Systemic immune-inflammation index in dural arteriovenous fistula: a feasible biomarker reflecting its clinical characteristics.

PURPOSE: The systemic immune-inflammation index (SII), a marker of systemic inflammation, can be calculated using peripheral blood tests. Although the SII has been reported as a feasible biomarker in various cerebrovascular diseases, no studies have explored in dural arteriovenous fistula (DAVF). A retrospective cohort study was performed to test whether the SII reflects the clinical characteristics of DAVF and whether this index could serve as a feasible biomarker. METHODS: This study included 28 patients who underwent endovascular treatment (39 sessions) for DAVF between 2014 and 2023. The SII was calculated using the following formula: platelet count multiplied by neutrophil count divided by lymphocyte count. We investigated the correlation between the SII and various clinical characteristics of DAVF, including symptom manifestation, and digital subtraction angiography findings. Additionally, we compared pre- and post-endovascular treatment changes in the SII. RESULTS: A significantly higher SII was observed in patients with multiple lesions, clinical symptoms (particularly aggressive symptoms), pseudophelebitic pattern (PPP), and sinus occlusion. Multivariate regression analysis revealed that the presence of symptoms (coefficient 270.9, P = 0.021) and PPP (coefficient 272.4, P = 0.017) were independent factors contributing to SII elevation. Notably, following endovascular treatment, there was a significant decrease in the elevated SII in patients whose symptoms resolved (P = 0.039) and where the DAVF was angiographically cured (P = 0.012). CONCLUSION: Elevation of the SII in patients with advanced DAVF and its decrease following endovascular treatment suggests that the SII reflects the disease condition and indicates its potential as a promising biomarker.

Sexual dimorphism in immune cell responses following stroke.

Recent bodies of work in regard to stroke have revealed significant sex differences in terms of risk and outcome. While differences in sex hormones have been the focus of earlier research, the reasons for these differences are much more complex and require further identification. This review covers differences in sex related immune responses with a focus on differences in immune cell composition and function. While females are more susceptible to immune related diseases, they seem to have better outcomes from stroke at the experimental level with reduced pro-inflammatory responses. However, at the clinical level, the picture is much more complex with worse neurological outcomes from stroke. While the use of exogenous sex steroids can replicate some of these findings, it is apparent that many other factors are involved in the modulation of immune responses. As a result, more research is needed to better understand these differences and identify appropriate interventions and risk modification.

ADAPT First-Line Strategy for MCA Mainstem Occlusion; Analysis for Optimal Salvage Therapy and its Related Factor.

OBJECTIVES: A direct first-pass aspiration technique (ADAPT) is an attractive interventional technique for mechanical thrombectomy (MT), which could achieve recanalization quickly and safely at a small amount of material resources. To clarify its usefulness, our ADAPT first-line strategy for middle cerebral artery (MCA)-mainstem occlusion was retrospectively analyzed. MATERIALS AND METHODS: We reviewed 54 consecutive patients who underwent MT for MCA-mainstem occlusion using ADAPT first-line strategy. A salvage procedure was concurrently conducted in cases that failed to achieve successful recanalization by ADAPT attempt alone. Procedural and clinical outcome were assessed in both ADAPT alone and Salvage groups. Further investigation was performed in cases that required salvage procedure to determine the reason, risk factors, and optimal procedure. RESULTS: Forty-one patients (75.9%) were able to achieve successful recanalization with ADAPT technique alone. In salvage group, the procedural time was longer, and rates of successful recanalization were lower than in ADAPT-alone group. No significant difference in the rates of favorable outcomes was observed. Among 13 patients who required salvage therapy, the major reason (eight cases) was intra-procedural "thrombus distal migration". Failure of recanalization was seen in two cases due to "inaccessibility". In patients who had "thrombus distal migration", occlusion in the proximal portion was more frequently observed than in patients who did not (p = 0.032, 63.6% vs. 23.3%). CONCLUSIONS: Our ADAPT first-line strategy for MCA-mainstem occlusion demonstrated favorable procedural and clinical outcomes, even in cases that required additional procedures. Further investigation and better understanding are required to refine this promising procedure.

A Direct Aspiration First Pass Technique for Vertebra-Basilar Occlusion: A Retrospective Comparison to Stent Retriever.

OBJECTIVES: This study aimed to assess the clinical usefulness of a direct aspiration first pass technique as a first-line strategy for mechanical thrombectomy in posterior circulation. MATERIALS AND METHODS: We examined 34 consecutive patients treated with mechanical thrombectomy for acute vertebrobasilar artery occlusion. Procedural and clinical outcomes were assessed and compared between patients treated with a direct aspiration first pass technique first-line strategy (ADAPT group) and stent retriever system first-line strategy (stent retriever group). RESULTS: Overall, successful reperfusion, complete reperfusion, and first-pass effects were achieved in 94.1%, 61.8%, and 50% of patients with acute ischemic stroke in vertebra-basilar artery occlusion treated with mechanical thrombectomy, respectively. The ADAPT group required a significantly shorter procedural time (p=.015) and fewer attempts (p=.0498) to achieve successful recanalization than the stent retriever group. The ADAPT group also tended to show better recanalization rates and first-pass effects than the stent retriever group. The rates of favorable outcomes seemed to be better, although insignificant, in the ADAPT group than in the stent retriever group (52.2% vs. 27.3%, p=.217). However, a significant correlation between the time required for reperfusion and clinical outcome was detected, and this will serve as the rationale for encouraging a direct aspiration first pass technique as a first-line strategy in the acute vertebra-basilar artery. CONCLUSIONS: The a direct aspiration first pass technique first-line strategy for mechanical thrombectomy in posterior circulation may achieve successful recanalization with fewer attempts and shorter durations than the stent retriever first-line strategy.

[Embolization of Arteriovenous Fistulae of the Maxillary Artery after Le Fort I Osteotomy:A Case Report].

BACKGROUND: Le Fort I osteotomy, one of the most common techniques applied to correct jaw deformities, is generally considered operatively safe. However, a few articles reported that this procedure can lead to formation of arteriovenous fistulae(AVF)involving the maxillary artery infrequently. CASE REPORT: A man in his 40s with a jaw deformity underwent Le Fort I osteotomy. Two days later, he noticed pulsating tinnitus in his right ear. Angiography revealed AVF between the proximal part of the maxillary artery(first segment)and the pterygoid plexus. On further evaluation, AVF were embolized with n-butyl-2-cyanoacrylate(NBCA). Obliteration of AVF was confirmed on the final angiography. The tinnitus resolved shortly after the embolization. CONCLUSION: Embolization with NBCA is a promising treatment for maxillary AVF after Le Fort I osteotomy.

Novel Hemoglobin-Based Oxygen Carrier Bound With Albumin Shows Neuroprotection With Possible Antioxidant Effects.

Background and Purpose- A hemoglobin-albumin cluster, 1 core of hemoglobin covalently bound with 3 shell albumins, designated as HemoAct was developed as a hemoglobin-based oxygen carrier. We aim to investigate neuroprotection by HemoAct in transient cerebral ischemia and elucidate its underlying mechanisms. Methods- Male rats were subjected to 2-hour transient middle cerebral artery occlusion and were then administered HemoAct transarterially at the onset of reperfusion. Neurological and pathological findings were examined after 24 hours of reperfusion to identify neuroprotection by HemoAct. Intermittent measurements of cortical blood flow and oxygen content were performed, and a histopathologic analysis was conducted on rats during the early phase of reperfusion to assess the therapeutic mechanism of HemoAct. In addition, the antioxidant effects of HemoAct were examined in hypoxia/reoxygenation-treated rat brain microvascular endothelial cells. Results- Neurological deterioration, infarct and edema development, and the activation of MMP-9 (matrix metalloprotease-9) and lipid peroxidation after 24 hours of reperfusion were significantly ameliorated by the HemoAct treatment. Reductions in blood flow and tissue partial oxygen pressure in the cortical penumbra after 6 hours of reperfusion were significantly ameliorated by the HemoAct treatment. The histopathologic analysis of the cortical penumbra revealed that HemoAct in HemoAct-treated rats showed superior microvascular perfusion with the mitigation of microvascular narrowing changes than autologous erythrocytes in nontreated rats. Although HemoAct extravasated into the ischemic core with serum protein, it did not induce an increase in serum extravasation or reactive oxygen species production in the ischemic core. In vitro experiments with rat brain microvascular endothelial cells revealed that HemoAct significantly suppressed cellular reactive oxygen species production in hypoxia/reoxygenation-treated cells, similar to albumin. Conclusions- HemoAct exerted robust neuroprotection in transient cerebral ischemia. Superior microvascular perfusion with an oxygen delivery capability and possible antioxidant effects appear to be the underlying neuroprotective mechanisms.

Superior Microvascular Perfusion of Infused Liposome-Encapsulated Hemoglobin Prior to Reductions in Infarctions after Transient Focal Cerebral Ischemia.

BACKGROUND: The development of cerebral infarction after transient ischemia is attributed to postischemic delayed hypoperfusion in the microvascular region. In the present study, we assessed the microvascular perfusion capacity of infused liposome-encapsulated hemoglobin (LEH) in a therapeutic approach for transient middle cerebral artery occlusion (tMCAO). METHODS: Two-hour middle cerebral artery occlusion rats were immediately subjected to intra-arterial infusion of LEH (LEH group) or saline (vehicle group) or no treatment (control group), and then to recanalization. Neurological findings, infarct and edema progression, microvascular endothelial dysfunction, and inflammatory reactions were compared between the 3 groups after 24 hours of reperfusion. Microvascular perfusion in the early phase of reperfusion was evaluated by hemoglobin immunohistochemistry and transmission electron microscopy. RESULTS: The LEH group achieved significantly better results in all items evaluated than the other groups. Hemoglobin immunohistochemistry revealed that the number of hemoglobin-positive microvessels was significantly greater in the LEH group than in the other groups (P < .01), with microvascular perfusion being more likely in narrow microvessels (≤5 µm in diameter). An electron microscopic examination revealed that microvessels in the control group were compressed and narrowed by swollen astrocyte end-feet, whereas those in the LEH group had a less deformed appearance and contained LEH particles and erythrocytes. CONCLUSION: The results of the present study demonstrated that the infusion of LEH reduced infarctions after tMCAO with more hemoglobin-positive and less deformed microvessels at the early phase of reperfusion, suggesting that the superiority of the microvascular perfusion of LEH mediates its neuroprotective effects.

[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.

[Intradural arachnoid cyst associated with syringomyelia: a case report].

An intradural arachnoid cyst is a relatively rare condition, occurring within the spinal subarachnoid space. We present the even-more rare case of an intradural arachnoid cyst associated with syringomyelia at the same spinal level. The patient was a 66-year-old man who presented with bilateral leg numbness and gait disturbance. Magnetic resonance imaging (MRI) revealed an intradural arachnoid cyst located dorsal to, and compressing, the thoracic spinal cord at the level of the 7th thoracic vertebra (Th 7). In addition, syringomyelia existed at the level of Th 8, slightly caudal to the intradural arachnoid cyst. We dissected the cyst but did not perform any surgical procedures for the syringomyelia. Post-operative MRI showed that the cyst had disappeared and the syringomyelia had spontaneously shrunk. The patient was discharged with improvement in his numbness and gait disturbance. There are a few case reports of intradural arachnoid cysts associated with syringomyelia, but recent evidence suggests that its occurrence is more common than previously thought. A combination of these two diseases is thought to be caused by blockage of cerebrospinal fluid (CSF) flow, which is also thought to cause adhesive arachnoiditis. For this reason, resection of the arachnoid cyst could improve the CSF flow and contribute to the shrinkage of syringomyelia. Furthermore, early treatment may correlate with improvement in radiological findings and neurological symptoms.

Long-term Outcomes of Combined Revascularization Surgery for Moyamoya Disease in the Elderly: A Single Institute Experience.

The opportunity to treat older patients with Moyamoya disease (MMD) is increasing. However, the surgical outcomes after combined direct and indirect revascularization for elderly patients with MMD are not fully understood, especially for those ≥60 years old. This retrospective study examined 232 consecutive hemispheres of 165 adults with MMD who underwent combined revascularization. Clinical features and surgical outcomes were compared between the elderly (≥60 years) and nonelderly group (<60 years). Thirteen (5.6%, 64.4 ± 4.0 years old) and 219 hemispheres (94.4%, 40.2 ± 10.8 years old) were included in the elderly and nonelderly group, respectively. The proportion of clinical presentations before surgery did not differ. However, the prevalence of hypertension and hyperlipidemia was significantly higher in the elderly group than in the nonelderly group. Meanwhile, hyperthyroidism was observed only in the nonelderly group. No significant intergroup differences were observed in the incidence of perioperative complications occurring within four weeks postsurgery. Notably, the elderly group was more prone to develop perioperative intracerebral hemorrhage (odds ratio (OR) 3.14, 95% confidence interval (CI) 0.45-13.5) than the nonelderly group. During a median follow-up period of 7.8 years, the incidence of stroke recurrence occurring later than four weeks postsurgery was not significantly different between the groups (hazard ratio, 1.19; 95% CI 0.133-10.6). The prevalence of independent outcomes (76.9% vs. 90.4%, P = 0.14) and mortality (7.7% vs. 1.4%, P = 0.21) did not differ significantly between the elderly and nonelderly groups, respectively. Perioperative intracerebral hemorrhage may be common in the elderly and should be considered to achieve a favorable surgical outcome.

Effective Smartphone Application Use for Postoperative Management of Moyamoya Disease.

Continuous and careful management is necessary after revascularization surgery for moyamoya disease (MMD). The postoperative information has been shared in person or by telephone and emails among doctors; however, this is not always efficient. We aimed to describe the feasibility of remote diagnosis and text chats using a smartphone application on postoperative MMD management. Twenty consecutive patients who underwent combined direct and indirect revascularization for MMD were prospectively investigated in this study. In ten patients, the operator viewed postoperative images uploaded on a smartphone screen using the Join application (Allm Inc., Tokyo, Japan). The doctors shared the radiological findings and treatment plans using the group text chat function and performed postoperative management. We evaluated the intermodality agreements of radiological findings between the smartphone screen and conventional viewer. Postoperative courses were compared between the two patient groups that used or did not use the application. All postoperative images were uploaded to the cloud server and the operator viewed them remotely on the smartphone screen without restriction of location. Detected abnormal findings were cerebral hyperperfusion (CHP), CHP-related watershed shift phenomenon, fluid-attenuated inversion recovery cortical hyperintensity, high signal intensity on diffusion-weighted imaging, CHP-related crossed cerebellar diaschisis, and hypoperfusion. Radiological agreement between the modalities was good in all cases, and additional findings were not obtained on the conventional viewer. The postoperative courses of the Join group were as good as those of the control group. Remote radiological diagnosis and text chat using a smartphone application were feasible and useful for efficient and safe postoperative MMD management.

Visual dysfunction and neurodegeneration caused by severe inflammatory optic neuropathy after coil embolization of a paraclinoid aneurysm: illustrative case.

BACKGROUND: Visual impairment due to delayed optic neuropathy is a rare complication of the endovascular treatment of paraclinoid aneurysms. An inflammatory response induced in the treated aneurysm wall is a known mechanism underlying this pathophysiology. The authors describe a case with severe and progressive optic neuropathy leading to neuronal degeneration and severe visual dysfunction. OBSERVATIONS: A 42-year-old female with a history of surgical clipping for a paraclinoid aneurysm presented with a recurrence. Although the patient was unaware of any visual dysfunction, a preoperative ophthalmological examination revealed mild inferior quadrantanopia in the left eye. The coil embolization procedure was uneventful; however, the following day, the patient experienced progressive visual impairment, which worsened despite the initiation of steroid therapy. Ophthalmological examination revealed a severe decrease in visual acuity and further deterioration of the visual field. Magnetic resonance imaging showed remarkable swelling and edema of the left optic nerve adjacent to the treated aneurysm. Despite continued steroid therapy, the patient's visual function did not recover well due to subsequent optic nerve degeneration. LESSONS: Optic neuropathy after endovascular procedures can lead to severe visual dysfunction. Careful management is essential, particularly when treating a symptomatic paraclinoid aneurysm, even if symptoms are only apparent on detailed examination.

Ivy sign, misery perfusion, and asymptomatic moyamoya disease: FLAIR imaging and (15)O-gas positron emission tomography.

BACKGROUND: The prevalence of ivy sign on fluid-attenuated inversion recovery (FLAIR) imaging in patients with asymptomatic moyamoya disease is unclear. The aim of this study was to clarify the incidence of ivy sign in these patients, as well as the correlation between MRI and (15)O gas PET findings. METHODS: A retrospective analysis including 16 consecutive patients with asymptomatic moyamoya disease enrolled between 2001 and 2010 in a single center. FLAIR imaging at the initial visit was categorized as ivy sign present, negative, or equivocal. Hemodynamic and metabolic parameters were quantified in 11 of 16 patients by (15)O-gas positron emission tomography, and the relationship between ivy sign and (15)O-gas PET parameters was analyzed. Cerebrovascular events within the follow-up period (54 ± 28 months) were also examined. RESULTS: Five of 16 asymptomatic moyamoya patients (31.3 %) had positive ivy sign (6/30 hemispheres, 20 %). In (15)O-gas PET examinations, 18 % of 22 hemispheres had elevated oxygen extraction fraction values that were significantly associated with positive ivy sign. Of these 16 asymptomatic moyamoya patients, six patients (37.5 %) underwent combined surgical revascularization. In this series, no patients experienced ischemic stroke, but one had intraventricular bleeding 1 year after surgery. CONCLUSIONS: Ivy sign on FLAIR imaging is still not rare in patients with moyamoya disease, even when asymptomatic. Although optimal management is still under debate, ivy sign may be an indicator of misery perfusion, and patients with asymptomatic moyamoya disease and ivy sign on FLAIR imaging will benefit from more careful follow-up.

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.

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.

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.

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.

Effects of clinical outcomes by modification of patient selection protocol based on premorbid independence for mechanical thrombectomy in older adult patients.

OBJECTIVES: Since the beneficial effect attained by mechanical thrombectomy (MT) seems to be worse in older than in the younger population, the establishment of an ideal and distinctive patient selection protocol in older is warranted. Herein, we modified our patient selection protocol based on age and premorbid independence in older adult patients. MATERIALS AND METHODS: We retrospectively reviewed 141 consecutive patients with acute ischemic stroke who were treated with MT between 2015 and 2020. We started to restrict the indication of MT in very old patients (≥85-year-old) with severe premorbid functional independence (≥modified Rankin Scale [mRS] 3) in 2018. Clinical outcomes before the modification of protocol (period 1) were compared to after (period 2). RESULTS: Although there were no significant differences in median mRS at 90 days and the rates of favorable outcomes (mRS 0-2) between both periods, rates of poor outcomes (mRS 5, 6) significantly decreased (37.3% vs. 19.7%, P = 0.021) during period 2 compared with period 1. For older adults (≥80-year-old), median mRS was significantly better (P = 0.012) during period 2 than period 1. During period 1, rates of favorable outcomes were significantly lower (P = 0.004) in older than in younger. However, this significant difference was diminished (P = 0.28) during period 2. CONCLUSION: Our modified patient selection protocol in older adults, not only limited by age but also premorbid function, improved the therapeutic outcome of MT. In rapidly aging society, further investigations facilitating a better understanding are necessary to establish an optimal patient selection protocol.

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.

[A successful treatment for a case of idiopathic syringomyelia with syrinx located in the anterior horn].

Idiopathic syringomyelia not associated with Chiari malformation, tumor, nor tetherd cord syndrome has not been frequently reported. So the clinical significance and optimum treatment strategy for this disease remains unclear. We report a 37-year-old man who was diagnosed as having idiopathic syringomyelia and was treated successfully using implantation of a syringo-subarachnoid shunt. The patient suffered gradual worsening of sensory disturbance in the upper extremities, and Magnetic resonance imaging demonstrated a large syrinx located in the cervical spinal cord (C2-3), located mainly at the left anterior horn. We performed syringo-subarachnoid shunt for syringomyelia under partial hemilaminectomy. During the surgery, the spinal cord was markedly rotated and dorsal root entry had shifted to the midline because of the large syrinx. In order to perform myelotomy at the dorsal root entry zone, we needed additional drilling to the medial portion of the lamina. After this procedure, we were able to perform implantation of the syringo-subarachnoid shunt safely. After the operation, the syrinx collapsed immediately and no neurological deficit was observed. The patient was discharged 2 weeks after the operation. Idiopathic syringomyelia in which the syrinx has deviated to the anterior horn is rare. In those cases, we consider that sufficient hemilaminectomy for the midline should be performed.