Posterior Circulation Aneurysms.

Posterior circulation aneurysms have a higher tendency to rupture and become symptomatic in comparison to anterior circulation aneurysms. Current treatment modalities for aneurysms in these locations vary widely including microsurgical clipping, trapping with bypass, wrapping, and various endovascular methods such as coiling, balloon or stent-assisted coiling, flow diversion, and vessel sacrifice, among others.Overall, surgical versus endovascular treatment of posterior circulation aneurysms continue to be a controversial topic in cerebrovascular neurosurgery. At our center, multi-disciplinary assessments including surgeons capable of both endovascular and microsurgical treatments of these aneurysms are employed to guide the treatment strategies. As advancements in both fields are made, this will continue to be a topic for debate. Anatomy and individual patient's characteristics will dictate the correct approach and therefore proficiency in the microsurgical techniques required to treat these aneurysms will continue to be both relevant and important.

Head and neck arteriovenous malformations: University of Tennessee experience, 2012-2022.

OBJECTIVE: Head and neck arteriovenous malformations (AVMs) are complex lesions that represent a subset of vascular anomalies (VAs). The authors present an analysis of their institutional experience managing these lesions as a multidisciplinary team. METHODS: A retrospective chart review was performed of head and neck AVM patients treated at the authors' institution from 2012 to 2022. Recorded data included patient demographic characteristics, details of clinical presentation, Schöbinger clinical scale and Yakes AVM classification results, and details of all endovascular and surgical treatments. The primary outcome of the study was clinical response to treatment. Angiographic occlusion and complication rates were reported. Chi-square tests were used for comparative statistics. RESULTS: Sixteen patients (9 female, 56%) with AVMs of the head and neck presented from age 3 to 77 years. The Schöbinger stage was stage II in 56% of patients (n = 9) and stage III in 44% of patients (n = 7). The Yakes AVM classification was nidus type (2a, 2b, or 4) in 7 patients (43%) and fistula type (1, 3a, or 3b) in 9 patients (57%). The majority of patients (n = 11, 69.0%) were managed with embolization as the only treatment modality, with an average of 1.5 embolizations/patient (range 1-3). Surgical resection was employed in 5 patients (4 in combination with embolization). Symptom resolution and symptom control were achieved in 69% and 31% of patients, respectively, in the entire cohort. A radiographic cure was demonstrated in 50% of patients. There were no statistical differences in clinical outcomes or radiographic cure rates between patients treated with different modalities. CONCLUSIONS: Head and neck AVMs can be treated successfully with a primarily endovascular management strategy by a multidisciplinary team with the goal of symptomatic control.

Yield of ASPECTS and Collateral CTA Selection for Mechanical Thrombectomy within 6-24 hours from Symptom Onset in a Hub and Spoke System.

BACKGROUND: Recent extended window trials support the benefit of mechanical thrombectomy in anterior circulation large vessel occlusions with clinical-radiographic dissociation. Using trial imaging criteria, 6% were found eligible for MT in the EW in a hub-and-spoke system. We examined the eligibility and outcomes in consecutive extended window-mechanical thrombectomy patients using more pragmatic selection criteria. METHODS: We retrospectively analyzed single-institution data of anterior circulation large vessel occlusions patients presenting between 6-24 h who underwent mechanical thrombectomy based on a priori determined criteria including non-contrast CT head ASPECTS ≥ 6 and/or CTA collateral scores ASITN/SIR 2-4. Primary outcomes consisted of post-mechanical thrombectomy TICI 2b-3 and 3-month modified Rankin scores; safety outcomes consisted of in-hospital mortality and symptomatic intracerebral hemorrhage. RESULTS: 767 consecutive acute ischemic strokes patients presented within the 6-24 hour window, and of these 48 (6%) anterior circulation large vessel occlusions patients underwent mechanical thrombectomy. In this cohort the mean age was 63±17 years, 56% were male, the median NIHSS was 16 [IQR 10-19], the median ASPECTS was 9 (IQR 8-10), and 79% (n=38) had good CTA collaterals. Occlusions were primarily M1 MCA (46%), with 29% tandem occlusions. Successful recanalization (mTICI 2b or 3) was achieved in 73% (n=35), while 6% (n=3) of patients developed symptomatic intracerebral hemorrhage. In-hospital mortality was 25% (n=12) while 40% (n=19) achieved 3-month modified Rankin Scores 0-2. CONCLUSIONS: Our data suggest the use of pragmatic imaging approach of ASPECTS ≥6 with CTA collateral grade in extended time window which is already established in most hospitals.

Low profile sheaths in pediatric neurointervention: a multicenter experience.

BACKGROUND: Pediatric neurointervention is challenged by the appropriateness of adult catheters and devices. This multicenter report on the smallest groin access sheaths offers technical notes and clinical outcomes in the pediatric neurointerventional population. METHODS: All pediatric neurointerventional cases from 2019 to 2021 were reviewed for use of a 3.3F Pediavascular or a 4F Merit Prelude Ideal low profile sheath. Hospital records were reviewed for complications and technical notes and compared with arterial groin access with the 4F Terumo Pinnacle in infants less than 1 year old, before the low profile sheaths at one author's institution were introduced. RESULTS: From January 1, 2019 to March 31, 2021 there were 347 procedures performed at Boston Children's Hospital and University of Wisconsin. Forty-four procedures in 26 patients were identified in which a 3.3F (38 cases, 20 patients) or 4F (6 cases, 6 patients) sheath was used. The average age was 2.2 years (1.5 days to 18 years). Retinoblastoma intra-arterial chemotherapy infusion (18 of 44) was the most common indication. The remaining procedures comprised vein of Galen embolization (12), diagnostic cerebral angiography (13), and one preoperative tumor embolization. Morbidity included a groin hematoma and decreased pulses (4.5%). No major groin complications occurred. There was no statistically significant difference compared with the historical cohort (132 procedures), which had seven instances of decreased pulses (5.3%, p>0.05). CONCLUSION: The 3.3F Pediavascular and 4F Merit Prelude Ideal sheaths are easily incorporated into the pediatric neurointerventionalist's armamentarium for infants and readily accommodate various microcatheters for distal embolization and catheterization.

Wide Arterial Sparing Encephalo-Duro-Synangiosis for Moyamoya: Surgical Technique and Outcomes.

BACKGROUND: Moyamoya is managed by surgical revascularization, but no standardized method has yet been universally adopted. OBJECTIVE: To describe a new indirect bypass technique for pediatric moyamoya, wide arterial sparing encephalo-duro-synangiosis (WASEDS), which provides a much wider area of revascularization with minimal compromise to the middle meningeal arterial tree compared with traditional procedures. Initially used as a salvage technique after failed encephalo-duro-arterio-synangiosis, its success later motivated its use as a first-line procedure. METHODS: Clinical and radiographic records of patients who underwent WASEDS for moyamoya from 2009 to 2020 were reviewed. Brain perfusion relative cerebral blood volume on the side of the WASEDS procedure was calculated. Two-tailed paired t tests were performed to identify the statistically significant differences ( P ≤ .05). RESULTS: WASEDS was successfully performed on 8 patients for a total of 14 cerebral hemispheres. Age ranged from 2 to 25 years. There were no mortalities. The average clinical and radiographic follow-up was 49.79 months (range 2-126 months), demonstrating improvement in neurological condition and no postoperative stroke and significant diminution or cessation of transient ischemic attacks in all patients. Relative cerebral blood volume increased 9.24% after the WASEDS procedure ( P = .012). There were no neurological complications. There were 2 pseudomeningoceles related to the extensive dural openings. CONCLUSION: WASEDS is a safe and effective indirect revascularization technique for both primary and salvage techniques. It provides an extensive area of cortical revascularization with no compromise of the middle meningeal vasculature and subjective reports of early improvement in cognition and behavior. The main disadvantage is elevated risk of pseudomeningocele secondary to the large craniotomy.

Sequential Flow Diversion After Nitinol Stent Placement for a Large, Matricidal Cavernous Internal Carotid Artery Aneurysm: Technical Video.

The Surpass Evolve flow diverter is a novel 64-wire braided intravascular stent approved to treat unruptured large or giant saccular wide-neck or fusiform intracranial aneurysms of the intracranial internal carotid artery.1-3 Flow diverting stents have been used for the treatment of previously stented aneurysms, including residual aneurysms following prior flow diversion.5-8 This patient initially presented with a large symptomatic matricidal cavernous ICA aneurysm4 that was treated with stand-alone Neuroform Atlas stenting at an outside hospital. Here we present a video demonstrating the placement of sequential Surpass Evolve flow diverter stents within a Neuroform Atlas nitinol stent.

Intraoperative application of a new-generation 3D IV-DSA technology in resection of a hemorrhagic cerebellar AVM.

Although intravenous digital subtraction angiography (IV-DSA), cone-beam CT, and rotational angiography are well-established technologies, using them in a single system in the hybrid operating room to acquire high-quality noninvasive 3D images is a recent development. This video demonstrates microsurgical excision of a ruptured cerebellar arteriovenous malformation (AVM) in a 66-year-old male followed by intraoperative IV-DSA acquisition using a new-generation system (Artis Icono). IV-DSA confirmed in real time that no residual remained following excision without the need to reposition the patient. To the best of the authors' knowledge, this is the first surgical video to demonstrate the simplified workflow and application of this technology in neurovascular surgery. The video can be found here: https://youtu.be/bo5ya9DQQPw.

Fracture and Embolization of Distal Guide Catheter During Neuroendovascular Intervention.

BACKGROUND: Embolic strokes mainly result from cardiac or vascular origins, but there are instances when they can arise from iatrogenic foreign bodies. Catheter coatings or retained microcatheters are mainly implicated in foreign body embolism following neuroendovascular intervention. However, there are no known descriptions for free-floating and/or dislodged microcatheter fragments in the literature. CASE DESCRIPTION: We report the clinical details, imaging findings, and management of a 69-year-old woman who underwent elective pipeline embolization of an incidental right paraophthalmic artery aneurysm and suffered distal embolization of the radiopaque marker from a distal guide catheter (088 Neuron Max, Penumbra, Alameda, California, USA) used during neuroendovascular intervention. To the best of our knowledge, this is the first reported case of distal embolism from an unprovoked fracture of a neurointerventional catheter. CONCLUSIONS: Knowledge of several salvage techniques is essential in preventing major cerebrovascular complications. It is imperative that a multilevel approach should be taken when treating foreign body embolism.

Leptomeningeal Enhancement Is Associated with Transient Neurologic Deficits after Flow Diversion of Intracranial Aneurysms.

OBJECTIVE: To evaluate the relationship between blood-brain barrier disruption and transient neurologic deficits (TNDs) after neuroendovascular interventions (NEIs) using postcontrast T2/FLAIR (pcFLAIR) imaging. METHODS: This is a prospective study of 41 consecutive patients undergoing flow diversion therapy for unruptured aneurysm treatment. Patients underwent postprocedural magnetic resonance imaging within 24 hours of the procedure, including diffusion-weighted imaging (DWI) and pcFLAIR sequences. Regression analyses were performed to identify risk factors for developing TNDs. RESULTS: In total, 13 patients (31.7%) developed neurologic complications ranging from visual field defects to dense hemiplegia. All deficits were transient, resolving spontaneously within 72 hours. Five of 13 patients (38.5%) with TNDs had presence of lesions on DWI whereas the remaining 8 patients (61.5%) did not. In contrast, all patients who developed TNDs had leptomeningeal enhancement on pcFLAIR imaging, and no patient with normal pcFLAIR imaging developed TNDs. Regression analysis revealed the extent of pcFLAIR enhancement is associated with development of postprocedure neurologic deficits (P < 0.0001). Video electroencephalography monitoring was performed in 4 symptomatic patients manifesting severe deficits. In all instances electroencephalography demonstrated ipsilateral hemispheric slowing and eventual resolution corresponding to ensuing clinical improvement. Only 1 of these 4 patients presented with a lesion on DWI. CONCLUSIONS: This study challenges conventional dogma that TNDs are ischemic in etiology and suggests blood-brain barrier impairment may be a potential alternative mechanism. These findings are applicable to stroke and other reversible neurologic diseases.