elucidated the demographic and radiologic data, surgical morbidity and mortality, and long-term outcome in 135 Japanese patients who underwent a total of 142 CEAs due to 70%-99% stenosis of the internal carotid artery at our hospitals over a 10-year period. The prevalence of risk factors was similar to those found in previous studies in Western countries. Surgical mortality (0.7%) and morbidity (2.8%) were relatively low. Blood flow studies done immediately after CEA revealed postoperative hyperperfusion in 8 patients (5.6%), but none of these patients exhibited related symptoms. Over the mean follow-up period of 38.7 months, a total of 9 patients died (6.7%), due mainly to malignancies. Cerebrovascular events occurred in 12 patients (8.5%), including ipsilateral ischemic stroke in 2 (1.4%). In addition, 11 patients (8.2%) developed vascular disorders in other organs, including coronary artery disease and chronic renal failure. Follow-up radiologic examination revealed restenosis of >50% in 3 carotid arteries (2.1%). Stenosis of the contralateral carotid arteries progressed to >70% in 12 patients (9.2%). This study strongly suggests that microsurgical CEA is feasible and effective in preventing subsequent ipsilateral ischemic stroke in Japanese patients; however, long-term medical and radiologic surveillance is essential to reduce the incidence of ischemic stroke in other areas and of vascular disorders in other organs to improve prognosis.