Comparison of the Clinical Outcome of Carotid Artery Stenting Between Institutions With a Treatment Strategy Based on Risk Factors and Those With First-Line Treatment.

PURPOSE: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended based on certain risk factors. The volume of an institution's treatment experience may be associated with good clinical outcomes. There is a dilemma between the treatment strategy based on risk factors and the experience volume. Therefore, we investigated the clinical outcomes of CAS performed at institutions that selected the treatment strategy based on risk factors and those that performed CAS at the first-line treatment. MATERIALS AND METHODS: Patients who underwent CAS at 5 institutions were included in this retrospective case-control study. We defined CEA/CAS institutions as those that selected the treatment option based on risk factors, and CAS-first institutions as those that performed CAS as the first-line treatment. We investigated cases of ischemic stroke, hemorrhagic stroke, myocardial infarction, and deaths within 30 days of the intervention between the CEA/CAS- and CAS-first institution groups. One-to-one propensity score matching was performed to compare rates of ischemic and hemorrhagic strokes within 30 days of the intervention. RESULTS: A total of 239 and 302 patients underwent CAS at the CEA/CAS institutions and CAS-first institutions, respectively; ischemic stroke occurred in 12 (5.0%) and 7 patients (2.3%), respectively (p=0.09). No differences in major ischemic strokes (0.8% vs 1.3%; p=0.59), hemorrhagic strokes (0.4% vs 0.3%; p=0.87), or deaths (0.0% vs 0.7%; p=0.21) were observed. Myocardial infarction did not occur in either group. Propensity score analysis showed that ischemic stroke (odds ratio: 1.845, 95% confidence interval: 0.601-5.668, p=0.28) and hemorrhagic stroke (odds ratio: 1.000, 95% confidence interval: 0.0061-16.418, p=1.00) were not significantly associated with either institution group. CONCLUSIONS: The CAS-specific treatment strategies for CAS can achieve the same level of outcomes as the treatment strategy based on risk factors. The CAS performed based on risk factors in CEA/CAS institutions and the treatment of more than 30 patients/year/institution in CAS-first institutions were associated with good clinical outcomes.

Modification by an aspiration catheter for vessel stretching in thrombectomy using a stent retriever in vitro.

OBJECTIVES: Post-thrombectomy subarachnoid hemorrhage, which is caused by vessel stretching when retrieving a stent retriever (SR), is a complication of endovascular mechanical thrombectomy (EVT) using an SR. This in vitro study examined the association between EVT for middle cerebral artery (MCA) occlusion and M2 vessel stretching depending on the positioning of the SR or combined use of SR and aspiration catheter (AC) technique (CBT). MATERIALS AND METHODS: A silicone vascular model was used. The maximum migration distance (MMD) in the anteroposterior view of an X-ray impermeable metal marker located at an M2 trunk 20 mm distal to the M1-2 bifurcation in angiographic images during an SR retrieval was calculated. According to the positioning of SR deployment (distal or proximal) and use of an AC [SR alone without an AC (SR alone) group, stent retrieval into an AC (SA) group, and stent-AC retrieval as a unit into a guiding catheter (SA unit) group], 60 attempts were conducted with each group of 10 attempts. RESULTS: In distal SR deployment, the MMD in the CBT group, consisting of SA and SA unit groups, was significantly smaller than the SR alone group (1.36 ± 0.32 mm VS 2.39 ± 1.10 mm; p = 0.001). In proximal SR deployment, the CBT group showed a tendency to decrease MMD (1.38 ± 0.33 mm VS 1.63 ± 0.28 mm; p = 0.077). CONCLUSIONS: This in vitro study showed that CBT might help modify the stretching of M2 when an SR is distally deployed in MCA occlusion.

Outflow angle: a risk factor for thromboembolic complications in coil embolisation for treating unruptured middle cerebral artery bifurcation aneurysms.

BACKGROUND: Thromboembolic complications are a relevant risk in coil embolisation of cerebral aneurysms. This retrospective study aimed to assess the treatment outcomes of unruptured middle cerebral artery (MCA) bifurcation aneurysms and the predictors for thromboembolic complications based on the aneurysm morphological characteristics. We examined the following three features: inflow angle, outflow angle (OA), and bifurcation angle, formed by the aneurysm and neighbouring blood vessels. METHODS: A total of 32 MCA bifurcation aneurysms were retrospectively investigated in 32 patients treated consecutively at our institute between April 2008 and March 2019. The predictors for thromboembolic complications were analysed in two groups: patients with and without thromboembolic complications. RESULTS: Perioperative thromboembolic complications were detected in six patients (18.8%), including two and six intra- and post-procedural thromboembolic complications, respectively; all cases were resolved. Regarding the aneurysms' morphological characteristics, the group with thromboembolic complications showed a significantly smaller OA (55.58° ± 14.05° vs. 86.04° ± 28.58°, P = 0.01) than the group without complications. Multivariate analysis revealed that smoking habits and OA < 70° were significant predictors of thromboembolic complications (smoking habits: P = 0.01, odds ratio [OR]: 6.89, 95% confidence interval [CI]: 3.78-12.62; OA < 70°: P = 0.04, OR: 3.19, 95% CI: 1.52-6.56). CONCLUSIONS: Our findings indicate significant pre-procedural predictors of thromboembolic complications to consider for safe treatment; clipping should be preferred to coil embolisation in high-risk patients. The method of choice should be considered in each case to allow the safe treatment of unruptured MCA aneurysms.

Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial.

IMPORTANCE: Whether intravenous thrombolysis is needed in combination with mechanical thrombectomy in patients with acute large vessel occlusion stroke is unclear. OBJECTIVE: To examine whether mechanical thrombectomy alone is noninferior to combined intravenous thrombolysis plus mechanical thrombectomy for favorable poststroke outcome. DESIGN, SETTING, AND PARTICIPANTS: Investigator-initiated, multicenter, randomized, open-label, noninferiority clinical trial in 204 patients with acute ischemic stroke due to large vessel occlusion enrolled at 23 hospital networks in Japan from January 1, 2017, to July 31, 2019, with final follow-up on October 31, 2019. INTERVENTIONS: Patients were randomly assigned to mechanical thrombectomy alone (n = 101) or combined intravenous thrombolysis (alteplase at a 0.6-mg/kg dose) plus mechanical thrombectomy (n = 103). MAIN OUTCOMES AND MEASURES: The primary efficacy end point was a favorable outcome defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 2 at 90 days, with a noninferiority margin odds ratio of 0.74, assessed using a 1-sided significance threshold of .025 (97.5% CI). There were 7 prespecified secondary efficacy end points, including mortality by day 90. There were 4 prespecified safety end points, including any intracerebral hemorrhage and symptomatic intracerebral hemorrhage within 36 hours. RESULTS: Among 204 patients (median age, 74 years; 62.7% men; median National Institutes of Health Stroke Scale score, 18), all patients completed the trial. Favorable outcome occurred in 60 patients (59.4%) in the mechanical thrombectomy alone group and 59 patients (57.3%) in the combined intravenous thrombolysis plus mechanical thrombectomy group, with no significant between-group difference (difference, 2.1% [1-sided 97.5% CI, -11.4% to ∞]; odds ratio, 1.09 [1-sided 97.5% CI, 0.63 to ∞]; P = .18 for noninferiority). Among the 7 secondary efficacy end points and 4 safety end points, 10 were not significantly different, including mortality at 90 days (8 [7.9%] vs 9 [8.7%]; difference, -0.8% [95% CI, -9.5% to 7.8%]; odds ratio, 0.90 [95% CI, 0.33 to 2.43]; P > .99). Any intracerebral hemorrhage was observed less frequently in the mechanical thrombectomy alone group than in the combined group (34 [33.7%] vs 52 [50.5%]; difference, -16.8% [95% CI, -32.1% to -1.6%]; odds ratio, 0.50 [95% CI, 0.28 to 0.88]; P = .02). Symptomatic intracerebral hemorrhage was not significantly different between groups (6 [5.9%] vs 8 [7.7%]; difference, -1.8% [95% CI, -9.7% to 6.1%]; odds ratio, 0.75 [95% CI, 0.25 to 2.24]; P = .78). CONCLUSIONS AND RELEVANCE: Among patients with acute large vessel occlusion stroke, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority. TRIAL REGISTRATION: umin.ac.jp/ctr Identifier: UMIN000021488.

Predictors of Clopidogrel Hyper-Responsiveness in Neuro-Interventional Procedures.

BACKGROUND: Hyper-responsiveness to clopidogrel abnormally inhibits platelet aggregation and increases hemorrhagic complications. The present study investigated clinical factors related to clopidogrel hyper-responsiveness in neuro-interventional procedures. METHODS: Two hundred twenty-four patients receiving clopidogrel for coil embolization to treat unruptured cerebral aneurysm or carotid artery stenting to treat carotid artery stenosis at the internal carotid artery origin were retrospectively reviewed for their P2Y12 reactivity unit (PRU) values and clinical characteristics. Hyper-responsiveness to clopidogrel was defined as a PRU of <95. RESULTS: The mean PRU was 218.2 ± 77.8. Hyper-responsiveness to clopidogrel was observed in 12 patients (5.4%). Hyper-responsiveness was observed in younger patients, patients with a lower concentration of hemoglobin A1c, and patients with a higher low-density lipoprotein cholesterol (LDL-C) concentration compared with non-hyper-responsive patients (P = 0.01, P < 0.01, P < 0.01, respectively). On analysis of concomitant drugs, the patients in the hyper-responsive group were less frequently administered calcium channel blockers (CCBs) compared with the non-hyper-responsive group (P = 0.01). No significant differences in the usage of proton pump inhibitors or statins were observed. A LDL-C concentration of >120 mg/dL and no usage of CCBs were significant independent predictors of hyper-responsiveness to clopidogrel with a multivariate analysis (OR; 6.16, 95% CI, 1.57-26.64, P = 0.01, OR; 0.09, 95% CI, 0.01-0.82, P = 0.03, respectively). CONCLUSION: The present study shows that a higher LDL-C concentration and no usage of CCBs are independent predictors of clopidogrel hyper-responsiveness. These results are useful to predict perioperative hemorrhagic complications. Considering dose reduction of clopidogrel or alternative drugs in high risk cases is necessary to prevent perioperative hemorrhagic complications.

High HMGA2 expression without gene rearrangement in meningiomas.

High mobility group AT-hook 2 (HMGA2) is a non-histone transcriptional regulator protein. Aberrant expression of the HMGA2 gene (HMGA2) and structural rearrangement at the chromosomal region 12q14 with HMGA2 involvement have been reported in several mesenchymal tumors. We analyzed truncated and full-length HMGA2 expression in 55 cases of meningioma, the most common brain tumor of mesenchymal origin. Fluorescence in situ hybridization and 3'-rapid amplification of cDNA ends were used to investigate the possibility of gene rearrangements. Moreover, the relationship between HMGA2 expression and clinicopathological features was assessed. Compared with normal brain tissues, 95% of the meningioma tissues exhibited increased HMGA2 expression. In 14 cases, the expression of truncated HMGA2 was more than two-fold higher than that of paired full-length HMGA2. Chromosomal translocation involving the chromosomal region 12q14 was undetectable. No significant correlation was found between the Ki-67 labeling index and HMGA2 expression and between the HMGA2 expression and the clinicopathological features. The majority of the meningioma cases displayed increased HMGA2 expression, which was not attributed to the chromosomal rearrangement at the corresponding region. Similar to that in the other mesenchymal tumors, increased HMGA2 expression was not associated with tumor cell proliferation in meningiomas.

Increased Twist and ZEB2 expression in a cutaneous metastasis of high-grade glioma.

Extra-central nervous system metastasis of gliomas is extremely rare, and the biological mechanism underlying it remains poorly understood. Epithelial-to-mesenchymal transition (EMT) has received attention as one of the important processes of cancer metastasis. Here we describe the case of a 32-year-old man with cutaneous metastasis of high-grade glioma, together with the analysis of EMT-related molecules. Our patient presented with a high-grade glioma in the right frontal lobe. Cutaneous metastasis under the surgical scar developed 17 months after complete resection of the intracranial tumor. Histopathology of both the original and metastatic tumors revealed hypercellularity; the tumors predominantly comprised glial tumor cells with poor cellular processes. Immunohistochemical analysis demonstrated intense expression of nestin, focal expression of glial fibrillary acid protein, and absence of expression of oligodendrocyte transcription factor 2, endothelial membrane antigen, or neurofilament. Genetic analyses could not provide definitive diagnostic information of glioma subtypes. Immunohistochemical analysis for EMT-related biomarkers demonstrated increased Twist, zinc finger E-box-binding homeobox 2 (ZEB2), matrix metalloproteinase 2 (MMP2), and MMP9 expressions in tumor cells of the metastatic lesion compared with those of the primary lesion. Slug, E-cadherin, and N-cadherin expression were absent in both primary and metastatic lesions; however, ZEB1 expression was present in both. Our results suggest that Twist, ZEB2, MMP2, and MMP9 facilitate cutaneous metastasis of gliomas.

[Spontaneous Retroclival Subdural Hematoma Diagnosed Using Magnetic Resonance Imaging in an Adult Patient:A Case Report].

Spontaneous retroclival subdural hematoma is rare among adults. To the best of our knowledge, only six cases have been reported. A 73-year-old man presented with sudden severe headache, diplopia, and dysarthria, with no history of trauma. Head CT revealed a retrociliary hematoma. No obvious causes of bleeding, such as cerebral aneurysms or malformations, were detected. Conservative treatment was provided to the patient. MRI showed an intraventricular hemorrhage and a space between the basilar artery and hematoma three days after onset. The hematoma almost disappeared on day 7. MRI, particularly T2-weighted sagittal MRI, is effective in localizing hematomas and confirming intraventricular hemorrhages.

Transvenous embolisation via an occluded inferior petrosal sinus for cavernous sinus dural arteriovenous fistulas.

AIM OF THE STUDY: We retrospectively searched for cases of transvenous embolisation for cavernous sinus dural arteriovenous fistulas. MATERIALS AND METHODS: Twenty-five cases underwent transvenous embolisation via the inferior petrosal sinus (IPS). IPS was probed using a standard 0.035-inch guidewire for microcatheter navigation, which was successful in all cases. RESULTS: IPS was occluded in 17 cases (68%). Only one case experienced a complication, where the approach was changed to the contralateral side because of internal jugular vein injury. The relationship between the external auditory canal and the IPS route was reviewed in 18 cases using digital angiography (lateral view). The guidewire passed across, above, or below the external auditory canal in 10 (56%), six (33%), and two (11%) cases, respectively. CLINICAL IMPLICATIONS: No previous reports have analysed the relationship between the external auditory canal and the IPS route. We present a safe and successful technique for approaching the cavernous sinus via the IPS.

[Dissecting Internal Carotid Aneurysm Causing Epistaxis:A Case Report].

We report a rare case of a ruptured dissecting internal carotid aneurysm caused epistaxis without a history of trauma or infection. An 89-year-old woman experienced epistaxis and suffered from hemorrhagic shock at her previous hospital. Head computed tomography(CT)images revealed a ruptured internal carotid aneurysm protruding into the Onodi cell, the most posterior ethmoidal sinus, which extends superolaterally to the sphenoid sinus. Cerebral angiography demonstrated a multilobular-shaped dissecting aneurysm with a maximal diameter of 6.7mm at the cavernous portion of the internal carotid artery(ICA). Overlapping stenting was performed to prevent recanalization. However, a fatal subarachnoid hemorrhage occurred 2 days after the procedure due to the progression of the dissection to the intracranial ICA. The anatomical characteristics of the ethmoidal sinus could be associated with the occurrence of epistaxis. A ruptured small ICA aneurysm with an Onodi cell might cause epistaxis without a history of trauma or infection.

Thromboembolic events associated with single balloon-, double balloon-, and stent-assisted coil embolization of asymptomatic unruptured cerebral aneurysms: evaluation with diffusion-weighted MR imaging.

INTRODUCTION: The introduction of the balloon remodeling and stent-assisted technique has revolutionized the approach to coil embolization for wide-neck aneurysms. The purpose of this study was to determine the frequency of thromboembolic events associated with single balloon-assisted, double balloon-assisted, and stent-assisted coil embolization for asymptomatic unruptured aneurysms. METHODS: A retrospective review was undertaken by 119 patients undergoing coiling with an adjunctive technique for unruptured saccular aneurysms (64 single balloon, 12 double balloon, 43 stent assisted). All underwent diffusion-weighted imaging (DWI) within 24 h after the procedure. RESULTS: DWI showed hyperintense lesions in 48 (40%) patients, and ten (21%) of these patients incurred neurological deterioration (permanent, two; transient, eight). Hyperintense lesions were detected significantly more often in procedures with the double balloon-assisted technique (7/12, 58%) than with the single balloon-assisted technique (16/64, 25%, p = 0.05). Occurrence of new lesions was significantly higher with the use of stent-assisted technique (25/43, 58%) than with the single balloon-assisted technique (p = 0.001). Symptomatic ischemic rates were similar between the three groups. The increased number of microcatheters was significantly related to the DWI abnormalities (two microcatheters, 15/63 (23.8%); three microcatheters, 20/41 (48.8%) (p = 0.008); four microcatheters, 12/15 (80%) (p = 0.001)). CONCLUSION: Thromboembolic events detected on DWI related to coil embolization for unruptured aneurysms are relatively common, especially in association with the double balloon-assisted and stent-assisted techniques. Furthermore, the number of microcatheters is highly correlated with DWI abnormalities. The high rate of thromboembolic events suggests the need for evaluation of platelet reactivity and the addition or change of antiplatelet agents.

[A case of glioblastoma multiforme in the pineal region with intraventricular hemorrhage].

INTRODUCTION: Glioblastoma multiforme (GBM) is a very rare type of tumor involving the pineal region. No case of pineal region GBM with tumoral hemorrhage has ever been reported. Here, we present the first such case report. CASE REPORT: A 65-year-old man presented with sudden-onset disturbance of consciousness. CT revealed intraventricular hemorrhage and acute hydrocephalus. The patient was treated by an emergent operation for ventricular drainage. MRI with contrast media showed a heterogeneous enhanced area in the pineal region. The patient underwent endoscopic biopsy surgery and a third ventriculostomy for non-communicating hydrocephalus. The pathological diagnosis was high-grade glioma, indicating the need for tumor removal via the occipital transtentorial approach. The tumor was removed subtotally and radiation and chemotherapy courses were then started. CONCLUSION: Pineal GBM with tumoral hemorrhage has never been reported before. Endoscopic operations are useful for rapid decision making prior to radical surgery.

Influence of size ratio on retreatment after coil embolization for unruptured bifurcation aneurysms.

Background: Aneurysm size is considered a risk factor for aneurysm rupture, and even small aneurysms may rupture, especially bifurcation aneurysms (BAs), which are occasionally detected. Therefore, we aimed to investigate the predictors of retreatment after coil embolization for unruptured BAs, with a particular focus on the absolute and relative size of the aneurysm (size ratio [SR]). Methods: To evaluate the predictors of retreatment, patients were divided into two groups: those with and those without retreatment. Patient characteristics and radiographic assessments were compared between the groups. SR was defined as the ratio of the maximum aneurysm diameter and the average diameter of the parent artery. Results: Overall, 181 unruptured BAs in 176 patients were investigated. The mean age of the patients was 63.8 ± 9.6 years. The mean aneurysm size and SR were 7.18 ± 2.94 mm and 2.49 ± 1.32, respectively. Further, 12 aneurysms with retreatment (6.6 %) and 169 aneurysms without retreatment were compared. In univariate analysis, SR was significantly higher in the group with retreatment (P = 0.02), but aneurysm size was not significantly different between the groups (P = 0.09). Multivariable analysis revealed that SR > 2.6 was a significant predictor of retreatment (P = 0.03; odds ratio: 10.41; 95 % confidence interval: 2.1-51.73). Conclusions: This study showed that SR influences retreatment after coil embolization for unruptured BAs. Therefore, if the aneurysm size and parent artery diameter were small, as in cases with a large SR, meticulous follow-up after coil embolization is required to detect recurrence and recanalization.

Cytotoxic Lesions of the Corpus Callosum Associated with Aneurysmal Subarachnoid Hemorrhage May Influence Shunt-Dependent Chronic Hydrocephalus.

BACKGROUND: Cytotoxic lesions of the corpus callosum (CLOCCs) are occasionally associated with aneurysmal subarachnoid hemorrhage (aSAH). The effects of aSAH on clinical outcomes in such cases are unclear. The present study aimed to investigate the frequency and characteristics of CLOCCs associated with aSAH to ascertain the predictors of shunt-dependent chronic hydrocephalus (SDCH) after aSAH. METHODS: We retrospectively investigated cases of aSAH treated by coil embolization. Patients were divided into those with and without CLOCCs. Between-group differences were evaluated, including clinical outcomes and the characteristics of both the patients and the aneurysms. Patients were divided into those with and without SDCH to identify predictive factors of SDCH after aSAH focusing on CLOCCs. RESULTS: This single-center study included 196 patients with aSAH. All patients received coil embolization between April 2013 and March 2020. CLOCCs were detected in 38 (19.4%) patients. In the group with CLOCCs, male sex, poor severity grade at onset, acute hydrocephalus, SDCH (all P < 0.01), and Fisher group 3 or 4 (P = 0.04) were significantly more common than in the group without CLOCCs. Diabetes and CLOCCs were significant predictors of SDCH after aSAH in multivariate analysis (diabetes: P < 0.01, odds ratio: 6.73, 95% confidence interval: 1.61-28.09; CLOCCs: P < 0.01, odds ratio: 6.86, 95% confidence interval: 2.87-16.38). CONCLUSIONS: CLOCCs and SDCH were common in patients with poor-grade aSAH, and CLOCCs were independent predictors of SDCH after aSAH. Meticulous follow-up is necessary to detect SDCH after aSAH, especially in patients with poor-grade aSAH and CLOCCs.

A Novel Braided Stent With Customized Simulation Software for Treatment of Intracranial Aneurysms: Multicenter Prospective Trial Before Unrestricted Clinical Application.

BACKGROUND AND OBJECTIVES: Planning/guidance software became important tools for physicians' presurgical optimal decision-making. However, there are no intracranial stent products with specifically associated simulation software. We report the "premarket" clinical trial of a new braided stent with a customized simulation software. METHODS: A stent system with 3 mesh density types (16, 24, and 32 wire mesh) was designed based on computational flow dynamics technology, and a simulation software (virtual stent planner [VSP]) was developed for the optimal stent deployment planning. Stents were selected after simulation on preoperative 3D-processed angioimages, and accuracy of the VSP was evaluated. RESULTS: Thirty-three unruptured intracranial aneurysms were successfully treated with VSP guidance. Twenty aneurysms (61%) were anterior circulation aneurysms, and 13 (39%) were posterior circulation aneurysms. The average aneurysm size was 7.1 mm, and the mean follow-up period was 19.2 months (11-39.0). There was no major recurrence or retreatment during follow-up, 2 morbidity cases, and no mortality. VSP planning presented slightly smaller stent dimensions compared with postdeployment: 24.2 vs 25.5 mm average, error -1.3 mm, and difference rate-5.46%. CONCLUSION: Based on this result, the new stents and software guidance system were approved by the Ministry of Health and Welfare as a combined medical device. VSP provided precise deployment with minimal error compared with actual stent and can contribute to better stent deployment even for less experienced physicians.

Efficacy and Safety of Lumbar Drainage before Endovascular Treatment for Ruptured Intracranial Aneurysms.

Objective: Intraoperative rebleeding during endovascular treatment for ruptured intracranial aneurysms is associated with poor prognosis. Lumbar drainage is performed preoperatively to control intracranial pressure; however, it is associated with a risk of brain herniation or rebleeding because intracranial pressure may change rapidly. Therefore, this study aimed to examine the efficacy and safety of preoperative lumbar drainage. Methods: This retrospective study enrolled 375 patients who underwent endovascular treatment of ruptured intracranial aneurysms at our institution between April 2013 and March 2018. The incidence of rebleeding and clinical outcomes were compared between patients who did and did not undergo preoperative lumbar drainage. Results: Among the 375 patients with ruptured intracranial aneurysms, 324 (86.0%) and 51 (14.0%) patients did and did not undergo lumbar drainage, respectively. The incidence of rebleeding was 11/324 (3.4%) and 2/51 (3.9%) in lumbar drainage and nonlumbar drainage groups, respectively, with no statistical differences (p = 0.98). Of the rebleeding cases, 9/11 (81%) and 2/2 (100%) in lumbar drainage and nonlumbar drainage groups, respectively, were due to intraoperative bleeding, and 2/11 (19%) in the lumbar drainage group, the causes of the rebleeding were undetermined. The incidence of symptomatic vasospasm did not differ significantly between the groups (13.2% vs. 11.8%, P = 0.776), while the incidence of hydrocephalus (24.6% vs. 11.8%, P = 0.043) and meningitis (15.2% vs. 5.9%, P = 0.075) were slightly higher in the lumbar drainage group. Favorable clinical outcomes (modified Rankin Scale score <2) at discharge were less frequent in the lumbar drainage group (55.3% vs. 70.0%, P = 0.051). No significant differences were observed in the propensity score-matched analysis. Conclusion: Lumbar drainage before endovascular treatment for ruptured intracranial aneurysms is a safe procedure that does not increase the incidence of rebleeding.

Acute Distal Migration and Shortening of the Flow-Redirection Endoluminal Device: A Case Report.

Objective: The flow diverter (FD) is a promising device. Apart from two main complications, hemorrhagic and ischemic ones, stent migration is reportedly an unusual complication. In particular, distal migration of the FD has rarely been reported. We report a case of asymptomatic acute distal migration of the flow-redirection endoluminal device (FRED). Case Presentation: A 50-year-old woman was incidentally diagnosed with an unruptured right internal carotid-ophthalmic artery aneurysm with a maximum diameter of 8.0 mm, and she subsequently underwent endovascular treatment with FRED. Based on the vessel diameter (3.8 mm proximal and 3.6 mm distal to the aneurysm), a 4.0-mm-diameter and 18-mm-long FRED was deployed without postoperative complications. However, on MRA 12 months after treatment, the aneurysm was not occluded; angiography showed distal migration of the FRED. The postoperative MRA and skull X-ray images were retrospectively reviewed to determine the period of the migration. The skull X-ray images and the signal loss area due to the FRED on MRA 1 day after the treatment had already demonstrated the migration of the FRED. In the second treatment, a 4.0-mm-diameter and 23-mm-long FRED was deployed in an overlapping fashion up to the proximal part of the carotid siphon. Prompt identification of distal migration of the FD without neurologic signs could be challenging. Conclusion: It is important to follow up meticulously with MRA and skull X-ray images after FD treatment for detecting stent migrations as early as possible.

Possible Contribution of the Aspiration Catheter in Preventing Post-stent Retriever Thrombectomy Subarachnoid Hemorrhage.

PURPOSE: This study aimed to identify factors related to the incidence of post-thrombectomy subarachnoid hemorrhage (PTSAH). METHODS: This retrospective, observational cohort study enrolled consecutive patients with acute ischemic stroke (AIS) due to the internal carotid artery (IC) top or middle cerebral artery (MCA) M1 or M2 segment occlusion who underwent single-pass stent retriever (SR) treatment between January 2015 and May 2022 at two acute care hospitals. RESULTS: Of the 54 included patients, 10 were in the PTSAH group (18.5%). The occlusion sites were IC top (31.5%), M1 segment (48.1%), and M2 segment (20.4%). Aspiration catheters (ACs) were used in 32 (59.3%) patients; however, the combined technique (AC advancement at least to the most proximal marker of SR) was actually used in 26 (48.1%) patients because a ledge effect at the ophthalmic artery origin from the IC interfered with distal navigation of the ACs. The baseline patient characteristics did not differ between the groups. M2 segment occlusion in the PTSAH and non-PTSAH groups were 40.0% and 15.9%, respectively (p = 0.19). More ACs were used in the non-PTSAH group (65.9% vs. 30.0%, p = 0.07). Significantly fewer combined techniques were performed in the PTSAH group (10.0% vs. 56.8%, p = 0.01). In multivariate analysis adjusted by variables with M2 segment occlusion and the combined technique, the combined technique (odds ratio 0.098; 95% confidence interval, 0.011-0.887; p = 0.039) was identified as a significantly associated factor for PTSAH. There was one PTSAH case (1.9%) with symptom worsening. CONCLUSION: The combined technique significantly influenced PTSAH occurrence as a preventive factor.

Inflow Angle and Height-Width Ratio are Predictors of Incomplete Occlusion at One and Two Years After Flow Diverter Treatment for Small- and Medium-Sized Internal Carotid Artery Aneurysms.

OBJECTIVE: We investigated the association between the inflow angle of aneurysms and their occlusion status at 1 and 2 years after flow diverter (FD) treatment. METHODS: We retrospectively analyzed 42 consecutive patients from a single center with 43 untreated, unruptured internal carotid artery (ICA) proximal to communicating segment, saccular aneurysms sized <12 mm. RESULTS: At 1 year posttreatment, the complete occlusion (CO) rate was 58.1%. On univariate analyses, the proportion of inflow angle >90° was significantly lower in the CO group than in the incomplete occlusion group (20.0% VS. 83.3%; P < 0.001). The CO incidence decreased with a height-width (H/W) ratio of <1.2 (P = 0.059). On multivariate analysis, an H/W ratio of <1.2 (odds ratio [OR], 0.076; P = 0.027) and an inflow angle of >90° (OR, 0.020; P = 0.0011) significantly influenced CO at 1 year post FD. At 2 years posttreatment, the CO rate was 76.3% (29/38 cases with available follow-up data). On univariate analyses, in the CO group compared to the incomplete occlusion group, the proportion of H/W ratio <1.2 was significantly lower (P = 0.005) and the proportion of inflow angle >90° was significantly lower (P = 0.021); aneurysm dome size tended to be larger (8.5 mm vs. 7.1 mm; P = 0.080). On multivariate analysis, an H/W ratio <1.2 (OR, 0.042; P = 0.015) and an inflow angle >90° (OR: 0.088; P = 0.031) significantly influenced CO at 2 years post FD. CONCLUSIONS: The inflow angle of >90° and H/W ratio <1.2 may significantly influence the CO rate in small- or medium-sized internal carotid artery aneurysms 1 and 2 years post FD.

Impact of size ratio on thromboembolic events based on diffusion-weighted imaging after coil embolization for unruptured basilar apex aneurysm.

PURPOSE: Coil embolization is one of the main endovascular treatment for basilar apex aneurysms (BAAs), and thromboembolic events are important complications of coil embolization. Even in small aneurysms, there is a risk of rupture, and aggressive treatment should be considered for unruptured BAAs. Using diffusion-weighted imaging (DWI), the study aimed to investigate thromboembolic events after coil embolization for unruptured BAAs by focusing on the absolute aneurysm size and relative aneurysm size (size ratio [SR]). METHODS: To evaluate the predictors of thromboembolic events, patients were divided into those with and without hyperintensity on DWI after coil embolization. Patient and radiographic characteristics were compared between the two groups. SR was defined as the maximum aneurysm diameter divided by the average parent artery diameter. RESULTS: Fifty-six unruptured BAAs in 56 patients were investigated. The mean aneurysm size and SR were 7.61 ± 2.18 mm and 2.74 ± 1.45, respectively. Postprocedural hyperintensity on DWI was detected in 17 patients (30.4%). SR was significantly larger in the group with hyperintensity on DWI (3.75 ± 1.97 vs. 2.3 ± 0.82, P < 0.01) in the univariate analysis. Multivariate analysis revealed that SR> 3.0 was a significant predictor of thromboembolic events after coil embolization for unruptured BAAs (odds ratio: 12.15; 95% confidence interval: 2.95-49.98; P < 0.01). CONCLUSIONS: This study showed that SR is a predictor of thromboembolic events after coil embolization for unruptured BAAs. Therefore, if even in small BAAs, if the BAAs dome height is large compared to the diameter of the posterior cerebral artery (e.g., there is a large SR), preoperative evaluation of the use of antiplatelet therapy is important, particularly to prevent thromboembolic events.