Follow-up care compliance among patients diagnosed with unruptured intracranial aneurysms.

OBJECTIVES: Periodic imaging follow-up for patients with unruptured intracranial aneurysms (UIA) is crucial, as studies indicate higher rupture risk with aneurysm growth. However, few studies address patient adherence to follow-up recommendations. This study aims to identify compliance rates and factors influencing follow-up adherence. METHODS: Patients with a UIA were identified from our institution's database from 2011-2021. Follow-up imaging (CT/MR Angiogram) was advised at specific intervals. Patients were categorized into compliant and non-compliant groups based on first-year compliance. Factors contributing to compliance were assessed through multivariate logistic regression. Phone interviews were conducted with non-compliant patients to understand reasons for non-adherence. RESULTS: Among 923 UIA diagnosed patients, 337 were randomly selected for analysis. The median follow-up period was 1.4 years, with a 42% first-year compliance rate. The mean aneurysm size was 3.3 mm. Five patients had a rupture during follow-up, of which 4 died. Compared with patients consulting specialists at the initial diagnosis, those seen by non-specialists exhibited lower compliance (OR 0.25, p < 0.001). Loss to follow-up was greatest during transition from emergency service to specialist appointments. Patients who spoke languages other than English exhibited poorer compliance than those speaking English (OR 0.20, p = 0.01). CONCLUSIONS: Significant amounts of UIA patients at low rupture risk were lost to follow-up before seeing UIA specialists. Main non-compliance factors include inadequate comprehension of follow-up instructions, poor care transfer from non-specialists to specialist, and insurance barriers.

Impact of Target Artery Size on the Performance of Aspiration Thrombectomy: Insights from a Swine Model with Real-Time Visualization.

A novel swine model was developed to investigate the underlying reasons for the failure of aspiration thrombectomy. The model allows direct visualization of the target artery during thrombectomy in vessels of different sizes. The behavior of the target artery undergoing aspiration thrombectomy was recorded with high-resolution digital microscopy and fluoroscopic visualization, providing valuable insight into how the different sizes of treated arteries affect the effectiveness of mechanical thrombectomy.

Rescue therapy after thrombectomy for large vessel occlusion due to underlying atherosclerosis: review of literature.

In this review article, we summarized the current advances in rescue management for reperfusion therapy of acute ischemic stroke from large vessel occlusion due to underlying intracranial atherosclerotic stenosis (ICAS). It is estimated that 24-47% of patients with acute vertebrobasilar artery occlusion have underlying ICAS and superimposed in situ thrombosis. These patients have been found to have longer procedure times, lower recanalization rates, higher rates of reocclusion and lower rates of favorable outcomes than patients with embolic occlusion. Here, we discuss the most recent literature regarding the use of glycoprotein IIb/IIIa inhibitors, angioplasty alone, or angioplasty with stenting for rescue therapy in the setting of failed recanalization or instant/imminent reocclusion during thrombectomy. We also present a case of rescue therapy post intravenous tPA and thrombectomy with intra-arterial tirofiban and balloon angioplasty followed by oral dual antiplatelet therapy in a patient with dominant vertebral artery occlusion due to ICAS. Based on the available literature data, we conclude that glycoprotein IIb/IIIa is a reasonably safe and effective rescue therapy for patients who have had a failed thrombectomy or have residual severe intracranial stenosis. Balloon angioplasty and/or stenting may be helpful as a rescue treatment for patients who have had a failed thrombectomy or are at risk of reocclusion. The effectiveness of immediate stenting for residual stenosis after successful thrombectomy is still uncertain. Rescue therapy does not appear to increase the risk of sICH. Randomized controlled trials are warranted to prove the efficacy of rescue therapy.

Stroke Preventability in Large Vessel Occlusion Treated With Mechanical Thrombectomy.

Objective: The preventability of strokes treated by mechanical thrombectomy is unknown. The purpose of this study was to analyze stroke preventability for patients treated with mechanical thrombectomy for large vessel occlusion. Methods: We conducted retrospective analyses of 300 patients (mean ± SE age 69 ± 0.9 years, range 18-97 years; 53% male) treated with mechanical thrombectomy for large vessel occlusion from January 2008 to March 2019. We collected data including demographics, NIH Stroke Scale (NIHSS) at onset, and (beginning in 2015) classified 90-day outcome by modified Rankin Scale (mRS). Patients were evaluated using a Stroke Preventability Score (SPS, 0 to 10 points) based on how well patients had been treated given their hypertension, hyperlipidemia, atrial fibrillation, and prior stroke history. We examined the relationship of SPS with NIHSS at stroke onset and with mRS outcome at 90 days. Results: SPS was calculated for 272 of the 300 patients, with mean ± SE of 2.1 ± 0.1 (range 0-8); 89 (33%) had no preventability (score 0), 120 (44%) had low preventability (score 1-3), and 63 (23%) had high preventability (score 4 or higher). SPS was significantly correlated with age (r = 0.32, p < 0.0001), while NIHSS (n = 267) was significantly higher (p = 0.03) for patients with high stroke preventability vs. low/no preventability [18.8 ± 0.92 (n = 62) vs. 16.5 ± 0.51 (n = 205)]. Among 118 patients with mRS, outcome was significantly worse (p = 0.04) in patients with high stroke preventability vs. low/no preventability [4.7 ± 0.29 (n = 28) vs. 3.8 ± 0.21 (n = 90)]. The vast majority of patients with high stroke preventability had inadequately treated atrial fibrillation (85%, 53/62). Conclusions: Nearly one quarter of stroke patients undergoing mechanical thrombectomy had highly preventable strokes. While stroke preventability showed some relationship to stroke severity at onset and outcome after treatment, preventability had the strongest association with age. These findings emphasize the need for improved stroke prevention in the elderly.

A Smartphone Application as a Telemedicine Tool for Stroke Care Management.

Since smartphone applications are revolutionizing telemedicine, a new application specifically for stroke care (JOIN) was designed. Addition of the JOIN smartphone application to the stroke treatment workflow in our hospital was assessed. JOIN has key functions that may improve the care of stroke patients, including the ability to (1) exchange information such as patient data and medical images in real-time throughout the entire process of patient management; (2) track each step of the protocol from door to discharge; and (3) facilitate real-time interaction of all team members via text, audio, and a video chat system. Two periods, 2.7 years before the implementation of JOIN (Pre-JOIN) with 37 patients and 2.2 years after (Post-JOIN) with 54 patients, were compared, and the workflow for all 91 patients who had a cerebral infarction and were treated with tissue plasminogen activator (tPA) and/or thrombectomy between October 2012 and July 2017 was reviewed. There were noticeable reductions in overall patient management time, including times for door-to-imaging, starting tPA treatment, and endovascular intervention with JOIN. Staff members were unanimously satisfied with JOIN, due to the increased efficiency of information exchange and the ability for real-time discussions with different professionals when needed. No significant changes in patient outcomes (as assessed by modified Rankin Scale [mRS] scores) at 3 months and in the total cost for the treatment were observed. A smartphone-based application with the capability of sharing information instantaneously among healthcare professionals facilitated time-sensitive, acute care of ischemic stroke patients.

Visual complications after coil embolization of internal carotid artery aneurysms at the ophthalmic segment.

BACKGROUND: Coil embolization of aneurysms of the ophthalmic segment of the internal carotid artery (ICA-OphA ANs) has potential risks of visual complications. We analyzed this risk and focused on the relationship of the ophthalmic artery (OphA) origin with the aneurysm neck. METHODS: From January 2003 to April 2018, 179 unruptured ICA-OphA ANs were treated with endovascular surgery in our institution. Two ruptured and four aneurysms with missing data were excluded. Finally, 173 unruptured aneurysms were included in this study. The aneurysms were classified into three groups according to the location of the OphA origin: Separate, Shared, and Dome type. We retrospectively assessed visual complications based on the relationship between types of aneurysm and postoperative angiographic findings for the OphA. RESULTS: Visual deficits remained permanent in eleven cases (6.4%). In the Dome type, visual complications were significantly more frequent compared to the Separate type. Change in the OphA flow was significantly associated with a higher complication rate of 2.9%, but patients with changed OphA flow had a significant rate of 7.5% (p = 0.020). We found no significant difference in the incidence of visual complications concerning the use of perioperative antithrombotic therapy. CONCLUSIONS: The location of OphA origin regarding the aneurysmal neck and postoperative OphA flow were significantly correlated with the visual outcome after coil embolization for ICA-OphA ANs. Post-procedural flow in the OphA was an important factor affecting the rate of ischemic retinal complications. Retinal embolic events occurred with preserved flow in the OphA, albeit at a lower rate.

Flow Diverter Apposition in Patients with Large or Giant Intracranial Aneurysms Evaluated on Three-Dimensional Fusion Images Acquired by High-Resolution Cone-Beam Computed Tomography and Digital Subtraction Angiography.

OBJECTIVE: To investigate flow diverter (FD) apposition on fused images acquired by high-resolution cone-beam computed tomography (CBCT) and 3-dimensional (3D) digital subtraction angiography. METHODS: Patients with large or giant internal carotid artery aneurysms treated with Pipeline FDs who underwent CBCT imaging at our institution between October 2016 and May 2019 were included. Two neurosurgeons measured the maximum malapposition between FDs and vessel walls on 3D fusion images of high-resolution CBCT images displaying the FD and 3D digital subtraction angiography images displaying the vessels. Associations between the relative malapposition, FD diameter, vessel diameter, proximal and distal vessel diameter discrepancy, and siphon angle were evaluated by linear regression analysis. Inter-rater and intermethod (3D and 2D image) agreements of the malapposition measurements were assessed by Bland-Altman analysis and by interclass correlation coefficients. RESULTS: Images of 2 patients were excluded because of image artifacts or fusion errors, and 3D fusion images were acquired in the remaining 26 patients. Our results did not suggest that relative malapposition was associated with vessel diameter (P = 0.12), vessel diameter discrepancy (P = 0.60), or syphon angle (P = 0.34), but relative malapposition increased by an estimated 13% (95% confidence interval: 4%-23%, P = 0.006) for each 1 mm increase in FD diameter. Inter-rater and intermethod agreements for apposition measurements were excellent and good, respectively. CONCLUSIONS: Three-dimensional fusion images provided clear visualization of structures of both the stent and parent artery with excellent diagnostic reliability. Careful deployment may be needed for FDs with larger diameters, as they tended to have larger relative malapposition.

Comparison of Clinical Outcomes After Stent-Assisted Coiling with 3 Types of Self-Expanding Laser-Cut Stents in Patients with Wide-Necked Intracranial Aneurysms.

OBJECTIVE: We report the clinical outcomes of stent-assisted coiling for wide-necked intracranial aneurysms using 3 low-profile laser-cut stents and compare the results according to stent type. METHODS: All patients treated with stent-assisted coiling for their intracranial aneurysms at our hospital between July 2010 and September 2019 were reviewed. We selected patients with Enterprise, Neuroform EZ, or Neuroform Atlas stents who underwent imaging follow-up and investigated aneurysm and stent features, stent-related complications, recanalization, and retreatment rates. We compared the retreatment risk among the patients treated with the 3 stent types using Kaplan-Meier survival analysis and Cox regression analysis. RESULTS: We evaluated 364 consecutive cases (103 Enterprise, 105 Neuroform EZ, and 156 Neuroform Atlas stents). Neuroform Atlas was more frequently used in distal vessels: 8 (7.8%) Enterprise, 2 (1.9%) Neuroform EZ, and 41 (26.3%) Neuroform Atlas cases, respectively. The median follow-up durations were 6.49, 4.91, and 1.24 years for the Enterprise, Neuroform EZ, and Neuroform Atlas cases, respectively, and retreatment was performed in 11 (10.1%), 9 (8.6%), and 6 (3.8%) cases. In the first 2 years of follow-up, the estimated retreatment risk ratios for Neuroform EZ and Neuroform Atlas with Enterprise as reference were 0.63 (95% confidence interval, 0.24-1.65; P = 0.35) and 0.54 (95% confidence interval, 0.18-1.59; P = 0.26), respectively. CONCLUSIONS: Neuroform Atlas stents were more frequently deployed in small-caliber vessels compared with the other 2 types of stents. The complication rate and retreatment risk until at least 1 year after the aneurysm treatment appeared to be similar for the 3 stent types.

4D Digital Subtraction Angiography for the Temporal Flow Visualization of Intracranial Aneurysms and Vascular Malformations.

PURPOSE: To assess the benefit and radiation dose of four-dimensional (4D) digital subtraction angiography (DSA) - a time resolved three-dimensional (3D) DSA application - to evaluate the flow and architecture of aneurysms and vascular malformations. METHODS: All patients with cerebrovascular disease were considered who underwent 4D-DSA at our institution between January 2015 and February 2016. For the aneurysm patients, we evaluated the image quality in terms of the visualization of contrast flow in the aneurysm on a 3-point scale (excellent, fair and poor). Interrater agreement between two raters was estimated using Cohen's Kappa statistics. For the shunt disease patients, the additional information obtained from the 4D-DSA was described for each disease. The median radiation dose and volume of contrast medium required for the acquisitions were estimated. RESULTS: A total of 173 patients underwent 4D-DSA; 126 intracranial aneurysms, 10 arteriovenous malformations (AVM), 15 dural arteriovenous fistula (dAVF) and 22 other diseases. For aneurysm patients, excellent and fair visualization of the intra-aneurysmal flow was observed in 27.7%, 72.3%, and excellent (κ = 0.9) agreement between the raters was found. For AVM and dAVF patients, 4D-DSA clarified the complex vasculature by viewing the discrete time phase of contrast filling. Median radiation dose for intracranial lesions was 79.6 mGy for 6s 4D-DSA, and 175 mGy for 12s 4D-DSA. The median amount of contrast medium used was 18.0 ml for 6s 4D-DSA and 21.0 ml for 12s 4D-DSA. CONCLUSIONS: 4D-DSA provided additional information regarding intra-aneurysmal flow and contributed to detect different component of nidus or shunt points.

Electrospinning and Post-Spun Chain Conformations of Synthetic, Hydrophobic Poly(α-amino acid)s.

Electrospinning and post-spun conformations of hydrophobic poly(α-amino acid)s are described in this study. The poly(α-amino acid)s, poly(Gly), poly(L-Ala), poly(L-Val), and poly(L-Leu) were synthesized via corresponding N-carboxy-a-amino acid anhydrides. The average molecular weight and degree of polymerization of these polymers were determined by N-terminus labeling using 2,4-dinitrofluorobenzene and by viscometry in the case of poly(Gly). These poly(α-amino acid)s were electrospun from trifluoroacetic acid or trifluoroacetic acid/dichloromethane solutions. The FT-IR spectroscopy and wide-angle X-ray diffraction indicated that the electrospun poly(L-Ala) and poly(L-Leu) fibers predominantly adopts α-helical structure, whereas poly(L-Val) and poly(Gly) fibers exhibited mainly ß-strand and random coil structures, respectively.

Evaluation of Balloon Test Occlusion Before Therapeutic Carotid Artery Occlusion: Flat Detector Computed Tomography Cerebral Blood Volume Imaging versus Single-Photon Emission Computed Tomography.

OBJECTIVE: We aimed to compare flat detector computed tomography cerebral blood volume (FD-CBV) imaging to single-photon emission computed tomography (SPECT) as an adjunctive technique during balloon test occlusion (BTO) in patients with intracranial aneurysms or tumors. METHODS: Twelve patients who underwent SPECT (99mTc-ethyl cysteinate dimer) and FD-CBV imaging during BTO were enrolled. Color-coded cerebral blood flow (CBF) images and color-coded FD-CBV images were generated and visually inspected whether there were asymmetries between the ipsilateral and contralateral cerebral hemispheres. Region of interest measurements were performed on the color-coded images at the same locations for both modalities. The mean interhemispheric region of interest ratios were calculated, and the ratio between these were estimated using linear regression models. RESULTS: Ten patients had no symptoms during BTO. Two patients developed subtle but inconclusive neurologic changes approximately 10 minutes after balloon inflation; their images showed asymmetric color-coded images with decreased CBF and FD-CBV in the ipsilateral hemisphere. The mean interhemispheric ratio of CBF was significantly smaller in patients with subtle changes than in those without (0.84 vs. 0.98; P < 0.001). Similarly, the mean interhemispheric ratio of FD-CBV was significantly smaller in patients with subtle changes than in those without (0.88 vs. 1.06; P = 0.01). No patient showed increased CBF or FD-CBV in the ipsilateral hemisphere. CONCLUSIONS: The patients with decreased CBF on SPECT also showed decreased FD-CBV in the ipsilateral hemisphere. FD-CBV imaging may be useful as an adjunctive technique for BTO before potential therapeutic carotid artery occlusion.

Visualization of stent apposition after stent-assisted coiling of intracranial aneurysms using high resolution 3D fusion images acquired by C-arm CT.

PURPOSE: We used an imaging technique based on 3-dimensional (3D) C-arm CT to assess the apposition of three types of stents after coiling of intracranial aneurysms. METHODS: All patients with intracranial aneurysms were considered who received stent-assisted coiling with Enterprise2, Neuroform EZ, or Neuroform Atlas stents confirmed by C-arm CT imaging at our institution between June 2015 and November 2017. A 3D digital subtraction angiography (DSA) scan for vessel imaging followed by a high-resolution cone beam CT (HR-CBCT) scan for coil and stent imaging was performed. The images were fused to obtain dual volume 3D fusion images. We investigated malapposition of the stent trunk (crescent sign) and of the stent edges (edge malapposition) and used the χ2 statistic to test for an association with stent types. Inter-rater agreement between two raters was estimated using Cohen's kappa statistics. RESULTS: We evaluated 75 consecutive cases. Enterprise2 stents were used in 22 cases, Neuroform EZ in 26, and Neuroform Atlas in 27 cases. By stent type, crescent sign was detected in 27% of Enterprise2, 8% of Neuroform EZ, and none of Neuroform Atlas stents (p=0.007), while edge malapposition was detected in 27% of Enterprise2, 58% of Neuroform EZ, and 30% of Neuroform Atlas stents (p=0.05). Excellent (κ=0.81) and good (κ=0.78) agreement between the raters was found for the detection of edge apposition and crescent sign, respectively. CONCLUSION: Stent malapposition was clearly visualized by dual volume 3D imaging. The Neuroform Atlas stents showed good apposition even in vessels with strong curvature.

Preoperative Light Transmission Aggregometry Values Predict for Thromboembolic Complications After Stent-Assisted Coil Embolization.

OBJECTIVE: Risk control of thromboembolic complications (TECs) during stent-assisted coil embolization (SACE) for unruptured intracranial aneurysms (UIAs) is crucial for satisfactory treatment outcomes. We retrospectively evaluated the data from our cohort of SACE for UIAs to analyze the role of anatomical, clinical, and stent type-related factors to determine the optimal preoperative values of light transmission aggregometry (LTA) for TEC prevention. METHODS: From July 2015 to May 2018, we retrospectively analyzed the data from 132 patients with SACE-treated UIAs at our hospital. Data regarding the aneurysm location, maximum diameter, stent type used, preoperative LTA value, and ischemic and hemorrhagic complications were collected. Aspirin 100 mg and clopidogrel 75 mg were started 7 days before surgery, with a "boost" dose (an additional 75 mg of clopidogrel for an LTA value >60%) added after August 2016 to address clopidogrel resistance. After multivariate analysis, we developed our original combined parameter termed the thromboembolic predictor (TEP). Receiver operating characteristic (ROC) analysis for TEP and each significant variable was performed. RESULTS: TECs were confirmed in 5 of the 132 patients (3.8%) and hemorrhagic complications in 9 of the 132 patients (6.8%). From the multivariate analysis results, the LTA value and maximum diameter were chosen as significant variables and included in the TEP. ROC analysis of the LTA value revealed a sensitivity and specificity of 0.866 and 0.600, respectively (area under the curve, 0.747), with a cutoff of 62%. TEP permitted the establishment of an optimal LTA value according to the aneurysm maximum diameter to predict for TECs. The complication rate for the Neuroform EZ, Enterprise, Neuroform Atlas, and LVIS stents was 2.9%, 10.5%, 1.4%, and 14.3%, respectively. CONCLUSIONS: The preoperative LTA value contributes to the prediction of TECs after SACE for UIAs. The TEP (relating the LTA cutoff to aneurysm size) allows for improved antiplatelet therapy adjustment before SACE to reduce TECs.

Combination of high-resolution cone beam computed tomography and metal artefact reduction software: a new image fusion technique for evaluating intracranial stent apposition after aneurysm treatment.

We introduce a new imaging technique to improve visualisation of stent apposition after endovascular treatment of brain aneurysms employing high-resolution cone beam CT and three-dimensional digital subtraction angiography. After performing a stent-assisted coil embolisation of brain aneurysm, the image datasets were processed with a metal artefact reduction software followed by the automated image fusion programmes. Two patients who underwent aneurysm coiling using a Neuroform stent were evaluated. The reconstructed 3D images showed a detailed structure of the stent struts and identified malappositions of the deployed stents. Case 1 showed good apposition on the outer curvature side of the carotid siphon, while the inner curvature side showed prominent malapposition. Case 2, with multiple aneurysms, showed good apposition on both outer and inner curvature sides, although inward prolapse of the struts was observed. This new imaging technique may help evaluate stent apposition after the endovascular aneurysm treatment.

Accuracy of Length of Virtual Stents in Treatment of Intracranial Wide-Necked Aneurysms.

BACKGROUND AND PURPOSE: Precise stent deployment is important for successful treatment of intracranial aneurysms by stent-assisted coiling (SAC). We evaluated the accuracy of virtual stents generated using commercial stent planning software by comparing the length of virtual and actually deployed intracranial laser cut stents on three-dimensional digital subtraction angiography (3D-DSA) images. METHODS: We retrospectively analyzed the data of 75 consecutive cases of intracranial wide-necked aneurysms treated with the SAC technique using laser cut stents. Based on 3D-DSA images acquired by C-arm CT, stent sizing and placement were intraoperatively simulated by a commercial software application. The difference in length of the stents was estimated by measuring proximal discrepancies between the end points of the virtual and actually deployed stents on fused pre-procedural and post-procedural 3D-DSA images. Discrepancies between distal stent end points were manually minimized. The Kruskal-Wallis test was applied to test whether stent location, type, and length had an effect on difference in length between virtual and real stent. RESULTS: The median difference in length between virtual and real stents was 1.58 mm with interquartile range 1.12-2.12 mm. There was no evidence for an effect of stent location (p = 0.23), stent type (p = 0.33), or stent length (p = 0.53) on difference in length between virtual and real stents. CONCLUSIONS: Stent planning software allows 3D simulation of laser cut stents overlain on 3D-DSA images of vessels and may thus be useful for stent selection and deployment of laser cut stents during stent-assisted coiling of intracranial aneurysms.

Time-resolved magnetic resonance angiography (TR-MRA) for the evaluation of post coiling aneurysms; A quantitative analysis of the residual aneurysm using full-width at half-maximum (FWHM) value.

Magnetic resonance image (MRI) is now widely used for imaging follow-up for post coiling brain aneurysms. However, the accuracy on the estimation of residual aneurysm, which is crucial for the retreatment planning, remains to be controversial. The purpose of this study is to evaluate a new post-processing technique that provides improved estimation of the residual aneurysm after coil embolization. One hundred aneurysms on 93 patients who underwent coil embolization for brain aneurysm were evaluated using the 1.5 Tesla time-resolved magnetic resonance angiography (TR-MRA) one year after the treatment. To minimize the inter-observer variability caused by the window level adjustment, an automatic post processing protocol using the full-width at half-maximum (FWHM) value was utilized. The result was then compared with that from the conventional cerebral angiography. Of the 97 aneurysms that underwent both TR-MRA and DSA, 23 (23.7%) showed residual neck / dome during follow-up. After window level adjustment, the size of the parent artery in the TR-MRA was consistent with that in the DSA. The reconstructed Volume Rendering images provided clear contours of the residual aneurysms and contributed to the understanding the configuration of residual aneurysm. The largest and the smallest diameter of the residual aneurysms was larger in the TR-MRA than in the DSA (8.05 vs. 7.72 mm, p = 0.0004; 4.99 vs. 4.19 mm, p = 0.007 respectively). The sensitivity, specificity, and positive and negative predictive values of TR-MRA compared to DSA were 100%, 97%, 73%, and 100%, respectively. Using the FWHM value to optimize the window level adjustment, the size of the residual component observed in the TR-MRA was larger compared to that in the DSA whereas the size of neck and the parent artery showed consistency between the two modalities. This image processing technique can be used as an effective screening tool for evaluating residual component in post-coiling brain aneurysms.

Ischemic Stroke Detection by Analyzing Heart Rate Variability in Rat Middle Cerebral Artery Occlusion Model.

Although early reperfusion therapy is effective for acute ischemic stroke, limited therapeutic time-window resulted in only 10% of patients receiving reperfusion therapy. A fast and reliable stroke detection method is desired so that patients can receive early reperfusion therapy. It has been reported that ischemic stroke affects heart rate variability (HRV), which reflects activities of the autonomic nervous function. Thus, ischemic stroke may be detected at an acute stage through monitoring HRV. This paper proposes an HRV-based ischemic stroke detection algorithm by using multivariate statistical process control (MSPC), which is a well-known anomaly detection algorithm. As a feasibility study before collecting a large amount of clinical data from human patients, this paper used the middle cerebral artery occlusion (MCAO) model in rats for collecting HRV data shortly after ischemic stroke onsets. The 11 MCAO-operated rats and 11 sham-operated rats were prepared, and HRV data of three sham-operated rats were used for model construction. The data on the other 19 rats were used for its validation. The experimental result showed that sensitivity and specificity of the proposed algorithm were 82% and 75%, respectively. Thus, the present work shows the possibility of realizing an HRV-based ischemic stroke detection system for human patients.

[Outcome of Coil Embolization for Subarachnoid Hemorrhage Accompanied with Intracerebral Hematoma].

OBJECT: Aneurysmal subarachnoid hemorrhage(SAH)associated with intracerebral hematoma(ICH)typically has a poor outcome. SAH with ICH tends to have a worse prognosis than SAH alone. The aim of the present study was to evaluate whether coil embolization during endovascular surgery with ventricle drainage and without ICH evacuation is an appropriate treatment. METHODS: A retrospective review was conducted between March 2012 and May 2015. Thirteen patients with SAH with ICH who underwent coil embolization were retrospectively analyzed. Modified Rankin Scale(mRS)scores were compared for postoperative clinical outcomes of different hematoma locations. RESULTS: All ruptured aneurysms in the present series of patients were treated using endovascular surgery. Six patients underwent additional ventricle drainage. Only one patient underwent craniotomy for evacuation of the hematoma following coil embolization. Despite ten out of thirteen patients(76.9%)having a preoperative SAH clinical grade, as evaluated using the World Federation of Neurosurgical Societies grading system of IV or V, six(46.2%)patients had a favorable outcome(mRS=0-2). CONCLUSIONS: Coil embolization for ruptured aneurysms, especially those located in the frontal lobe, with ICH and without cerebral herniation may be a feasible alternative and less invasive treatment.

Estimated pretreatment hemodynamic prognostic factors of aneurysm recurrence after endovascular embolization.

BACKGROUND: Hemodynamic factors play important roles in aneurysm recurrence after endovascular treatment. OBJECTIVE: Predicting the risk of recurrence by hemodynamic analysis using an untreated aneurysm model is important because such prediction is required before treatment. METHODS: We retrospectively analyzed hemodynamic factors associated with aneurysm recurrence from pretreatment models of five recurrent and five stable posterior communicating artery (Pcom) aneurysms with no significant differences in aneurysm volume, coil packing density, or sizes of the dome, neck, or Pcom. Hemodynamic factors of velocity ratio, flow rate, pressure ratio, and wall shear stress were investigated. RESULTS: Among the hemodynamic factors investigated, velocity ratio and flow rate of the Pcom showed significant differences between the recurrence group and stable group (0.630 ± 0.062 and 0.926 ± 0.051, P= 0.016; 56.4 ± 8.9 and 121.6 ± 6.7, P= 0.008, respectively). CONCLUSIONS: Our results suggest that hemodynamic factors may be associated with aneurysm recurrence among Pcom aneurysms. Velocity and flow rate in the Pcom may be a pretreatment prognostic factor for aneurysm recurrence after endovascular treatment.