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BackgroundDigital subtraction angiography (DSA) is the gold-standard method of assessing arterial blood flow and blockages prior to endovascular thrombectomy.ObjectiveTo detect anatomical features and arterial occlusions with DSA using artificial intelligence techniques.MethodsWe included 82 patients with acute ischemic stroke who underwent DSA imaging and whose carotid terminus was visible in at least one run. Two neurointerventionalists labeled the carotid location (when visible) and vascular occlusions on 382 total individual DSA runs. For detecting the carotid terminus, positive and negative image patches (either containing or not containing the internal carotid artery terminus) were extracted in a 1:1 ratio. Two convolutional neural network architectures (ResNet-50 pretrained on ImageNet and ResNet-50 trained from scratch) were evaluated. Area under the curve (AUC) of the receiver operating characteristic and pixel distance from the ground truth were calculated. The same training and analysis methods were used for detecting arterial occlusions.ResultsThe ResNet-50 trained from scratch most accurately detected the carotid terminus (AUC 0.998 (95% CI 0.997 to 0.999), pConclusionThese results may serve as an unbiased standard for clinical stroke trials, as optimal standardization would be useful for core laboratories in endovascular thrombectomy studies, and also expedite decision-making during DSA-based procedures.

OBJECTIVE Microsurgical resection of arteriovenous malformations (AVMs) can be aided by staged treatment consisting of stereotactic radiosurgery followed by resection in a delayed fashion. This approach is particularly useful for high Spetzler-Martin (SM) grade lesions because radiosurgery can reduce flow through the AVM, downgrade the SM rating, and induce histopathological changes that additively render the AVM more manageable for resection. The authors present their 28-year experience in managing AVMs with adjunctive radiosurgery followed by resection. METHODS The authors retrospectively reviewed records of patients treated for cerebral AVMs at their institution between January 1990 and August 2019. All patients who underwent stereotactic radiosurgery (with or without embolization), followed by resection, were included in the study. Of 1245 patients, 95 met the eligibility criteria. Univariate and multivariate regression analyses were performed to assess relationships between key variables and clinical outcomes. RESULTS The majority of lesions treated (53.9%) were high grade (SM grade IV–V), 31.5% were intermediate (SM grade III), and 16.6% were low grade (SM grade I–II). Hemorrhage was the initial presenting sign in half of all patients (49.5%). Complete resection was achieved among 84% of patients, whereas 16% had partial resection, the majority of whom received additional radiosurgery. Modified Rankin Scale (mRS) scores of 0–2 were achieved in 79.8% of patients, and 20.2% had poor (mRS scores 3–6) outcomes. Improved (44.8%) or stable (19%) mRS scores were observed among 63.8% of patients, whereas 36.2% had a decline in mRS scores. This includes 22 patients (23.4%) with AVM hemorrhage and 6 deaths (6.7%) outside the perioperative period but prior to AVM obliteration. CONCLUSIONS Stereotactic radiosurgery is a useful adjunct in the presurgical management of cerebral AVMs. Multimodal therapy allowed for high rates of AVM obliteration and acceptable morbidity rates, despite the predominance of high-grade lesions in this series of patients.

Adenoid cystic carcinoma of the lacrimal gland is an aggressive, malignant epithelial neoplasm. We report the case of a 30-year-old male with lacrimal gland adenoid cystic carcinoma treated with neoadjuvant intra-arterial chemotherapy through the internal carotid artery, followed by orbital exenteration and chemoradiation. Treatment response was evaluated using a novel combination of pre- and posttreatment genome sequencing coupled with immunohistochemical evaluation, which showed diffuse tumor apoptosis. A posttreatment decrease in variant allele frequency of the NOTCH1 mutation, and robust tumor cytoreduction on imaging, supports exploration of NOTCH1 analysis as a potential marker of cisplatin sensitivity. The use of genome sequencing and immunohistochemical evaluation could provide a more targeted therapeutic assessment of neoadjuvant intra-arterial chemotherapy in the management of lacrimal gland adenoid cystic carcinoma.

Introduction Dural arteriovenous fistulae (DAVF) are vascular lesions with arteriovenous shunting that may be treated with surgical obliteration or endovascular embolization. Some DAVF, such as anterior cranial fossa DAVF (AC-DAVF) derive their arterial supply from ophthalmic artery branches in nearly all cases, and trans-arterial embolization carries a risk of vision loss. We determined the efficacy and safety of trans-ophthalmic artery embolization of DAVF. Materials and methods We performed a retrospective cohort study of all patients with DAVF treated by trans-ophthalmic artery embolization from 2012 to 2020. Primary outcome was angiographic cure of the DAVF. Secondary outcomes included vision loss, visual impairment, orbital cranial nerve injury, stroke, modified Rankin Scale at 90-days, and mortality. Results 12 patients met inclusion criteria (9 males; 3 females). 10 patients had AC-DAVF. Patient age was 59.7 ± 9.5 (mean ± SD) years. Patients presented with intracranial hemorrhage (4 patients), headache (4 patients), amaurosis fugax (1 patients), or were incidentally discovered (2 patients). DAVF Cognard grades were: II (1 patient), III (6 patients), and IV (5 patients). DAVF were embolized with Onyx (10 patients), nBCA glue (1 patient), and a combination of coils and Onyx (1 patient). DAVF cure was achieved in 11 patients (92%). No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision attributed to posterior ischemic optic neuropathy. 90-day mRS was 0 (10 patients) and 1 (2 patients). Conclusions Trans-ophthalmic artery embolization is an effective and safe treatment for DAVF.

BackgroundPrecise delivery of liquid embolic agents (LEAs) remains a challenge in the endovascular treatment of dural arteriovenous fistulae (dAVFs) and cerebral arteriovenous malformations (cAVMs). Despite significant advances in the past decade, LEA reflux and catheter navigability remain shortcomings of current endovascular technology, particularly in small and tortuous arteries. The Scepter Mini dual-lumen balloon microcatheter aims to address these issues by decreasing the distal catheter profile (1.6 French) while allowing for a small (2.2 mm diameter) balloon at its tip.MethodsWe report our initial experience with the Scepter Mini in two patients with anterior cranial fossa dAVFs that were treated with transophthalmic artery embolization.ResultsIn both patients, the Scepter Mini catheter was able to be safely advanced into the distal ophthalmic artery close to the fistula site, and several centimeters past the origins of the central retinal and posterior ciliary arteries. A single Onyx injection without any reflux resulted in angiographic cure of the dAVF in both cases, and neither patient suffered any vision loss.ConclusionsThese initial experiences suggest that the Scepter Mini represents a significant advance in the endovascular treatment of dAVFs and cAVMs and will allow for safer and more efficacious delivery of LEAs into smaller and more distal arteries while diminishing the risk of LEA reflux.

Rationale and Objectives Our primary aim was to improve radiology reports by increasing concordance of target lesion measurements with oncology records using radiology preprocessors (RP). Faster notification of incidental actionable findings to referring clinicians and clinical radiologist exam interpretation time savings with RPs quantifying tumor burden were also assessed. Materials and Methods In this prospective quality improvement initiative, RPs annotated lesions before radiologist interpretation of CT exams. Clinical radiologists then hyperlinked approved measurements into interactive reports during interpretations. RPs evaluated concordance with our tumor measurement radiologist, the determinant of tumor burden. Actionable finding detection and notification times were also deduced. Clinical radiologist interpretation times were calculated from established average CT chest, abdomen, and pelvis interpretation times. Results RPs assessed 1287 body CT exams with 812 follow-up CT chest, abdomen, and pelvis studies; 95 (11.7%) of which had 241 verified target lesions. There was improved concordance (67.8% vs. 22.5%) of target lesion measurements. RPs detected 93.1% incidental actionable findings with faster clinician notification by a median time of 1 hour (range: 15 minutes–16 hours). Radiologist exam interpretation times decreased by 37%. Conclusions This workflow resulted in three-fold improved target lesion measurement concordance with oncology records, earlier detection and faster notification of incidental actionable findings to referring clinicians, and decreased exam interpretation times for clinical radiologists. These findings demonstrate potential roles for automation (such as AI) to improve report value, worklist prioritization, and patient care.

PurposeOur aims were to describe characteristic radiographic features of two power injectable medical access ports (MAPs) on various imaging modalities for rapid and precise identification; and to demonstrate the value of this approach in identifying other types of MAPs via “pictorial atlas”.MethodsWe analyzed two commonly seen MAPs at our clinical center, Smart Port® CT-Injectable Port and PowerPort® M.R.I.® Implantable Port. Photographs of these two MAPs were retrospectively compared with identity-verified MAPs seen on chest X-ray (CXR), computed tomography (CT) and dual energy subtraction radiography (DESR) images from routine patient encounters at our clinical center. Visualized radiographic features were used for MAP differentiation and identification.ResultsBased on selected patient case examples for these two MAPs, physical characteristics seen on imaging were used for MAP identification. These properties included port body and chamber shape; location and number of suture holes; and radiopaque and radiolucent features. Each imaging modality provided a unique set of radiographic features and highlighted specific components of each MAP for rapid and precise identification. CXR offered better visualization of unique MAP features compared to CT.ConclusionsRadiographic imaging can serve as a tool for medical staff to quickly identify MAPs. Hospital-specific “pictorial atlases” can be developed to display MAPs along with their associated distinctive radiographic and physical features for rapid and precise identification. This may be useful for large referral centers that see a wide array of MAPs by mitigating complications associated with MAP misidentification and usage, thus improving patient care.

Background and Purpose— Imaging is frequently used to select acute stroke patients for intra-arterial therapy. Quantitative cerebral blood flow can be measured noninvasively with arterial spin labeling magnetic resonance imaging. Cerebral blood flow levels in the contralateral (unaffected) hemisphere may affect capacity for collateral flow and patient outcome. The goal of this study was to determine whether higher contralateral cerebral blood flow (cCBF) in acute stroke identifies patients with better 90-day functional outcome. Methods— Patients were part of the prospective, multicenter iCAS study (Imaging Collaterals in Acute Stroke) between 2013 and 2017. Consecutive patients were enrolled after being diagnosed with anterior circulation acute ischemic stroke. Inclusion criteria were ischemic anterior circulation stroke, baseline National Institutes of Health Stroke Scale score ≥1, prestroke modified Rankin Scale score ≤2, onset-to-imaging time Results— Seventy-seven patients (41 women) met the inclusion criteria with median (interquartile range) age of 66 (55–76) yrs, onset-to-imaging time of 4.8 (3.6–7.7) hours, and baseline National Institutes of Health Stroke Scale score of 13 (9–20). Median cCBF was 38.9 (31.2–44.5) mL per 100 g/min. Higher cCBF predicted good outcome at day 90 (odds ratio, 4.6 [95% CI, 1.4–14.7]; P =0.01), after controlling for baseline National Institutes of Health Stroke Scale, diffusion-weighted imaging lesion volume, and intra-arterial therapy. Conclusions— Higher quantitative cCBF at baseline is a significant predictor of good neurological outcome at day 90. cCBF levels may inform decisions regarding stroke triage, treatment of acute stroke, and general outcome prognosis. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT02225730.

There is consistent demand for clinical exposure from students interested in radiology; however, the COVID-19 pandemic resulted in fewer available options and limited student access to radiology departments. Additionally, there is increased demand for radiologists to manage more complex quantification in reports on patients enrolled in clinical trials. We present an online educational curriculum that addresses both of these gaps by virtually immersing students (radiology preprocessors, or RPs) into radiologists' workflows where they identify and measure target lesions in advance of radiologists, streamlining report quantification. RPs switched to remote work at the beginning of the COVID-19 pandemic in our National Institutes of Health (NIH). We accommodated them by transitioning our curriculum on cross-sectional anatomy and advanced PACS tools to a publicly available online curriculum. We describe collaborations between multiple academic research centers and industry through contributions of academic content to this curriculum. Further, we describe how we objectively assess educational effectiveness with cross-sectional anatomical quizzes and decreasing RP miss rates as they gain experience. Our RP curriculum generated significant interest evidenced by a dozen academic and research institutes providing online presentations including radiology modality basics and quantification in clinical trials. We report a decrease in RP miss rate percentage, including one virtual RP over a period of 1 year. Results reflect training effectiveness through decreased discrepancies with radiologist reports and improved tumor identification over time. We present our RP curriculum and multicenter experience as a pilot experience in a clinical trial research setting. Students are able to obtain useful clinical radiology experience in a virtual learning environment by immersing themselves into a clinical radiologist's workflow. At the same time, they help radiologists improve patient care with more valuable quantitative reports, previously shown to improve radiologist efficiency. Students identify and measure lesions in clinical trials before radiologists, and then review their reports for self-evaluation based on included measurements from the radiologists. We consider our virtual approach as a supplement to student education while providing a model for how artificial intelligence will improve patient care with more consistent quantification while improving radiologist efficiency.

Objectives To describe the method and clinical efficacy of awake computed tomography (CT)–guided percutaneous balloon compression (PBC) as a treatment for trigeminal neuralgia (TN). Design In this case series, patients with TN were treated with awake CT-guided PBC and followed up for treatment efficacy and complications for 12 months. Setting A single-center study. Subjects A total of 66 patients with medical treatment–refractory TN were recruited for the study. Methods The procedure was performed under moderate sedation. A balloon catheter was inserted through a trocar needle to reach Meckel’s cavity under CT guidance. The position and optimal shape of the contrast-filled balloon were confirmed with CT three-dimensional reconstruction. Compression of the trigeminal ganglion was considered complete when the patient notified operators about facial hypoesthesia or the resolution of TN symptoms. All patients were followed up monthly for 12 months to monitor treatment efficacy and complications. Results The average trigeminal ganglion compression time was 272 ± 81 seconds, at which point the patients reported significant facial hypoesthesia compared with the contralateral side or resolution of triggered pain in the affected area. All patients had resolution of TN symptoms for 6 months, with a 1-year recurrence rate of 13%. The overall safety profile was improved with the technique described in this study. Side effects, such as hypoesthesia and mastication weakness, were overall mild and did not impact patients’ quality of life. Some complications that historically have been associated with PBC, such as diplopia and keratitis, were not present. Conclusions This new awake CT-guided PBC technique produces better outcomes than the traditional PBC under fluoroscopy guidance and general anesthesia.

BackgroundHigh-flow fistulas related to plexiform nidi are found in 40% of large brain arteriovenous malformations (AVMs). Endovascular occlusion of intranidal fistulas before plexiform components is empirically considered safe, but potential ensuing dangerous re-routing of flow through plexiform vessels may in theory raise their rupture risk. It remains unclear whether it is safer to embolize plexiform or fistulous vessels initially. We used a novel biomathematical AVM model to compare theoretical hemodynamic changes and rupture risks on sequential embolizations of both types of nidus vessels.MethodsWe computationally modeled a theoretical AVM as an electrical circuit containing a nidus consisting of a massive stochastic network ensemble comprising 1000 vessels. We sampled and individually simulated 10 000 different nidus morphologies with a fistula angioarchitecturally isolated from its adjacent plexiform nidus. We used network analysis to calculate mean intravascular pressure (Pmean) and flow rate within each nidus vessel; and Monte Carlo analysis to assess overall risks of nidus rupture when simulating sequential occlusions of vessel types in all 10 000 nidi.ResultsWe consistently observed lower nidus rupture risks with initial fistula occlusion in different network morphologies. Intranidal fistula occlusion simultaneously reduced Pmeanand flow rate within draining veins.ConclusionsInitial occlusion of AVM fistulas theoretically reduces downstream draining vessel hypertension and lowers the risk of rupture of an adjoining plexiform nidus component. This mitigates the theoretical concern that fistula occlusion may cause dangerous redistribution of hemodynamic forces into plexiform nidus vessels, and supports a clinical strategy favoring AVM fistula occlusion before plexiform nidus embolization.

Collegiate football athletes are subject to repeated traumatic brain injuriesthat may cause brain injury. The hippocampus is composed of several distinct subfields with possible differential susceptibility to injury. The aim of this study is to determine whether there are longitudinal changes in hippocampal subfield volume in collegiate football. A prospective cohort study was conducted over a 5-year period tracking 63 football and 34 volleyball male collegiate athletes. Athletes underwent high-resolution structural magnetic resonance imaging, and automated segmentation provided hippocampal subfield volumes. At baseline, football (n = 59) athletes demonstrated a smaller subiculum volume than volleyball (n = 32) athletes (−67.77 mm(3); p = 0.012). A regression analysis performed within football athletes similarly demonstrated a smaller subiculum volume among those at increased concussion risk based on athlete position (p = 0.001). For the longitudinal analysis, a linear mixed-effects model assessed the interaction between sport and time, revealing a significant decrease in cornu ammonis area 1 (CA1) volume in football (n = 36) athletes without an in-study concussion compared to volleyball (n = 23) athletes (volume difference per year = −35.22 mm(3); p = 0.005). This decrease in CA1 volume over time was significant when football athletes were examined in isolation from volleyball athletes (p = 0.011). Thus, this prospective, longitudinal study showed a decrease in CA1 volume over time in football athletes, in addition to baseline differences that were identified in the downstream subiculum. Hippocampal changes may be important to study in high-contact sports.

OBJECTIVEArteriovenous malformations (AVMs) of the basal ganglia and thalamus are particularly difficult lesions to treat, accounting for 3%–13% of all AVMs in surgical series and 23%–44% of malformations in radiosurgery series. The goal of this study was to report the results of multimodal management of basal ganglia and thalamic AVMs and investigate the factors that influence radiographic cure and good clinical outcomes.METHODSThis study was a retrospective analysis of a prospectively maintained database of all patients treated at the authors’ institution. Clinical, radiological, follow-up, and outcome data were analyzed. Univariate and multivariate analyses were conducted to explore the influence of various factors on outcome.RESULTSThe results and data analysis pertaining to 123 patients treated over 32 years are presented. In this cohort, radiographic cure was achieved in 50.9% of the patients. Seventy-five percent of patients had good clinical outcomes (stable or improved performance scores), whereas 25% worsened after treatment. Inclusion of surgery and radiosurgery independently predicted obliteration, whereas nidus diameter and volume predicted clinical outcomes. Nidus volume/diameter and inclusion of surgery predicted the optimal outcome, i.e., good clinical outcomes with lesion obliteration.CONCLUSIONSGood outcomes are possible with multimodal treatment in these complex patients. Increasing size and, by extension, higher Spetzler-Martin grade are associated with worse outcomes. Inclusion of multiple modalities of treatment as indicated could improve the chances of radiographic cure and good outcomes.

BackgroundThe extended time window for endovascular therapy in adult stroke represents an opportunity for stroke treatment in children for whom diagnosis may be delayed. However, selection criteria for pediatric thrombectomy has not been defined.MethodsWe performed a retrospective cohort study of patients aged ResultsTwelve children were included: 8/12 (66.7%) were female, mean age 9.7±5.0 years, median National Institutes of Health Stroke Scale (NIHSS) 11.5 (IQR 10–14). Stroke etiology was cardioembolic in 75%, dissection in 16.7%, and cryptogenic in 8.3%. For 2/5 with perfusion imaging, Tmax >4 s appeared to better correlate with NIHSS. Nine patients (75%) were treated: seven underwent thrombectomy alone; one received IV alteplase and thrombectomy, and one received IV alteplase alone. Favorable outcome was achieved in 78% of treated patients versus 0% of untreated patients (P=0.018). All untreated patients had poor outcome, with death (n=2) or severe disability (n=1) at follow-up. Among treated patients, older children (12.8±2.9 vs 4.2±5.0 years, P=0.014) and children presenting as outpatient (100% vs 0%, P=0.028) appeared to have better outcomes.ConclusionsPerfusion imaging is feasible in pediatric stroke and may help identify salvageable tissue in extended time windows, though penumbral thresholds may differ from adult values. Further studies are needed to define criteria for thrombectomy in this unique population.

BACKGROUND Traditional moyamoya disease (MMD) classification relies on morphological digital subtraction angiography (DSA) assessment, which do not reflect hemodynamic status, clinical symptoms, or surgical treatment outcome. OBJECTIVE To (1) validate the new Berlin MMD preoperative symptomatology grading system and (2) determine the clinical application of the grading system in predicting radiological and clinical outcomes after surgical revascularization. METHODS Ninety-six MMD patients (192 hemispheres) with all 3 investigations (DSA, magnetic resonance imaging [MRI], Xenon-CT) performed preoperatively at our institution (2007-2013) were included. Two clinicians independently graded the imaging findings according to the proposed criteria. Patients' modified Rankin Score (mRS) scores (preoperative, postoperative, last follow-up), postoperative infarct (radiological, clinical) were collected and statistical correlations performed. RESULTS One hundred fifty-seven direct superficial temporal artery-middle cerebral artery bypasses were performed on 96 patients (66 female, mean age 41 yr, mean follow-up 4.3 yr). DSA, MRI, and cerebrovascular reserve capacity were independent factors associated hemispheric symptomatology (when analyzed individually or in the combined grading system). Mild (grade I), moderate (grade II), severe (grade III) were graded in 45, 71, and 76 hemispheres respectively; of which, clinical symptoms were found in 33% of grade I, 92% of grade II, 100% of grade III hemispheres (P

We present a severe case of progressive autoimmune pneumonitis requiring surgical intervention in a patient with the monogenic syndrome, autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). APECED is caused by loss-of-function mutations in the autoimmune regulator (AIRE) gene, which lead to impaired central immune tolerance and autoimmune organ destruction including pneumonitis, an underrecognized, life-threatening complication. When clinicians evaluate patients with pneumonitis, recurrent mucosal candidiasis, and autoimmunity, APECED should be considered in the differential. Additionally, in patients with established APECED, a chest computed tomography is preferred to identify pneumonitis early on and to promptly initiate lymphocyte-directed immunomodulatory treatment, which can prevent irreversible lung destruction.

OBJECTIVE Hemifacial spasm (HFS) is a debilitating neuromuscular disorder with limited treatment options. The current study describes a novel minimally invasive procedure that provided effective and sustained relief for patients with HFS. The authors provide a detailed description of the awake CT-guided percutaneous radiofrequency ablation (RFA) of the facial nerve for treatment of HFS, and they examine its clinical efficacy. This is the first time in the literature that this procedure has been applied and systematically analyzed for HFS. METHODS Patients with a history of HFS were recruited between August 2018 and April 2020. Those with a history of cerebellopontine lesions, coagulopathy, ongoing pregnancy, cardiac pacemaker or defibrillator implants, or who declined the procedure were excluded from the study. Fifty-three patients who met the study criteria were included and underwent awake CT-guided RFA. Under minimal sedation, a radiofrequency (RF) needle was used to reach the stylomastoid foramen on the affected side under CT guidance, and the facial nerve was localized using a low-frequency stimulation current. Patients were instructed to engage facial muscles as a proxy for motor monitoring during RFA. Ablation stopped when the patients’ hemifacial contracture resolved. Patients were kept for inpatient monitoring for 24 hours postoperatively and were followed up monthly to monitor resolution of HFS and complications for up to 19 months. RESULTS The average duration of the procedure was 32–34 minutes. Postoperatively, 91% of the patients (48/53) had complete resolution of HFS, whereas the remaining individuals had partial resolution. A total of 48 patients reported mild to moderate facial paralysis immediately post-RFA, but most resolved within 1 month. No other significant complication was observed during the study period. By the end of the study period, 5 patients had recurrence of mild HFS symptoms, whereas only 2 patients reported dissatisfaction with the treatment results. CONCLUSIONS The authors report for the first time that awake CT-guided RFA of the facial nerve at the stylomastoid foramen is a minimally invasive procedure and can be an effective treatment option for HFS.

Introduction Anterior cranial fossa dural arteriovenous fistulas (dAVFs) represent up to 10% of all dAVFs and have traditionally been treated surgically. These lesions derive their arterial supply from the bilateral anterior ethmoidal arteries (ophthalmic artery branches) in nearly all cases. Embolization via the ophthalmic artery poses unique technical challenges due to its small caliber and risk of vision loss. To date, there is a paucity of literature regarding the safety and efficacy of performing endovascular embolizations via the ophthalmic artery. Advances in endovascular therapy, including highly trackable microcatheters and balloon microcatheters, offer the potential for safe and successful embolization via the ophthalmic artery. Here we describe our experience of anterior cranial fossa dAVF treatment by endovascular embolization via the ophthalmic artery. Materials and Methods We conducted a retrospective cohort study of consecutive patients with anterior cranial fossa dAVF treated by ophthalmic artery embolization at two neurovascular centers from 2012 to 2020. Primary outcome was angiographic cure of the dAVF. Secondary outcome measures included vision loss, modified Rankin Scale at 90-days, mortality, and any other iatrogenic treatment complications. Results 10 patients met inclusion criteria, which included 8 male and 2 females. Mean patient age was 61.9 (SD 8.0) years. DAVF Cognard grades were: II (1 patient), III (5 patients), and IV (4 patients). 4 patients presented with cerebral hemorrhage due to the dAVF. 6 patients presented with headache, aphasia, amaurosis fugax, or were asymptomatic and incidentally discovered. The most commonly embolized arterial feeding vessels were the anterior and posterior ethmoidal arteries (n=8) and the recurrent meningeal artery (n=2). Embolysates included Onyx (8 cases), nBCA glue (1 case), and a combination of coils and Onyx (1 case). 4 cases were performed with balloon microcatheters. Complete dAVF cure was achieved in 9 patients (90%). Two patients had delayed washout of the ophthalmic artery after embolization which was treated with aspirin without subsequent visual defect. No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision in the left hemi-field suggestive of posterior ischemic optic neuropathy. 90 day mRS was 0 (7 patients), 1 (2 patients), and not yet available for one patient. Conclusions Anterior cranial fossa dAVF embolization can be safely performed through the ophthalmic artery with high angiographic cure rates and a low risk of vision loss or other complications. Disclosures V. Mayercik: None. N. Telischak: None. E. Sussman: None. B. Pulli: None. R. Dodd: None. M. Marks: None. H. Do: None. J. Heit: None.

Introduction Acute carotid stent occlusion (CSO) is a rare complication of endovascular carotid stent placement that requires emergent intervention. We describe angioplasty or combined angioplasty and aspiration thrombectomy as a new endovascular technique for CSO treatment. The technique is compared to others previously described in the literature. Methods We performed a retrospective cohort study of all patients who underwent endovascular treatment (ET) of acute symptomatic CSO from January 2008 to March 2018 at our neurovascular referral center. Patient demographics, endovascular treatment details, and outcome data were determined from the electronic medical record. Primary outcome was successful stent recanalization and cerebral reperfusion (modified thrombolysis in cerebral infarction (mTICI) score IIB-III). Secondary outcomes were National Institutes of Health Stroke Scale (NIHSS) shift from presentation to discharge, mortality, and modified Rankin Scale (mRS) score at 3 months. Additionally, a literature review (years 2008-2019) was performed to characterize other techniques for ET of CSO. Results Four patients who underwent ET of acute CSO were identified. ET treatment by angioplasty (n = 1) or combined aspiration thrombectomy and angioplasty (n = 3) resulted in carotid stent recanalization in all patients. Tandem intracranial occlusions were present in three patients (75%), and successful cerebral reperfusion was achieved in all patients. Patient symptoms improved (mean NIHSS shift -5.3 ± 7.2 at discharge). One patient died of a symptomatic reperfusion hemorrhage and another died of cardiac complications by 3-month follow-up. The mRS scores of the surviving patients were 1 and 3. Previously described studies (n = 14) using different and varied techniques had moderate recanalization rates and outcomes. Conclusion Combined aspiration thrombectomy and angioplasty for the neurointerventional treatment of acute CSO leads to high rates of stent recanalization and cerebral reperfusion. The recanalization rate here is improved compared to previously reported techniques. Further multicenter studies are required to risk-stratify patients for specific ET interventions.

Introduction: Surgical treatment of arteriovenous malformations (AVMs), particularly higher grade lesions, can be aided by staged treatment consisting of stereotactic radiosurgery (SRS) followed by surgical resection in a delayed fashion. This strategy can be used to downgrade the AVM S-M grade, reduce blood flow through the AVM and often results in histopathological changes making AVMs more amenable to microsurgical resection. We present our 28-year clinical experience in managing AVMs with pre-operative SRS as a surgical adjunct. Methods: We retrospectively reviewed and analyzed records of all patients treated for cerebral AVMs between February 1991 and July 2019 at our institution. All patients that underwent SRS, with and without embolization, followed by microsurgery were included in the study. Of the 1245 cerebral AVM patients treated at our institution, 62 patients met eligibility criteria. Univariate and multivariate regression analysis was performed where appropriate to examine relationships between key variables and outcomes. Results: The majority of lesions (50%) were high grade (SM 4-5), 28.6% were intermediate (SM 3), while 21.4% were low grade (SM 1-2). Hemorrhage was the presenting sign among 22.6% of patients. Complete resection was achieved among 64.5%, 79% and 82% of patients after first, second and third surgical stages respectively; 16.1% of patients had partial resection requiring further treatment. Radiographic cure was achieved among 53 patients (85.5%), while 8 (12.9%) patients had residual AVM at last follow up. Six of 8 patients without radiographic cure received post-operative SRS. Thirty-seven patients (63.8%) had improved (26, 44.8%) or stable mRS scores (11, 19%), while 21 (36.2%) had a decline in mRS at final follow up compared to mRS at presentation; this includes 4 (6.9%) deaths due to hemorrhage, outside of the perioperative period, but occurring during follow up prior to AVM obliteration. Conclusion: SRS is a useful adjunct in the surgical management of cerebral AVMs. Multimodal therapy allowed for high obliteration rates with acceptable morbidity in this series of patients with predominantly high grade AVMs.

Background and Purpose— Parenchymal hemorrhage (PH) after endovascular mechanical thrombectomy in acute ischemic stroke leads to worse outcomes. Better clinical and imaging biomarkers of symptomatic reperfusion PH are needed to identify patients at risk. We identified clinical and imaging predictors of reperfusion PH after endovascular mechanical thrombectomy with attention to early cerebral veins (ECVs) on postreperfusion digital subtraction angiography. Methods— We performed a retrospective cohort study of consecutive acute ischemic stroke patients undergoing endovascular mechanical thrombectomy at our neurovascular referral center. Clinical and imaging characteristics were collected from patient health records, and random forest variable importance measures were used to identify predictors of symptomatic PH. Predictors of secondary outcomes, including 90-day mortality, functional dependence (modified Rankin Scale score, >2), and National Institutes of Health Stroke Scale shift, were also determined. Diagnostic test characteristics of ECV for symptomatic PH were determined using a receiver operating characteristic analysis. Differences between patients with and without symptomatic PH were assessed with Fisher exact test and the Wilcoxon rank sum (Mann–Whitney U test) test at the 0.05 significance level. Results— Of 64 patients with anterior circulation large-vessel occlusion identified, 6 (9.4%) developed symptomatic PH. ECV was the strongest predictor of symptomatic PH with more than twice the importance of the next best predictor, male sex. Although ECV was also predictive of 90-day mortality and functional dependence, other characteristics were more important than ECV for these outcomes. The sensitivity and specificity of ECV alone for subsequent hemorrhage were both 0.83, with an area under the curve of 0.83 and 95% confidence interval of 0.66 to 1.00. Conclusions— ECV on postendovascular mechanical thrombectomy digital subtraction angiography is highly diagnostic of subsequent symptomatic reperfusion hemorrhage in this data set. This finding has important implications for post-treatment management of blood pressure and anticoagulation.

Background and Purpose— Proximal artery vasospasm and delayed cerebral ischemia (DCI) after cerebral aneurysm rupture result in reduced cerebral perfusion and microperfusion and significant morbidity and mortality. Intravoxel incoherent motion (IVIM) magnetic resonance imaging extracts microvascular perfusion information from a multi-b value diffusion-weighted sequence. We determined whether decreased IVIM perfusion may identify patients with proximal artery vasospasm and DCI. Methods— We performed a pilot retrospective cohort study of patients with ruptured cerebral aneurysms. Consecutive patients who underwent a brain magnetic resonance imaging with IVIM after ruptured aneurysm treatment were included. Patient demographic, treatment, imaging, and outcome data were determined by electronic medical record review. Primary outcome was DCI development with proximal artery vasospasm that required endovascular treatment. Secondary outcomes included mortality and clinical outcomes at 6 months. Results— Sixteen patients (11 females, 69%; P =0.9) were included. There were no differences in age, neurological status, or comorbidities between patients who subsequently underwent endovascular treatment of DCI (10 patients; DCI+ group) and those who did not (6 patients; DCI− group). Compared with DCI− patients, DCI+ patients had decreased IVIM perfusion fraction f (0.09±0.03 versus 0.13±0.01; P =0.03), reduced diffusion coefficient D (0.82±0.05 versus 0.92±0.07×10 −3 mm 2 /s; P =0.003), and reduced blood flow–related parameter fD * (1.18±0.40 versus 1.83±0.40×10 −3 mm 2 /s; P =0.009). IVIM pseudodiffusion coefficient D * did not differ between DCI− (0.011±0.002) and DCI+ (0.013±0.005 mm 2 /s; P =0.4) patients. No differences in mortality or clinical outcome were identified. Conclusions— Decreased IVIM perfusion fraction f and blood flow–related parameter fD * correlate with DCI and proximal artery vasospasm development after cerebral aneurysm rupture.

Objective The feasibility and usefulness of transradial catheterization for coronary and neuro-intervention are well known. However, the anatomical change in the catheterized radial artery (RA) is not well understood. Herein, we present the results of ultrasonographic observation of the RA after routine transradial cerebral angiography (TRCA). Methods Patients who underwent routine TRCA with pre- and post-procedure Doppler ultrasonography (DUS) of the catheterized RA were enrolled. We then recorded and retrospectively reviewed the diameter and any complicated features of the RA observed on DUS, and the factors associated with the diameter and complications were analyzed. Results A total of 223 TRCAs across 181 patients were enrolled in the current study. The mean RA diameter was 2.48 mm and was positively correlated with male gender (p

Arteriovenous malformations are a vascular anomaly typically present at birth, characterized by an abnormal connection between an artery and a vein (bypassing the capillaries). These high flow lesions can vary in size and location. Therapeutic approaches are limited, and AVMs can cause significant morbidity and mortality. Here, we describe our current understanding of the pathogenesis of arteriovenous malformations based on preclinical and clinical findings. We discuss past and present accomplishments and challenges in the field and identify research gaps that need to be filled for the successful development of therapeutic strategies in the future.

Background Intracranial atherosclerotic disease may result in ischemic infarction and has a high rate of recurrent ischemic strokes despite medical therapy. Patients who fail medical therapy may undergo endovascular treatment with cerebral artery angioplasty and possible Wingspan stent placement. We present a unique case of Wingspan delivery microcatheter fracture that resulted in a retained foreign body and an endovascular salvage maneuver. Case description An elderly patient presented with an acute ischemic stroke due to a severe stenosis in the proximal left middle cerebral artery (MCA). The patient failed non-invasive medical treatment and underwent endovascular treatment with angioplasty and Wingspan stent placement. Following Wingspan stent deployment, the stent delivery catheter fractured, and the retained catheter fragment resulted in MCA occlusion. The foreign body was retrieved by balloon catheter inflation within an intermediate catheter adjacent to the proximal end of the fractured catheter and removal of the entire construct (TRAP technique). Conclusions Wingspan delivery microcatheter fracture is a rare event. The TRAP technique may be used for successful retrieval of a retained foreign body.

Background Subarachnoid hemorrhage (SAH) secondary to rupture of a blister aneurysm (BA) results in high morbidity and mortality. Endovascular treatment with the pipeline embolization device (PED) has been described as a new treatment strategy for these lesions. We present the first reported case of PED retraction and foreshortening after treatment of a ruptured internal carotid artery (ICA) BA. Case description A middle-aged patient presented with SAH secondary to ICA BA rupture. The patient was treated with telescoping PED placement across the BA. After 5 days from treatment, the patient developed a new SAH due to re-rupture of the BA. Digital subtraction angiography revealed an increase in caliber of the supraclinoid ICA with associated retraction and foreshortening of the PED that resulted in aneurysm uncovering and growth. Conclusions PED should be oversized during ruptured BA treatment to prevent device retraction and aneurysm regrowth. Frequent imaging follow up after BA treatment with PED is warranted to ensure aneurysm occlusion.

Objectives Percutaneous radiofrequency ablation (RFA) of the gasserian ganglion through the foramen ovale and the glossopharyngeal nerve at the jugular foramen is a classical approach to treating trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GPN), respectively. However, it can be technically challenging with serious complications. We have thus developed a novel technique utilizing C-arm and computerized tomography (CT) guidance to block TN and GPN. Our goals were to describe a three-dimensional image-based technique to improve patient comfort and to decrease procedural time associated with needle guidance. Study design Consecutive procedures were reviewed. Setting Academic hospital. Methods Three patients with classical TN and GPN and 15 patients with atypical facial pain (AFP) were treated. Numeric rating scale (NRS) scores for pain at pretreatment and at one, three, and 12 months post-treatment were recorded. The primary clinical outcome (50% or more reduction in NRS) and secondary adverse clinical outcome (hematoma, facial numbness, etc.) were monitored. Results We had a 100% technical success with respect to appropriate needle positioning. All three classical TN/GPN patients had both immediate and sustained pain relief. Complications were minimal. The 15 AFP patients, however, showed more variable results, with only five (33%) having sustained pain relief, while in the other 10 (67%) patients, we observed suboptimal response. Conclusions We present a novel method and single-center experience with C-arm and CT-guided RFA of facial pain. Quick and accurate needle placement will help future advancements in the RFA algorithm so that more durable and consistent effects can be attained, reducing uncertainty with respect to needle placement as a confounder. The RFA procedure in our study had a satisfying effect for classical TN/GPN patients but was less successful for AFP patients, though it did mirror the results from previous studies. Limitations This study is limited by its small sample size and nonrandomized design.

Embolization has been proposed to reduce the size of the arteriovenous malformation (AVM) nidus in advance of radiosurgical treatment. Embolization followed by radiosurgery for brain AVMs, however, is controversial.We assessed the impact of embolization on nidal size before radiosurgical treatment and evaluated cure rates and complications by using embolization followed by radiosurgery.A retrospective review of our institutional AVM database identified 91 patients treated from 1995 to 2009 with embolization followed by radiosurgery. Pre- and postembolization AVM volumes were measured with angiography, and the modified radiation-based AVM scores (RBAS) also were calculated pre- and postembolization. RBAS determined from pre-embolization volumes were correlated with postradiosurgical obliteration.Median AVM volume declined from 18.8 mL (interquartile range, 10.2-32.2 mL) to 9.9 mL (3.1-19.2 mL) after embolization, P0.00003. Median RBAS scores decreased from 2.6 mL (1.8-3.9 mL) to 1.8 mL (1.0-2.8 mL), P0.00003. Two of 91 (2.2%) had new fixed deficits after embolization; however, no patient had new disabling deficits (modified Rankin Scale score2). A total of 71 of 91 (79%) have had3 years' follow-up, and 40 (56%) had complete obliteration, with 38 (53%) having excellent outcomes (complete obliteration without neurologic decline). Excellent outcome was seen in 90% of patients with modified RBAS score1, 66% of patients with score 1-1.5, 50% patients with score 1.5-2, and 43% of patients with score2.These data suggest that embolization of brain AVMs can safely and effectively reduce the treatment volume before radiosurgery. Combined therapy with embolization and radiosurgery does not appear to adversely affect rates of excellent outcome.

OBJECTIVE Majewski osteodysplastic primordial dwarfism Type II (MOPD II) is a rare genetic disorder. Features of it include extremely small stature, severe microcephaly, and normal or near-normal intelligence. Previous studies have found that more than 50% of patients with MOPD II have intracranial vascular anomalies, but few successful surgical revascularization or aneurysm-clipping cases have been reported because of the diminutive arteries and narrow surgical corridors in these patients. Here, the authors report on a large series of patients with MOPD II who underwent surgery for an intracranial vascular anomaly. METHODS In conjunction with an approved prospective registry of patients with MOPD II, a prospectively collected institutional surgical database of children with MOPD II and intracranial vascular anomalies who underwent surgery was analyzed retrospectively to establish long-term outcomes. RESULTS Ten patients with MOPD II underwent surgery between 2005 and 2012; 5 patients had moyamoya disease (MMD), 2 had intracranial aneurysms, and 3 had both MMD and aneurysms. Patients presented with transient ischemic attack (TIA) (n = 2), ischemic stroke (n = 2), intraparenchymal hemorrhage from MMD (n = 1), and aneurysmal subarachnoid hemorrhage (n = 1), and 4 were diagnosed on screening. The mean age of the 8 patients with MMD, all of whom underwent extracranial-intracranial revascularization (14 indirect, 1 direct) was 9 years (range 1–17 years). The mean age of the 5 patients with aneurysms was 15.5 years (range 9–18 years). Two patients experienced postoperative complications (1 transient weakness after clipping, 1 femoral thrombosis that required surgical repair). During a mean follow-up of 5.9 years (range 3–10 years), 3 patients died (1 of subarachnoid hemorrhage, 1 of myocardial infarct, and 1 of respiratory failure), and 1 patient had continued TIAs. All of the surviving patients recovered to their neurological baseline. CONCLUSIONS Patients with MMD presented at a younger age than those in whom aneurysms were more prevalent. Microneurosurgery with either intracranial bypass or aneurysm clipping is extremely challenging but feasible at expert centers in patients with MOPD II, and good long-term outcomes are possible.

Background Acute ischemic stroke patients with a large-vessel occlusion but mild symptoms (NIHSS ≤ 6) pose a treatment dilemma between medical management and endovascular thrombectomy. Aims To evaluate the differences in clinical outcomes of endovascular thrombectomy-eligible patients with target-mismatch perfusion profiles who undergo either medical management or endovascular thrombectomy. Methods Forty-seven patients with acute ischemic stroke due to large-vessel occlusion, NIHSS ≤ 6, and a target-mismatch perfusion imaging profile were included. Patients underwent medical management or endovascular thrombectomy following treating neurointerventionalist and neurologist consensus. The primary outcome measure was NIHSS shift. Secondary outcome measures were symptomatic intracranial hemorrhage, in-hospital mortality, and 90-day mRS scores. The primary intention-to-treat and as-treated analyses were compared to determine the impact of crossover patient allocation on study outcome measures. Results Forty-seven patients were included. Thirty underwent medical management (64%) and 17 underwent endovascular thrombectomy (36%). Three medical management patients underwent endovascular thrombectomy due to early clinical deterioration. Presentation NIHSS ( P = 0.82), NIHSS shift ( P = 0.62), and 90-day functional independence (mRS 0–2; P = 0.25) were similar between groups. Endovascular thrombectomy patients demonstrated an increased overall rate of intracranial hemorrhage (35.3% vs. 10.0%; P = 0.04), but symptomatic intracranial hemorrhage was similar between groups ( P = 0.25). In-hospital mortality was similar between groups ( P = 0.46), though all two deaths in the medical management group occurred among crossover patients. Endovascular thrombectomy patients demonstrated a longer length of stay (7.6 ± 7.2 vs. 4.3 ± 3.9 days; P = 0.04) and a higher frequency of unfavorable discharge to a skilled-nursing facility ( P = 0.03) rather than home ( P = 0.05). Conclusions Endovascular thrombectomy may pose an unfavorable risk-benefit profile over medical management for endovascular thrombectomy-eligible acute ischemic stroke patients with mild symptoms, which warrants a randomized trial in this subpopulation.

Introduction Recent landmark randomized clinical trials have demonstrated that endovascular thrombectomy (EVT) leads to improved outcomes in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Although elderly patients were excluded from several of these initial trials, the available data suggests a benefit of EVT in octogenarian patients with AIS due to LVO. However, the efficacy of EVT in the nonagenarian patient population remains uncertain. Methods We performed a retrospective cohort study of a prospectively-maintained stroke database at a single comprehensive stroke center. Inclusion criteria were: age 80–99 years, LVO, core infarct Results 108 patients met inclusion criteria, including 79 octogenarians (73%) and 29 nonagenarians (27%). Mean octogenarian age was 84.2 years (SD 2.8) versus 92 years (SD 2.3) in nonagenarians. Nonagenarians were more likely to be female (86% versus 58%; p Conclusions Nonagenarian patients undergoing EVT for AIS due to LVO are at significantly higher risk of symptomatic reperfusion hemorrhage compared with octogenarians, despite similar stroke- and treatment-related factors. While there was a strong trend towards higher mortality rates and worse long-term functional outcomes in nonagenarians, the difference was not statistically significant in this relatively small retrospective study. Additional prospective and randomized studies are necessary to evaluate the efficacy of EVT in elderly patients, including nonagenarians. Disclosures E. Sussman: None. B. Martin: None. M. Mlynash: None. M. Marks: None. D. Marcellus: None. G. Albers: None. M. Lansberg: None. R. Dodd: None. H. Do: None. J. Heit: None.

Background Theoretical modeling allows investigations of cerebral arteriovenous malformation (AVM) hemodynamics, but current models are too simple and not clinically representative. We developed a more realistic AVM model based on graphics processing unit (GPU) computing, to replicate highly variable and complex nidus angioarchitectures with vessel counts in the thousands—orders of magnitude greater than current models. Methods We constructed a theoretical electrical circuit AVM model with a nidus described by a stochastic block model (SBM) of 57 nodes and an average of 1000 plexiform and fistulous vessels. We sampled and individually simulated 10,000 distinct nidus morphologies from this SBM, constituting an ensemble simulation. We assigned appropriate biophysical values to all model vessels, and known values of mean intravascular pressure (Pmean) to extranidal vessels. We then used network analysis to calculate Pmean and volumetric flow rate within each nidus vessel, and mapped these values onto a graphic representation of the nidus network. We derived an expression for nidus rupture risk and conducted a model parameter sensitivity analysis. Results Simulations revealed a total intranidal volumetric blood flow ranging from 268 mL/min to 535 mL/min, with an average of 463 mL/min. The maximum percentage rupture risk among all vessels in the nidus ranged from 0% to 60%, with an average of 29%. Conclusion This easy to implement biomathematical AVM model, allowed by parallel data processing using advanced GPU computing, will serve as a useful tool for theoretical investigations of AVM therapies and their hemodynamic sequelae.

Introduction: The newly-extended time window for endovascular therapy represents a major opportunity for stroke treatment in children, for whom diagnosis is often delayed. However, no guidelines exist to determine how best to select children for thrombectomy, or if it is beneficial. We report all children presenting to our institution with large vessel occlusion (LVO), outline our criteria for thrombectomy, and discuss imaging and outcomes in this unique population. Methods: We reviewed prospective data on all patients < 18 years presenting with LVO. Demographic, clinical, imaging and outcome data were documented for each patient. Key inclusion criteria for thrombectomy were 1) NIHSS ≥ 6; 2) last known well (LKW) < 24 hours prior; 3) imaging suggestive of eloquent tissue at risk (diffusion-perfusion mismatch on MRI or ASPECTS >7 on CT). Results: Nine children presented acutely with stroke symptoms and an LVO; clinical and imaging data are shown in Table 1. All patients met clinical criteria for thrombectomy (NIHSS ≥ 6, LKW Conclusion: Perfusion imaging is feasible in pediatric stroke and may help identify salvageable tissue in extended time windows. Applying strict criteria to determine endovascular eligibility may lead to better outcomes in children, though further studies evaluating optimal perfusion thresholds in children are needed.

Trigeminal neuralgia is a facial pain syndrome characterized by excruciating, paroxysmal, electric shock-like pain attacks in the sensory distribution of the trigeminal nerve. Medical management remains the first line of treatment. When this fails, surgical management needs to be considered. Percutaneous interventional procedures such as glycerol rhizotomy, radiofrequency (RF) thermocoagulation, and balloon compression of the trigeminal ganglion and its branches are some of the most commonly used procedures as they avoid exposure to general anesthesia, provide successful short-term results, and are available to people with significant co-morbidities. Of these, RF is the most often used. The V2 and V3 branches of the trigeminal nerve are most commonly affected, and are thus the most frequent targets for RF interventions. These procedures may be performed using conventional fluoroscopic, ultrasound, or CT-guided imaging, including combined flat-panel CT and fluoroscopy. This chapter summarizes these common ablation techniques targeting the V2 branch of the trigeminal nerve.

BackgroundSclerotherapy is one of the most commonly used minimally invasive interventions in the treatment of macrocystic lymphatic malformations (LMs). Several different sclerosing agents and injection protocols have been reported in the literature, each with varying degrees of success. The safety and efficacy of the treatments have not been evaluated comparatively in the pediatric population.MethodsChart review of pediatric patients with macrocystic/mixed head and neck LMs who underwent sclerotherapy using OK-432, doxycycline, or ethanolamine oleate at Lucile Packard Children's Hospital at Stanford during 2000–2014. Clinical evaluation and radiographic imaging were reviewed to assess lesion characteristics and response to sclerotherapy following each treatment session. The post-intervention clinical response was categorized as excellent, good, fair, or poor.ResultsAmong the 41 pediatric cases reviewed, 10 patients were treated with OK-432, 19 patients received doxycycline, and 12 patients received ethanolamine. In univariate analysis, different sclerosants had similar effectiveness after the first injection and final clinical outcome (p=0.5317). In multivariate analysis controlling for disease severity stage as well as disease characteristics (macrocystic vs mixed subtypes), different sclerosants also had similar effectiveness after the first injection (p=0.1192). Radiologic analysis indicated an 84.5% average volume reduction, with similar effectiveness between the different sclerosants (p=0.9910).ConclusionsIn this series of LM cases treated at Stanford, we found that doxycycline, OK-432, and ethanolamine oleate sclerotherapy appear to have a similar safety and efficacy profile in the treatment of macrocystic and mixed LMs of the head and neck in the pediatric population.

The full utility of diagnostic cerebral angiography, an invasive cerebrovascular imaging technique, is currently debated. Our goal was to determine trends in diagnostic cerebral angiography utilization and associated complications from 1999 through 2009. The National Inpatient Sample (NIS) was used to identify patients who received primary cerebral angiography from 1999-2009 in the United States. We observed trends in discharge volume, total mean charge, and post-procedural complications for this population. Data was based on sample projections and analyzed using univariate and multivariate regression. There were a total of 424,105 discharges indicating primary cerebral angiography nationwide from 1999-2009. The majority of these cases (65%) were in patients older than 55years. Embolic stroke was the most frequent complication, particularly in the oldest age bracket, occurring in 16,304 patients. The risk for complications increased with age (p0.0001) and with other underlying health conditions. Pulmonary, deep vein thrombosis, and renal associated comorbidities resulted in the greatest risk for developing post-procedural complications. Throughout the study period case volume for cerebral angiography remained constant while total charge per patient increased from $17,365 in 1999 to $45,339 in 2009 (p0.001). While the overall complication rate for this invasive procedure is relatively low, the potential risk for embolic stroke in older patients is significant. It is worth considering less invasive diagnostic techniques for an older and at risk patient population.

Collegiate football athletes are subject to repeated head impacts. The purpose of this study was to determine whether this exposure can lead to changes in brain structure. This prospective cohort study was conducted with up to 4 years of follow-up on 63 football (high-impact) and 34 volleyball (control) male collegiate athletes with a total of 315 MRI scans (after exclusions: football n ​= ​50, volleyball n ​= ​24, total scans ​= ​273) using high-resolution structural imaging. Volumetric and cortical thickness estimates were derived using FreeSurfer 5.3’s longitudinal pipeline. A linear mixed-effects model assessed the effect of group (football vs. volleyball), time from baseline MRI, and the interaction between group and time. We confirmed an expected developmental decrement in cortical thickness and volume in our cohort (p ​

Background Endovascular treated cerebral aneurysms have a greater recurrence rate compared with microsurgical clip ligation. Despite recent endovascular advances, microsurgical clip ligation might be the treatment of choice for certain previously endovascular treated recurrent aneurysms. We report on our single-center experience with 76 previously coiled and/or stent-coiled aneurysms. Objective To analyze the surgical and radiologic outcome after clipping of previous endovascular treated recurrent cerebral aneurysms. Methods Patients were retrospectively identified. Demographic data, aneurysm size, location, perioperative coil extraction, occlusion rate, and complication rate were recorded. Patients were divided into a previously coiled-only group (COG) and a previously stent-assisted coiled group (SAC). Results Seventy-five patients with 76 aneurysms were included. Sixty-nine patients were included in the COG, 7 patients in the SAC group. Complete or acceptable near-complete occlusion was obtained in 95% of patients in the COG and 57% in the SAC group. Two patients in the COG (2.9%) died postoperatively of a major stroke. One patient died of rehemorrhage after wrapping of an aneurysm. Minor complications occurred in 8.7%. In the SAC group, the mortality was 0%, with 1 major stroke (14.2%), 1 minor stroke (14.2%), and 1 cranial nerve palsy (14.2%). Intraoperative coil extraction and previous stent-assisted coiling were significant predictors of complication rate (P = 0.025 and P = 0.0036 respectively). Previous stent-assisted coiling was a significant predictor of incomplete occlusion (P = 0.036). Conclusions Microsurgical clipping of previously endovascular treated recurrent aneurysms is an effective treatment with high obliteration rates. Previously stent-assisted coiling and intraoperative coil extraction are predictors of worse outcome and incomplete occlusion.

Introduction/purpose MRI offers potential benefits over CT in selection for endovascular stroke thrombectomy. Despite this, only one-fourth of patients in the recently published DAWN and Defuse-3 trials were selected with MRI. Often, the major concern with MR utilization involves possibility of delayed treatment given the time associated with acquisition. Moreover, many patients being evaluated for acute ischemic stroke treatment will already have CT with CTA and possibly CTP and it is unclear whether additional information gleaned from an MR would change management. We present our single center experience in utilization of MRI for acute stroke. Materials and methods We retrospectively reviewed all stroke interventional radiology (SIR) activations at Stanford from February 2017 to February 2018. We assessed our breakdown of preprocedure imaging selection, the amount of time associated with obtaining imaging (looking at the arrival time to hospital, time of first image acquisition, and time to entering the angiography suite for each case). We paid particular attention to cases where patients had an outside CT and received an MR upon arrival to Stanford to see how often the MR acquisition changed management. We then selected a few representative cases for discussion. Results We identified 193 patients from February 2017 to February 2018 to be included in this study. In keeping with our practice pattern, the vast majority of cases (almost 85%) were through interfacility transfers from outside hospitals. Only a minority of our cases came through our institution’s emergency department. Almost all patients coming through interfacility transfers had CT and CTA prior to transfer. Patients who underwent mechanical thrombectomy who had preprocedure MRIs did not experience delay in treatment. Door to first image time did not vary between CT and MR as expected. The average time from first image acquisition to cath lab arrival time also did not differ significantly (27 min with MRI versus 21 with CT/CTA/CTP). Approximately 38% of cases underwent endovascular treatment. Moreover, in cases where outside CT, CTA and/or CTP were available, MR at our institution often was helpful assessing for size of core infarct (which not infrequently hanged from time of initial outside CT imaging acquisition), provided better assessment of collaterals over CTA, and thereby frequently influenced management. Conclusion MRI offers advantages over CT in endovascular stroke therapy selection, particularly with regards to assessing size of core infarction (which does not infrequently change from the time a transfer is called to the time a patient arrives at a comprehensive stroke center) and determining collateral status. MRI selection also does not necessarily confer a delay in treatment if key stroke systems of care are in place. Disclosures A. Patel: None. U. Manzoor: None. A. Iyer: None. H. Do: None. M. Wintermark: None. M. Marks: None. R. Dodd: None.

Introduction: Arterial spin labeling (ASL) MRI can non-invasively measure quantitative CBF. Evaluation of hemodynamics in the ipsilateral hemisphere is a common practice for selecting patients for therapy. In this study, we hypothesized that the contralateral CBF (cCBF) may identify patients with high collateral capacity and better outcome. Hypothesis: In acute stroke, higher CBF in the unaffected hemisphere is associated with better neurological outcome. Methods: Patients were part of the prospective ‘iCAS’ (imaging the Collaterals in Acute Stroke) study. Inclusion criteria were: ischemic hemispheric stroke (< 16 hrs onset to imaging time [OIT]), age>=18, informed consent, and technically adequate imaging including GRE, DWI, and 3D pseudocontinuous ASL. Outcomes were assessed by NIHSS at baseline, day 1, and day 5; and mRS at day 30 and day 90. After image registration to an MNI template, mean cCBF was calculated at standard ASPECTS levels in the contralateral hemisphere. Patients were dichotomized by median cCBF into low and high cCBF groups. Results are reported as medians with interquartile ranges [IQR]. Outcome differences were assessed with Wilcoxon (NIHSS) and Fisher’s exact test (mRS). Results: 61 patients met inclusion criteria: 32 F, age 66 yrs [54-77], OIT 4.8 hrs [3.4-7.2], baseline NIHSS 13 [8-19], 36 underwent thrombectomy [28 with final TICI >= 2b], cCBF 38.8 [31-46] ml/100 g/min. There was no difference between groups in age, gender, OIT, or reperfusion. Median NIHSS at baseline/day1/day5 for low and high cCBF groups was 13/14/11 and 12/6/4, respectively, which was significantly different on day 1 (p=.009) and day 5 (p=.031). Patients with higher cCBF had lower contralateral arterial transit time (p=.029) and better day 90 mRS (p=.029). Conclusion: Higher ASL cCBF predicts better outcome in acute stroke independent of baseline NIHSS and reperfusion status. This may reflect a better underlying capacity for collateral flow to the ischemic hemisphere.

Introduction: A paradigm shift in the management of intracerebral aneurysms occurred after the favorable outcomes of coiling were established. Over time, coiled aneurysms have shown high recurrence rates requiring retreatment. Methods: We conducted a retrospective study of all patients who underwent surgical clipping of a previously coiled recurrent intracerebral aneurysm between 1997 and 2017 at our institution. Results: 70 patients met the inclusion criteria. Mean age was 56.4 years (range, 28-77 years), and 40% were male. 61 patients (87%) initially presented with subarachnoid hemorrhage. The mean aneurysm size before clipping was 10.9mm. The average number of endovascular procedures prior to clipping was 1.13 (range 1-3). Indications for clipping included coil compaction in 40%, growing aneurysm base from partially coiled aneurysms in 50%, daughter sac formation in 4%, refilling of the dome in 1.4%, and rebleed in 4%. Coils were extracted in 6 patients (8.6%). Among the 57 patients with post-operative angiograms, 49 aneurysms (86%) showed complete angiographic obliteration, whereas 8 aneurysms (14%) demonstrated small post-clipping residuals. 7.1% of patients sustained minor complications. 3 patients had small clinical strokes that resolved within 2 months, 1 cranial nerve palsy, and 1 infected bone flap. 5.7% of patients suffered a major complication including 2 with severe strokes leading to withdrawal of care, 1 with significant strokes leading to poor functional status, and 1 extraaxial hematoma requiring evacuation. In univariate analyses, the risk of having post-clipping residual was associated with larger aneurysm size (p=0.04) and increased number of prior endovascular procedures (p=0.020). Coil extraction was associated with a greater risk of postoperative complications (p=0.027). Conclusion: In conclusion, surgical clipping is an effective therapy for the treatment of recurrent coiled aneurysms, that carries a 5.7% risk of major complications. Further studies should compare the incidence of aneurysm obliteration, rebleed, and complications between clipping versus additional endovascular treatment for these challenging aneurysms.

Trigeminal neuralgia is a facial pain syndrome characterized by excruciating, paroxysmal, electric shock-like pain attacks in the sensory distribution of the trigeminal nerve. Medical management remains the first line of treatment. When this fails, surgical management needs to be considered. Percutaneous interventional procedures such as glycerol rhizotomy, radiofrequency (RF) thermocoagulation, and balloon compression of the trigeminal ganglion and its branches are some of the most commonly used procedures as they avoid exposure to general anesthesia, provide successful short-term results, and are available to people with significant co-morbidities. Of these, RF is the most often used. The V2 and V3 branches of the trigeminal nerve are most commonly affected, and are thus the most frequent targets for RF interventions. These procedures may be performed using conventional fluoroscopic, ultrasound, or CT-guided imaging, including combined flat-panel CT and fluoroscopy. This chapter summarizes these common ablation techniques targeting the V2 branch of the trigeminal nerve.