Safety and functional outcomes of early antiplatelet therapy within 24 hours following mechanical thrombectomy for secondary prevention in emergent large-vessel occlusion strokes: a registry study.

OBJECTIVE: The aim of this study was to demonstrate the safety and functional outcomes of antiplatelet use within 24 hours following mechanical thrombectomy (MT). METHODS: A retrospective review of prospectively collected data for consecutive patients who underwent MT for acute ischemic stroke (AIS) between 2016 and 2020 was performed. Patient demographics, comorbidities, Alberta Stroke Program Early CT Score (ASPECTS), antiplatelet use, neurological status, and tissue plasminogen activator use were collected. Patients were stratified into two groups, early (< 24 hours) or late (> 24 hours), based on when antiplatelet therapy was initiated post-MT. The primary outcome was safety, determined based on the rate of symptomatic intracranial hemorrhage (sICH) and inpatient mortality. The secondary outcome was functional independence (defined as modified Rankin Scale [mRS] score ≤ 2) at discharge and 30 days and 90 days postoperatively. The two cohorts were compared using univariate analysis. Multiple imputations were used to create complete data sets for missing data. Multivariable analysis was used to identify predictors for sICH and functional outcomes. RESULTS: A total of 190 patients met inclusion criteria (95 per group). Significant differences between the early and late groups included sex, preoperative intravenous thrombolysis, angioplasty, stent placement, and thrombectomy site. ICH (symptomatic and asymptomatic) and inpatient mortality were not significantly different between the groups. The mRS score was significantly lower at discharge (p < 0.001), 30 days (p = 0.011), and 90 days (p = 0.024) following MT in the early group. Functional independence was significantly higher in the early antiplatelet group at discharge (p = 0.015) and at 30 days (p = 0.006). Early antiplatelet use was independently associated with significantly increased odds of achieving functional independence at discharge (OR 3.07, p = 0.007) and 30 days (OR 5.78, p = 0.004). Early antiplatelet therapy was not independently associated with increased odds of sICH. CONCLUSIONS: Early antiplatelet initiation after MT in patients with AIS was independently associated with significantly increased odds of improved postoperative functional outcomes without increased odds of developing sICH.

Endovascular Treatment of Arteriovenous Malformations of the Head and Neck: Focus on the Yakes Classification and Outcomes.

PURPOSE: To evaluate endovascular treatment of head and neck arteriovenous malformations (AVMs) based on the Yakes AVM classification and correlate treatment approach with clinical and angiographic outcomes. MATERIALS AND METHODS: A retrospective single-center study was performed in patients who underwent endovascular treatment of head and neck AVMs between January 2005 and December 2017. Clinical and operative records, imaging, and postoperative courses of patients were reviewed. Clinical stage was determined according to the Schobinger classification. AVM architecture and treatment approaches were determined according to the Yakes classification. Primary outcomes were clinical and angiographic treatment success rates and complication rates, with analysis according to the Yakes classification. RESULTS: A total of 29 patients (15 females) were identified, with a mean age of 30.6 years. Downgrading of the Schobinger clinical classification was achieved in all patients. Lesions included 8 Yakes type IIa, 5 type IIb, 1 type IIIa and IIIb, and 14 type IV. Lesions were treated using an intra-arterial, nidal, or transvenous approach, using ethanol and liquid embolic agents. Arteriovenous shunt eradication of >90% was achieved in 22 of 28 patients (79%), including 9 of 13 (69%) of Yakes type IV lesions and 13 of 15 (87%) of the other types. There were 5 significant complications in 79 procedures (6%), including 4 of 50 (8%) in Yakes type IV lesions. CONCLUSIONS: Schobinger stage was downgraded in all patients. Arteriovenous shunt eradication of >90% was achieved in most patients. Yakes type IV lesions required more sessions, and shunt eradication was higher in the Yakes II and III groups.

A Population-Based Study of Intracerebral Hemorrhage Survivors' Outcomes.

BACKGROUND: We evaluated 3-month neurologic, functional, cognitive, and quality of life (QOL) outcomes in intracerebral hemorrhage (ICH) overall, and by sex and ethnicity in a population-based study. METHODS: Spontaneous ICH patients were identified from the Brain Attack Surveillance in Corpus Christi project (November 2008 to December 2013). Outcomes included neurologic (National Institutes of Health Stroke Scale: range 0-42), functional (activities of daily living/instrumental activities of daily living score: range 1-4, higher worse), cognitive (Modified Mini-Mental State Examination [3MSE]: range 0-100), and QOL (short-form stroke-specific QOL scale: range 0-5, higher better). Ethnic and sex differences were assessed with Tobit regression adjusted for age, sex, or ethnicity, and presenting Glasgow coma scale. RESULTS: A total of 245 patients completed baseline interviews, with 103 (42%) dying prior to follow-up, leaving 142 eligible for outcome assessment. Three-month follow-up was completed in 100 (neurologic), 107 (functional), 79 (cognitive), and 83 (QOL) participants. Median age was 66 years (interquartile range 58.0-77.0). Cognitive outcomes were worse in Mexican Americans (MA) compared to non-Hispanic whites (NHW) after multivariable adjustment (MA scoring 13.3 3MSE points lower than NHW [95% confidence interval: 5.8, 20.7; P = .0005]). There was no difference by sex or ethnicity in neurological, functional, or QOL outcomes, and no sex differences in cognitive outcomes. CONCLUSIONS: In this population-based study, worse cognitive outcomes were found in MAs compared with NHW. There were no differences between neurologic, functional, and QOL outcomes in ICH survivors based on sex or ethnicity.

Advanced Neuroimaging Techniques: Basic Principles and Clinical Applications.

Advanced neuroimaging techniques are increasingly being implemented in clinical practice as complementary tools to conventional imaging because they can provide crucial functional information about the pathophysiology of a variety of disorders. Therefore, it is important to understand the basic principles underlying them and their role in diagnosis and management. In this review, we will primarily focus on the basic principles and clinical applications of perfusion imaging, diffusion imaging, magnetic resonance spectroscopy, functional MRI, and dual-energy computerized tomography. Our goal is to provide the reader with a basic understanding of these imaging techniques and when they should be used in clinical practice.

Use of the Pipeline embolization device in the treatment of iatrogenic intracranial vascular injuries: a bi-institutional experience.

OBJECTIVE Flow-diverting devices have been used for the treatment of complex intracranial vascular pathology with success, but the role of these devices in treating iatrogenic intracranial vascular injuries has yet to be clearly defined. Here, the authors report their bi-institutional experience with the use of the Pipeline embolization device (PED) for the treatment of iatrogenic intracranial vascular injuries. METHODS The authors reviewed a retrospective cohort of patients with iatrogenic injuries to the intracranial vasculature that were treated with the PED between 2012 and 2016. Data collection included demographic data, indications for treatment, number and sizes of PEDs used, and immediate and follow-up angiographic and clinical outcomes. RESULTS Four patients with a mean age of 47.5 years (range 18-63 years) underwent PED placement for iatrogenic vessel injuries. In 3 patients, the intracranial internal carotid artery (ICA) was injured during transnasal tumor resection. In 1 patient, a basilar apex injury occurred during endoscopic third ventriculostomy. Three patients had a pseudoaneurysm as a result of vessel injury, and 1 patient had frank ICA laceration and extravasation. All 3 pseudoaneurysms were successfully treated with PED deployment. The ICA laceration was refractory to PED placement, and the vessel was subsequently occluded endovascularly. All 4 patients had a good clinical outcome (modified Rankin Scale score of 0 or 1). CONCLUSIONS The use of the PED is feasible in the management of iatrogenic pseudoaneurysms of the intracranial vasculature. In cases of frank vessel perforation, an alternative strategy such as covered stent placement should be considered. Endovascular or surgical vessel occlusion remains the definitive treatment in cases of refractory hemorrhage.

Neurovascular emergencies: imaging diagnosis and neurointerventional treatment.

Neurovascular emergencies, consisting of acute ischemic stroke, non-traumatic aneurysmal subarachnoid hemorrhage, arteriovenous malformation, dural arteriovenous fistula, and carotid- cavernous fistula, can have an acute presentation to the emergency department. Radiologists should have an understanding of these processes and their imaging findings in order to provide a prompt and accurate diagnosis. Neurointerventional radiology plays a critical role in providing additional diagnostic information and potentially curative treatment. Understanding the grading scales used to evaluate and prognosticate these neurovascular emergencies can help expedite management for best possible patient outcomes.

Endovascular Treatment of Noncavernous Dural Arteriovenous Fistulas: Analysis of Outcomes with and without Ethylene Vinyl Alcohol.

OBJECTIVE: Noncavernous dural arteriovenous fistulas (DAVFs) are uncommon lesions that can be treated from an endovascular approach using various embolic materials. The purpose of this study was to evaluate our outcomes for endovascular treatment of DAVFs with and without the use of ethylene vinyl alcohol (EVOH). METHODS: We performed a retrospective analysis of 65 patients treated for DAVF at our institution from January 1995 to May 2015. Lesions were classified as aggressive or benign, based on angiography according to Cognard classification. Demographic data, medical comorbidities, presenting symptoms, treatment modality, treatment outcomes, and complications were evaluated for each group. Primary outcome was defined as angiographic occlusion for an aggressive DAVF, and resolution of clinical symptoms for a benign DAVF. RESULTS: The primary outcome was met in 47 (82.5%) of 57 cases with endovascular therapy alone; 23 (69.7%) of 33 aggressive fistulas; and 24 (100.0%) of 24 benign fistulas. There was a 5% overall complication rate. The primary outcome was achieved via endovascular approach in 80.0% (24 of 30) of cases with EVOH, and 85.2% (23 of 27) of cases without EVOH (P = .73). There was a 6% complication rate for procedures using EVOH versus 3% for cases without EVOH (P = 1.00), a 13% clinical recurrence rate for cases using EVOH compared to .0% when EVOH was not used (P = .24), and no angiographic recurrences in either group (P = 1). There were no procedure-related mortalities. CONCLUSIONS: Endovascular treatment of DAVFs has a high success rate and low complication rate. Our experience demonstrated no difference in outcomes between lesions treated with EVOH and those treated without EVOH.

Successful treatment of a Musculoskeletal Tumor Society grade 3 aneurysmal bone cyst with N-butyl cyanoacrylate embolization and percutaneous cryoablation.

This report presents a 13-year-old girl with an aggressive skeletal lesion involving the posterior elements of the cervicothoracic junction. The lesion was determined to be a Musculoskeletal Tumor Society grade 3 aneurysmal bone cyst based on imaging and pathologic findings. The cyst was treated with endovascular n-butyl cyanoacrylate embolization and percutaneous cryoablation with sensory and motor-evoked potential monitoring. Follow-up imaging at 16 months demonstrated significant reduction in the size of the lesion, with no evidence of recurrence.

Issues in the diagnosis and management of the papilledema shunt.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) that shunt blood into the transverse or superior sagittal venous sinuses cause papilledema by raising intracranial pressure ("the papilledema shunt"). Such fistulas pose unique diagnostic and therapeutic challenges. METHODS: Case report and literature review. RESULTS: In a patient presenting with papilledema, non-invasive brain vascular imaging disclosed subtle signs of a DAVF. Digital angiography delineated the DAVF and revealed cortical venous reflux. After three transarterial embolizations with ethylene vinyl alcohol, the DAVF was closed and papilledema resolved. CONCLUSIONS: The imaging features of a DAVF that cause papilledema may be subtle on non-invasive vascular imaging. If overlooked, and lumbar puncture is performed, there is a substantial risk of brain herniation. Cortical venous reflux, which may be relatively common in these DAVFs, impels the need for endovascular closure. The transvenous route, often employed for closing cavernous sinus DAVFs, should be avoided because of the dangers of dural venous sinus thrombosis.

A comparison of particulate and Onyx embolization in preoperative devascularization of carotid body tumors.

INTRODUCTION: Preoperative embolization of a carotid body tumor (CBT) is a useful adjunct prior to surgical excision because it decreases operative blood loss and improves surgical outcomes. Traditionally, this is performed by transarterial particulate embolization (TAPE). More recently, direct percutaneous embolization (DPE) with Onyx is recognized as a promising technique for preoperative embolization. We compared these two techniques in patients treated for CBTs at our institution. METHODS: We retrospectively reviewed cases of preoperative devascularization of CBT from 1 January 1995 through 1 September 2012. Patient cases were placed into two groups: TAPE and DPE. Operative blood loss, operative length, angiographic devascularization, embolization procedure complications, operative transfusion requirements, postoperative hospital stay, intensive care unit (ICU) stay, and procedure-related mortalities were compared. RESULTS: A total of 17 patients underwent preoperative devascularization of their CBT with TAPE technique and ten patients using the DPE technique with Onyx. Average operative blood loss was significantly higher in the TAPE group (Mann-Whitney U test, p = 0.04). Operative time was also higher, although this difference was not significant. Two patients required intraoperative blood transfusions in the TAPE group while none required transfusions in the DPE group. There was no significant difference in ICU stay or length of hospitalization. One serious embolization procedure complication occurred in the TAPE group and none in the DPE group. CONCLUSION: Operative blood loss in the DPE group was significantly less than the TAPE group. Blood transfusion requirement, operative time, and complications were less in the DPE group, although they did not reach statistical significance.

Preoperative computed tomography perfusion in pediatric moyamoya disease: a single-institution experience.

OBJECTIVE: Moyamoya disease is a progressive occlusive arteriopathy for which surgical revascularization is indicated. In this retrospective study, the authors investigated the use of preoperative CT perfusion with the aim of establishing pathological data references. METHODS: The authors reviewed the medical records of children with moyamoya disease treated surgically at one institution between 2016 and 2019. Preoperative CT perfusion studies were used to quantify mean transit time (MTT), cerebral blood volume (CBV), cerebral blood flow (CBF), and time to peak (TTP) for the anterior, middle, and posterior cerebral artery vascular territories for each patient. CT perfusion parameter ratios (diseased/healthy hemispheres) and absolute differences were compared between diseased and normal vascular territories (defined by catheter angiography studies). Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values for CT perfusion parameters for severe angiographic moyamoya were calculated. RESULTS: Nine children (89% female) had preoperative CT perfusion data; 5 of them had evidence of unilateral hemispheric disease and 4 had bilateral disease. The mean age at revascularization was 77 months (range 40-144 months). The etiology of disease was neurofibromatosis type 1 (3 patients), Down syndrome (2), primary moyamoya disease (2), cerebral proliferative angiopathy (1), and sickle cell disease (1). Five patients had undergone unilateral revascularization. Among these patients, pathological vascular territories demonstrated increased MTT in 66% of samples, increased TTP in 66%, decreased CBF in 47%, and increased CBV in 87%. Severe moyamoya (Suzuki stage ≥ 4) had diseased/healthy ratios ≥ 1 for MTT in 78% of cases, for TTP in 89%, for CBF in 67%, and for CBV in 89%. The MTT and TTP region of interest ratio ≥ 1 demonstrated 89% sensitivity, 67% specificity, 80% PPV, and 80% NPV for the prediction of severe angiographic moyamoya disease. CONCLUSIONS: Pathological hemispheres in these children with moyamoya disease demonstrated increased MTT, TTP, and CBV and decreased CBF. The authors' results suggest that preoperative CT perfusion may, with high sensitivity, be useful in deciphering perfusion mismatch in brain tissue in children with moyamoya disease. More severe angiographic disease displays a more distinct correlation, allowing surgeons to recognize when to intervene in these patients.

Analysis of human emboli and thrombectomy forces in large-vessel occlusion stroke.

OBJECTIVE: This study's purpose was to improve understanding of the forces driving the complex mechanical interaction between embolic material and current stroke thrombectomy devices by analyzing the histological composition and strength of emboli retrieved from patients and by evaluating the mechanical forces necessary for retrieval of such emboli in a middle cerebral artery (MCA) bifurcation model. METHODS: Embolus analogs (EAs) were generated and embolized under physiological pressure and flow conditions in a glass tube model of the MCA. The forces involved in EA removal using conventional endovascular techniques were described, analyzed, and categorized. Then, 16 embolic specimens were retrieved from 11 stroke patients with large-vessel occlusions, and the tensile strength and response to stress were measured with a quasi-static uniaxial tensile test using a custom-made platform. Embolus compositions were analyzed and quantified by histology. RESULTS: Uniaxial tension on the EAs led to deformation, elongation, thinning, fracture, and embolization. Uniaxial tensile testing of patients' emboli revealed similar soft-material behavior, including elongation under tension and differential fracture patterns. At the final fracture of the embolus (or dissociation), the amount of elongation, quantified as strain, ranged from 1.05 to 4.89 (2.41 ± 1.04 [mean ± SD]) and the embolus-generated force, quantified as stress, ranged from 63 to 2396 kPa (569 ± 695 kPa). The ultimate tensile strain of the emboli increased with a higher platelet percentage, and the ultimate tensile stress increased with a higher fibrin percentage and decreased with a higher red blood cell percentage. CONCLUSIONS: Current thrombectomy devices remove emboli mostly by applying linear tensile forces, under which emboli elongate until dissociation. Embolus resistance to dissociation is determined by embolus strength, which significantly correlates with composition and varies within and among patients and within the same thrombus. The dynamic intravascular weakening of emboli during removal may lead to iatrogenic embolization.

Endovascular Thrombectomy for Pediatric Acute Ischemic Stroke: A Multi-Institutional Experience of Technical and Clinical Outcomes.

BACKGROUND: Endovascular thrombectomy is a promising treatment for acute ischemic stroke in children, but outcome and technical data in pediatric patients with large-vessel occlusions are lacking. OBJECTIVE: To assess technical and clinical outcomes of thrombectomy in pediatric patients. METHODS: We undertook a retrospective cohort study of pediatric patients who experienced acute ischemic stroke from April 2017 to April 2019 who had immediate, 30-, and 90-d follow-up. Patients were treated with endovascular thrombectomy at 5 US pediatric tertiary care facilities. We recorded initial and postprocedural modified Thrombolysis in Cerebral Infarction (mTICI) grade ≥ 2b, initial and postprocedural Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score, and pediatric modified Rankin scale (mRS) score 0 to 2 at 90 d. RESULTS: There were 23 thrombectomies in 21 patients (mean age 11.6 ± 4.9 yr, median 11.5, range 2.1-19; 52% female). A total of 19 (83%) thrombectomies resulted in mTICI grade ≥ 2b recanalization. The median PedNIHSS score was 13 on presentation (range 4-33) and 2 (range 0-26) at discharge (mean reduction 11.3 ± 6.1). A total of 14 (66%) patients had a mRS score of 0 to 2 at 30-d follow-up; 18/21 (86%) achieved that by 90 d. The median mRS was 1 (range 0-4) at 30 d and 1 (range 0-5) at 90 d. One patient required a blood transfusion after thrombectomy. CONCLUSION: In this large series of pediatric patients treated with endovascular thrombectomy, successful recanalization was accomplished via a variety of approaches with excellent clinical outcomes; further prospective longitudinal study is needed.

Neuroprotection for ischemic stroke in the endovascular era: A brief report on the future of intra-arterial therapy.

Mechanical thrombectomy is now at the forefront of the treatment of large vessel acute ischemic stroke (AIS). Selective intra-arterial (IA) access has opened a new avenue for neuroprotection in AIS that has the potential to maximize local benefit while minimizing systemic effects. On a cellular level, neuroprotective strategies are aimed at reducing inflammation and free-radical formation, maintaining blood-brain barrier fidelity, and preventing cellular death. Strategies under investigation include IA infusion of neuroprotective agents, IA administration of stem cells, and selective IA hypothermia. In this technical report, we briefly discuss pathologic mechanisms in AIS and highlight potential neuroprotective strategies that are administered selectively via the IA route.

Development of bilateral dural arteriovenous fistulae following pial synangiosis for moyamoya syndrome: case report.

Moyamoya syndrome predisposes patients to ischemic or hemorrhagic stroke due to progressive narrowing of intracranial vessels with subsequent small-vessel collateralization. Dural arteriovenous fistulae (DAVFs) are most commonly noted after venous sinus or cortical vein thrombosis and are believed to be primarily due to venous hypertension and elevated sinus pressures, although there is no known association with moyamoya syndrome, or with surgical treatment for moyamoya disease (MMD). The authors present the case of a 14-year-old girl with Down syndrome treated using pial synangiosis for MMD who subsequently was noted to have bilateral DAVFs. This case provides a new perspective on the origins and underlying pathophysiology of both moyamoya syndrome and DAVFs, and also serves to highlight the importance of monitoring the moyamoya population closely for de novo cerebrovascular changes after revascularization procedures.

Brain tissue iron quantification by MRI in intracerebral hemorrhage: Current translational evidence and pitfalls.

Intracerebral hemorrhage (ICH) is a common subtype of hemorrhagic stroke with devastating consequences with no specific treatment. There is, however, substantial evidence for iron-mediated neurotoxicity in animal ICH models. Non-invasive quantification of the peri-hematomal tissue iron based on MRI has shown some promise in animal models and is being validated for clinical translation. This commentary reviews evidence for this approach and discusses potential pitfalls.

A national analysis of 9655 pediatric cerebrovascular malformations: effect of hospital volume on outcomes.

OBJECTIVE: Comprehensive multicenter data on the surgical treatment of pediatric cerebrovascular malformations (CVMs) in the US are lacking. The goal of this study was to identify national trends in patient demographics and assess the effect of hospital case volume on outcomes. METHODS: Admissions for CVMs (1997-2012) were identified from the nationwide Kids' Inpatient Database. Admissions with and without craniotomy were reviewed separately. Patients were categorized by whether they were treated at low-, medium-, or high-volume centers (< 10, 10-40, > 40 cases/year, respectively). A generalized linear model was used to evaluate the association of hospital pediatric CVM case volume and clinical variables assessing outcomes. RESULTS: Among the 9655 patients, 1828 underwent craniotomy and 7827 did not. Patient age and race differed in the two groups, as did the rate of private medical payers. High-volume hospitals had fewer nonroutine discharges (11.2% [high] vs 16.4% [medium] vs 22.3% [low], p = 0.0001). For admissions requiring craniotomy, total charges ($106,282 [high] vs $126,215 [medium] vs $134,978 [low], p < 0.001) and complication rates (0.09% [high] vs 0.11% [medium] vs 0.16% [low], p = 0.001) were lower in high-volume centers. CONCLUSIONS: This study revealed that further investigation may be needed regarding barriers to surgical treatment of pediatric CVMs. The authors found that surgical treatment of pediatric CVM at high-volume centers is associated with significantly fewer complications, better dispositions, and lower costs, but for noncraniotomy patients, low-volume centers had lower rates of complications and death and lower costs. These findings may support the consideration of appropriate referral of CVM patients requiring surgery or with intracranial hemorrhage toward high-volume, specialized centers.

Moderate Sedation for Pipeline Embolization of Posterior Circulation Disease: Technical Note from a Single Center.

OBJECTIVE: Flow diversion has been an important addition to endovascular neurosurgery, but its use in the posterior circulation remains controversial. Our goal is to describe the safety and efficacy of moderate sedation during flow diversion for posterior circulation lesions (aneurysms or dissecting pseudoaneurysms). METHODS: The authors retrospectively reviewed the medical records of all patients who underwent placement of a Pipeline embolization device for a posterior circulation lesion using moderate sedation at a single institution from August 2012 through November 2017. Clinical data and outcomes were evaluated. RESULTS: Fifteen consecutive patients were identified: 8 female, 7 male (mean age 52.2 ± 16.3 years, range 15-81). Eleven lesions were located in the vertebral artery, 1 in the posterior inferior cerebellar artery, 2 in the posterior cerebral artery, and 1 in the basilar artery. All patients underwent flow diversion with Pipeline embolization devices. One patient experienced an acute occlusion of the basilar artery during the procedure that required revascularization. Mean fluoroscopy time was 35.6 ± 16.5 minutes (range 15.5-75). Mean follow-up time was 12.7 ± 8.8 months (range 3-36). No patient had new neurologic deficits in the perioperative or postoperative period. Conversion to general anesthesia was not required in any case. CONCLUSIONS: Moderate sedation is safe and feasible in patients undergoing flow diversion for posterior circulation lesions. In addition, its use may allow for more rapid identification of procedural complications, facilitating emergent treatment and decreasing procedure-related morbidity.