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Randomized controlled trials (RCTs) have demonstrated powerful efficacy of endovascular thrombectomy (EVT) for large vessel occlusion in the anterior circulation. The effect of EVT for acute basilar artery occlusion (BAO) in the posterior circulation remains unproven. Here, we highlight the latest findings of observational studies and RCTs of EVT for BAO, with a focus on the predictors of functional outcomes, the limitations of recent RCTs, and critical thinking on future study design. Pooled data from large retrospective studies showed 36.4% favorable outcome at 3 months and 4.6% symptomatic intracranial hemorrhage (sICH). Multivariate logistic regression analysis revealed that higher baseline NIHSS score, pc-ASPECTS

BackgroundGiant cell arteritis (GCA) is a systemic vasculitis that may cause ischemic stroke. Rarely, GCA can present with aggressive intracranial stenoses, which are refractory to medical therapy. Endovascular treatment (EVT) is a possible rescue strategy to prevent ischemic complications in intracranial GCA but the safety and efficacy of EVT in this setting are not well-described.MethodsA systematic literature review was performed to identify case reports and series with individual patient-level data describing EVT for intracranial GCA. The clinical course, therapeutic considerations, and technique of seven endovascular treatments in a single patient from the authors' experience are presented.ResultsThe literature review identified 9 reports of 19 treatments, including percutaneous transluminal angioplasty (PTA) with or without stenting, in 14 patients (mean age 69.6 ± 6.3 years). Out of 12 patients 8 (66.7%) with sufficient data had > 1 pre-existing cardiovascular risk factor. All patients had infarction on MRI while on glucocorticoids and 7/14 (50%) progressed despite adjuvant immunosuppressive agents. Treatment was PTA alone in 15/19 (78.9%) cases and PTA + stent in 4/19 (21.1%). Repeat treatments were performed in 4/14 (28.6%) of patients (PTA-only). Non-flow limiting dissection was reported in 2/19 (10.5%) of treatments. The indications, technical details, and results of PTA are discussed in a single illustrative case. We report the novel use of intra-arterial calcium channel blocker infusion (verapamil) as adjuvant to PTA and as monotherapy, resulting in immediate improvement in cerebral blood flow.ConclusionEndovascular treatment, including PTA with or without stenting or calcium channel blocker infusion, may be effective therapies in medically refractory GCA with intracranial stenosis.

The transradial approach (TRA) is an effective and safe alternative to transfemoral access for diagnostic neuroangiography and craniocervical interventions. While the technical aspects of supraclavicular intervention are well-described, there are little data on the TRA for thoracolumbar angiography and intervention. The authors describe the feasibility of the TRA for preoperative thoracic tumor embolization, emphasizing technique, device selection, navigation, and catheterization of thoracolumbar segmental arteries. This approach extends the benefits of TRA to spinal interventional neuroradiology.

Background: Spinal epidural arteriovenous fistulas (seAVF) are a rare subset of vascular lesions that are most commonly found in the cervical levels. Unlike spinal dural AVF, seAVF are typically supplied by multiple arteries, including direct branches from the vertebral artery, which increases the risk of nontarget embolization using a transarterial endovascular approach. In these cases, transvenous embolization may be a preferable option, but accessing the cervical epidural venous space, also termed the internal vertebral venous plexus, can be challenging and requires advanced foreknowledge of cervical venous channels. Methods: The authors review salient neurovascular anatomy and present 2 techniques for endovascular access of the cervical epidural space to treat seAVF. Results: The physiology and structure of the cervical internal vertebral venous plexus is briefly reviewed. Next, the authors describe 2 complementary methods for transvenous access to the cervical internal vertebral venous plexus via the jugular vein (cranial‐caudal) and the vertebral vein (caudal‐cranial). The first approach involves retrograde microcatheterization via the jugular bulb and condylar veins. The second approach involves direct antegrade approach via the vertebral vein, arising from the brachiocephalic vein. Both approaches enable stable catheter positioning for coil embolization at remote cervical levels to treat a wide spectrum of seAVF. Conclusions: Accessing the cervical epidural venous space is technically demanding and requires effective planning and knowledge of relevant spinal venous anatomy. These techniques are important tools for safe and effective endovascular treatment of seAVF.

BackgroundDural arteriovenous fistulas (AVF) of the foramen magnum region (FMR) are technically challenging lesions to treat. Transvenous (TV), transarterial (TA), and surgical approaches have been described, but the optimum treatment strategy is not defined.ObjectiveTo report treatment strategies and outcomes for FMR-AVF at a single, high-volume referral center.MethodsA retrospective review from January 2010 to August 2020 identified patients with FMR-AVF at a single referral center. Angiographic features, treatment (observation, endovascular, surgical), and follow-up of angiographic and clinical results were recorded. The technical aspects of TV embolization are then presented in detail.Results29 FMR-AVF were identified in 28 patients. Of these, 24/29 (82.8%) were treated and 5/29 (17.2%) were observed. Treatment was endovascular in 21/24 (87.5%), combined (endovascular+surgical) in 2/24 (8.3%), and surgical in 1/24 (4.2%). Endovascular treatments were 76.2% TV, 14.3% TA, and 9.5% combined TV/TA. Sufficient follow-up data were available for 20/28 (71.4%) with mean follow-up of 16.8 months. No AVF recurrence was seen for TA/TV, combined endovascular/surgical, or surgical groups, and there was one recurrence (7.1%) in the TV group. Symptomatic improvement was seen in all groups: TV (71.4% complete, 28.6% partial), TA (66.7% complete, 33.3% no follow-up), TV+TA (100% partial), endovascular/surgical (100% complete), and surgical (100% partial). Minor non-neurologic complications included 1/14 (7.1%) in the TV group and 1/3 (33.3%) in the TA/TV group.ConclusionEndovascular treatment is safe and effective for most FMR-AVF. TV embolization has a high cure rate with few complications.

Large, wide-necked basilar apex aneurysms are difficult to treat. Microsurgical clipping can result in neurologic morbidity and mortality. Endovascular treatment often leaves remnants that need retreatment and/or stent placement with dual antiplatelet therapy. The Woven EndoBridge (WEB) is an intrasaccular flow disruption device that can be used without dual antiplatelet therapy. However, the WEB cannot typically be used in large or giant aneurysms > 10 mm because the largest diameter device is the 11 × 9.6 mm single layer sphere (SLS). We present a case in which we use a PulseRider aneurysm neck reconstruction device in the basilar artery to assist in WEB deployment within a 22 mm basilar apex aneurysm with 14 mm neck, thereby permitting aspirin monotherapy postoperatively.

Background For patients with acute ischemic stroke undergoing endovascular mechanical thrombectomy with x-ray angiography, the use of adjuncts to maintain vessel patency, such as stents or antiplatelet medications, can increase risk of periprocedural complications. Criteria for using these adjuncts are not well defined. Purpose To evaluate use of MRI to guide critical decision making by using a combined biplane x-ray neuroangiography 3.0-T MRI suite during acute ischemic stroke intervention. Materials and Methods This retrospective observational study evaluated consecutive patients undergoing endovascular intervention for acute ischemic stroke between July 2019 and May 2020 who underwent either angiography with MRI or angiography alone. Cerebral tissue viability was assessed by using MRI as the reference standard. For statistical analysis, Fisher exact test and Student t test were used to compare groups. Results Of 47 patients undergoing acute stroke intervention, 12 patients (median age, 69 years; interquartile range, 60-77 years; nine men) underwent x-ray angiography with MRI whereas the remaining 35 patients (median age, 80 years; interquartile range, 68-86 years; 22 men) underwent angiography alone. MRI results influenced clinical decision making in one of three ways: whether or not to perform initial or additional mechanical thrombectomy, whether or not to place an intracranial stent, and administration of antithrombotic or blood pressure medications. In this initial experience, decision making during endovascular acute stroke intervention in the combined angiography-MRI suite was better informed at MRI, such that therapy was guided in real time by the viability of the at-risk cerebral tissue. Conclusion Integrating intraprocedural 3.0-T MRI into acute ischemic stroke treatment was feasible and guided decisions of whether or not to continue thrombectomy, to place stents, or to administer antithrombotic medication or provide blood pressure medications. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lev and Leslie-Mazwi in this issue.

Acute neurologic deficits in the postoperative period after carotid endarterectomy (CEA) can prompt extensive diagnostic evaluation. Reversible cerebral vasoconstriction syndrome (RCVS) is an underrecognized cause of acute neurologic deficit after CEA. We present the case of RCVS in an 84-year-old male patient who had experienced left limb weakness after CEA, prompting multiple code stroke activations. The present case is novel because the obtained computed tomography perfusion imaging studies demonstrated abnormalities that have not been previously described in patients with RCVS. These findings, combined with the cerebral angiography findings, led to the rapid diagnosis and delivery of intra-arterial vasodilator therapy. He experienced subsequent resolution of his symptoms and radiologic abnormalities.

Background and Purpose: The management of unruptured intracranial aneurysms remains controversial. The decisions to treat are heavily informed by estimated risk of bleeding. However, these estimates are imprecise, and better methods for stratifying the risk or tailoring treatment strategy are badly needed. Here, we demonstrate an initial proof-of-principle concept for endovascular biopsy to identify the key molecular pathways and gene expression changes associated with aneurysm formation. We couple this technique with single cell RNA sequencing (scRNAseq) to develop a roadmap of the pathogenic changes of a dolichoectatic vertebrobasilar aneurysm in a patient with polyarteritis nodosa. Methods: Endovascular biopsy and fluorescence activated cell sorting was used to isolate the viable endothelial cells (ECs) using the established techniques. A single cell RNA sequencing (scRNAseq) was then performed on 24 aneurysmal ECs and 23 patient-matched non-aneurysmal ECs. An integrated panel of bioinformatic tools was applied to determine the differential gene expression, enriched signaling pathways, and cell subpopulations hypothesized to drive disease pathogenesis. Results: We identify a subset of 7 (29%) aneurysm-specific ECs with a distinct gene expression signature not found in the patient-matched control ECs. A gene set enrichment analysis identified these ECs to have increased the expression of genes regulating the leukocyte-endothelial cell adhesion, major histocompatibility complex (MHC) class I, T cell receptor recycling, tumor necrosis factor alpha (TNFα) response, and interferon gamma signaling. A histopathologic analysis of a different intracranial aneurysm that was later resected yielded a diagnosis of polyarteritis nodosa and positive staining for TNFα. Conclusions: We demonstrate feasibility of applying scRNAseq to the endovascular biopsy samples and identify a subpopulation of ECs associated with cerebral aneurysm in polyarteritis nodosa. Endovascular biopsy may be a safe method for deriving insight into the disease pathogenesis and tailoring the personalized treatment approaches to intracranial aneurysms.

Background and purposeDo children have an increased risk for brain arteriovenous malformation (AVM) recurrence compared with adults and does this risk vary depending on initial presentation with AVM rupture?MethodsWe retrospectively studied 115 patients initially presenting with brain AVM under age 25 years who underwent complete surgical resection of the AVM as documented by digital subtraction angiography (DSA) and had delayed follow-up DSA to evaluate for AVM recurrence after apparent initial cure.ResultsThe mean time from baseline DSA to follow-up DSA was 2.3 years, ranging from 0 to 15 years. Twelve patients (10.4% of the 115 patient cohort and 16.7% of 72 patients with hemorrhage at initial presentation) demonstrated AVM recurrence on follow-up DSA. All patients with recurrence initially presented with intracranial hemorrhage, and intracranial hemorrhage was a significant predictor of recurrence (log rank P=0.037). Among patients with initial hemorrhage, the 5-year recurrence rate was 17.8% (95% CI, 8.3%-35.7%). All recurrences occurred in patients who were children at the time of their initial presentation; the oldest was 15 years of age at the time of initial AVM surgery. The 5-year recurrence rate for children (0-18 years of age) with an initial presentation of hemorrhage was 21.4% (95% CI, 10.1%-41.9%). Using Cox regression, we found the risk of AVM recurrence decreased by 14% per each year increase in age at the time of initial surgical resection (hazard ratio=0.86 [95% CI, 0.75-0.99]; P=0.031).ConclusionsThere is a high rate of recurrence of apparently cured brain AVMs in children who initially present with AVM rupture. Imaging follow-up is warranted to prevent re-rupture.

ObjectivePreoperative embolization of brain arteriovenous malformations (AVMs) is performed to facilitate resection, although its impact on surgical performance has not been clearly defined. The authors tested for associations between embolization and surgical performance metrics.MethodsThe authors analyzed AVM cases resected by one neurosurgeon from 2006 to 2017. They tested whether cases with and without embolization differed from one another with respect to patient and AVM characteristics using t-tests for continuous variables and Fisher's exact tests for categorical variables. They used simple and multivariable regression models to test whether surgical outcomes (blood loss, resection time, surgical clip usage, and modified Rankin Scale [mRS] score) were associated with embolization. Additional regression analyses integrated the peak arterial afferent contrast normalized for the size of the region of interest (Cmax/ROI) into models as an additional predictor.ResultsThe authors included 319 patients, of whom 151 (47%) had preoperative embolization. Embolized AVMs tended to be larger (38% with diameter > 3 cm vs 19%, p = 0.001), less likely to have hemorrhaged (48% vs 63%, p = 0.013), or be diffuse (19% vs 29%, p = 0.045). Embolized AVMs were more likely to have both superficial and deep venous drainage and less likely to have exclusively deep drainage (32% vs 17% and 12% vs 23%, respectively; p = 0.002). In multivariable analysis, embolization was not a significant predictor of blood loss or mRS score changes, but did predict longer operating times (+29 minutes, 95% CI 2-56 minutes; p = 0.034) and increased clip usage (OR 2.61, 95% CI 1.45-4.71; p = 0.001). Cmax/ROI was not a significant predictor, although cases with large Cmax/ROI tended to have longer procedure times (+25 minutes per doubling of Cmax/ROI, 95% CI 0-50 minutes; p = 0.051).ConclusionsIn this series, preoperative embolization was associated with longer median resection times and had no association with intraoperative blood loss or mRS score changes.

There is limited data describing endothelial cell (EC) gene expression between aneurysms and arteries partly because of risks associated with surgical tissue collection. Endovascular biopsy (EB) is a lower risk alternative to conventional surgical methods, though no such efforts have been attempted for aneurysms. We sought (1) to establish the feasibility of EB to isolate viable ECs by fluorescence-activated cell sorting (FACS), (2) to characterize the differences in gene expression by anatomic location and rupture status using single-cell qPCR, and (3) to demonstrate the utility of unsupervised clustering algorithms to identify cell subpopulations. EB was performed in 10 patients (5 ruptured, 5 non-ruptured). FACS was used to isolate the ECs and single-cell qPCR was used to quantify the expression of 48 genes. Linear mixed models and exploratory multilevel component analysis (MCA) and self-organizing maps (SOMs) were performed to identify possible subpopulations of cells. ECs were collected from all aneurysms and there were no adverse events. A total of 437 ECs was collected, 94 (22%) of which were aneurysmal cells and 319 (73%) demonstrated EC-specific gene expression. Ruptured aneurysm cells, relative controls, yielded a median p value of 0.40 with five genes (10%) with p values

OBJECTIVE Intracranial dural arteriovenous fistulas (DAVFs) are rare in children. This study sought to better characterize DAVF presentation, angioarchitecture, and treatment outcomes. METHODS Children with intracranial DAVFs between 1986 and 2013 were retrospectively identified from the neurointerventional database at the authors' institution. Demographics, clinical presentation, lesion angioarchitecture, treatment approaches, angiographic outcomes, and clinical outcomes were assessed. RESULTS DAVFs constituted 5.7% (22/423) of pediatric intracranial arteriovenous shunting lesions. Twelve boys and 10 girls presented between 1 day and 18 years of age; boys presented at a median of 1.3 years and girls presented at a median of 4.9 years. Four of 8 patients ≤ 1 year of age presented with congestive heart failure compared with 0/14 patients > 1 year of age (p = 0.01). Five of 8 patients ≤ 1 year old presented with respiratory distress compared with 0/14 patients > 1 year old (p = 0.0021). Ten of 14 patients > 1 year old presented with focal neurological deficits compared with 0/8 patients ≤ 1 year old (p = 0.0017). At initial angiography, 16 patients harbored a single intracranial DAVF and 6 patients had 2-6 DAVFs. Eight patients (38%) experienced DAVF obliteration by the end of treatment. Good clinical outcome (modified Rankin Scale score 0-2) was documented in 77% of patients > 1 year old at presentation compared with 57% of patients ≤ 1 year old at presentation. Six patients (27%) died. CONCLUSIONS Young children with DAVFs presented predominantly with cardiopulmonary symptoms, while older children presented with focal neurological deficits. Compared with other pediatric vascular shunts, DAVFs had lower rates of angiographic obliteration and poorer clinical outcomes.

OBJECT Large arteriovenous malformations (AVMs) remain difficult to treat, and ideal treatment parameters for volume-staged stereotactic radiosurgery (VS-SRS) are still unknown. The object of this study was to compare VS-SRS treatment outcomes for AVMs larger than 10 ml during 2 eras; Era 1 was 1992-March 2004, and Era 2 was May 2004-2008. In Era 2 the authors prospectively decreased the AVM treatment volume, increased the radiation dose per stage, and shortened the interval between stages. METHODS All cases of VS-SRS treatment for AVM performed at a single institution were retrospectively reviewed. RESULTS Of 69 patients intended for VS-SRS, 63 completed all stages. The median patient age at the first stage of VS-SRS was 34 years (range 9-68 years). The median modified radiosurgery-based AVM score (mRBAS), total AVM volume, and volume per stage in Era 1 versus Era 2 were 3.6 versus 2.7, 27.3 ml versus 18.9 ml, and 15.0 ml versus 6.8 ml, respectively. The median radiation dose per stage was 15.5 Gy in Era 1 and 17.0 Gy in Era 2, and the median clinical follow-up period in living patients was 8.6 years in Era 1 and 4.8 years in Era 2. All outcomes were measured from the first stage of VS-SRS. Near or complete obliteration was more common in Era 2 (log-rank test, p = 0.0003), with 3- and 5-year probabilities of 5% and 21%, respectively, in Era 1 compared with 24% and 68% in Era 2. Radiosurgical dose, AVM volume per stage, total AVM volume, era, compact nidus, Spetzler-Martin grade, and mRBAS were significantly associated with near or complete obliteration on univariate analysis. Dose was a strong predictor of response (Cox proportional hazards, p < 0.001, HR 6.99), with 3- and 5-year probabilities of near or complete obliteration of 5% and 16%, respectively, at a dose < 17 Gy versus 23% and 74% at a dose ≥ 17 Gy. Dose per stage, compact nidus, and total AVM volume remained significant predictors of near or complete obliteration on multivariate analysis. Seventeen patients (25%) had salvage surgery, SRS, and/or embolization. Allowing for salvage therapy, the probability of cure was more common in Era 2 (log-rank test, p = 0.0007) with 5-year probabilities of 0% in Era 1 versus 41% in Era 2. The strong trend toward improved cure in Era 2 persisted on multivariate analysis even when considering mRBAS (Cox proportional hazards, p = 0.055, HR 4.01, 95% CI 0.97-16.59). The complication rate was 29% in Era 1 compared with 13% in Era 2 (Cox proportional hazards, not significant). CONCLUSIONS VS-SRS is an option to obliterate or downsize large AVMs. Decreasing the AVM treatment volume per stage to ≤ 8 ml with this technique allowed a higher dose per fraction and decreased time to response, as well as improved rates of near obliteration and cure without increasing complications. Reducing the volume of these very large lesions can facilitate a surgical approach for cure.

PurposeTo develop a strategy of achieving targeted collection of endothelial cells (ECs) by endovascular methods and analyzing the gene expression profiles of collected single ECs.Methods and results134 ECs and 37 leukocytes were collected from four patients' intra-iliac artery endovascular guide wires by fluorescence activated cell sorting (FACS) and analyzed by single-cell quantitative RT-PCR for expression profile of 48 genes. Compared to CD45+ leukocytes, the ECs expressed higher levels (p < 0.05) of EC surface markers used on FACS and other EC related genes. The gene expression profile showed that these isolated ECs fell into two clusters, A and B, that differentially expressed 19 genes related to angiogenesis, inflammation and extracellular matrix remodeling, with cluster B ECs have demonstrating similarities to senescent or aging ECs.ConclusionCombination of endovascular device sampling, FACS and single-cell quantitative RT-PCR is a feasible method for analyzing EC gene expression profile in vascular lesions.

BackgroundVein of Galen malformations (VOGMs) are rare and complex congenital arteriovenous fistulas. The clinical and radiological features of VOGMs and their relation to clinical outcomes are not fully characterized.ObjectiveTo examine the clinical and radiological features of VOGMs and the predictors of outcome in patients.MethodsWe retrospectively reviewed the available imaging and medical records of all patients with VOGMs treated at the University of California, San Francisco between 1986 and 2013. Radiological and clinical features were identified. We applied the modified Rankin Scale to determine functional outcome by chart review. Predictors of outcome were assessed by χ(2) analyses.ResultsForty-one cases were confirmed as VOGM. Most patients (78%) had been diagnosed with VOGM in the first year of life. Age at treatment was bimodally distributed, with predominantly urgent embolization at

Background and purposeEndovascular sampling and characterization from patients can provide very useful information about the pathogenesis of different vascular diseases, but it has been limited by the lack of an effective method of endothelial cell (EC) enrichment. We optimized the EC yield and enrichment from conventional guide wires by laser capture microdissection (LCM) and fluorescence activated cell sorting (FACS) technique, and addressed the feasibility of using these enriched ECs for downstream gene expression detection.MethodsIliac artery endovascular samples from 10 patients undergoing routine catheter angiography were collected using conventional 0.038 in. J-shape guide wires. Each of these samples was equally divided into two parts, which were respectively used for EC enrichment by immunocytochemistry-coupled LCM or multiple color FACS. After RNA extraction and reverse transcription, the amplified cDNA was used for quantitative polymerase chain reaction (qPCR).ResultsFixed ECs, with positive CD31 or vWF fluorescent signal and endothelial like nucleus, were successfully separated by LCM and live single ECs were sorted on FACS by a seven color staining panel. EC yields by LCM and FACS were 51 ± 22 and 149 ± 56 respectively (P < 0.001). The minimum number of fixed ECs from ICC-coupled LCM for acceptable qPCR results of endothelial marker genes was 30, while acceptable qPCR results as enriched by FACS were attainable from a single live EC.ConclusionBoth LCM and FACS can be used to enrich ECs from conventional guide wires and the enriched ECs can be used for downstream gene expression detection. FACS generated a higher EC yield and the sorted live ECs may be used for single cell gene expression detection.

ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae.

Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms "fenestration" or "fenestrated" with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms.

BackgroundThe use of ethylene-vinyl alcohol copolymer for liquid embolization of cranial vascular lesions has resulted in microcatheter fragments entrapped in patients following endovascular procedures. Undergoing subsequent diagnostic MRI examinations poses a safety concern due to the possibility of radiofrequency heating of the metallic braid incorporated into the microcatheter. Heating of nitinol, tungsten, and polyetheretherketone (PEEK) braided microcatheters was assessed and compared using a phantom model.MethodsMicrocatheters coupled with fluoroptic temperature probes were embedded in a polyacrylamide gel within a head and torso phantom. Experiments were performed at 1.5 T and 3 T, analyzing the effects of different catheter immersion lengths, specific absorption rate (SAR) levels, short clinical scans, long clinical scans, and microcatheter fragment lengths.ResultsThe maximal increase in temperature for the nitinol braided microcatheter during a 15 min scan was 3.06°C using the T1 fast spin echo sequence at 1.5 T and 0.45°C using the balanced steady state free precession sequence at 3 T. The same scans for fragment lengths of 9, 18, 36, and 72 cm produced maximal temperature rises of 0.68, 0.80, 1.70, and 1.07°C at 1.5 T, respectively. The temperature changes at 3 T for these fragment lengths were 0.66, 0.83, 1.07, and 0.72°C, respectively. The tungsten and PEEK braided microcatheters did not demonstrate heating.ConclusionsSubstantial heating of nitinol braided microcatheters occurred and was a function of SAR level and geometric considerations. SAR and time limitations on MR scanning are proposed for patients with this microcatheter entrapped in their vasculature. In contrast, tungsten and PEEK braided microcatheters showed potential safe use in MRI.

Contrast staining of brain parenchyma identified on non-contrast CT performed after DSA in patients with acute ischemic stroke (AIS) is an incompletely understood imaging finding. We hypothesize contrast staining to be an indicator of brain injury and suspect the fate of involved parenchyma to be cerebral infarction. Seventeen years of AIS data were retrospectively analyzed for contrast staining. Charts were reviewed and outcomes of the stained parenchyma were identified on subsequent CT and MRI. Thirty-six of 67 patients meeting inclusion criteria (53.7%) had contrast staining on CT obtained within 72 hours after DSA. Brain parenchyma with contrast staining in patients with AIS most often evolved into cerebral infarction (81%). Hemorrhagic transformation was less likely in cases with staining compared with hemorrhagic transformation in the cohort that did not have contrast staining of the parenchyma on post DSA CT (6% versus 25%, respectively, OR 0.17, 95% CI 0.017 - 0.98, p = 0.02). Brain parenchyma with contrast staining on CT after DSA in AIS patients was likely to infarct and unlikely to hemorrhage.

The absence of safe and reliable methods to harvest vascular tissue in situ limits the discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders such as aneurysms. We investigated the feasibility and comparable efficacy of endothelial cell collection using a spectrum of endovascular coils. Nine detachable coils ranging in k coefficient (0.15-0.24), diameter (4.0 mm-16.0 mm), and length (8.0 cm-47.0 cm) were tested in pigs. All coils were deployed and retrieved within the iliac artery of pigs (three coils/pig). Collected coils were evaluated under light microscopy. The total and endothelial cells collected by each coil were quantified. The nucleated cells were identified by Wright-Giemsa and DAPI stains. Endothelial and smooth muscle cells were identified by CD31 and α-smooth muscle actin antibody staining. Coils were deployed and retrieved without technical difficulty. Light microscopy demonstrated sheets of cellular material concentrated within the coil winds. All coils collected cellular material while five of nine (55.6%) coils retrieved endothelial cells. Coils collected mean endothelial cell counts of 89.0±101.6. Regression analysis demonstrated a positive correlation between increasing coil diameter and endothelial cell counts (R(2)=0.52, p = 0.029). Conventional detachable coils can be used to harvest endothelial cells. The number of endothelial cells collected by a coil positively correlated with its diameter. Given the widespread use of coils and their well-described safety profile their potential as an endovascular biopsy device would expand the availability of tissue for cellular and molecular analysis.

Purpose: Intracranial aneurysm (IA) growth is associated with increased morbidity. We sought to establish a quantitative computational method based on contrast-enhanced MR angiography (CE-MRA) for estimating aneurysmal volume changes over time.Materials and Methods: Computational volume calculations were tested against a distensible phantom. Untreated patients with IA were followed longitudinally with annual MRI. Maximal linear dimensions along the longitudinal axis and two transverse axes were determined by visual review of maximum intensity projection (MIP) data, and aneurysm volume was approximated as (length x width x height)/2. Averages of the visual approximations were compared to the lumenal volume as determined with a computational algorithm using the MRI data.Results: MRI-based measurements accurately represented volume changes in the phantom (R-2 = 0.97, Y = 1.06x + 271 CM3). In the clinical study there were a total of 11 intervals of one-year follow-up in six patients (mean +/- SD age = 53 +/- 20 years). The raw one-year growth using the computational volume was 9% +/- 17%. The corresponding value for the averaged measurement of the reviewers was 8% +/- 14%. Neither the mean values nor the SDs were different (P = .51).Conclusion: MRI-based measurement of aneurysm volume appears feasible for longitudinal studies of aneurysm natural history.

Background Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations. Objective To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data. Methods A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis. Results The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point. Conclusions This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features. [ABSTRACT FROM AUTHOR]

Background Percutaneous sclerotherapy is an effective treatment for lymphatic malformations (LM) of the head and neck in adults. The purpose of this study was to examine the indications and efficacy of sclerotherapy for head/neck LM in the neonate and infant population. Methods We retrospectively reviewed patients treated with percutaneous sclerotherapy for LM of the head/neck at age ≤12 months at a single vascular anomalies clinic. The clinical, anatomic, and technical aspects of each treatment, complications, and post-treatment clinical and imaging outcomes were analyzed. Results 22 patients underwent 36 treatments during the first year of life. Median age at first treatment was 6.2 months (range 2-320 days). Severe airway compromise was the most frequent indication for treatment (31.8%). Sclerosants included doxycycline (80.5%), sodium tetradecyl sulfate (55.5%), bleomycin (11.1%) and ethanol (2.8%). There were no immediate procedure-related complications; sclerosant-related laboratory complications included transient metabolic acidosis (8.3%) and hemolytic anemia (5.5%). Median follow-up was 3.7 years (IQR 0.6-4.8). 47.6% of patients showed >75% lesion size reduction and 19.0% showed minimal response (<25% improvement). At last follow-up, 71.4% of children were developmentally normal and asymptomatic, 23.8% had recurring symptoms, and 4.8% required permanent tracheostomy. Patients with ongoing symptoms or limited response to percutaneous sclerotherapy (33.3%) were treated with long-term sirolimus. Conclusions Percutaneous sclerotherapy is a safe and effective treatment for symptomatic LM of the head and neck in neonates and infants. Treatment strategy and management of recurrent symptoms requires consensus from an experienced, multidisciplinary team. [ABSTRACT FROM AUTHOR]

Cerebral oximetry is normally placed on the upper forehead to monitor the frontal lobe cerebral tissue oxygen saturation (SctO.sub.2). We present a case in which the SctO.sub.2 was simultaneously monitored at both frontal and parietal regions during internal carotid artery (ICA) stenting. Our case involves a 79-year-old man who presented after a sudden fall and was later diagnosed with a watershed ischemic stroke in the distal fields perfused by the left middle cerebral artery. He had diffuse atherosclerotic occlusive lesions in the carotid and cerebral arterial systems including an 85 % stenotic lesion in the left distal cervical ICA. The brain territory perfused by the left ICA was devoid of collateral flow from anterior and posterior communicating arteries due to an abnormal circle of Willis. During stenting, the SctO.sub.2 monitored at both frontal and parietal regions tracked the procedure-induced acute flow change. However, the baseline SctO.sub.2 values of frontal and parietal regions differed. The SctO.sub.2-MAP correlation was more consistent on the stroked hemisphere than the non-stroked hemisphere. This case showed that SctO.sub.2 can be reliably monitored at the parietal region, which is primarily perfused by the ICA. SctO.sub.2 of the stroked brain is more pressure dependent than the non-stroked brain., Author(s): Lingzhong Meng[sup.1] , Melanie Hall[sup.1] , Fabio Settecase[sup.2] , Randall T. Higashida[sup.2] , Adrian W. Gelb[sup.1] Author Affiliations: (1) Department of Anesthesia and Perioperative Care, University of California, San [...]