Brinjikji, Waleed

OBJECTIVEOver the last half century, there have been isolated case reports of purely arterial malformations. In this study, the authors report a consecutive series of patients with pure arterial malformations, emphasizing the clinical and radiological features of these lesions.METHODSPure arterial malformations were defined as dilated, overlapping, and tortuous arteries with a coil-like appearance and/or a mass of arterial loops without any associated venous component. Demographic characteristics of the patients, cardiovascular risk factors, presentation, radiological characteristics, and follow-up data were collected. Primary outcomes were new neurological symptoms including disability, stroke, and hemorrhage.RESULTSTwelve patients meeting the criteria were identified. Ten patients were female (83.3%) and 2 were male (16.6%). Their mean age at diagnosis was 26.2 ± 11.6 years. The most common imaging indication was headache (7 patients [58.3%]). In 3 cases the pure arterial malformation involved the anterior cerebral arteries (25.0%); in 4 cases the posterior communicating artery/posterior cerebral artery (33.3%); in 2 cases the middle cerebral artery (16.6%); and in 1 case each, the superior cerebellar artery, basilar artery/anterior inferior cerebellar artery, and posterior inferior cerebellar artery. The mean maximum diameter of the malformations was 7.2 ± 5.0 mm (range 3–16 mm). Four lesions had focal aneurysms associated with the pure arterial malformation, and 5 were partially calcified. In no cases was there associated intracranial hemorrhage or infarction. One patient underwent treatment for the pure arterial malformation. All 12 patients had follow-up (mean 29 months, median 19 months), and there were no cases of disability, stroke, or hemorrhage.CONCLUSIONSPure arterial malformations are rare lesions that are often detected incidentally and probably have a benign natural history. These lesions can affect any of the intracranial arteries and are likely best managed conservatively.

Aim To describe the impact of steps towards reduction of procedural doses of radiation during neuroendovascular procedures. Methods Phantom exposures under controlled circumstances were performed using a Rando-Alderson adult-sized head phantom. Customized imaging protocols were devised for pediatric and adult imaging and implemented in clinical use. Outcome data for estimated skin doses (ESD) and dose–area product (DAP) following pediatric and adult diagnostic and interventional procedures over 4.5 years were analyzed retrospectively. Results Dose estimates were reduced by 50% or more after introduction of customized imaging protocols in association with modification of personnel behavior compared with doses recorded with previously used vendor-recommended protocols. Discussion Substantial reductions in radiation use during neuroendovascular procedures can be achieved through a combination of equipment modification and operator behavior.

Background and Purpose— There is currently controversy on the ideal anesthesia strategy during mechanical thrombectomy for acute ischemic stroke. We performed a systematic review and meta-analysis of studies comparing clinical and angiographic outcomes of patients undergoing general anesthesia (GA group) and those receiving either local anesthesia or conscious sedation (non-GA group). Methods— A literature search on anesthesia and endovascular treatment of acute ischemic stroke was performed. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome at 90 days (modified Rankin Score≤2), symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, and time to groin puncture. Results— Twenty-two studies (3 randomized controlled trials and 19 observational studies), including 4716 patients (1819 GA and 2897 non-GA) were included. In the nonadjusted analysis, patients in the GA group had higher odds of death (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.66–2.45) and respiratory complications (OR, 1.70; 95% CI, 1.22–2.37) and lower odds of good functional outcome (OR, 0.58; 95% CI, 0.48–0.64) compared with the non-GA group. There was no difference in procedure time between the 2 primary comparison groups. When adjusting for baseline National Institutes of Health Stroke Scale, GA was still associated with lower odds of good functional outcome (OR, 0.59; 95% CI, 0.29–0.94). When considering studies performed in the stent-retriever/aspiration era, there was no significant difference in good neurological outcome rates (OR, 0.84; 95% CI, 0.67–1.06). Conclusions— Acute ischemic stroke patients undergoing intra-arterial therapy may have worse outcomes when treated with GA as compared with conscious sedation/local anesthesia. However, major limitations of current evidence (ie, retrospective studies and selection bias) indicate a need for adequately powered, multicenter randomized controlled trials to answer this question.

Intracranial aneurysms are heterogeneous in histopathology and imaging appearance. The biological behavior of different types of aneurysms is now known to depend on the structure and physiology of the aneurysm wall itself in addition to intraluminal flow and other luminal features. Aneurysm wall structure and imaging markers of physiology such as aneurysm wall enhancement have been assessed in many prior investigations using conventional-resolution MRI. Recently, high-resolution vessel wall imaging (HR-VWI) techniques with MRI have been introduced. Reports of findings on high-resolution imaging have already emerged for many types of aneurysms demonstrating detailed characterization of wall enhancement, thickness, and components, but many questions remain unexplored. This review discusses the key HR-VWI literature to date. Aneurysm wall findings on conventional-resolution MRI are also discussed as these may help one understand the potential utility and findings on HR-VWI for various aneurysm types. The authors have illustrated these points with several examples demonstrating both features already described in the literature and novel cases demonstrating the potential for future clinical and research applications.

Background and Purpose— Because of the perceived risk of contrast-induced acute kidney injury (AKI), many centers require pre-imaging serum creatinine levels, potentially delaying care. We performed a systematic review and meta-analysis evaluating AKI rates in patients with acute ischemic stroke receiving computed tomographic angiography (CTA) and computed tomographic perfusion (CTP). Methods— We searched MEDLINE, EMBASE, and the Web of Science through December 2016 for studies reporting on AKI in patients with acute ischemic stroke receiving CTA/CTP. Using a random-effects model, estimates were pooled across studies. Outcomes of interest were (1) the odds of AKI in patients receiving CTA/CTP versus noncontrast computed tomography, (2) overall rate of AKI and hemodialysis in patients with acute ischemic stroke undergoing CTA/CTP, and (3) the odds of CTA/CTP-associated AKI among patients with and without chronic kidney disease. Results— Fourteen studies were included (6 case–control studies and 8 single-arm studies) with 5727 CTA/CTP and 981 noncontrast computed tomography patients. In case–control studies, AKI was significantly lower among CTA/CTP patients compared with noncontrast computed tomography patients (odds ratio=0.47; 95% confidence interval=0.33–0.68; P <0.01). Adjusting for baseline creatinine, there was no difference in AKI rates between groups (odds ratio=0.34; 95% confidence interval=0.10–1.21). The overall rate of AKI in CTA/CTP patients was 3% (95% confidence interval=2%–4%). The overall rate of hemodialysis in the CTA/CTP group was 0.07% (3 of 4373). There was no difference in AKI among CTA/CTP patients with and without chronic kidney disease (odds ratio=0.63; 95% confidence interval=0.34–1.12). Conclusions— Nonrandomized evidence suggests that CTA/CTP are not associated with statistically significant increase in risk of AKI in patients with stroke, even those with known chronic kidney disease.

Background and Purpose— To test the hypothesis that developmental venous anomalies (DVAs) may develop in the postnatal period, we studied the age-related prevalence of DVAs on contrast-enhanced magnetic resonance imaging. Methods— Reports from a consecutive series of head magnetic resonance images with intravenous contrast performed over a 2-year period at our institution were reviewed. Studies reporting the presence of a DVA were retrieved and reviewed by a neuroradiologist. Patients were divided into 4 age groups: (1) <1 year old (neonates/infants), (2) 1 to 5 years old (toddlers and preschoolers), (3) 6 to 17 years old (grade schoolers), and (4) ≥18 years old (adults), and DVA prevalence by age group was studied. Results— A total of 18 073 individuals were included. DVA prevalence in the neonate/infant age group was 1.5% (5/335) compared with 7.1% (51/714) in the toddler/preschool age group. In both the grade-school age group and adult age group, DVA prevalence was 9.6% (150/1557 and 1483/15 467, respectively). Neonates/infants were significantly less likely to have DVAs than other age groups ( P <0.001). Conclusions— We found a very low prevalence of DVAs on contrast-enhanced magnetic resonance imaging in patients <1 year old which was significantly lower than other age groups. These findings suggest that postnatal changes in venous architecture and drainage patterns may contribute to the development of DVAs.

Limited data exist on clot composition and detailed characteristics of arterial thrombi associated with large vessel occlusion in acute ischemic stroke. Advances in endovascular thrombectomy and related imaging modalities have created a unique opportunity to analyze thrombi removed from cerebral arteries. Insights into thrombus composition, etiology, physical properties and neurovascular interactions may lead to future advancements in acute ischemic stroke treatment and improved clinical outcomes. Advances in imaging techniques may enhance clot characterization and inform therapeutic decision-making prior to treatment and reveal stroke etiology to guide secondary prevention. Current imaging techniques can provide some information about thrombi, but there remains much to evaluate about relationships that may exist among thrombus composition, occlusion characteristics and treatment outcomes. Improved pathophysiological characterization of clot types, their properties and how these properties change over time, together with clinical correlates from ongoing studies, may facilitate revascularization with thrombolysis and thrombectomy. Interdisciplinary approaches covering clinical, engineering and scientific aspects of thrombus research will be key to advancing the understanding of thrombi and improving acute ischemic stroke therapy. This consensus statement integrates recent research on clots and thrombi retrieved from cerebral arteries and provides a rationale for further analyses, including current opportunities and limitations.