Citations

OBJECTIVEDelayed cerebral ischemia (DCI) and aneurysm rebleeding contribute to morbidity and mortality in aneurysmal subarachnoid hemorrhage (aSAH); however, the relationship between their impacts on overall functional outcome is incompletely understood.METHODSThe authors conducted a cohort study of all aSAH during the study period from 2001 to 2016. Primary end points were overall functional outcome and ischemic aSAH sequelae, defined as delayed cerebral ischemia (DCI), DCI with infarction, symptomatic vasospasm (SV), and global cerebral edema (GCE). Outcomes were compared between the rebleed and nonrebleed cohorts overall and after propensity-score matching (PSM) for risk factors and treatment modality. Univariate and multivariate ordered logistic regression analyses for functional outcomes were performed in the PSM cohort to identify predictors of poor outcome.RESULTSFour hundred fifty-five aSAH cases admitted within 24 hours of aneurysm rupture were included, of which 411 (90%) experienced initial aneurysm ruptures only, while 44 (10%) had clinically confirmed rebleeding. In the overall cohort, rebleeding was associated with significantly worse functional outcome, longer intensive care unit length of stay (LOS), and GCE (all p < 0.01); treatment modality, overall LOS, DCI, DCI with infarction, and SV were nonsignificant. In the PSM analysis of 43 matched rebleed and 43 matched nonrebleed cases, only poor functional outcome and GCE remained significantly associated with rebleeding (p < 0.01 and p = 0.02, respectively). Multivariate regression identified that both rebleeding (HR 21.5, p < 0.01) and DCI (HR 10.1, p = 0.01) independently predicted poor functional outcome.CONCLUSIONSRebleeding and DCI after aSAH are highly morbid and potentially deadly events after aSAH, which appear to have independent negative impacts on overall functional outcome. Early rebleeding did not significantly affect the risk of delayed ischemic complications.

Abstract Flow diverters have drastically changed the landscape of intracranial aneurysm treatment and are now considered first-line therapy for select lesions. Their mechanism of action relies on intrinsic alteration in hemodynamic parameters, both at the parent artery and within the aneurysm sac. Moreover, the device struts act as a nidus for endothelial cell growth across the aneurysm neck ultimately leading to aneurysm exclusion from the circulation. In silico computational analyses and investigations in preclinical animal models have provided valuable insights into the underlying biological basis for flow diverter therapy. Here, we review the present understanding pertaining to flow diverter biology and mechanisms of action, focusing on stent design, induction of intra-aneurysmal thrombosis, endothelialization, and alterations in hemodynamics.

Background and Purpose— Racial and ethnic disparities in the access to mechanical thrombectomy (MT) for treatment of acute ischemic stroke (AIS) secondary to large vessel occlusion have been previously described. The effect of recent randomized trials validating MT as an effective therapy for AIS secondary to large vessel occlusion on such disparities has not been investigated. Methods— Information on admissions for AIS to endovascular centers occurring between January 2016 and September 2018 was obtained from a national database. The number of patients receiving IV-tPA (intravenous tissue-type plasminogen activator) and MT at each institution was determined, and patient demographics were characterized according to age, sex, race/ethnicity, and insurance status. Comparisons of patients who did and did not undergo MT and between patients of different racial and ethnic backgrounds were performed. Demographic variables independently associated with the utilization of MT were identified using multivariate linear regression analysis. Results— There were 206 853 admissions to 173 endovascular centers during the time period of interest. The overall utilization of MT was 8.4%. The utilization of MT for black/Hispanic patients was lower than that among white/non-Hispanic patients (7.0% versus 9.8%; P <0.001). Black/Hispanic patients were also less likely to receive IV-tPA (16.2% versus 20.5%; P <0.001) and to be admitted to the endovascular center after transfer from a different hospital (20.0% versus 30.1%; P <0.001). On multivariate linear regression analysis, increasing institutional proportions of patients with female sex (β=−0.601; P <0.001), insurance with Medicaid or uninsured status (β=−0.153; P =0.029), and black/Hispanic race/ethnicity (β=−0.062; P =0.046) were independently associated with lower institutional utilization of MT. Conclusions— Despite the mainstream acceptance of MT for the treatment of AIS secondary to large vessel occlusion, racial and ethnic disparities in the utilization of MT persist.

Background Clot perviousness in large vessel occlusion has been shown to be associated with improved recanalization outcomes with mechanical thrombectomy and intravenous thrombolysis. Objective To evaluate the association between clot perviousness based on thrombus attenuation increase (TAI) on CT, and histologic composition of clots in acute ischemic stroke (AIS). Methods A retrospective review was completed of patients with AIS secondary to large vessel occlusion, non-contrast CT (NCCT) and CT angiography (CTA) images, and histologic analysis of the retrieved clot. TAI was measured by subtracting clot attenuation on NCCT from the attenuation on CTA. Up to 3 regions of interest (ROIs) were evaluated on each clot; the average attenuation was used for analysis if multiple ROIs were assessed. Pervious clots were defined as TAI ≥10 Hounsfield units (HUs); impervious clots had TAI <10 HU. Histopathologic analyses of clots were assessed for relative compositions of red blood cells (RBCs), white blood cells (WBCs), fibrin, and platelets/other. Results 57 patients were included. Pervious clots were more likely to be RBC rich (p=0.04); impervious clots were more likely to be fibrin and WBC rich (p=0.01 for both). Pervious clots also had greater RBC density than impervious clots (49.8% and 33.0%, respectively; p=0.006); fibrin density of pervious clots was lower than that of impervious clots (17.8% and 23.2%, respectively; p=0.02). Conclusion Clot perviousness, assessed on NCCT and CTA imaging, is associated with higher RBC density and lower fibrin density, offering a possible explanation for the higher rates of successful thrombectomy and favorable clinical outcome seen in such patients.

Background Hemicrania continua is a primary headache disorder characterized by a continuous, unilateral headache associated with ipsilateral cranial autonomic features that responds to indomethacin. By definition, the symptoms are not referable to an underlying structural pathology. However, several cases of secondary hemicrania continua related to underlying structural lesions have been reported. Case We present a case of a 53‐year‐old male with a prolonged, right‐sided headache associated with intermittent right‐sided ptosis, conjunctival injection, tearing, and nasal congestion, suggestive of hemicrania continua, who was found to have an indirect carotid‐cavernous fistula, and who, after endovascular treatment of the fistula, had resolution of his symptoms. Conclusion Alternative, and perhaps less common, causes of headache should be considered when the clinical presentation is atypical or does not clearly fulfill diagnostic criteria for primary headache disorders. Carotid cavernous fistulas should be included within this differential, and represent a potentially treatable and reversible cause of otherwise refractory headache.

Background and Purpose— Nearly 30% of large vessel occlusion acute ischemic stroke clots are from an unknown source. We assessed histological clot composition in a series of patients with large vessel occlusion and investigated correlations between clot composition and stroke pathogenesis. Methods— As part of the multi-institutional STRIP registry (Stroke Thromboembolism Registry of Imaging and Pathology), consecutive emboli retrieved during mechanical thrombectomy were stained using Martius Scarlett Blue and analyzed using machine learning software. We assessed proportions of red blood cells, fibrin, platelets, and white blood cells. Correlations between clot components and stroke pathogenesis (large artery atherosclerosis, cardioembolism, and stroke of undetermined pathogenesis) were assessed using SPSS22. Results— One hundred five patients were included. The proportion of platelet-rich clots (55.0% versus 21.2%; P =0.005) and percentage of platelet content (22.1±4.2% versus 13.9±14.2%; P =0.03) was significantly higher in the large artery atherosclerosis group compared with the cardioembolic group. The proportion of platelet-rich clots (50.0% versus 21.2%; P =0.024) was also significantly higher in the cryptogenic group compared with cardioembolic cases. Large artery atherosclerosis and cryptogenic cases had a similar proportion of platelet-rich clots (55.0% versus 50.0%; P =0.636). There was no significant difference between stroke pathogenesis and the other major clot components. Conclusions— High platelet content of emboli is associated with a large artery atherosclerosis etiology of large vessel occlusion.

An 80-year-old female presented with a long history of severe pulsatile tinnitus, vertigo, and decreased hearing. She was found to have a large right-sided tentorial arteriovenous fistula (AVF) with enlarged deep draining veins, including the vein of Rosenthal. The patient underwent Onyx embolization of the fistula via a combined transarterial and transvenous approach resulting in complete obliteration of the fistula. Her symptoms improved immediately after the procedure and at 6-months’ follow-up she was clinically asymptomatic with no evidence of residual fistula on neuroimaging. Transvenous embolization of AVF is at times necessary when transarterial access is not possible. The video can be found here: https://youtu.be/uOMHY7eaOoQ .

Objectives Remote ischemic preconditioning has been proposed as a possible potential treatment for ischemic stroke. However, neuroprotective benefits of the pre-procedural administration of remote ischemic preconditioning have not been investigated in patients undergoing an elective endovascular intracranial aneurysm repair procedure. This study investigated the safety and feasibility of remote ischemic preconditioning in patients with an unruptured intracranial aneurysm who undergo elective endovascular treatment. Methods In this single-center prospective study, patients with an unruptured intracranial aneurysm undergoing elective endovascular treatment with flow diverters or coiling were recruited. Patients received three intermittent cycles of 5 minutes arm ischemia followed by reperfusion using manual blood cuff inflation/deflation less than 5 hours prior to endovascular treatment. Patients were monitored and followed up for remote ischemic preconditioning-related adverse events and ischemic brain lesions by diffusion -weighted magnetic resonance imaging within 48 hours following endovascular treatment. Results A total of seven patients aged 60 ± 5 years with an unruptured intracranial aneurysm successfully completed a total of 21 sessions of remote ischemic preconditioning and the required procedures. Except for two patients who developed skin petechiae over their arms, no other serious procedure-related adverse events were observed as a result of the remote ischemic preconditioning procedure. On follow-up diffusion -weighted magnetic resonance imaging, a total of 19 ischemic brain lesions with a median (interquartile range) volume of 245 (61–466) mm 3 were found in four out of seven patients. Conclusions The application of remote ischemic preconditioning prior to endovascular intracranial aneurysm repair was well tolerated, safe and clinically feasible. Larger sham-controlled clinical trials are required to determine the safety and efficacy of this therapeutic strategy in mitigating ischemic damage following endovascular treatment of intracranial aneurysms.