Three-dimensional Images Fusion Method Useful for Preoperative Simulation of Clipping Surgery for Cerebral Aneurysms.

This study aimed to introduce a three-dimensional (3D) images fusion method for preoperative simulation of aneurysm clipping. Consecutive unruptured aneurysm cases treated with surgical clipping from March 2021 to October 2023 were included. In all cases, preoperative images of plain computed tomography (CT), CT angiography, magnetic resonance imaging (MRI) 3D fluid-attenuated inversion recovery, 3D heavily T2-weighted images, and 3D rotational angiography were acquired and transported into a commercial software (Ziostation2 Plus, Ziosoft, Inc. Tokyo, Japan). The software provided 3D images of skull, arteries including aneurysms, veins, and brain tissue that were freely rotated, magnified, trimmed, and superimposed. Using the 3D images fusion method, two operators predicted clips to be used in the following surgery. The predicted clips and actually used ones were compared to give agreement scores for the following factors: (1) type of clips (simple or fenestrated), (2) shape of clips (straight, curved, angled, or bayonet), and (3) clipping strategy (single or multiple). The agreement score ranged from 0 to 3 because a score of 1 or 0 was given for agreement or disagreement on each factor. Interoperator reproducibility was also evaluated. During the study period, 44 aneurysms from 37 patients were clipped. All procedures were successfully completed, thanks to the precisely reproduced surgical corridors with the 3D images fusion method. Agreement in clip prediction was good with mean agreement score of 2.4. Interobserver reproducibility was also high with the kappa value of 0.79. The 3D images fusion method was useful for preoperative simulation of aneurysm clipping.

Cilostazol May Improve Outcomes Even in Patients with Aneurysmal Subarachnoid Hemorrhage Aged 75 Years and Older: Multicenter Cohort Study and Propensity Score-Matched Analyses.

BACKGROUND: The opportunities to treat elderly patients with aneurysmal subarachnoid hemorrhage (aSAH) are increasing globally, but the outcome remains poor. This study seeks to investigate treatment-related factors that can modify functional outcomes in patients with aSAH aged ≥75 years. METHODS: A total of 202 patients with aSAH aged ≥75 years prospectively enrolled in 9 primary stroke centers from 2013 to 2021 were retrospectively analyzed. Clinical variables including treatments for hydrocephalus, angiographic vasospasm, and delayed cerebral ischemia were compared between patients with good (modified Rankin Scale [mRS] score 0-2) and poor (mRS score 3-6) outcomes at 90 days from onset, followed by multivariate analyses to find independent outcome determinants. A modifiable treatment-related variable was evaluated after propensity score matching with adjustments for age, sex, pre-onset mRS score, aSAH severity, and treatment modality. RESULTS: More than half of patients showed World Federation of Neurological Societies grades IV-V on admission. Univariate analyses showed that advanced age, worse pre-onset mRS score, more severe neurologic status on admission, higher modified Fisher grade on admission computed tomography scans, and acute and chronic hydrocephalus were associated with poor outcomes. In contrast, administration of a phosphodiesterase type III inhibitor, cilostazol, was associated with good outcomes in both univariate (P = 0.036) and multivariate analyses (adjusted odds ratio, 0.305; 95% confidence interval, 0.097-0.955; P = 0.042). Propensity score matching analyses showed that patients treated with cilostazol had better outcomes (P = 0.016) with fewer incidences of delayed cerebral infarction (P = 0.008). CONCLUSIONS: Even in patients with aSAH aged ≥75 years, cilostazol administration may lead to better outcomes by suppressing the development of delayed cerebral infarction.

Computational fluid dynamics for predicting the growth of small unruptured cerebral aneurysms.

OBJECTIVE: Larger cerebral aneurysms are more likely to enlarge, but even small aneurysms can grow. The aim of this study was to investigate the hemodynamic characteristics regarding the growth of small aneurysms using computational fluid dynamics (CFD). METHODS: The authors analyzed 185 patients with 215 unruptured cerebral aneurysms with a maximum diameter of 3-5 mm, registered in a multicenter prospective observational study of unruptured aneurysms (Systematic Multicenter Study of Unruptured Cerebral Aneurysms Based on Rheological Technique at Mie) from January 2013 to February 2022. Based on findings on repeated images, aneurysms were divided into a stable group (182 aneurysms) and a growth group (33 aneurysms). The authors developed the high shear concentration ratio (HSCR), in which high wall shear stress (HWSS) was defined as a value of 110% of the time-averaged wall shear stress of the dome. High shear area (HSA) was defined as the area with values above HWSS, and the ratio of the HSA to the surface area of the dome was defined as the HSA ratio (HSAR). They also created the flow concentration ratio (FCR) to measure the concentration of the inflow jet. Multivariate logistic regression analysis was performed to determine morphological variables and hemodynamic parameters that independently characterized the risk of growth. RESULTS: The growth group had a significantly higher projection ratio (0.74 vs 0.67, p = 0.04) and volume-to-ostium area ratio (1.72 vs 1.44, p = 0.02). Regarding the hemodynamic parameters, the growth group had significantly higher HSCR (6.39 vs 4.98, p < 0.001), lower HSAR (0.28 vs 0.33, p < 0.001), and lower FCR (0.61 vs 0.67, p = 0.005). In multivariate analyses, higher HSCR was significantly associated with growth (OR 0.81, 95% CI 7.06 e-1 to 9.36 e-1; p = 0.004). CONCLUSIONS: HSCR may be a useful hemodynamic parameter to predict the growth of small unruptured cerebral aneurysms.

Evaluation of Intra-Aneurysmal Residual Blood Flow with the iMSDE T1-Black Blood Imaging after Flow Diverter Treatment.

Objective: We aimed to evaluate the efficacy of the "improved motion-sensitized driven-equilibrium (iMSDE)"-prepared T1-weighted black blood (T1-BB) MRI for monitoring treatment effect with a flow diverter (FD) for cerebral aneurysms. Methods: Following the exclusion of concomitant coiling and retreatment cases from 60 consecutive cases of cerebral aneurysms treated with FDs at our institution, 32 with imaging data were included in the analysis. Detectability of residual blood flow within the aneurysms was validated as follows: 1) comparison of MRI sequences (iMSDE-prepared T1-BB images, T1-weighted images [ T1WI], and time-of-flight [ TOF]-MRA) in cases of incompletely occluded aneurysms and 2) comparison of angiography and MRI sequences in the same period. Results: 1) The probability of diagnosing intra-aneurysmal blood flow was significantly higher with iMSDE-prepared T1-BB (iMSDE-prepared T1-BB vs. T1WI, p <0.001; iMSDE-prepared T1-BB vs. TOF-MRA, p <0.001). 2) The diagnostic accuracy of residual aneurysmal blood flow was significantly higher with iMSDE-prepared T1-BB than that with T1WI (p = 0.032). Furthermore, in cases of incomplete occlusion, the probability of detecting intra-aneurysmal blood flow was significantly higher with iMSDE-prepared T1-BB (iMSDE-prepared T1-BB vs. T1WI, p <0.001; iMSDE-prepared T1-BB vs. TOF-MRA, p = 0.023). Conclusion: Our results demonstrated that iMSDE-prepared T1-BB could help distinguish between blood flow and thrombus within the aneurysms after FD treatment, especially in the early stages of FD treatment.

[Dural Arteriovenous Fistula:Indications and Outcomes].

The diagnosis of dural arteriovenous fistulas(DAVF)has advanced with the development of imaging techniques. The indication for treatment of DAVF is generally based on classification according to the venous drainage pattern, which determines whether the presentation is benign or aggressive. In recent years, with the introduction of Onyx, transarterial embolization has been increasingly used, and outcomes have improved, although some conditions are more suitable for transvenous embolization. It is important to select an optimal approach based on location and angioarchitecture. Since DAVF is a rare vascular disease with limited evidence, further validation of clinical results is needed to provide more established treatment guidelines.

Plasma SPARC Elevation in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage.

Matricellular proteins have been implicated in pathologies after subarachnoid hemorrhage (SAH). To find a new therapeutic molecular target, the present study aimed to clarify the relationships between serially measured plasma levels of a matricellular protein, secreted protein acidic and rich in cysteine (SPARC), and delayed cerebral ischemia (DCI) in 117 consecutive aneurysmal SAH patients with admission World Federation of Neurological Surgeons (WFNS) grades I-III. DCI developed in 25 patients with higher incidences of past history of hypertension and dyslipidemia, preoperative WFNS grade III, modified Fisher grade 4, spinal drainage, and angiographic vasospasm. Plasma SPARC levels were increased after SAH, and significantly higher in patients with than without DCI at days 7-9, and in patients with VASOGRADE-Yellow compared with VASOGRADE-Green at days 1-3 and 7-9. However, there were no relationships between plasma SPARC levels and angiographic vasospasm. Receiver-operating characteristic curves differentiating DCI from no DCI determined the cut-off value of plasma SPARC ≥ 82.1 ng/ml at days 7 - 9 (sensitivity, 0.800; specificity, 0.533; and area under the curve, 0.708), which was found to be an independent determinant of DCI development in multivariate analyses. This is the first study to show that SPARC is upregulated in peripheral blood after SAH, and that SPARC may be involved in the development of DCI without angiographic vasospasm in a clinical setting.

A Unique Technique to Adjust Snare Position for Coil Retrieval in Tortuous Vessel During Aneurysm Coil Embolization: A Technical Case Report.

OBJECTIVE: Although snares are useful devices to retrieve an intravascular foreign body, the control of snares is often difficult. We present a safe and effective technique to adjust snare position in the tortuous vessel for coil retrieval during endovascular coil embolization. METHODS: We describe a case of a protruding coil during coil embolization that was successfully retrieved using a unique technique to adjust snare position and discuss additional intraprocedural bailout strategies for retrieving a coil during endovascular coil embolization. RESULTS: The patient was a 44-year-old female with unruptured right internal carotid artery (ICA) aneurysm that had grown over a 1.5-year period. Coil embolization was performed. After detachment of final coil and microcatheter removal, the final coil protruded into the ICA and floated. Coil retrieval using a snare was attempted, but the snare could not be placed around the coil tail and coil retrieval could not be achieved. The following technique was used to allow adjustment of snare position. First, a microguidewire and a microcatheter were guided into the M2 and M1 segment of the middle cerebral artery as monorail guides of the snare, respectively. Next, the snare was advanced over the microcatheter. Around C2 segment of the ICA, the microcatheter and the snare were manipulated as a unit. Thus, the snare could be placed around the protruding coil tail and the coil was retrieved successfully. CONCLUSIONS: This technique may be widely adapted for various situations when using a snare.

Effects of New-Generation Antiepileptic Drug Prophylaxis on Delayed Neurovascular Events After Aneurysmal Subarachnoid Hemorrhage.

Neuroelectric disruptions such as seizures and cortical spreading depolarization may contribute to the development of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH). However, effects of antiepileptic drug prophylaxis on outcomes remain controversial in SAH. The authors investigated if prophylactic administration of new-generation antiepileptic drugs levetiracetam and perampanel was beneficial against delayed neurovascular events after SAH. This was a retrospective single-center cohort study of 121 consecutive SAH patients including 56 patients of admission World Federation of Neurological Surgeons grades IV - V who underwent aneurysmal obliteration within 72 h post-SAH from 2013 to 2021. Prophylactic antiepileptic drugs differed depending on the study terms: none (2013 - 2015), levetiracetam for patients at high risks of seizures (2016 - 2019), and perampanel for all patients (2020 - 2021). The 3rd term had the lowest occurrence of delayed cerebral microinfarction on diffusion-weighted magnetic resonance imaging, which was related to less development of DCI. Other outcome measures were similar among the 3 terms including incidences of angiographic vasospasm, computed tomography-detectable delayed cerebral infarction, seizures, and 3-month good outcomes (modified Rankin Scale 0 - 2). The present study suggests that prophylactic administration of levetiracetam and perampanel was not associated with worse outcomes and that perampanel may have the potential to reduce DCI by preventing microcirculatory disturbances after SAH. Further studies are warranted to investigate anti-DCI effects of a selective α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor antagonist perampanel in SAH patients in a large-scale prospective study.

Plasma Fibulin-5 Levels as an Independent Predictor of a Poor Outcome after an Aneurysmal Subarachnoid Hemorrhage.

Aneurysmal subarachnoid hemorrhage (SAH) is a poor-outcome disease with a delayed neurological exacerbation. Fibulin-5 (FBLN5) is one of matricellular proteins, some of which have been involved in SAH pathologies. However, no study has investigated FBLN5's roles in SAH. This study was aimed at examining the relationships between serially measured plasma FBLN5 levels and neurovascular events or outcomes in 204 consecutive aneurysmal SAH patients, including 77 patients (37.7%) with poor outcomes (90-day modified Rankin Scale 3-6). Plasma FBLN5 levels were not related to angiographic vasospasm, delayed cerebral ischemia, and delayed cerebral infarction, but elevated levels were associated with severe admission clinical grades, any neurological exacerbation and poor outcomes. Receiver-operating characteristic curves indicated that the most reasonable cut-off values of plasma FBLN5, in order to differentiate 90-day poor from good outcomes, were obtained from analyses at days 4-6 for all patients (487.2 ng/mL; specificity, 61.4%; and sensitivity, 62.3%) and from analyses at days 7-9 for only non-severe patient (476.8 ng/mL; specificity, 66.0%; and sensitivity, 77.8%). Multivariate analyses revealed that the plasma FBLN5 levels were independent determinants of the 90-day poor outcomes in both all patients' and non-severe patients' analyses. These findings suggest that the delayed elevation of plasma FBLN5 is related to poor outcomes, and that FBLN5 may be a new molecular target to reveal a post-SAH pathophysiology.

Non-Fasting Hypertriglyceridemia Burden as a Residual Risk of the Progression of Carotid Artery Stenosis.

The relationships between repeated non-fasting triglyceride (TG) measurements and carotid stenosis progression during follow-ups have never been investigated. In 111 consecutive carotid arteries of 88 patients with ≥50% atherosclerotic stenosis on at least one side, who had ≥3 blood samples taken during ≥one-year follow-ups, clinical variables were compared between carotid arteries with and without subsequent stenosis progression. To evaluate non-fasting TG burden, a new parameter area [TG ≥ 175] was calculated by integrating non-fasting TG values ≥ 175 mg/dL (i.e., TG values minus 175) with the measurement intervals (year). Carotid stenosis progression occurred in 22 arteries (19.8%) during the mean follow-up period of 1185 days. Younger age, symptomatic stenosis, higher mean values of TG during follow-ups, the area [TG ≥ 175], mean TG values ≥ 175 mg/dL and maximum TG values ≥175 mg/dL were significant factors related to the progression on univariate analyses. The cut-off value of the area [TG ≥ 175] to discriminate carotid stenosis progression was 6.35 year-mg/dL. Multivariate analyses demonstrated that symptomatic stenosis and the area [TG ≥ 175] ≥ 6.35 year-mg/dL were independently related to carotid stenosis progression. In conclusion, the area [TG ≥ 175] was an independent risk factor for carotid stenosis progression, and this study suggests the importance to continuously control non-fasting TG levels < 175 mg/dL during follow-ups to prevent carotid stenosis progression.

Vertebral artery dissecting aneurysm rupture under severe COVID-19.

Objective: We report a rare case of subarachnoid hemorrhage (SAH) caused by a ruptured vertebral artery (VA) dissecting aneurysm (DA) under severe COVID-19 treatment, and discuss the potential relationships. Case presentation: A 58-year-old woman with COVID-19 fell into severe pneumonia needing mechanical ventilation at 10 days post-onset (day 10). The patient had no risk factors for DA or stroke other than COVID-19 infection. At day 17 when weaning ventilatory management, her systolic blood pressure was transiently elevated, and her consciousness did not recover thereafter. Computed tomography (CT) at day 21 revealed SAH with modified Fisher grade 4, and CT angiography revealed a DA in the right VA just distal to the right posterior inferior cerebellar artery (PICA). The DA was treated emergently with internal trapping by endovascular coiling, while the right PICA was preserved. Postoperative course was uneventful, and 2-time negative SARS-CoV-2 PCR results were obtained at day 45. The patient recovered to 4-month modified Rankin Scale 2. Conclusions: Although it is not clear from the present case alone whether SARS-CoV-2 infection causes SAH by a ruptured VA DA, the accumulation of more cases and further studies are warranted to clarify the relationships between SARS-CoV-2 infection and ruptured intracranial DAs.

Posterior Communicating Artery-incorporated Internal Carotid-Posterior Communicating Artery Aneurysms Prone to Recur After Coil Embolization.

OBJECTIVE: The objective was to clarify predisposing factors of recurrence after coil embolization for internal carotid-posterior communicating artery (IC-Pcom) aneurysms. METHODS: The medical records were retrospectively reviewed and patients harboring IC-Pcom aneurysms treated with coil embolization between June 2004 and June 2020 were identified. Aneurysms whose 3-dimensional images were available, whose initial treatment was performed during the study period, and whose follow-up term was more than 1 year were included. Information of the patients, the aneurysms and Pcoms, the initial treatment, and angiographic outcomes were collected. The IC-Pcom aneurysms were divided into Pcom-incorporated when their neck mainly rode on the Pcom or non-Pcom-incorporated when their neck mainly rode on the internal carotid artery or the classification was equivocal. Relationship between these factors and recurrence was analyzed. RESULTS: Fifty-seven IC-Pcom aneurysms from 55 patients were recruited. Fifteen of the 57 aneurysms were categorized into Pcom-incorporated. Eighteen of the 57 aneurysms recurred. Mean follow-up term was 74.3 months and mean duration between the initial treatment and recurrence was 47.9 months. On univariate analyses, ruptured (P = 0.004), fetal-type Pcom (P = 0.002), and Pcom-incorporated (P < 0.001) were significantly correlated with recurrence. Multivariate analysis demonstrated that Pcom-incorporated aneurysms were significantly associated with recurrence (P < 0.001) along with ruptured (P = 0.027). Kaplan-Meier estimate demonstrated that cumulative recurrence-free rate was significantly lower in Pcom-incorporated aneurysms compared with non-Pcom-incorporated aneurysms (log-rank P < 0.001). CONCLUSIONS: Pcom-incorporated IC-Pcom aneurysms were susceptible to recur after coil embolization, especially when ruptured and the incorporated Pcom was fetal-type.

Folding Deformation of Open-Cell Stents in Carotid Artery Stenting: Report of Three Cases and Review of Literature.

Objective: We describe 3 cases with folding deformation of a PRECISE (Cordis, Miami, FL, USA) stent in carotid artery stenting (CAS). Case Presentations: The 3 cases with cervical carotid stenosis consisted of 3 males around 80 years old and included 2 symptomatic lesions. During CAS, distal embolic protection was established using a Mo.Ma (Medtronic, Minneapolis, MN, USA) along with a filter device in 2 cases and an Optimo (Tokai Medical Products, Aichi, Japan) along with a filter device in 1 case. For the filter device, either FilterWire EZ (Boston Scientific, Natick, MA, USA) or Spider FX (Covidien, Irvine, CA, USA) was employed. In all cases, a PRECISE stent was deployed after pre-dilation performed using a percutaneous transluminal angioplasty (PTA) balloon with the diameter of 2.5 to 3 mm. Post-dilation was performed after the stent deployment using a PTA balloon whose diameter was about 80% of that of the normal distal internal carotid artery. In all cases, cone-beam CT taken after the deployment of a stent showed folding deformation of the stent. In 2 cases, heavily calcified plaque hampered self-expansion of the stent, which resulted in the stent deformation. On the other hand, in the remaining 1 case, a distal shaft of the Mo.Ma caused the stent deformation, which was likely accelerated by head rotation and cervical compression that was performed to resolve difficulties for a filter retrieval device to pass through the stent, and post-dilation after the stenting. Conclusion: Heavily calcified plaque and a distal shaft of a Mo.Ma would result in stent deformation.

Retrograde Angiography to Detect Dropped Thrombus in Mechanical Thrombectomy.

OBJECTIVE: The risk of embolization to distal territory or to new territory in mechanical thrombectomy remains a major issue despite advancements in technological device. This condition can be caused by a large and firm dropped thrombus without passing through a guiding catheter during stent retriever or aspiration catheter withdrawal. This report introduced a novel technique referred to as retrograde angiography to detect dropped thrombus. METHODS: The retrograde angiography to detect dropped thrombus technique is a kind of retrograde angiography that consists of a contrast medium injection via a distal microcatheter and aspiration through an inflated balloon-guiding catheter. This method was used to detect dropped thrombus at the balloon-guiding catheter tip when back flow was blocked from the balloon-guiding catheter after stent retriever or aspiration catheter withdrawal. We retrospectively reviewed four consecutive patients who underwent the retrograde angiography to detect dropped thrombus technique during mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion in the anterior circulation between January 2018 and January 2021. RESULTS: Three of four patients had dropped thrombus, which was diagnosed with the technique and retrieved completely with subsequent procedures while maintaining the balloon-guiding catheter inflated. None of the patients experienced embolization to distal territory/embolization to new territory, and a successful reperfusion was achieved in all four cases. CONCLUSIONS: The retrograde angiography to detect dropped thrombus is a technique to detect a dropped thrombus at the balloon-guiding catheter tip and allows us to retrieve it with subsequent mechanical thrombectomy procedures while maintaining the balloon-guiding catheter inflated and it may be useful for reducing the risk of embolization to distal territory/embolization to new territory.

Nonfasting Triglyceride as an Independent Predictor of Carotid Restenosis After Carotid Endarterectomy or Carotid Artery Stenting.

OBJECTIVE: Nonfasting serum triglyceride (TG) level is attracting more and more attention as an atherosclerosis-promoting factor. However, no study has investigated the relationships between nonfasting TG levels and carotid restenosis after carotid endarterectomy (CEA) or carotid artery stenting (CAS). This study was conducted to investigate if nonfasting TG levels can be used to assess a risk for carotid restenosis after CEA or CAS. METHODS: This was a single-center retrospective study. We reviewed 201 consecutive primary carotid artery revascularization procedures (39 CEAs and 162 CASs), which were performed from 2008 to 2018 for 179 patients (163 men and 16 women) with atherosclerotic carotid stenosis, and were followed up for at least 1 year. Clinical variables including nonfasting lipid profiles and findings of magnetic resonance plaque imaging were compared between groups with and without postprocedural carotid restenosis (≥50% stenosis on ultrasonography). RESULTS: During a mean follow-up period of 1413 days, 24 of 201 carotid stenosis procedures (11.9%) suffered restenosis after successful revascularization procedures. Multivariate analyses demonstrated that nonfasting TG level was the only independent risk factor of postprocedural restenosis. The receiver operating characteristic curve analyses revealed that a cutoff value of nonfasting TG to discriminate postprocedural carotid restenosis was 127.5 mg/dL, which was much lower than the upper limit of normal. CONCLUSIONS: This study showed that nonfasting TG level may be a useful marker to predict carotid restenosis after CEA or CAS, and could be a new therapeutic target to prevent carotid restenosis after revascularization procedures.

Higher Non-fasting Serum Triglyceride Preceding the Carotid Stenosis Progression.

The present study was conducted to investigate whether non-fasting serum triglyceride (TG) levels can be used to assess a risk for the progression of carotid artery stenosis. This was a single-center retrospective study. Consecutive 96 patients with ≥50% stenosis of at least unilateral cervical internal carotid artery and normal fasting serum low-density lipoprotein cholesterol (LDL-C) levels of ≤140 mg/dL were followed up for at least 1 year (mean, 3.1 years), and clinical variables were compared between patients with and without carotid stenosis progression (≥10% increases in the degree on ultrasonography). Carotid stenosis progression was shown in 21 patients, associated with less frequent treatment with calcium channel blockers (CCBs), higher non-fasting TG and glucose levels. In carotid artery-based analyses including <50% stenosis side, stenosis progression was shown in 23 of 121 arteries except for those with complete occlusion and less than 1-year follow-up period because of carotid artery stenting (CAS) or carotid endarterectomy (CEA). Stenosis progression was more frequently observed in symptomatic and/or radiation-induced lesions, and was also accompanied with less frequent treatment with CCBs, higher non-fasting TG and glucose levels in carotid artery-based analyses. The receiver operating characteristic (ROC) curve analyses revealed that a cutoff value of non-fasting TG to discriminate carotid stenosis progression was 169.5 mg/dL for carotid arteries with the baseline stenosis of <50%, and 154.5mg/dL for those of ≥50%. Non-fasting TG level was an independent risk factor of carotid stenosis progression, and more strict control of non-fasting TG may be necessary for higher degree of carotid artery stenosis.

Higher Plasma Osteopontin Concentrations Associated with Subsequent Development of Chronic Shunt-Dependent Hydrocephalus After Aneurysmal Subarachnoid Hemorrhage.

A matricellular protein osteopontin (OPN) is considered to exert neuroprotective and healing effects on neurovascular injuries in an acute phase of aneurysmal subarachnoid hemorrhage (SAH). However, the relationships between OPN expression and chronic shunt-dependent hydrocephalus (SDHC) have never been investigated. In 166 SAH patients (derivation and validation cohorts, 110 and 56, respectively), plasma OPN levels were serially measured at days1-3, 4-6, 7-9, and 10-12 after aneurysmal obliteration. The OPN levels and clinical factors were compared between patients with and without subsequent development of chronic SDHC. Plasma OPN levels in the SDHC patients increased from days 1-3 to days 4-6 and remained high thereafter, while those in the non-SDHC patients peaked at days 4-6 and then decreased over time. Plasma OPN levels had no correlation with serum levels of C-reactive protein (CRP), a systemic inflammatory marker. Univariate analyses showed that age, modified Fisher grade, acute hydrocephalus, cerebrospinal fluid drainage, and OPN and CRP levels at days 10-12 were significantly different between patients with and without SDHC. Multivariate analyses revealed that higher plasma OPN levels at days 10-12 were an independent factor associated with the development of SDHC, in addition to a more frequent use of cerebrospinal fluid drainage and higher modified Fisher grade at admission. Plasma OPN levels at days 10-12 maintained similar discrimination power in the validation cohort and had good calibration on the Hosmer-Lemeshow goodness-of-fit test. Prolonged higher expression of OPN may contribute to the development of post-SAH SDHC, possibly by excessive repairing effects promoting fibrosis in the subarachnoid space.

Evaluation of Contact Force between Aneurysm Model and Coil for Embolization of Intracranial Aneurysms.

Objective: To ensure safe coil embolization for intracranial aneurysms, it is important to investigate the contact force between the coil and the aneurysm wall. However, it is unclear how the catheter tip position and the diameter of the secondary loop of the coil influence the contact force. In this study, we measured the contact force between a coil and an aneurysm biomodel under different conditions. Methods: A commercially available coil was inserted through a microcatheter into a silicone rubber aneurysm model at a constant speed (1 mm/s) using an automatic stage, and the contact force between the coil and the aneurysm wall was measured by a force sensor attached on the aneurysm model. The inner diameter of the spherical aneurysm was 5 mm. The effects of varying the position of the catheter tip (near dome, center, near neck) and the diameter of the secondary coil (4.5 mm) were evaluated. Results: When the catheter tip was inserted more deeply into the aneurysm (especially near the dome), the contact force increased. The contact force also increased as the secondary coil diameter was increased with the catheter tip near and in the center of the dome. Conclusion: These results suggest that the catheter tip position and the secondary coil diameter affect the contact force. In particular, the contact force should be considered large with the catheter tip near the dome to ensure safe coil deployment.

A Case of Suspected Metallic Embolism after Carotid Artery Stenting.

A case in which metallic embolism was suspected after carotid artery stenting (CAS) is described. A 79-year-old woman was referred to our hospital because of a severe stenosis of the left cervical internal carotid artery (ICA). Carotid ultrasound revealed that the plaque was fibrous and was accompanied with partial calcification. The carotid stenosis was treated by CAS. The magnetic resonance imaging (MRI) taken in the following day of the CAS demonstrated that a new abnormal spot at the left frontal lobe. The spot appeared as a signal void on T1, T2, diffusion, susceptibility-weighted image (SWI), and fluid attenuated inversion recovery (FLAIR) image, and was surrounded by a high-signal halo on T2 and diffusion-weighted images (DWIs). The spot also demonstrated "blooming" appearance on SWIs. Despite the lesion she was asymptomatic all through the postoperative course, and she left our hospital on postoperative day 6. Follow-up MRI obtained 27 months after the CAS demonstrated that the lesion remained at the left frontal lobe without any signal changes. The patient remained asymptomatic at the last follow-up. Considering the location of the new abnormal spot (in the vascular territory of the catheterized vessel), these imaging characteristics and asymptomatic clinical course, the spot likely suggested metallic embolism. This is the first case in which the metallic embolism was suspected after CAS.