Factors associated with the new appearance of cerebral microbleeds after endovascular treatment for unruptured intracranial aneurysms.

PURPOSE: Endovascular treatment of unruptured intracranial aneurysms may increase cerebral microbleeds (CMBs) in postprocedural T2*-weighted MRIs, which may be a risk for future intracerebral hemorrhage. This study examined the characteristics of postprocedural CMBs and the factors that cause their increase. METHODS: The patients who underwent endovascular treatment for unruptured intracranial aneurysms from April 2016 to February 2018 were retrospectively analyzed. Treatment techniques for endovascular treatment included simple coiling, balloon-assisted coiling, stent-assisted coiling, or flow diverter placement. To evaluate the increase in CMBs, a head MRI including diffusion-weighted imaging and T2*-weighted MRIs was performed on the preprocedural day; the first postprocedural day; and at 1, 3, and 6 months after the procedure. RESULTS: Among the 101 aneurysms that were analyzed, 38 (37.6%) showed the appearance of new CMBs. In the multivariate analysis examining the causes of the CMB increases, chronic kidney disease, a higher number of preprocedural CMBs, and a higher number of diffusion-weighted imaging-positive lesions on the first postprocedural day were independent risk factors. Furthermore, a greater portion of the increased CMBs was found in cortical and subcortical lesions of the treated vascular perfusion area within 1 month after the procedure. CONCLUSION: In endovascular treatment for unruptured intracranial aneurysms, CMBs tended to increase in patients with small vessel disease before the procedure, and it was also implicated in hemorrhagic changes after periprocedural microinfarction.

Deep Learning-Derived High-Level Neuroimaging Features Predict Clinical Outcomes for Large Vessel Occlusion.

Background and Purpose- For patients with large vessel occlusion, neuroimaging biomarkers that evaluate the changes in brain tissue are important for determining the indications for mechanical thrombectomy. In this study, we applied deep learning to derive imaging features from pretreatment diffusion-weighted image data and evaluated the ability of these features in predicting clinical outcomes for patients with large vessel occlusion. Methods- This multicenter retrospective study included patients with anterior circulation large vessel occlusion treated with mechanical thrombectomy between 2013 and 2018. We designed a 2-output deep learning model based on convolutional neural networks (the convolutional neural network model). This model employed encoder-decoder architecture for the ischemic lesion segmentation, which automatically extracted high-level feature maps in its middle layers, and used its information to predict the clinical outcome. Its performance was internally validated with 5-fold cross-validation, externally validated, and the results compared with those from the standard neuroimaging biomarkers Alberta Stroke Program Early CT Score and ischemic core volume. The prediction target was a good clinical outcome, defined as a modified Rankin Scale score at 90-day follow-up of 0 to 2. Results- The derivation cohort included 250 patients, and the validation cohort included 74 patients. The convolutional neural network model showed the highest area under the receiver operating characteristic curve: 0.81±0.06 compared with 0.63±0.05 and 0.64±0.05 for the Alberta Stroke Program Early CT Score and ischemic core volume models, respectively. In the external validation, the area under the curve for the convolutional neural network model was significantly superior to those for the other 2 models. Conclusions- Compared with the standard neuroimaging biomarkers, our deep learning model derived a greater amount of prognostic information from pretreatment neuroimaging data. Although a confirmatory prospective evaluation is needed, the high-level imaging features derived by deep learning may offer an effective prognostic imaging biomarker.

Predicting Clinical Outcomes of Large Vessel Occlusion Before Mechanical Thrombectomy Using Machine Learning.

Background and Purpose- The clinical course of acute ischemic stroke with large vessel occlusion (LVO) is a multifactorial process with various prognostic factors. We aimed to model this process with machine learning and predict the long-term clinical outcome of LVO before endovascular treatment and to compare our method with previously developed pretreatment scoring methods. Methods- The derivation cohort included 387 LVO patients, and the external validation cohort included 115 LVO patients with anterior circulation who were treated with mechanical thrombectomy. The statistical model with logistic regression without regularization and machine learning algorithms, such as regularized logistic regression, linear support vector machine, and random forest, were used to predict good clinical outcome (modified Rankin Scale score of 0-2 at 90 days) with standard and multiple pretreatment clinical variables. Five previously reported pretreatment scoring methods (the Pittsburgh Response to Endovascular Therapy score, the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale index, the Totaled Health Risks in Vascular Events score, the Houston Intra-Arterial Therapy score, and the Houston Intra-Arterial Therapy 2 score) were compared with these models for the area under the receiver operating characteristic curve. Results- The area under the receiver operating characteristic curve of random forest, which was the worst among the machine learning algorithms, was significantly higher than those of the standard statistical model and the best model among the previously reported pretreatment scoring methods in the derivation (the area under the receiver operating characteristic curve were 0.85±0.07 for random forest, 0.78±0.08 for logistic regression without regularization, and 0.77±0.09 for Stroke Prognostication using Age and National Institutes of Health Stroke Scale) and validation cohorts (the area under the receiver operating characteristic curve were 0.87±0.01 for random forest, 0.56±0.07 for logistic regression without regularization, and 0.83±0.00 for Pittsburgh Response to Endovascular Therapy). Conclusions- Machine learning methods with multiple pretreatment clinical variables can predict clinical outcomes of patients with anterior circulation LVO who undergo mechanical thrombectomy more accurately than previously developed pretreatment scoring methods.

Unexpected coil mass migration during transvenous embolization of a dural arteriovenous fistula resolved with guidewire-assisted snaring technique.

Endovascular embolization is a standard treatment for dural arteriovenous fistulas (dAVFs). Although it is considered relatively safe, intraoperative and postoperative complications can occur. Herein, a rare case of unexpected coil mass migration requiring a retrieval procedure during sinus occlusion for a transverse-sigmoid sinus dAVF (TSdAVF) is described. An 83-year-old man presented with worsening decline in cognitive function. Magnetic resonance angiography showed a TSdAVF. Since his symptoms seemed to be a result of the TSdAVF, transvenous embolization preserving the normal cranial venous circulation was planned. During sinus occlusion, including embolization of the shunted pouch of the TSdAVF, unexpected migration of the coil mass to the confluence of the superior sagittal sinus and the transverse sinus occurred. The migrated coil mass impeded venous circulation in the superior sagittal sinus. Since the presence of the coil mass at the confluence could have had catastrophic sequelae, the coil mass was retrieved using a guidewire-assisted snaring technique. Sinus occlusion was subsequently completed with repositioning of the coil mass at the target site. The TSdAVF resolved, with no recurrence confirmed for 1 year. Clinicians should be aware that coil mass migration can unexpectedly occur during sinus occlusion performed for treatment of a TSdAVF. The guidewire-assisted snaring technique might be effective in resolving this intraoperative complication.

An extremely rare complication during carotid artery stenting using a Wallstent: Migration of a stent holder of a Carotid Wallstent.

BACKGROUND: Carotid artery stenting (CAS) is an established treatment for internal carotid artery stenosis (ICS). The Carotid Wallstent is commonly used as a stent device in CAS procedures. Rare complications associated with the use of the Carotid Wallstent in CAS procedures include delayed shortening and incomplete stent expansion due to displacement of a marker ring. However, there have been no previous reports of a stent holder becoming unpredictably detached from a Carotid Wallstent during a procedure, requiring the additional deployment of another Carotid Wallstent. CASE PRESENTATION: The case of a 72-year-old man with progressive ICS is described. Since the ICS was resistant to medical treatment, CAS was planned to prevent ischemic events. During the procedure, a Mo.Ma Ultra and a carotid guardwire were used for proximal and distal protection, respectively. Following the introduction of those protective devices, a Carotid Wallstent was deployed at the stenotic lesion of the ICS. After the deployment of the Carotid Wallstent, a stent holder unpredictably detached was identified in the lumen of the Carotid Wallstent. Since it was impossible to mechanically retrieve the detached stent holder, another Carotid Wallstent was deployed to trap the substance. Postoperatively, the substance was identified as a stent holder of the first Carotid Wallstent. CONCLUSION: This is the first report of an extremely rare complication concerning a Carotid Wallstent in CAS.

Spontaneous Cerebrospinal Fluid Rhinorrhea With Meningoencephalocele Recurrence After Placement of a Lumboperitoneal Shunt: A Case Report.

Cerebrospinal fluid rhinorrhea associated with meningoencephalocele is usually treated surgically. During the perioperative period, cerebrospinal fluid diversion may be employed to control intracranial pressure, but there are few indications for this method. A 51-year-old female presented with cerebrospinal fluid rhinorrhea associated with meningoencephalocele and underwent surgical repair followed by the placement of a lumboperitoneal shunt. However, cerebrospinal fluid leakage recurred, requiring a second surgery. Lumbar drainage effectively controls intracranial pressure, but it does not cure bone defects. The use of these devices should be carefully considered based on the patient's condition.

Adult cerebral high-grade glioneuronal tumor with perivascular or pseudopapillary growth co-existing with low-grade tumor: a case report.

An unusual, small cell-predominant, high-grade glioneuronal tumor in the occipital lobe of a 49-year-old man that co-existed with a low-grade tumor is reported. The tumor consisted of two distinct components: the major component was a dense proliferation of primitive small cells showing bidirectional neuronal and glial differentiation; and the minor component consisted of a proliferation of well-differentiated astrocytes intermingled with mature neuronal cells. In the former component, perivascular pseudorosette-like or pseudopapillary growth reminiscent of ependymoma or papillary glioneuronal tumor (PGNT), respectively, was prominent, and hypertrophic astrocytic cells were located just outside the central blood vessels. Small cells were immunoreactive for Olig2, synaptophysin, and, less frequently, for glial fibrillary acidic protein. The low-grade component included Rosenthal fibers, hemosiderin deposition, and perivascular lymphocytic infiltration, thus closely resembling ganglioglioma. Cytogenetic studies did not demonstrate any mutations or rearrangements of the genes IDH1, IDH2, H3F3A, BRAF, FGFR1, or TERT promoter. The tumor recurred and spread along the ventricular surface three years after total removal. The small cell-predominant, high-grade component was considered to have evolved from the ganglioglioma-like, low-grade component. The histopathologic resemblance of the high-grade component to PGNT was a special feature.

Reactive hyperplasia of vascular pericytes in meningioma: immunohistochemical and ultrastructural studies of two cases.

An isolated proliferation of pericytes is a unique vascular reaction seen almost exclusively in the stroma of secretory meningioma. We report the results of immunohistochemical and ultrastructural studies of a pericytic proliferation that was found in two cases of meningioma (a secretory meningioma of the sphenoid ridge and a parasagittal atypical meningioma showing predominantly fibroblastic features). Pericytes had hyperchromatic nuclei and scant cytoplasm, and showed stratification or formed small clusters within the walls of small blood vessels. They occasionally showed close contact with pseudopsammoma bodies in secretory meningioma. Pericytes showed immunoreactivity for α-smooth muscle actin but were not immunoreactive for desmin. They also exhibited characteristic ultrastructural features of pericytes, including the presence of microfilaments and abundant pinocytotic vesicles, and investment by the basal lamina. This isolated pericytic proliferation is likely a peculiar response of the vascular wall, probably induced by some cytokines secreted from neoplastic meningothelial cells. The close contact of proliferating pericytes with pseudopsammoma bodies suggests a close pathogenetic association between them. The occurrence of pericytic proliferation that was found in our second case (atypical meningioma with predominantly fibroblastic features) is exceptional and has not been documented to date.

Developed Circuminfundibular Anastomosis Associated with Vascular Abnormalities.

We report a 74-year-old male patient who presented with left hemiplegia and disturbance of consciousness. Computed tomography revealed diffuse subarachnoid hemorrhage, which was prominent in the right Sylvian and basal cisterns. Digital subtraction angiography revealed absence of the C2 segment of the right internal carotid artery (ICA) and a significantly developed circuminfundibular anastomosis. Occlusion of the bilateral vertebral arteries (VAs) was also seen. The upper basilar artery was supplied by the circuminfundibular anastomosis and collaterals from the VAs. Since the source of bleeding was unclear, the patient was treated conservatively. Circuminfundibular anastomosis is a potential anastomosis around the pituitary stalk. It is formed by the superior hypophyseal arteries, prechiasmal arteries, and infundibular arteries bilaterally. Agenesis of the contralateral ICA often leads to development of ICA-ICA anastomoses. In this case, the anastomosis developed due to agenesis of the C2 segment of the right ICA and occlusion of the bilateral VAs.

Impact of the position of the aspiration catheter to the first pass effect during the combined technique.

The first pass effect, defined as achieving a complete recanalization with a single thrombectomy procedure, was recently established as a critical procedural performance metric for mechanical thrombectomy. Therefore, the purpose of this study was to evaluate whether the rate of the first pass effect improved when capturing the proximal end of the thrombus by aspiration catheter (CAPTAC) was achieved in mechanical thrombectomy using combined techniques. A prospectively-maintained acute stroke database was used to perform a retrospective review of patients who matched our eligibility criteria of (1) acute cardioembolic stroke, (2) middle cerebral artery (M1, M2) occlusions, and (3) treated with combined techniques as the first-pass procedure. The primary endpoint was the first pass effect. Eighty-one cases were included in the final analysis. CAPTAC was achieved in 42 cases (52%). The first pass effect was achieved more frequently in the CAPTAC group compared with the non-CAPTAC group (52% vs 18%, respectively; P = 0.001). CAPTAC was significantly higher during the period when new generation aspiration catheters were used (67% vs 43%, respectively; P = 0.04). CAPTAC was an independent predictor of achieving the first pass effect (odds ratio, 5.0; 95% confidence interval, 1.8-14; P = 0.001). Achievement of CAPTAC in combined techniques was associated with a significant improvement in the rate of the first pass effect. The use of the newer generation aspiration catheters may contribute to more effect treatment in combined techniques.

Fenestration of the cavernous internal carotid artery associated with a persistent primitive trigeminal artery.

Fenestration of the cavernous segment of the internal carotid artery (ICA) is an extremely rare variant with unknown clinical significance. We present two cases of this variant, both of which were associated with a persistent primitive trigeminal artery (PPTA). Large dual channels of the ICA were seen extending from the part immediately distal to the origin of the PPTA to the C3 segment of the ICA. We speculate that coexistence of the two vascular anomalies might be due to failed regression or a remnant of the primitive arterial network during the same early gestation period in which development of the PTA takes place (3-5 mm crown-rump length stage).

"Tailor-made" Total Cerebral Protection during Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) is an alternative treatment to surgical aortic valve replacement for treating severe aortic stenosis. With the increased use of TAVI, the risk of cerebrovascular complications during the procedure has become an emerging problem. We evaluated the safety and feasibility of our total cerebral protection methods using embolic protection devices (EPDs) for carotid artery stenting. We collected the results of cases in which the clinical team determined that our protection method was necessary among patients undergoing TAVI from May to October 2019 in our medical center. We applied this method to patients who had a potentially high risk of cerebrovascular events during the procedure. The methods of protection were selected comprehensively based on the potential of collateralization of brain perfusion when some arteries were blocked with a balloon, accessibility of the brain arteries, and the ability to cover the brain arteries with devices. Five patients, aged 83.8 ± 1.8 years, were included in the study. Technical success was achieved in all five patients. No cases showed any new neurological symptoms after the procedures; however, head MRI on the day after showed new ischemic lesions in three of five cases (60%). In all cases, emboli were found in the collected filters. This report demonstrates protection of the entire perfusion area in each case using EPDs in patients at high risk of intraoperative embolism. The methods we used were feasible and can potentially reduce cerebrovascular events following TAVI.

Symptomatic Cavernous Internal Carotid Artery Aneurysm Complicated by Simultaneous Rapid Growth of the Intra-aneurysmal and Parent Artery Thromboses.

Cavernous internal carotid artery (ICA) aneurysm complicated by simultaneous and spontaneous formation of thromboses in the aneurysm and the parent artery is a rare clinical condition. Although the majority of patients have good outcomes, some patients experience severe ischemic stroke. Here, we report a case of symptomatic large cavernous ICA aneurysm complicated by rapid growth of an intra-aneurysmal thrombosis with simultaneous parent artery thrombosis. A 68-year-old female presented with sudden-onset diplopia, right ptosis, right conjunctival hyperemia, and paresthesia of the right face. Magnetic resonance imaging (MRI) and digital subtract angiography (DSA) revealed the presence of a large partially thrombosed aneurysm in the cavernous portion of the right ICA. We planned endovascular embolization using a flow-diverting (FD) stent. Dual-antiplatelet therapy (DAPT) with aspirin and clopidogrel was started 2 weeks prior to treatment. Although the neurological state was stable, DSA conducted on the day of the endovascular treatment showed rapid growth of an intra-aneurysmal thrombosis and de novo thrombosis in the parent artery. Direct aspiration was performed via a distal support catheter with proximal blood flow arrest using a balloon-guide catheter, and the FD stent was successfully deployed. The patient's symptoms improved postoperatively and DSA obtained 12 months after the procedure confirmed complete occlusion of the aneurysm. Although the exact mechanism of simultaneous thrombosis formation of the aneurysm and its parent artery remains unclear, it is important to recognize that rapid growth of the thrombosis increases the risk of ischemic stroke.

Treatment of Aneurysms in Persistent Primitive Trigeminal Arteries with Stent-Assisted Coil Embolization.

Objective: Persistent primitive trigeminal artery (PPTA) is a rare condition in which a fetal carotid-basilar anastomosis persists into adulthood. PPTA aneurysms often necessitate endovascular treatment and adjunctive techniques, such as stent- or balloon-assisted techniques, are sometimes selected. This case report describes two women in their sixties with unruptured right PPTA aneurysms who underwent stent-assisted coil embolization procedures, with consideration of the anatomical features in each case. Case Presentations: One patient presented with an aneurysm at the bifurcation of the PPTA and the basilar artery (BA), which was classified as Saltzman type 1 with a hypoplastic vertebral artery (VA)-BA system. A stent was deployed from the BA to the PPTA to cover the neck of the aneurysm and coil embolization was performed. The second patient presented with an aneurysm at the bifurcation of the PPTA and the internal carotid artery (ICA), which was classified as Saltzman type 2 with a hypoplastic VA-BA system. A stent was deployed from the PPTA to the petrous segment of the ICA covering the neck of the aneurysm and coil embolization was performed. In both patients, the 1-year follow-up digital subtraction angiography (DSA) showed that the aneurysms had not recurred. Conclusion: The PPTA aneurysms were successfully treated with stent-assisted coil embolization. The treatment strategy should be devised in accordance with both the lesion site and the PPTA variant.

Clopidogrel response predicts thromboembolic events associated with coil embolization of unruptured intracranial aneurysms: A prospective cohort study.

OBJECTIVE: Periprocedural thromboembolic events are a serious complication associated with coil embolization of unruptured intracranial aneurysms. However, no established clinical rule for predicting thromboembolic events exists. This study aimed to clarify the significance of adding preoperative clopidogrel response value to clinical factors when predicting the occurrence of thromboembolic events during/after coil embolization and to develop a nomogram for thromboembolic event prediction. METHODS: In this prospective, single-center, cohort study, we included 345 patients undergoing elective coil embolization for unruptured intracranial aneurysm. Thromboembolic event was defined as the occurrence of intra-procedural thrombus formation and postprocedural symptomatic cerebral infarction within 7 days. We evaluated preoperative clopidogrel response and patients' clinical information. We developed a patient-clinical-information model for thromboembolic event using multivariate analysis and compared its efficiency with that of patient-clinical-information plus preoperative clopidogrel response model. The predictive performances of the two models were assessed using area under the receiver-operating characteristic curve (AUC-ROC) with bootstrap method and compared using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). RESULTS: Twenty-eight patients experienced thromboembolic events. The clinical model included age, aneurysm location, aneurysm dome and neck size, and treatment technique. AUC-ROC for the clinical model improved from 0.707 to 0.779 after adding the clopidogrel response value. Significant intergroup differences were noted in NRI (0.617, 95% CI: 0.247-0.987, p < .001) and IDI (0.068, 95% CI: 0.021-0.116, p = .005). CONCLUSIONS: Evaluation of preoperative clopidogrel response in addition to clinical variables improves the prediction accuracy of thromboembolic event occurrence during/after coil embolization of unruptured intracranial aneurysm.

Intracranial Subdural Abscess Caused by Actinomyces meyeri Related to Dental Treatment: A Case Report.

Intracranial subdural abscess is a rare condition. Although brain abscess is often reported in relation to dental infection, reports of intracranial subdural abscess are few. Actinomyces spp. forms part of the normal flora of the oral, gastrointestinal, and genital tract, and is rarely the cause of intracranial infection; moreover, the pathogen Actinomyces meyeri is very rare. We report an exceptional case of intracranial subdural abscess caused by A. meyeri and related to dental treatment. A 57-year-old woman initially presented with a 5-day history of headache. Because left arm numbness and weakness became apparent, she was admitted to our department. She had a history of hypertension and dental problems requiring tooth extractions. Diffusion-weighted imaging (DWI) showed a 1-cm right convexity hyperintense mass above the postcentral gyrus. A post-gadolinium T1-weighted image showed a thin hypointense area with peripheral rim enhancement in the right subdural space that appeared to partially thicken in the same location as the DWI-positive mass. She underwent emergent navigation-guided drainage and 4 mL of pus was obtained. Postoperatively, left arm numbness and weakness disappeared. Cultures showed growth of A. meyeri and Fusobacterium nucleatum. She was started on intravenous penicillin G and metronidazole. After a 4-week course of the intravenous antibiotics, her headache gradually improved and the abscess in the subdural space subsided. To our best knowledge this is the first case report of intracranial subdural abscess caused by A. meyeri associated with dental treatment.

Activatable Fluorescence Imaging of Macrophages in Cerebral Aneurysms Using Iron Oxide Nanoparticles Conjugated With Indocyanine Green.

BACKGROUND AND PURPOSE: Chronic inflammation is involved in the formation and enlargement of cerebral aneurysms (CAs), with macrophages playing a key role in the process. The present study evaluated visualization of macrophages present in CAs using an activatable fluorescent probe (IONP-ICG) comprising an iron oxide nanoparticles (IONPs) conjugated with indocyanine green (ICG). METHODS: IONP-ICG was intravenously administered to 15-week-old CA model rats (n = 8), and ex vivo near-infrared fluorescence (NIRF) imaging and histological assessment of exposed CAs and cerebral arteries were performed 48 h later. Similar evaluations were performed in the control group, which included CA model rats given IONPs or ICG (n = 8 each). RESULTS: ICG-derived NIRF signals were detected in three IONP-ICG group rats but not in IONP or ICG control groups. Among the three rats that exhibited signals, NIRF signal accumulation was observed in the CA of two rats and at the site of hemodynamic stress in the left posterior cerebral artery in one rat. Histologically, NIRF signals correlated strongly with macrophage localization. A total of 13 CAs formed in the IONP-ICG group. The number of macrophages in the CA wall was significantly greater in the two CAs that exhibited NIRF signals compared to the remaining 11 CAs that did not (P = 0.037). Moreover, all 11 CAs that did not exhibit NIRF signals were iron-negative, while the two CAs that exhibited NIRF signals were both iron-positive (P = 0.013). CONCLUSION: NIRF imaging using an activatable IONP-ICG probe is feasible for detecting the macrophage-rich regions in CAs and the cerebral artery wall, which is considered an early lesion in the process of CA formation.

Long-term Outcomes After Intraprocedural Aneurysm Rupture During Coil Embolization of Unruptured Intracranial Aneurysms.

BACKGROUND: The long-term outcomes of patients with intraprocedural aneurysm rupture (IPR) during endovascular coiling of unruptured intracranial aneurysms (UIAs) remain unclear. We investigated the long-term outcomes and predictors of neurological outcomes in patients who sustained IPR during coil embolization of UIAs. METHODS: We retrospectively analyzed the medical record of 312 untreated UIAs in 284 patients who underwent endovascular coiling between April 2013 and July 2018. RESULTS: The mean follow-up period for the entire cohort was 25.6 months. Twelve patients (3.8%) experienced IPR. The mean aneurysm size in the IPR cohort was significantly smaller than that in the no-IPR cohort (P = 0.045). The IPR cohort had a higher percentage of earlier subarachnoid hemorrhage from another aneurysm (P = 0.019), anterior communicating artery (AComA) aneurysm (P < 0.001), and basilar artery (BA) aneurysm (P = 0.022) than the no-IPR cohort. Neurologic deterioration was observed in 3 patients. The morbidity and mortality rates of the IPR cohort were 25% and 8.3%, respectively. Patients with IPR during coil embolization for AComA aneurysm did not develop neurological deterioration. Two of the 3 patients (66.7%) with a BA aneurysm had neurological deterioration. The proportion of patients with an mRS score of 0-2 at the last follow-up did not differ between the 2 cohorts (P = 0.608). CONCLUSIONS: The proportion of functionally independent patients did not differ between patients with and without IPR. Patients with BA aneurysms who developed an IPR tended to exhibit more unfavorable clinical courses than patients with AcomA aneurysms.

Ex Vivo Assessment of Various Histological Differentiation in Human Carotid Plaque with Near-infrared Spectroscopy Using Multiple Wavelengths.

We previously reported that near-infrared hyperspectral imaging enabled the localization of atherosclerotic plaques from outside the vessels, but not the optical characteristics of each histological component. Therefore, the near-infrared spectrum of each component was collected from the sliced section of the human carotid plaque obtained with endarterectomy and the optical characteristics were confirmed in several wavelengths. Based on this information, we assessed the diagnostic accuracy for ex vivo chemogram in each plaque component created with near-infrared spectroscopy (NIRS), using multiple wavelengths. The chemogram projected on the actual image of plaque was created based on light intensity and transmittance change at three wavelengths. The wavelengths that were mainly were 1440, 1620, 1730, and 1930 nm. We evaluated the accuracy of histological diagnosis in chemogram compared with pathological findings, analyzing interobserver agreement with κ-statistics. The chemograms that we created depicted the components of fibrous tissue, smooth muscle, lipid tissue, intraplaque hemorrhage, and calcification. Diagnostic odds ratio in each component was as follows: 259.6 in fibrous tissue, 144 in smooth muscle, 1123.5 in lipid tissue, 29.3 in intraplaque hemorrhage, and 136.3 in calcification. The κ-statistics revealed that four components, excluding intraplaque hemorrhage, had substantial or almost perfect agreement. Thus, this study demonstrated the feasibility of using chemogram focused on specific component during the histological assessment of atherosclerotic plaques, highlighting its potential diagnostic ability. Chemograms of various target components can be created by combining multiple wavelengths. This technology may prove to be useful in improving the histological assessment of plaque using NIRS.