A Transcriptomic Comparative Study of Cranial Vasculature

In genetic studies of cerebrovascular diseases, the optimal vessels to use as controls remain unclear. Our goal is to compare the transcriptomic profiles among 3 different types of control vessels: superficial temporal artery (STA), middle cerebral arteries (MCA), and arteries from the circle of Willis obtained from autopsies (AU). We examined the transcriptomic profiles of STA, MCA, and AU using RNAseq. We also investigated the effects of using these control groups on the results of the comparisons between aneurysms and the control arteries. Our study showed that when comparing pathological cerebral arteries to control groups, all control groups presented similar responses in the activation of immunological processes, the regulation of intracellular signaling pathways, and extracellular matrix productions, despite their intrinsic biological differences. When compared to STA, AU exhibited upregulation of stress and apoptosis genes, whereas MCA showed upregulation of genes associated with tRNA/rRNA processing. Moreover, our results suggest that the matched case-control study design, which involves control STA samples collected from the same subjects of matched aneurysm samples in our study, can improve the identification of non-inherited disease-associated genes. Given the challenges associated with obtaining fresh intracranial arteries from healthy individuals, our study suggests that using MCA, AU, or paired STA samples as controls are feasible strategies for future large-scale studies investigating cerebral vasculopathies. However, the intrinsic differences of each type of control should be taken into consideration when interpreting the results. With the limitations of each control type, it may be most optimal to use multiple tissues as controls.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study

BACKGROUND AND PURPOSE

Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes.

MATERIALS AND METHODS

A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals.

RESULTS

A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34).

CONCLUSIONS

This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

Asymptomatic Moyamoya Disease in a North American Adult Cohort

OBJECTIVE

The natural history of asymptomatic adult moyamoya disease (MMD) is unclear, and the benefit of treatment remains controversial. This study aimed to investigate the natural history of asymptomatic MMD in a North American cohort and to evaluate risk factors associated with and the effects of treatment on disease progression.

METHODS

Medical records from 3 institutions of consecutive adult patients with MMD diagnosed between 1984 and 2018 were retrospectively reviewed. Patients with unilateral or bilateral asymptomatic MMD were evaluated for subsequent development of infarction or hemorrhage. Multivariate Cox proportional hazards regression assessed risk factors associated with infarction or hemorrhage, adjusting for age, sex, race, initial Suzuki grade, hypertension, hyperlipidemia, diabetes, obesity, presence of aneurysms, smoking status, aspirin, and statin use at diagnosis.

RESULTS

We identified 106 hemispheres with asymptomatic MMD in 97 patients with mean 5.1 years (interquartile range, 1.0-7.9 years) of follow-up. Of 106 hemispheres, 59 were treated medically, and 47 were treated with revascularization with direct or indirect bypasses. The medical and surgical cohorts had a 1.9% and 1.3% annual rate of radiographic infarction or hemorrhage per hemisphere, respectively. Cox regression for radiographic events, including early postoperative events, showed no significant difference between the treatment groups (adjusted hazard ratio 0.34 [95% confidence interval 0.05-2.5]).

CONCLUSIONS

We found an overall 1.7% annual rate of radiographic infarction or hemorrhage in asymptomatic MMD hemispheres. Although we did not find a benefit to surgical treatment within the study period, asymptomatic patients with expected long-term survival may benefit from surgery given the sustained long-term benefits after surgery despite an initial postoperative risk.

Incidence and Outcomes of Registry-Based Acute Myocardial Infarction After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Acute myocardial infarction (AMI) is the rarest and least studied cardiac complication of aneurysmal subarachnoid hemorrhage (aSAH). Precise estimates of the incidence of AMI after aSAH are unavailable. Our goal was to estimate the incidence of registry-based AMI (rb-AMI) after aSAH and determine its association with clinical outcomes.

METHODS

Adult patients with aSAH in the National Inpatient Samples from 2002 to 2014 were included in the study. We evaluated risk factors for rb-AMI using univariate and multivariate regression models. Clinical outcomes that were assessed included functional status at discharge, in-patient mortality, length of stay, and total hospitalization cost, adjusting for patient demographics and cardiovascular risk factors through an inverse probability weighted analysis. Subgroup analyses were further performed stratified by rb-AMI type (ST-segment elevation myocardial infarction [STEMI] vs. non-STEMI [NSTEMI]).

RESULTS

A total of 139,734 patients with aSAH were identified, 3.6% of whom had rb-AMI. NSTEMI was the most common type of rb-AMI occurring after aSAH (71% vs. 29% for NSTEMI vs. STEMI, respectively). Patient characteristics associated with higher odds of rb-AMI included age, female sex, poor aSAH grade, and various cardiovascular risk factors. Rb-AMI was also associated with poor functional status at discharge, higher in-hospital mortality, and a longer and more costly hospital stay.

CONCLUSIONS

Rb-AMI occurs in 3.6% of patients with aSAH and is associated with poor functional status at discharge, higher in-patient mortality, and a longer and more costly hospitalization. Differentiating between different types of rb-AMI would be important in optimizing the management of patients with aSAH. Our definition of rb-AMI likely includes patients with neurogenic stress cardiomyopathy, which may confound the results.

Direct vs Indirect Revascularization in a North American Cohort of Moyamoya Disease

BACKGROUND

In adults with ischemic moyamoya disease (MMD), the efficacy of direct vs indirect revascularization procedures remains a matter of debate.

OBJECTIVE

To investigate the outcomes of ischemic MMD in a North American cohort treated by direct and indirect revascularizations.

METHODS

We retrospectively reviewed medical records of adult patients with MMD with ischemic presentation from 1984 to 2018 at the Brigham and Women's Hospital and Massachusetts General Hospital who underwent either direct or indirect bypasses. Early postoperative events and outcome at more than 6 mo postoperatively were evaluated using multivariable logistic regression analyses. Multivariable Cox proportional hazards regression analyses were used to evaluate delayed ischemic and hemorrhagic events. Analyses were performed per hemisphere.

RESULTS

A total of 95 patients with MMD and 127 hemispheres were included in this study. A total of 3.5% and 8.6% of patients had early surgical complications in the direct and indirect bypass cohorts, respectively (P = .24). Hemispheres with direct bypasses had fewer long-term ischemic and hemorrhagic events at latest follow-up (adjusted hazard ratio [HR] 0.19, 95% confidence interval [CI] 0.058-0.63, P = .007; median follow-up 4.5 [interquartile range, IQR 1-8] yr). There was no difference between the direct and indirect bypass groups when the endpoint was limited to infarction and hemorrhage only (P = .12). There was no difference in outcome (modified Rankin Scale [mRS] ≥ 3) between the 2 cohorts (P = .92).

CONCLUSION

There was no difference in early postoperative events, long-term infarction or hemorrhage, or clinical outcome between direct and indirect revascularization. However, there was a significant decrease in all ischemic and hemorrhagic events combined in direct revascularizations compared to indirect revascularizations.

Familial Predisposition and Differences in Radiographic Patterns in Spontaneous Nonaneurysmal Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) from an intracranial aneurysmal rupture is the most common nontraumatic etiology for SAH, but up to 15% of patients with SAH have no identifiable source.

OBJECTIVE

To assess familial predisposition to spontaneous nonaneurysmal SAH (naSAH) and to evaluate whether family history affects the severity of presentation and prognosis of this condition.

METHODS

We conducted a retrospective analysis of all spontaneous SAH with negative digital subtraction angiography from 2004 to 2018. Patients were divided into 2 groups: patients with first- or second-degree relatives with intracranial aneurysms and patients with no family history. Univariate and multivariate regression analyses were used to study patient presentation, radiographic patterns of hemorrhage, and clinical outcome.

RESULTS

A total of 100 patients met the inclusion criteria. There were no individuals with family history of naSAH. A total of 15 patients (15%) had at least one family member with an intracranial aneurysm, of which 12 (12%) presented as SAH. Patients without family history had a higher percentage of perimesencephalic presentation, whereas those with family history had a higher percentage of nonperimesencephalic SAH presentation (47% vs 13%, odds ratio [OR] 0.17 [95% CI 0.04, 0.81]).

CONCLUSION

We found a high rate of family history of intracranial aneurysms in patients who presented with naSAH. Although there was no difference in clinical outcome in patients with and without family history, there appears to be a higher percentage of nonperimesencephalic radiographic patterns of SAH in those with family history, suggesting possible different etiologies of these hemorrhages.

Abstract TP19: Thrombectomy in Medium Arteries Works for Distal Vessel Occlusions in Acute Ischemic Stroke - STRATIS

Background: Mechanical thrombectomy is established for large vessel occlusions in acute ischemic stroke, but the potential role in distal vessel occlusions of medium arteries is largely unknown. Such distal arterial segments have not been measured with respect to thrombectomy devices used during endovascular therapy. We conducted a systematic analysis of arterial size, segmental anatomy and stent retriever device performance during thrombectomy.

Methods: The STRATIS angiography core lab adjudicated the exact location of the occlusion, proximal and distal device deployment, relationship to arterial bifurcations and anatomical nomenclature. Arterial diameters were measured at all of these sites. Statistical analyses examined the relationship between these variables, arterial recanalization and eTICI reperfusion.

Results: Thrombectomy was performed with various device sizes, including Solitaire 4x40 in 36.3% (306/844), Solitaire 6x30 in 31.4% (265/844), Solitaire 4x20 in 26.4% (223/844), unspecified in 3.8% (32/844), Solitaire 6x20 in 1.3% (11/844) and Solitaire 4x15 in 0.8% (7/844). Arterial diameter at the occlusion site was median 2.17mm (1.40-3.59) in the distal M1, 1.67mm (0.81-2.98) in the proximal M2, 1.50mm (0.92-1.99) in the distal M2, 1.24mm (0.67-2.00) in the M3 and 1.88mm (1.49-1.94) in the P1. Considerable overlap was noted between arterial sizes at occlusion sites carrying different segmental arterial nomenclature or vessel names. During device deployment in STRATIS, median arterial diameter at the occlusion site was 2.4mm (IQR 1.9, 3.4), 2.9mm (IQR 2.2, 3.6) at the proximal stent marker and 1.4mm (IQR 1.2, 1.7) at the distal stent marker. Substantial eTICI reperfusion (2b-3) was achieved in all distal vessel occlusions (Table 1).

Conclusions: Substantial reperfusion may be achieved with currently available mechanical thrombectomy devices for distal vessel occlusions in medium arteries.

Abstract WP24: Arterial Tortuosity is a Potent Determinant of Safety in Endovascular Therapy for Ischemic Stroke

Background: Subarachnoid hemorrhage (SAH) associated with vessel injury during endovascular therapy for acute ischemic stroke is a known complication. Arterial anatomy may predispose to increased risk of SAH and technical safety, yet factors such as clot location, arterial size and tortuosity have not been explored. We examined these anatomical factors with respect to SAH during thrombectomy.

Methods: Arterial anatomy at the site of occlusion and mechanical thrombectomy during device deployment was detailed by the STRATIS core lab. Luminal diameters, arterial branching and segmental tortuosity were measured. Arterial tortuosity was quantified using the distance factor metric (DFM). Statistical analyses included descriptives of arterial anatomy, with univariate and multivariate modeling to predict SAH.

Results: Arterial tortuosity in each segment from the proximal cerebral arteries to the site of occlusion was quantified in 790 subjects treated with mechanical thrombectomy in STRATIS. Cumulative arterial tortuosity to the site of vessel occlusion was greater in distal lesions (Table 1). SAH was clearly linked with more distal thrombectomy (p=0.017), with 19.0% of distal M2, 16.7% of M3, 7.3% of distal M1, 5.8% of proximal M2, 2.4% of distal ICA and 2.1% of proximal M1. Multivariate prediction of SAH revealed that arterial diameter was unrelated to SAH (p=0.30) when accounting for tortuosity, whereas the presence of tortuosity tripled the risk of SAH (OR 3, p<0.05).

Conclusions: This novel systematic analysis of arterial tortuosity and angiographic anatomy during mechanical thrombectomy establishes tortuosity as a determinant of SAH, providing insight for future techniques and innovative device designs.

Predictive Score of Adverse Events After Carotid Endarterectomy: The NSQIP Registry Carotid Endarterectomy Scale

Background

The goal of this study was to create a comprehensive, integer‐weighted predictive scale of adverse events after carotid endarterectomy (CEA), which may augment risk stratification and patient counseling.

Methods and Results

The targeted carotid files from the prospective NSQIP (National Surgical Quality Improvement Program) registry (2011–2013) comprised the derivation population. Multivariable logistic regression evaluated predictors of a 30‐day adverse event (stroke, myocardial infarction, or death), the effect estimates of which were used to build a weighted predictive scale that was validated using the 2014 to 2015 NSQIP registry release. A total of 10 766 and 8002 patients were included in the derivation and the validation populations, in whom 4.0% and 3.7% developed an adverse event, respectively. The NSQIP registry CEA scale included 14 variables; the highest points were allocated for insulin‐dependent diabetes mellitus, high‐risk cardiac physiological characteristics, admission source other than home, an emergent operation, American Society of Anesthesiologists’ classification IV to V, modified Rankin Scale score ≥2, and presentation with a stroke. NSQIP registry CEA score was predictive of an adverse event (concordance=0.67), stroke or death (concordance=0.69), mortality (concordance=0.76), an extended hospitalization (concordance=0.73), and a nonroutine discharge (concordance=0.83) in the validation population, as well as among symptomatic and asymptomatic subgroups (P<0.001). In the validation population, patients with an NSQIP registry CEA scale score >8 and 17 had 30‐day stroke or death rates >3% and 6%, the recommended thresholds for asymptomatic and symptomatic patients, respectively.

Conclusions

The NSQIP registry CEA scale predicts adverse outcomes after CEA and can risk stratify patients with both symptomatic and asymptomatic carotid stenosis using different thresholds for each population.

Periprocedural intracranial hemorrhage after embolization of cerebral arteriovenous malformations: a meta-analysis

OBJECTIVE

The primary goal of the treatment of cerebral arteriovenous malformations (AVMs) is angiographic occlusion to eliminate future hemorrhage risk. Although multimodal treatment is increasingly used for AVMs, periprocedural hemorrhage after transarterial embolization is a potential endovascular complication that is only partially understood and merits quantification.

METHODS

Searching the period between 1990 and 2019, the authors of this meta-analysis queried the PubMed and Embase databases for studies reporting periprocedural hemorrhage (within 30 days) after liquid embolization (using cyanoacrylate or ethylene vinyl alcohol copolymer) of AVMs. Random effects meta-analysis was used to evaluate the pooled rate of flow-related hemorrhage (those attributed to alterations in AVM dynamics), technical hemorrhage (those related to procedural complications), and total hemorrhage. Meta-regression was used to analyze the study-level predictors of hemorrhage, including patient age, Spetzler-Martin grade, hemorrhagic presentation, embolysate used, intent of treatment (adjuvant vs curative), associated aneurysms, endovascular angiographic obliteration, year of study publication, and years the procedures were performed.

RESULTS

A total of 98 studies with 8009 patients were included in this analysis, and the mean number of embolization sessions per patient was 1.9. The pooled flow-related and total periprocedural hemorrhage rates were 2.0% (95% CI 1.5%-2.4%) and 2.6% (95% CI 2.1%-3.0%) per procedure and 3.4% (95% CI 2.6%-4.2%) and 4.8% (95% CI 4.0%-5.6%) per patient, respectively. The mortality and morbidity rates associated with hemorrhage were 14.6% and 45.1%, respectively. Subgroup analyses revealed a pooled total hemorrhage rate per procedure of 1.8% (95% CI 1.0%-2.5%) for adjuvant (surgery or radiosurgery) and 4.6% (95% CI 2.8%-6.4%) for curative intent. The treatment of aneurysms (p = 0.04) and larger patient populations (p < 0.001) were significant predictors of a lower hemorrhage rate, whereas curative intent (p = 0.04), angiographic obliteration achieved endovascularly (p = 0.003), and a greater number of embolization sessions (p = 0.03) were significant predictors of a higher hemorrhage rate. There were no significant differences in periprocedural hemorrhage rates according to the years evaluated or the embolysate utilized.

CONCLUSIONS

In this study-level meta-analysis, periprocedural hemorrhage was seen after 2.6% of transarterial embolization procedures for cerebral AVMs. The adjuvant use of endovascular embolization, including in the treatment of associated aneurysms and in the presurgical or preradiosurgical setting, was a study-level predictor of significantly lower hemorrhage rates, whereas more aggressive embolization involving curative intent and endovascular angiographic obliteration was a predictor of a significantly higher total hemorrhage rate.

Age-Dependent Radiographic Vasospasm and Delayed Cerebral Ischemia in Women After Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Recent literature suggests there are sex differences in delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). Our study serves to compare sex differences in radiographic vasospasm, DCI, and clinical outcome after aSAH, and to determine whether there are age-dependent differences.

METHODS

A total of 328 patients with ruptured cerebral aneurysms were evaluated for radiographic vasospasm, clinical deterioration, cerebral infarction, and modified Rankin Scale-determined clinical outcome at 6 months to 1 year after rupture. Multivariate regression analyses were performed to evaluate the associations between these outcome measures and sex, adjusting for age, hypertension, aneurysm location, admission Hunt and Hess grade, and modified Fisher grade.

RESULTS

After multivariate adjustment, women had higher rates of radiographic vasospasm (β = 0.35; 95% confidence interval [CI], 0.068-0.63; P = 0.015), clinical deterioration (odds ratio [OR], 2.8; 95% CI, 1.3-6.0; P = 0.008) and cerebral infarction (OR, 2.4; 95% CI, 1.0-5.5; P = 0.039), but no difference was observed in follow-up modified Rankin Scale (mRS) outcome score at 6 months to 1 year (P = 0.96). Older women (age >55 years) have a higher rate of clinical deterioration than men in the same age group (OR, 3.5; 95% CI, 1.0-12; P = 0.043). In contrast, younger women (age ≤55 years) had increased radiographic vasospasm (β = 0.55; 95% CI, 0.17-0.93; P = 0.005) and worse mRS outcome score (β = 0.042; 95% CI, -0.021 to 1.1; P = 0.042) compared with men.

CONCLUSIONS

Female sex is associated with a higher risk of radiographic vasospasm, clinical deterioration, and cerebral infarction. Furthermore, this association appears to be age-dependent. This study further supports the unique role of sex, and highlights the need to better understand the possible role of female hormones in the development of complications of subarachnoid hemorrhage.

Frameless Stereotactic Navigation during Insular Glioma Resection using Fusion of Three-Dimensional Rotational Angiography and Magnetic Resonance Imaging

BACKGROUND

Perioperative cerebral infarction is a potential complication of glioma resection, of which insular tumors are at higher risk because of the proximity of middle cerebral artery branches, including the lateral lenticulostriates and long insular arteries. In this study, 3 patients received three-dimensional rotational angiography, which was fused with magnetic resonance imaging (MRI) for frameless stereotactic navigation during dominant-hemisphere insular glioma resection.

METHODS

All patients obtained a preoperative catheter angiogram with a three-dimensional rotational acquisition of the ipsilateral internal carotid artery. The pixel-based axial three-dimensional angiography data, thin-cut structural MRI, tractography from diffusion tensor imaging, and expressive language activation from functional MRI were uploaded into the iPlan software (Brainlab, Heimstetten, Germany) and fused. The target tumor, regional blood vessels, adjacent functional areas, and their associated fiber tracts were segmented and overlaid on the appropriate MRI sequence. This image fusion was used preoperatively to visualize the relationship of the mass with the adjacent vasculature and intraoperatively for frameless stereotactic navigation to optimize preservation of arterial structures.

RESULTS

Three patients aged 27-60 years with excellent baseline functional status presented with seizures and were found to have a large dominant-hemisphere T2 hyperintense nonenhancing insular mass. Surgical resection was performed using multimodality neuronavigation. None sustained a postoperative arterial infarction or a perioperative neurologic deficit.

CONCLUSIONS

Neuronavigation using a fusion of three-dimensional rotational angiography with MRI is a technique that can be used for preoperative planning and during resection of insular gliomas to optimize preservation of adjacent arteries.

Adverse events after clipping of unruptured intracranial aneurysms: the NSQIP unruptured aneurysm scale

OBJECTIVE

The complex decision analysis of unruptured intracranial aneurysms entails weighing the benefits of aneurysm repair against operative risk. The goal of the present analysis was to build and validate a predictive scale that identifies patients with the greatest odds of a postsurgical adverse event.

METHODS

Data on patients who underwent surgical clipping of an unruptured aneurysm were extracted from the prospective National Surgical Quality Improvement Program registry (NSQIP; 2007-2014); NSQIP does not systematically collect data on patients undergoing intracranial endovascular intervention. Multivariable logistic regression evaluated predictors of any 30-day adverse event; variables screened included patient demographics, comorbidities, functional status, preoperative laboratory values, aneurysm location/complexity, and operative time. A predictive scale was constructed based on statistically significant independent predictors, which was validated using both NSQIP (2015-2016) and the Nationwide Inpatient Sample (NIS; 2002-2011).

RESULTS

The NSQIP unruptured aneurysm scale was proposed: 1 point was assigned for a bleeding disorder; 2 points for age 51-60 years, cardiac disease, diabetes mellitus, morbid obesity, anemia (hematocrit < 36%), operative time 240-330 minutes; 3 points for leukocytosis (white blood cell count > 12,000/μL) and operative time > 330 minutes; and 4 points for age > 60 years. An increased score was predictive of postoperative stroke or coma (NSQIP: p = 0.002, C-statistic = 0.70; NIS: p < 0.001, C-statistic = 0.61), a medical complication (NSQIP: p = 0.01, C-statistic = 0.71; NIS: p < 0.001, C-statistic = 0.64), and a nonroutine discharge (NSQIP: p < 0.001, C-statistic = 0.75; NIS: p < 0.001, C-statistic = 0.66) in both validation populations. Greater score was also predictive of increased odds of any adverse event, a major complication, and an extended hospitalization in both validation populations (p ≤ 0.03).

CONCLUSIONS

The NSQIP unruptured aneurysm scale may augment the risk stratification of patients undergoing microsurgical clipping of unruptured cerebral aneurysms.

Abstract TMP62: Emergency Triage to Predict Collaterals in Acute Ischemic Stroke: Imaging Bests Clinical Factors in the STRATIS Registry

Background: Collateral grade is an established determinant of outcomes in acute ischemic stroke (AIS). The triage, workflow and therapeutic options for AIS may be tailored to collaterals and identifying key predictors of collateral status may therefore be crucial. We hypothesized that degree of collateral circulation prior to endovascular therapy in AIS may be predicted at the time of initial patient evaluation and triage.

Methods: The STRATIS Registry showed that timelines, technical, and functional outcomes could be effectively attained in a large real-world cohort of endovascular therapy. Baseline clinical and imaging predictors of core lab adjudicated collateral grade (ASITN) by conventional angiography were determined, using multivariate modeling.

Results: 586 STRATIS subjects (67.5 ± 15.2 years, 52.7% male) presenting with AIS at 147.4 ± 101.8 min from symptom onset (TFSO) and median NIHSS score 17.0 (range 8.0,30.0) were analyzed. Collateral grade was poor (ASITN 0-1) in 81, moderate (ASITN 2) in 297 and good (ASITN 3-4) in 208. Baseline stroke severity inversely correlated with collaterals (NIHSS per point, OR 0.946, 0.916-0.977, p=0.001), yet no clinical variables such as age, sex or co-morbidities were predictive of collateral status. Less severe ASPECTS at imaging triage (median 9, range 2-10) was associated with better collateral grade (ASITN 0-1, median 7 (2-10); ASITN 2, 8 (3-10); ASITN 3-4, 9 (5-10), p<0.001) and the strongest predictor of collaterals during triage (per point, OR 1.608, 1.399-1.849, p<0.001). Interestingly, the predictive nature of ASPECTS was not modified by TFSO (p=NS). Specific ASPECTS regions (all cortical M1-M6, but no subcortical) affected by early ischemia were also predictive of collateral grade. In particular, insular ASPECTS changes at imaging triage was the strongest predictor of collateral grade (ASITN 0-1, 53/66 (80.3%); ASITN 2, 139/258 (53.9%); ASITN 3-4, 41/194 (21.1%), p<0.001).

Conclusions: Imaging, using only ASPECTS, during triage strongly predicts collateral grade, irrespective of time from symptom onset. Clinical variables, however, may not be used to accurately predict collaterals in the real-world practice of endovascular therapy.

Abstract WP62: Imaging With CT Perfusion Prior to Endovascular Therapy in STRATIS: Time to Rethink?

Background: Different neuroimaging triage strategies, including CT perfusion (CTP), are commonly used prior to endovascular therapy, often tailoring imaging approaches based on time from symptom onset. We analyzed whether the acquisition of CTP prior to endovascular therapy in STRATIS was related to clinical outcomes and if any possible link was noted based on time duration from symptom onset.

Methods: The STRATIS Core Lab analyzed all pre-procedural imaging in STRATIS, including the use of CTP. Acquisition of pre-procedural CTP was analyzed with respect to 90-day modified Rankin Score (mRS) clinical outcomes. Subgroup analyses explored whether this relationship was different in the 0-6 versus 6-8 hour interval from symptom onset.

Results: Among 984 subjects analyzed in STRATIS, 264 had pre-procedural CTP acquired by the imaging Core Laboratory. No association between CTP acquisition and mRS outcomes at 90 days was observed in the overall study cohort. However, among subjects treated over 6 hours from onset (n=119), a trend toward better outcomes was observed in those with CTP acquisition compared to those without (adjusted common odds ratio 1.86, p=0.092). This association was not present in subjects treated within 6 hours from onset (adjusted common odds ratio 1.10, p=0.498) (Figure).

Conclusions: Real-world data from STRATIS reveal that good clinical outcomes after endovascular therapy are not directly contingent on obtaining pre-procedural CTP. Subgroup analyses provide novel data that CTP may not be necessary 0-6 hours from onset, yet CTP may be linked with better outcomes in patients presenting after 6 hours.

Reoperation and readmission after clipping of an unruptured intracranial aneurysm: a National Surgical Quality Improvement Program analysis

OBJECTIVE

Although reoperation and readmission have been used as quality metrics, there are limited data evaluating the rate of, reasons for, and predictors of reoperation and readmission after microsurgical clipping of unruptured aneurysms.

METHODS

Adult patients who underwent craniotomy for clipping of an unruptured aneurysm electively were extracted from the prospective National Surgical Quality Improvement Program registry (2011–2014). Multivariable logistic regression and recursive partitioning analysis evaluated the independent predictors of nonroutine hospital discharge, unplanned 30-day reoperation, and readmission. Predictors screened included patient age, sex, comorbidities, American Society of Anesthesiologists (ASA) classification, functional status, aneurysm location, preoperative laboratory values, operative time, and postoperative complications.

RESULTS

Among the 460 patients evaluated, 4.2% underwent any reoperation at a median of 7 days (interquartile range [IQR] 2–17 days) postoperatively, and 1.1% required a cranial reoperation. The most common reoperation was ventricular shunt placement (23.5%); other reoperations were tracheostomy, craniotomy for hematoma evacuation, and decompressive hemicraniectomy. Independent predictors of any unplanned reoperation were age greater than 51 years and longer operative time (p ≤ 0.04). Readmission occurred in 6.3% of patients at a median of 6 days (IQR 5–13 days) after discharge from the surgical hospitalization; 59.1% of patients were readmitted within 1 week and 86.4% within 2 weeks of discharge. The most common reason for readmission was seizure (26.7%); other causes of readmission included hydrocephalus, cerebrovascular accidents, and headache. Unplanned readmission was independently associated with age greater than 65 years, Class II or III obesity (body mass index > 35 kg/m2), preoperative hyponatremia, and preoperative anemia (p ≤ 0.04). Readmission was not associated with operative time, complications during the surgical hospitalization, length of stay, or discharge disposition. Recursive partitioning analysis identified the same 4 variables, as well as ASA classification, as associated with unplanned readmission. The most potent predictors of nonroutine hospital discharge (16.7%) were postoperative neurological and cardiopulmonary complications; other predictors were age greater than 51 years, preoperative hyponatremia, African American and Asian race, and a complex vertebrobasilar circulation aneurysm.

CONCLUSIONS

In this national analysis, patient age greater than 65 years, Class II or III obesity, preoperative hyponatremia, and anemia were associated with adverse events, highlighting patients who may be at risk for complications after clipping of unruptured cerebral aneurysms. The preponderance of early readmissions highlights the importance of early surveillance and follow-up after discharge; the frequency of readmission for seizure emphasizes the need for additional data evaluating the utility and duration of postcraniotomy seizure prophylaxis. Moreover, readmission was primarily associated with preoperative characteristics rather than metrics of perioperative care, suggesting that readmission may be a suboptimal indicator of the quality of care received during the surgical hospitalization in this patient population.

Coiling Versus Microsurgical Clipping in the Treatment of Unruptured Middle Cerebral Artery Aneurysms: A Meta-Analysis

BACKGROUND

Open microsurgical clipping of unruptured intracranial aneurysms has long been the gold standard, yet advancements in endovascular coiling techniques have begun to challenge the status quo.

OBJECTIVE

To compare endovascular coiling with microsurgical clipping among adults with unruptured middle cerebral artery aneurysms (MCAA) by conducting a meta-analysis.

METHODS

A systematic search was conducted from January 2011 to October 2015 to update a previous meta-analysis. All studies that reported unruptured MCAA in adults treated by microsurgical clipping or endovascular coiling were included and cumulatively analyzed.

RESULTS

Thirty-seven studies including 3352 patients were included. Using the random-effects model, pooled analysis of 11 studies of microsurgical clipping (626 aneurysms) revealed complete aneurysmal obliteration in 94.2% of cases (95% confidence interval [CI] 87.6%-97.4%). The analysis of 18 studies of endovascular coiling (759 aneurysms) revealed complete obliteration in 53.2% of cases (95% CI: 45.0%-61.1%). Among clipping studies, 22 assessed neurological outcomes (2404 aneurysms), with favorable outcomes in 97.9% (95% CI: 96.8%-98.6%). Among coiling studies, 22 examined neurological outcomes (826 aneurysms), with favorable outcomes in 95.1% (95% CI: 93.1%-96.5%). Results using the fixed-effect models were not materially different.

CONCLUSION

This updated meta-analysis demonstrates that surgical clipping for unruptured MCAA remains highly safe and efficacious. Endovascular treatment for unruptured MCAAs continues to improve in efficacy and safety; yet, it results in lower rates of occlusion.

Cigarette smoking and outcomes after aneurysmal subarachnoid hemorrhage: a nationwide analysis

OBJECTIVE Although cigarette smoking is one of the strongest risk factors for cerebral aneurysm development and rupture, there are limited data evaluating the impact of smoking on outcomes after aneurysmal subarachnoid hemorrhage (SAH). Additionally, two recent studies suggested that nicotine replacement therapy was associated with improved neurological outcomes among smokers who had sustained an SAH compared with smokers who did not receive nicotine. METHODS Patients who underwent endovascular or microsurgical repair of a ruptured cerebral aneurysm were extracted from the Nationwide Inpatient Sample (NIS, 2009-2011) and stratified by cigarette smoking. Multivariable logistic regression analyzed in-hospital mortality, complications, tracheostomy or gastrostomy placement, and discharge to institutional care (a nursing or an extended care facility). Additionally, the composite NIS-SAH outcome measure (based on mortality, tracheostomy or gastrostomy, and discharge disposition) was evaluated, which has been shown to have excellent agreement with a modified Rankin Scale score greater than 3. Covariates included in regression constructs were patient age, sex, race/ethnicity, insurance status, socioeconomic status, comorbidities (including hypertension, drug and alcohol abuse), the NIS-SAH severity scale (previously validated against the Hunt and Hess grade), treatment modality used for aneurysm repair, and hospital characteristics. A sensitivity analysis was performed matching smokers to nonsmokers on age, sex, number of comorbidities, and NIS-SAH severity scale score. RESULTS Among the 5784 admissions evaluated, 37.1% (n = 2148) had a diagnosis of tobacco use, of which 31.1% (n = 1800) were current and 6.0% (n = 348) prior tobacco users. Smokers were significantly younger (mean age 51.4 vs 56.2 years) and had more comorbidities compared with nonsmokers (p < 0.001). There were no significant differences in mortality, total complications, or neurological complications by smoking status. However, compared with nonsmokers, smokers had significantly decreased adjusted odds of tracheostomy or gastrostomy placement (11.9% vs 22.7%, odds ratio [OR] 0.63, 95% confidence interval [CI] 0.51-0.78, p < 0.001), discharge to institutional care (OR 0.71, 95% CI 0.57-0.89, p = 0.002), and a poor outcome (OR 0.65, 95% CI 0.55-0.77, p < 0.001). Similar statistical associations were noted in the matched-pairs sensitivity analysis and in a subgroup of poor-grade patients (the upper quartile of the NIS-SAH severity scale). CONCLUSIONS In this nationwide study, smokers experienced SAH at a younger age and had a greater number of comorbidities compared with nonsmokers, highlighting the negative ramifications of cigarette smoking among patients with cerebral aneurysms. However, smoking was also associated with paradoxical superior outcomes on some measures, and future research to confirm and further understand the basis of this relationship is needed.

Pediatric Intracranial Aneurysms: Considerations and Recommendations for Follow-Up Imaging

BACKGROUND

Pediatric intracranial aneurysms (IAs) are rare. Compared with adult IAs, they are more commonly giant, fusiform, or dissecting. Treatment often proves more complex, and recurrence rate and de novo aneurysmogenesis incidence are higher. A consensus regarding the most appropriate algorithm for following pediatric IAs is lacking.

METHODS

We sought to generate recommendations based on the reported experience in the literature with pediatric IAs through a thorough review of the PubMed database, discussion with experienced neurointerventionalists, and our own experience.

RESULTS

Digital subtraction angiography (DSA) was utilized immediately post-operatively for microsurgically-clipped and endovascularly-treated IAs, at 6-12 months postoperatively for endovascularly-treated IAs, and in cases of aneurysmal recurrence or de novo aneurysmogenesis discovered by non-invasive imaging modalities. Computed tomographic angiography was the preferred imaging modality for long-term follow-up of microsurgically clipped IAs. Magnetic resonance angiography (MRA) was the preferred modality for following IAs that were untreated, endovascularly-treated, or microsurgically-treated in a manner other than clipping.

CONCLUSIONS

We propose incidental untreated IAs to be followed by magnetic resonance angiography without contrast enhancement. Follow-up modality and interval for treated pediatric IAs is determined by initial aneurysmal complexity, treatment modality, and degree of posttreatment obliteration. Recurrence or de novo aneurysmogenesis requiring treatment should be followed by digital subtraction angiography and appropriate retreatment. Computed tomography angiography is preferred for clipped IAs, whereas contrast-enhanced magnetic resonance angiography is preferred for lesions treated endovascularly with coil embolization and lesions treated microsurgically in a manner other than clipping.

Readmission After Aneurysmal Subarachnoid Hemorrhage: A Nationwide Readmission Database Analysis

BACKGROUND AND PURPOSE

The goal of this nationwide study is to evaluate the suitability of readmission as a quality indicator in the aneurysmal subarachnoid hemorrhage (SAH) population.

METHODS

Patients with aneurysmal SAH were extracted from the Nationwide Readmission Database (2013). Multivariable Cox proportional hazard regression was used to evaluate predictors of a 30-day readmission, and multivariable linear regression was used to analyze the association of hospital readmission rates with hospital mortality rates. Predictors screened included patient demographics, comorbidities, severity of SAH, complications from the SAH hospitalization, and hospital characteristics.

RESULTS

The 30-day readmission rate was 10.2% (n=346) among the 3387 patients evaluated, and the most common reasons for readmission were neurological, hydrocephalus, infectious, and venous thromboembolic complications. Greater number of comorbidities, increased severity of SAH, and discharge disposition other than to home were independent predictors of readmission (P≤0.03). Although hydrocephalus during the SAH hospitalization was associated with readmission for the same diagnosis, other readmissions were not associated with having sustained the same complication during the SAH hospitalization. Hospital mortality rate was inversely associated with hospital SAH volume (P=0.03) but not significantly associated with hospital readmission rate; hospital SAH volume was also not associated with SAH readmissions.

CONCLUSIONS

In this national analysis, readmission was primarily attributable to new medical complications in patients with greater comorbidities and severity of SAH rather than exacerbation of complications from the SAH hospitalization. Additionally, hospital readmission rates did not correlate with other established quality metrics. Therefore, readmission may be a suboptimal quality indicator in the SAH population.

Timing of Decompressive Hemicraniectomy for Stroke

Background and Purpose—

Previous clinical trials were not designed to discern the optimal timing of decompressive craniectomy for stroke, and the ideal surgical timing in patients with space-occupying infarction who do not exhibit deterioration within 48 hours is debated.

Methods—

Patients undergoing decompressive craniectomy for stroke were extracted from the Nationwide Inpatient Sample (2002–2011). Multivariable logistic regression evaluated the association of surgical timing with mortality, discharge to institutional care, and poor outcome (a composite end point including death, tracheostomy and gastrostomy, or discharge to institutional care). Covariates included patient demographics, comorbidities, year of admission, and hospital characteristics. However, standard stroke severity scales and infarct volume were not available.

Results—

Among 1301 admissions, 55.8% (n=726) underwent surgery within 48 hours. Teaching hospital admission was associated with earlier surgery ( P =0.02). The timing of intervention was not associated with in-hospital mortality. However, when evaluated continuously, later surgery was associated with increased odds of discharge to institutional care (odds ratio, 1.17; 95% confidence interval, 1.05–1.31, P =0.005) and of a poor outcome (odds ratio, 1.12; 95% confidence interval, 1.02–1.23; P =0.02). When evaluated dichotomously, the odds of discharge to institutional care and of a poor outcome did not differ at 48 hours after hospital admission, but increased when surgery was pursued after 72 hours. Subgroup analyses found no association of surgical timing with outcomes among patients who had not sustained herniation.

Conclusion

s—In this nationwide analysis, early decompressive craniectomy was associated with superior outcomes. However, performing decompression before herniation may be the most important temporal consideration.

Abstract TMP4: Serial ASPECTS from Baseline to 24 Hours: Impact of Endovascular Therapy in STRATIS

Background: Serial ASPECTS of ischemic stroke lesion evolution from baseline to 24-hours has been established as an effective surrogate endpoint in endovascular therapy. The use of this imaging shift has not been implemented beyond thrombectomy trials to estimate impact of endovascular therapy in large-scale registry data.

Methods: The STRATIS Imaging Core Lab, blind to all clinical data, independently determined ASPECTS scores on baseline and 24-hour studies. ASPECTS regional involvement and resulting total scores were analyzed in anterior circulation occlusions in STRATIS. Statistical analyses calculated the proportion of subjects with 0 ASPECTS score shift and separately, those with shifts >4, 5, 6 points. Clinical predictors of ASPECTS shift and regional involvement were determined.

Results: Baseline ASPECTS (n=517) was 8.2 ± 1.59 (median 8.0 (2, 10)) and 24-hour ASPECTS (n=547) was 6.0 ± 2.92 (median 7.0 (0, 10)). Serial ASPECTS (n=487) revealed change of -2.1 ± 2.41 (median-1.0 (-10, 3)). Absolutely no change in ASPECTS, or 0 shift from baseline to 24 hours, occurred in 157/487 (32%). Substantial ASPECTS decline of ≥4 occurred in 117/487 (24%), with ≥5 in 76/487 (16%) and ≥6 in 51/487 (10%). ASPECTS decline was linked with baseline collaterals (ASITN 4 (n=19; -0.9 ± 1.05); 3 (n=117; -0.8 ± 1.21); 2 (n=140; -2.6 ± 2.27); 1 (n=29; -3.6 ± 2.34); 0 (n=10; -4.2 ± 3.08)) and the degree of subsequent reperfusion (oTICI 3 (n=63; -1.1 ± 1.94); 2B (n=282; -1.9 ± 2.32); 2A (n=103; -3.4 ± 2.38); 1 (n=2; -3.0 ± 1.41); 0 (n=10; -4.0 ± 2.75)). Baseline predictors of ≥6 ASPECTS decline included previous TIA (OR 3.10 (95%CI 1.32, 7.31), diabetes (OR 2.23 (95%CI 1.22, 4.07)) and baseline NIHSS (OR 1.10 (95%CI 1.03, 1.16).

Conclusions: Frozen ASPECTS or 0 shift from baseline to 24 hours occurs in about 1/3 of all cases treated with endovascular therapy in a large-scale registry. Poor collaterals, prior TIA, diabetes and elevated baseline NIHSS may be important predictors of those likely to experience infarct evolution despite reperfusion, identifying optimal candidates for neuroprotection with endovascular therapy.

Abstract TP36: Collaterals Negate Time: Topography and Determinants of Baseline ASPECTS in STRATIS

Background: ASPECTS is routinely used to estimate ischemic lesion burden in acute stroke, yet the topography and influence of collaterals has been unexplored. Imaging selection for endovascular therapy in various time epochs may also be simplified with ASPECTS. We leveraged the large-scale registry data of STRATIS to discern the role of collaterals, time and other factors in ASPECTS topography at baseline.

Methods: The STRATIS Imaging Core Lab, blind to all clinical data, independently determined ASPECTS scores and regional involvement in anterior circulation occlusions. Collateral status on baseline angiography was scored by ASITN grade. Statistical analyses described ASPECTS regional involvement or topography based on arterial occlusion site and other variables available prior to intervention, determining the influence of collaterals and time duration from onset to imaging.

Results: Baseline ASPECTS (n=573) was median 8.0 (2, 10). ASPECTS regions involved were lenticular nuclei 62.3% (357/573), insula 42.2% (242/573), caudate 23.4% (134/573), M2 13.6% (78/573), M4 9.4% (54/573), M5 9.2% (53/573), M1 4.0% (23/573), M3 2.1% (12/573), M6 1.9% (11/573) and internal capsule 0.2% (1/573). Distinct patterns or topography differentiated ICA, M1 and M2 arterial occlusion sites at angiography. Overall, higher ASPECTS (7-10 vs. ≤ 6) was linked with more robust collaterals (p<0.001) and shorter duration from onset to CT (p=0.001), yet collateral grade was unrelated to time. Ordinal multivariate logistic regression on ASPECTS containing collateral grade and time (from onset to CT) as covariates demonstrated that they were significantly associated (p<0.001 and p=0.0024, respectively) with ASPECTS.

Conclusions: ASPECTS topography and the extent of ischemic changes are a product of arterial occlusion site, collateral status and time duration. ASPECTS may infer collateral status, a pivotal determinant of outcome in endovascular therapy, irrespective of time from symptom onset.

The impact of aspirin and anticoagulant usage on outcomes after aneurysmal subarachnoid hemorrhage: a Nationwide Inpatient Sample analysis

OBJECTIVE

Although aspirin usage may be associated with a decreased risk of rupture of cerebral aneurysms, any potential therapeutic benefit from aspirin must be weighed against the theoretical risk of greater hemorrhage volume if subarachnoid hemorrhage (SAH) occurs. However, few studies have evaluated the association between prehemorrhage aspirin use and outcomes. This is the first nationwide analysis to evaluate the impact of long-term aspirin and anticoagulant use on outcomes after SAH.

METHODS

Data from the Nationwide Inpatient Sample (NIS; 2006–2011) were extracted. Patients with a primary diagnosis of SAH who underwent microsurgical or endovascular aneurysm repair were included; those with a diagnosis of an arteriovenous malformation were excluded. Multivariable logistic regression was performed to calculate the adjusted odds of in-hospital mortality, a nonroutine discharge (any discharge other than to home), or a poor outcome (death, discharge to institutional care, tracheostomy, or gastrostomy) for patients with long-term aspirin or anticoagulant use. Multivariable linear regression was used to evaluate length of hospital stay. Covariates included patient age, sex, comorbidities, primary payer, NIS-SAH severity scale, intracerebral hemorrhage, cerebral edema, herniation, modality of aneurysm repair, hospital bed size, and whether the hospital was a teaching hospital. Subgroup analyses exclusively evaluated patients treated surgically or endovascularly.

RESULTS

The study examined 11,549 hospital admissions. Both aspirin (2.1%, n = 245) and anticoagulant users (0.9%, n = 108) were significantly older and had a greater burden of comorbid disease (p < 0.001); severity of SAH was slightly lower in those with long-term aspirin use (p = 0.03). Neither in-hospital mortality (13.5% vs 12.6%) nor total complication rates (79.6% vs 80.0%) differed significantly by long-term aspirin use. Additionally, aspirin use was associated with decreased odds of a cardiac complication (OR 0.57, 95% CI 0.36%–0.91%, p = 0.02) or of venous thromboembolic events (OR 0.53, 95% CI 0.30%–0.94%, p = 0.03). Length of stay was significantly shorter (15 days vs 17 days [12.73%], 95% CI 5.22%–20.24%, p = 0.001), and the odds of a nonroutine discharge were lower (OR 0.63, 95% CI 0.48%–0.83%, p = 0.001) for aspirin users. In subgroup analyses, the benefits of aspirin were primarily noted in patients who underwent coil embolization; likewise, among patients treated endovascularly, the adjusted odds of a poor outcome were lower among long-term aspirin users (31.8% vs 37.4%, OR 0.63, 95% CI 0.42%–0.94%, p = 0.03). Although the crude rates of in-hospital mortality (19.4% vs 12.6%) and poor outcome (53.6% vs 37.6%) were higher for long-term anticoagulant users, in multivariable logistic regression models these variations were not significantly different (mortality: OR 1.36, 95% CI 0.89%–2.07%, p = 0.16; poor outcome: OR 1.09, 95% CI 0.69%–1.73%, p = 0.72).

CONCLUSIONS

In this nationwide study, neither long-term aspirin nor anticoagulant use were associated with differential mortality or complication rates after SAH. Aspirin use was associated with a shorter hospital stay and lower rates of nonroutine discharge, with these benefits primarily observed in patients treated endovascularly.

The impact of body habitus on outcomes after aneurysmal subarachnoid hemorrhage: a Nationwide Inpatient Sample analysis

OBJECTIVE Although the prevalence of obesity is increasing rapidly both nationally and internationally, few studies have analyzed outcomes among obese patients undergoing cranial neurosurgery. The goal of this study, which used a nationwide data set, was to evaluate the association of both obesity and morbid obesity with treatment outcomes among patients with aneurysmal subarachnoid hemorrhage (SAH); in addition, the authors sought to analyze how postoperative complications for obese patients with SAH differ by the treatment modality used for aneurysm repair. METHODS Clinical data for adult patients with SAH who underwent microsurgical or endovascular aneurysm repair were extracted from the Nationwide Inpatient Sample (NIS). The body habitus of patients was classified as nonobese (body mass index [BMI] < 30 kg/m²), obese (BMI ≥ 30 kg/m² and ≤ 40 kg/m²), or morbidly obese (BMI > 40 kg/m²). Multivariable logistic regression analyzed the association of body habitus with in-hospital mortality rate, complications, discharge disposition, and poor outcome as defined by the composite NIS-SAH outcome measure. Covariates included patient demographics, comorbidities (including hypertension and diabetes), health insurance status, the NIS-SAH severity scale, treatment modality used for aneurysm repair, and hospital characteristics. RESULTS In total, data from 18,281 patients were included in this study; the prevalence of morbid obesity increased from 0.8% in 2002 to 3.5% in 2011. Obese and morbidly obese patients were significantly younger and had a greater number of comorbidities than nonobese patients (p < 0.001). Mortality rates for obese (11.5%) and morbidly obese patients (10.5%) did not significantly differ from those for nonobese patients (13.5%); likewise, no differences in neurological complications or poor outcome were observed among these 3 groups. Morbid obesity was associated with significantly increased odds of several medical complications, including venous thromboembolic (OR 1.52, 95% CI 1.01-2.30, p = 0.046) and renal (OR 1.64, 95% CI: 1.11-2.43, p = 0.01) complications and infections (OR 1.34, 95% CI 1.08-1.67, p = 0.009, attributable to greater odds of urinary tract and surgical site infections). Moreover, morbidly obese patients had higher odds of a nonroutine hospital discharge (OR 1.33, 95% CI 1.03-1.71, p = 0.03). Patients with milder obesity had decreased odds of some medical complications, including cardiac, pulmonary, and infectious complications, primarily among patients who had undergone coil embolization. CONCLUSIONS In this study involving a nationwide administrative database, milder obesity was not significantly associated with increased mortality rates, neurological complications, or poor outcomes after SAH. Morbid obesity, however, was associated with increased odds of venous thromboembolic, renal, and infectious complications, as well as of a nonroutine hospital discharge. Notably, milder obesity was associated with decreased odds of some medical complications, primarily in patients treated with coiling.

Onyx HD-500 for embolization of cerebral aneurysms

In this article, the indications for, technical principles of, and complications/outcomes after Onyx cerebral aneurysm embolization are reviewed.

Endovascular management of intracranial blister aneurysms: spectrum and limitations of contemporary techniques

Background

Intracranial blister aneurysms are rare lesions that are notoriously more difficult to treat than typical saccular aneurysms. High complication rates associated with surgery have sparked considerable interest in endovascular techniques, though not well-studied, to treat blister aneurysms.

Objective

To evaluate our experience using various endovascular approaches to treat blister aneurysms.

Methods

All consecutive blister aneurysms treated using an endovascular approach by the study authors over a 3-year period were retrospectively analyzed. A literature review was also performed.

Results

Nine patients with blister aneurysms underwent 11 endovascular interventions. In various combinations, stents were used in 8/11, coils in 5/11, and Onyx in 3/11 procedures. At mean angiographic follow-up of 200 days, 8/9 aneurysms were completely occluded by endovascular means alone requiring no further treatment and 1/9 aneurysms required surgical bypass/trapping after one failed surgical and two failed endovascular treatments. At mean clinical follow-up of 416 days, modified Rankin Scale scores were improved in six patients, stable in two, and worsened in one patient. One complication occurred in 11 procedures (9%), resulting in a permanent neurologic deficit. No unintended endovascular parent vessel sacrifice, intraprocedural aneurysmal ruptures, antiplatelet-related complications, post-treatment aneurysmal re-ruptures, or deaths occurred.

Conclusion

This series highlights both the spectrum and limitations of endovascular techniques currently used to treat blister aneurysms, including a novel application of stent-assisted Onyx embolization. Long-term follow-up and experience in larger studies are required to better define the role of endovascular therapy in the management of these difficult lesions.

Cerebral infarction secondary to vasospasm after perimesencephalic subarachnoid hemorrhage

Perimesencephalic subarachnoid hemorrhage (pSAH) has been described as a distinct form of subarachnoid hemorrhage (SAH) associated with good outcomes. We report a 48-year-old female who developed cerebral infarction due to severe diffuse vasospasm following pSAH. The patient presented with non-aneurysmal pSAH and was discharged home on day 5. However, one week later she developed an acute onset of right hemiparesis. A brain MRI showed acute infarctions on diffusion weighted imaging and her cerebral angiogram showed diffuse vasospasm. The patient received intra-arterial diltiazem and hypervolemic-hypertensive-hemodilution therapy with resulting resolution of the vasospasm and hemiparesis. While not as common as in SAH, there is a potential for the occurrence of cerebral infarction due to vasospasm after pSAH.