Neuroimaging of headaches associated with vascular disorders.

Headaches from vascular causes need to be differentiated from primary headaches because a misdiagnosis may lead to dire consequences for the patient. Neuroimaging is critical in identifying patients with vascular headaches and identifying the nature of the pathologic disorder causing these headaches. In addition, the imaging findings guide the physician regarding the optimal treatment modality for these lesions. This review summarizes the nuances of differentiating patients with secondary headaches related to vascular disease and discusses pertinent neuroimaging studies.

Endovascular management of adjacent tandem intracranial aneurysms: utilization of stent-assisted coiling and flow diversion.

BACKGROUND: Tandem intracranial aneurysms are aneurysms located along a single intracranial vessel. Adjacent tandem aneurysms arise within the same vascular segment and their presence often suggests diffuse parent vessel anomaly. Endovascular management of these rare lesions has not been well studied. In this retrospective observational study, we describe our experience treating adjacent tandem intracranial aneurysms with endovascular embolization. METHODS: We retrospectively reviewed records of patients with these lesions who underwent endovascular treatment between 2008 and 2013. RESULTS: Thirteen patients (mean age 60.8 years; 12 women) with 28 adjacent tandem aneurysms were treated during the study timeframe. Aneurysms were located along the clinoidal, ophthalmic, and communicating segments of the internal carotid artery in 12 patients and at the basilar apex in one patient. Average size was 8.4 mm. Six patients (12 aneurysms) were treated by flow diversion via the Pipeline embolization device (PED) and seven (16 aneurysms) by stent-assisted coiling, with coils successfully placed in 11 aneurysms. Clinical follow-up was available for an average of 26.1 months; postprocedural angiography was performed for 12 patients. Complete occlusion was achieved in nine of ten (90 %) PED-treated aneurysms and eight of 11 (72.7 %) treated by stent-assisted coiling (p = 0.44). Two patients treated by stent-assisted coiling required re-coiling for aneurysm recanalization. Overall, modified Rankin scale scores were 0-1 for 12 patients and 3 for one patient. CONCLUSIONS: Adjacent tandem intracranial aneurysms can be safely and effectively treated by either stent-assisted coiling or flow diversion. We prefer PED flow diversion due to better parent vessel reconstruction and lower recanalization risk.

Triple therapy versus dual-antiplatelet therapy for dolichoectatic vertebrobasilar fusiform aneurysms treated with flow diverters.

BACKGROUND: Dolichoectatic vertebrobasilar fusiform aneurysms (DVBFAs) have poor natural history when left untreated and high morbimortality when treated with microsurgery. Flow diversion (FD) with dual-antiplatelet therapy (DAPT) is feasible but carries high risk of perforator occlusion and progression of brainstem compression. Elaborate antithrombotic strategies are needed to preserve perforator patency while vessel remodeling occurs. We compared triple therapy (TT (DAPT plus oral anticoagulation)) and DAPT alone in patients with DVBFAs treated with FD. METHODS: Retrospective comparison of DAPT and TT in patients with DVBFAs treated with FD at eight US centers. RESULTS: The groups (DAPT=13, TT=14) were similar in age, sex, clinical presentation, baseline disability, and aneurysm characteristics. Radial access use was significantly higher in the TT group (71.4% vs 15.3%; P=0.006). Median number of flow diverters and adjunctive coiling use were non-different between groups. Acute ischemic stroke rate during the oral anticoagulation period was lower in the TT group than the DAPT group (7.1% vs 30.8%; P=0.167). Modified Rankin Scale score decline was significantly lower in the TT group (7.1% vs 69.2%; P=0.001). Overall rates of hemorrhagic complications (TT, 28.6% vs DAPT, 7.7%; P=0.162) and complete occlusion (TT, 25% vs DAPT, 54.4%; P=0.213) were non-different between the groups. Rate of moderate-to-severe disability at last follow-up was significantly lower in the TT group (21.4% vs 76.9%; P=0.007). CONCLUSIONS: Patients with DVBFAs treated with FD in the TT group had fewer ischemic strokes, less symptom progression, and overall better outcomes at last follow-up than similar patients in the DAPT group.

Hemodynamic-morphologic discriminants for intracranial aneurysm rupture.

BACKGROUND AND PURPOSE: the purpose of this study was to identify significant morphological and hemodynamic parameters that discriminate intracranial aneurysm rupture status using 3-dimensional angiography and computational fluid dynamics. METHODS: one hundred nineteen intracranial aneurysms (38 ruptured, 81 unruptured) were analyzed from 3-dimensional angiographic images and computational fluid dynamics. Six morphological and 7 hemodynamic parameters were evaluated for significance with respect to rupture. Receiver operating characteristic analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured aneurysms for each parameter. Significant parameters were examined by multivariate logistic regression analysis in 3 predictive models-morphology only, hemodynamics only, and combined-to identify independent discriminants, and the AUC receiver operating characteristic of the predicted probability of rupture status was compared among these models. RESULTS: morphological parameters (size ratio, undulation index, ellipticity index, and nonsphericity index) and hemodynamic parameters (average wall shear stress [WSS], maximum intra-aneurysmal WSS, low WSS area, average oscillatory shear index, number of vortices, and relative resident time) achieved statistical significance (P<0.01). Multivariate logistic regression analysis demonstrated size ratio to be the only independently significant factor in the morphology model (AUC, 0.83; 95% CI, 0.75 to 0.91), whereas WSS and oscillatory shear index were the only independently significant variables in the hemodynamics model (AUC, 0.85; 95% CI, 0.78 to 0.93). The combined model retained all 3 variables, size ratio, WSS, and oscillatory shear index (AUC, 0.89; 95% CI, 0.82 to 0.96). CONCLUSIONS: all 3 models-morphological (based on size ratio), hemodynamic (based on WSS and oscillatory shear index), and combined-discriminate intracranial aneurysm rupture status with high AUC values. Hemodynamics is as important as morphology in discriminating aneurysm rupture status.

Cellular and molecular responses of the basilar terminus to hemodynamics during intracranial aneurysm initiation in a rabbit model.

BACKGROUND/AIMS: Hemodynamics constitute a critical factor in the formation of intracranial aneurysms. However, little is known about how intracranial arteries respond to hemodynamic insult and how that response contributes to aneurysm formation. We examined early cellular responses at rabbit basilar termini exposed to hemodynamic insult that initiates aneurysmal remodeling. METHODS: Flow in the basilar artery was increased by bilateral carotid artery ligation. After 2 and 5 days, basilar terminus tissue was examined by immunohistochemistry and quantitative PCR. RESULTS: Within 2 days of flow increase, internal elastic lamina (IEL) was lost in the periapical region of the bifurcation, which experienced high wall shear stress and positive wall shear stress gradient. Overlying endothelium was still largely present in this region. IEL loss was associated with localized apoptosis and elevated expression of matrix metalloproteinases (MMPs) 2 and 9. A small number of inflammatory cells were sporadically scattered in the bifurcation adventitia and were not concentrated in regions of IEL loss and MMP elevation. Elevated MMP expression colocalized with smooth muscle α-actin in the media. CONCLUSION: The initial vascular response to aneurysm-initiating hemodynamic insult includes localized matrix degradation and cell apoptosis. Such destructive remodeling arises from intrinsic mural cells, rather than through inflammatory cell infiltration.

Characterization of critical hemodynamics contributing to aneurysmal remodeling at the basilar terminus in a rabbit model.

BACKGROUND AND PURPOSE: Hemodynamic insult by bilateral common carotid artery ligation has been shown to induce aneurysmal remodeling at the basilar terminus in a rabbit model. To characterize critical hemodynamics that initiate this remodeling, we applied a novel hemodynamics-histology comapping technique. METHODS: Eight rabbits received bilateral common carotid artery ligation to increase basilar artery flow. Three underwent sham operations. Hemodynamic insult at the basilar terminus was assessed by computational fluid dynamics. Bifurcation tissue was harvested on day 5; histology was comapped with initial postligation hemodynamic fields of wall shear stress (WSS) and WSS gradient. RESULTS: All bifurcations showed internal elastic lamina loss in periapical regions exposed to accelerating flow with high WSS and positive WSS gradient. Internal elastic lamina damage happened 100% of the time at locations where WSS was >122 Pa and WSS gradient was >530 Pa/mm. The degree of destructive remodeling accounting for internal elastic lamina loss, medial thinning, and luminal bulging correlated with the magnitude of the hemodynamic insult. CONCLUSIONS: Aneurysmal remodeling initiates when local hemodynamic forces exceed specific limits at the rabbit basilar terminus. A combination of high WSS and positive WSS gradient represents dangerous hemodynamics likely to induce aneurysmal remodeling.

Conscious sedation versus general anesthesia during endovascular therapy for acute anterior circulation stroke: preliminary results from a retrospective, multicenter study.

BACKGROUND AND PURPOSE: Patients undergoing intra-arterial therapy (IAT) for acute ischemic stroke receive either general anesthesia (GA) or conscious sedation. GA may delay time to treatment, whereas conscious sedation may result in patient movement and compromise the safety of the procedure. We sought to determine whether there were differences in safety and outcomes in GA patients before initiation of IAT. METHODS: A cohort of 980 patients at 12 stroke centers underwent IAT for acute stroke between 2005 and 2009. Only patients with anterior circulation strokes due to large-vessel occlusion were included in the study. A binary logistic-regression model was used to determine independent predictors of good outcome and death. RESULTS: The mean age was 66+/-15 years and median National Institutes of Health Stroke Scale score was 17 (interquartile range, 13-20). The overall recanalization rate was 68% and the symptomatic hemorrhage rate was 9.2%. GA was used in 44% of patients with no differences in intracranial hemorrhage rates when compared with the conscious sedation group. The use of GA was associated with poorer neurologic outcome at 90 days (odds ratio=2.33; 95% CI, 1.63-3.44; P<0.0001) and higher mortality (odds ratio=1.68; 95% CI, 1.23-2.30; P<0.0001) compared with conscious sedation. CONCLUSIONS: Patients placed under GA during IAT for anterior circulation stroke appear to have a higher chance of poor neurologic outcome and mortality. There do not appear to be differences in hemorrhagic complications between the 2 groups. Future clinical trials with IAT can help elucidate the etiology of the differences in outcomes.

Safety and effectiveness of endovascular therapy after 8 hours of acute ischemic stroke onset and wake-up strokes.

BACKGROUND AND PURPOSE: This is a retrospective review of patients who underwent endovascular recanalization > or = 8 hours after acute ischemic stroke symptom onset, including wake-up strokes, between June 2005 and June 2008. METHODS: Thirty patients with a premorbid modified Rankin score < or = 1 and NIHSS between 5 and 22 were included. All had admission CT, CTA, and CT perfusion scans to evaluate for salvageable brain tissue. Recanalization effectiveness was assessed by angiograms obtained within 30 hours after intervention. Patient, treatment characteristics, and immediate and 3-month outcomes were analyzed. RESULTS: Mean NIHSS at presentation was 13 (median=12). Mean interval between time last-seen well and angiogram was 12.75 hours (median=10). Twenty-six patients (86.7%) presented with complete-to-near-complete vessel occlusion (thrombolysis in myocardial infarction [TIMI] 0/1); 4 had partial vessel occlusion (TIMI 2). Interventions included intra-arterial pharmacological thrombolysis (n=10), mechanical thrombectomy(n=21; Merci, 16; intracranial stent, 9; extracranial stent, 3), angioplasty (n=14; intracranial, 11; extracranial, 3). Nine patients received GPIIb/IIIa inhibitors (eptifibatide); all received heparin. Partial-to-complete recanalization (TIMI 2/3) was achieved in 20 patients (66.7%). Procedure-related complications included vascular perforations (n=3) and femoral access site complication (n=1). One patient had an embolic anterior cerebral artery infarct during intervention; another had progression of brain stem infarct. Symptomatic intracerebral hemorrhage occurred in 3 patients (10%), with 2 being primarily subarachnoid in location. Total in-hospital mortality including procedural mortality, disease progression, or other comorbidities was 23.3% (n=7). Mean discharge NIHSS was 9.5, representing an overall NIHSS 3.5-point improvement. Overall, mean modified Rankin score at death or last follow-up (mean=10.6 months) was 4.2. At 3 months, total mortality was 33.3% (n=10), 20% had modified Rankin score < or = 2, and 33% had modified Rankin score < or = 3. Among survivors, mean modified Rankin score at 3-month follow-up was 3. CONCLUSION: Our data show that delayed endovascular revascularization of carefully selected patients is safe, effective, and improves clinical outcome.

Brain Bypass Surgery for Complex Middle Cerebral Artery Aneurysms: Evolving Techniques, Results, and Lessons Learned.

OBJECTIVE: To analyze a consecutive series of patients with middle cerebral artery (MCA) aneurysms who needed an adjunctive cerebral revascularization procedure to achieve aneurysm occlusion with preservation of flow through all MCA branches. METHODS: A total of 42 patients with 43 MCA aneurysms underwent 52 bypass procedures over 13 years. The location of the aneurysm were M1 trunk, M1 bifurcation, M2 and beyond. The bypasses performed included intracranial bypasses (resection with end to end anastomosis, end to side implantation, side to side anastomosis, and short interposition graft), extraintracranial bypasses (superficial temporal to middle cerebral artery anastomosis, and radial artery bypass graft, or saphenous vein graft), double bypasses, Y-grafts, and combined techniques. RESULTS: Forty-two of 43 aneurysms (98%) had patent bypasses at long-term follow-up. All 43 aneurysms were completely occluded at last follow-up. Six patients (14%) developed strokes related to the surgical treatment. At last follow-up, 36 patients had a modified Rankin score of 0-2, 5 patients had modified Rankin score 3-5, and 1 died. In this series, 31 (73.8%) patients improved, 8 (19%) patients had same functional status, and 3 (7.2%) patients deteriorated, including 1 patient who expired due to sepsis. The mean clinical follow-up duration was 39.3 months (0.4-124 months) and the mean radiological follow-up was 37 months (0.4-134 months). CONCLUSIONS: Cerebral revascularization is an important adjunct for treating MCA aneurysms and can be done safely. The article provides the insights we gained by rising through the learning curve.

Better Outcomes and Reduced Hospitalization Cost are Associated with Ultra-Early Treatment of Ruptured Intracranial Aneurysms: A US Nationwide Data Sample Study.

BACKGROUND: The benefit of surgical treatment of ruptured aneurysms is well established. OBJECTIVE: To determine whether ultra-early ruptured aneurysm treatment leads to not only improved outcomes but also reduced hospitalization cost. METHODS: Using 2008-2011 Nationwide Inpatient Sample data, we analyzed demographic, clinical, and hospital factors for nontraumatic subarachnoid hemorrhage (SAH) patients who were "directly" admitted to the treating hospital where they underwent intervention (clipping/coiling). Patients treated on the day of admission (day 0) formed the ultra-early cohort; others formed the deferred treatment cohort. All Patient Refined Diagnosis-Related Groups were also included in regression analyses. RESULTS: A total of 17 412 patients were directly admitted to a hospital following nontraumatic SAH where they underwent intervention (clipping/coiling). Mean patient age was 53.87 yr (median 53.00, standard deviation 14.247); 68.3% were women (n = 11 893). A total of 6338 (36.4%) patients underwent treatment on the day of admission (ultra-early). Patients who underwent treatment on day 0 had significantly more routine discharge dispositions than those treated >admission day 0 (P < .0001). In regression analysis, treatment on day 0 was protective against other than routine discharge disposition outcome (P < .0001; odds ratio 0.657; 95% confidence interval 0.614-0.838). Total cost incurred by hospitals was $4.36 billion. Mean cost of hospital charges in the ultra-early cohort was $239 126.05, which was significantly lower than that for the cohort treated >day 0 ($272 989.56, P < .001), Mann-Whitney U-test). Performance of an intervention on admission day 0 was protective against higher hospitalization cost (P < .0001; odds ratio 0.811; 95% confidence interval 0.732-0.899). CONCLUSION: Ultra-early treatment of ruptured aneurysms is significantly associated with better discharge disposition and decreased hospitalization cost.

Flow Diversion after Aneurysmal Subarachnoid Hemorrhage.

Flow diversion after aneurysmal subarachnoid hemorrhage (SAH) is the last treatment option for aneurysm occlusion when other methods of aneurysm treatment cannot be used because of the need for dual antiplatelet therapy. The authors' general protocol for treatment selection after aneurysmal SAH is provided to share with readers our approach to securing the aneurysm before embarking flow diversion for primary treatment or delayed adjunctive treatment to primary coiling. The authors' experience with flow diversion after aneurysmal SAH, review of pertinent literature, and the future of flow diversion after aneurysmal SAH are discussed.

Impact of transfer status on hospitalization cost and discharge disposition for acute ischemic stroke across the US.

OBJECT In this study, the authors used information provided in the Nationwide Inpatient Sample (NIS) to study the impact of transferring stroke patients from one facility to a center where they received some form of active stroke intervention (intravenous tissue plasminogen activator, thrombectomy, or a combination of both therapies). METHODS Patient demographic characteristics and hospital factors obtained from the 2008-2010 acute stroke NIS data were analyzed. Discharge disposition, hospitalization cost, and mortality were the dependent variables studied. Univariate analysis and multivariate binary logistic regression analysis were performed. Data analysis focused on the cohort of acute stroke patients who received some form of active intervention (55,913 of 1,311,511 patients in the NIS). RESULTS When overall outcome was considered, transferred patients had a significantly higher number of other-than-routine (OTR, i.e., other than discharge to home without home health care) discharge dispositions (p < 0.0001). In multivariate regression analysis including pertinent patient and hospital factors, transfer-in patients had significantly worse OTR discharge disposition (p < 0.0001, odds ratio [OR] 2.575, 95% CI 2.341-2.832). Mean hospitalization cost including an intervention was $70,325.11 for direct admissions and $97,546.92 for transferred patients. Transfer from another facility (p < 0.001, OR 1.677, 95% CI 1.548-1.817) was associated with higher hospitalization cost. CONCLUSIONS The study showed that hospital cost for acute stroke intervention is significantly higher for a transferred patient than for a direct admission. Moreover, the frequency of OTR discharge was significantly higher among transferred patients than direct admissions. Future strategies should focus on ways and means of transporting patients appropriately and directly to stroke centers.

The safety of Pipeline flow diversion in fusiform vertebrobasilar aneurysms: a consecutive case series with longer-term follow-up from a single US center.

OBJECT Pessimism exists regarding flow diversion for posterior circulation aneurysms because of reports of perforator territory infarcts and delayed ruptures. The authors report the results of patients who underwent Pipeline Embolization Device (PED) flow diversion using novel strategies for treatment of fusiform posterior circulation aneurysms, and compare these results with those from previously reported series. METHODS The authors conducted a retrospective review of data from consecutive patients with fusiform vertebrobasilar artery aneurysms treated with the PED. RESULTS This review resulted in the identification of 12 such patients (mean [± SD] age 55.1 ± 14.1 years). Eleven patients had symptoms; 1 had a dissecting aneurysm identified on imaging for neck pain. The average aneurysm size was 13.25 ± 4.5 mm. None of the aneurysms were ruptured or previously treated. The average clinical follow-up duration was 22.1 ± 10.7 months and radiological follow-up was 14.5 ± 11.1 months from the index PED treatment. One patient suffered a perforator stroke and had a modified Rankin Scale (mRS) score of 4 at last follow-up. Another patient had a retained stent pusher requiring retrieval via surgical cut-down but recovered to an mRS score of 0 at last follow-up. Eleven (91.7%) of 12 patients recovered to an mRS score of 0 or 1. Two patients had aneurysmal remnants at 7 and 10 months, respectively, after the index PED, which were retreated with PEDs. At last follow-up, all 12 aneurysms were occluded and PEDs were patent. The minimum follow-up duration was 12 months from the index PED treatment; no patient experienced delayed hemorrhage, stroke, or in-stent stenosis. CONCLUSIONS Flow diversion with selective adjunctive techniques is evolving to become a safer treatment option for posterior circulation aneurysms. This is the longest clinical follow-up duration reported for a single-center experience of flow-diversion treatment of these aneurysms.

Stent Retriever-Assisted Mechanical Thrombectomy for Acute Basilar Artery Occlusion: Single US Institution Experience.

BACKGROUND: Acute basilar artery occlusion causes devastating strokes that carry high mortality and morbidity. OBJECTIVE: To report the outcomes of mechanical thrombectomy in the posterior circulation with a focus on safety and efficacy of stent retrievers. METHODS: We retrospectively reviewed our endovascular database for all patients treated with stent retrievers for posterior circulation stroke between June 2012 and June 2014. Twelve patients were identified. The following data were analyzed: thrombus location, previous stroke or transient ischemic attack, thrombus etiology, comorbidities, time from presentation to initiation of endovascular treatment, time from start of angiography to revascularization, and whether intravenous tissue plasminogen activator was administered pre-thrombectomy. Outcome was considered poor when modified Rankin Scale score was >2. RESULTS: Mean patient age was 63.42 years (median, 64.5; range, 28-83 years); 7 were women. Successful recanalization (Thrombolysis in Cerebral Infarction grade 2b or 3) was achieved in 11 of 12 patients (91.7%). Mean discharge modified Rankin Scale score was 2.3 (median, 2.0; standard deviation 1.96; range, 0-6), with a favorable discharge outcome in 9 of 12 (75%) patients. Two patients died as inpatients. Mean follow-up modified Rankin Scale score was 1.4 (median, 1.00; standard deviation 1.075; range, 0-4). Good outcome was achieved in 9 of 10 (90%) patients at last follow-up (mean follow-up duration, 132.42 days [median, 90.50; standard deviation 80.2; range, 8-378 days]). CONCLUSION: Our single-institution study has shown that good clinical outcomes and successful recanalization with acceptable mortality can be achieved with current stent retrievers.

Endovascular therapy of wake-up strokes in the modern era of stent retriever thrombectomy.

BACKGROUND: Endovascular treatment of wake-up strokes (WUS) has been previously described, mostly with the use of pharmacological thrombolysis or first generation thrombectomy devices. OBJECTIVE: To describe outcomes of WUS treated with modern endovascular therapy since the Food and Drug Administration approval of stent retrievers, and to identify predictors of good clinical outcome in this population of stroke patients. METHODS: We performed a multicenter retrospective analysis of consecutive patients with WUS who underwent thrombectomy with stent retrievers Trevo (Stryker, Kalamazoo, Michigan, USA) and Solitaire FR (Covidien, Irvine, California, USA), or primary aspiration thrombectomy. We correlated favorable clinical outcomes with demographic, clinical, and technical characteristics. RESULTS: 52 patients were included in this study; 46 (88%) cases were treated with stent retrievers and 6 (12%) were treated with primary aspiration thrombectomy alone. Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b/3) was achieved in 36 (69%) patients. Favorable clinical outcome at 3 months, defined as a modified Rankin Scale score of 0-2, was achieved in 25 (48%) patients. Duration of intervention <30 min and its success, defined as TICI 2b/3 recanalization, were strong predictors of favorable clinical outcome at 90 days (p<0.001 and p<0.0001, respectively). CONCLUSIONS: Our study indicates that endovascular treatment of WUS with stent retrievers and aspiration thrombectomy is safe and effective.

Hyperacute Carotid Stent Thrombosis During Emergent Revascularization Treated with Intraarterial Eptifibatide After Systemic Administration of Recombinant Tissue Plasminogen Activator.

UNLABELLED: A 57-year-old woman with National Institutes of Health Stroke Scale (NIHSS) score of 26 was found to have an acute left carotid occlusion with tandem left M1 thrombus within 1.5 hours of symptom onset. After no neurologic improvement following standard-dose intravenous (IV) recombinant tissue plasminogen activator (rtPA), emergent neuroendovascular revascularization with carotid stenting and intracranial thrombectomy were performed under conscious sedation. Thrombolysis in myocardial infarction (TIMI)-3 flow restoration and symptom resolution were achieved postprocedure; however, complete carotid stent thrombosis was noted on final angiographic runs (25 minutes later), correlating with neurologic decline. Rapid administration of an intraarterial (IA) bolus dose of eptifibatide resulted in TIMI-3 flow restoration, with neurologic improvement. The patient was discharged three days postrevascularization on dual antiplatelet therapy with an NIHSS score of 1. Intraarterial (IA) eptifibatide can be an effective option for acute stent occlusion during emergent neuroendovascular revascularization after IV rtPA administration. ABBREVIATIONS: CLEARCombined approach to lysis utilizing eptifibatide and RtPACTcomputed tomographicFrFrenchGPglycoproteinIAintraarterialICAinternal carotid arteryIVintravenousMCAmiddle cerebral arteryNIHSSNational Institutes of Health Stroke ScalertPArecombinant tissue plasminogen activatorTIMIthrombolysis in myocardial infarction.

Correlation between cerebral blood volume values and outcomes in endovascular therapy for acute ischemic stroke.

BACKGROUND: Neurointerventionalists do not agree about the optimal imaging protocol when evaluating patients with acute stroke for potential endovascular revascularization. Preintervention cerebrovascular blood volume (CBV) has been shown to predict outcomes in patients undergoing intra-arterial stroke therapies. OBJECTIVE: To determine whether CBV can predict hemorrhagic transformation and clinical outcomes in patients selected for endovascular therapy for acute ischemic middle cerebral artery (MCA) stroke using a CT perfusion (CTP)-based imaging protocol. METHODS: We retrospectively reviewed cases of acute ischemic stroke due to MCA M1 segment occlusion and correlated favorable clinical outcomes (modified Rankin scale (mRS) ≤2) and radiographic outcomes with preintervention CBV values. All patients underwent whole-brain (320-detector-row) CTP imaging, and absolute CBV values of the affected and contralateral MCA territories were obtained separately for the cortical and basal ganglia regions. RESULTS: Relative CBV (rCBV) of the MCA cortical regions was significantly lower in patients with poor clinical outcomes than in those with favorable clinical outcomes (0.87±0.21 vs 1.02±0.09, p=0.0003), and a negative correlation was found between rCBV values and mRS score severity. rCBV of the basal ganglia region was significantly lower in patients with hemorrhagic infarction (p=0.004) and parenchymal hematoma (p=0.04) than in those without hemorrhagic transformation. CONCLUSIONS: We found that cortical CBV loss is predictive of poor clinical outcomes, whereas basal ganglia CBV loss is predictive of hemorrhagic transformation but without translation into poor clinical outcomes. Our study findings support published results of baseline preintervention CBV as a predictor of outcomes in patients undergoing intra-arterial stroke therapies.

Thrombus density predicts successful recanalization with Solitaire stent retriever thrombectomy in acute ischemic stroke.

BACKGROUND: Thrombus characteristics, including Hounsfield unit (HU) value to measure density and thrombus volume and length, can predict successful recanalization following IV thrombolysis with recombinant tissue plasminogen activator. Conflicting and limited data exist regarding the value of assessing thrombus properties in acute stroke cases treated with endovascular IA approaches. METHODS: We retrospectively reviewed cases of anterior circulation acute ischemic stroke in which a Solitaire stent retriever (ev3-Covidien) was the primary treatment device. We measured the following thrombus characteristics: absolute and corrected HU values; thrombus length and volume; clot burden score; and vessel bifurcation involvement. Fisher's exact test and the t test were used to study the association between these clot characteristics and successful recanalization (Thrombolysis in Cerebral Infarction (TICI) score 2b-3). RESULTS: We identified 41 patients with anterior circulation stroke treated with the Solitaire stent retriever as the primary treatment device. Successful recanalization (TICI score 2b-3) was achieved in 59% of cases. Higher absolute and corrected HU values were strongly predictive of successful recanalization (49.9±7.6 vs 43.8±6.6, p=0.01 for absolute HU values and 1.2±0.2 vs 1.0±0.1, p=0.03 for HU ratio in TICI 2b-3 and TICI 0-2a groups, respectively). There was no significant difference between recanalization and non-recanalization groups in the other thrombus characteristics studied. CONCLUSIONS: In acute stroke treated with Solitaire stent retriever thrombectomy, higher thrombus HU values are predictive of successful recanalization. Such information can be used in decision making when estimating recanalization success rate with different endovascular treatment approaches.