ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

Intracranial artery calcification: Frequency, determinants, and modification of outcomes from endovascular thrombectomy.

INTRODUCTION: Intracranial artery calcification (ICAC) is a common finding on computed tomography (CT) in patients presenting with large vessel occlusion acute ischemic stroke (LVO-AIS) and could serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). METHODS: This was a retrospective cohort study analyzing consecutive patients undergoing CT head prior to EVT between 2016 and 2020. Extent of ICAC proximal to the target vessel was scored using a validated grading scale examining thickness and circumferential extent of calcifications. The relationship between 3 levels of ICAC burden and procedural, clinical, and safety outcomes was analyzed. RESULTS: Among 86 patients meeting inclusion criteria, ICAC of any degree was present in 72.1 %. Median ICAC score was 3 [IQR 0-4]. There was a U-shaped association between ICAC score and successful reperfusion: 90.9 %, 65.7 %, and 94.4 % in the low, intermediate, and high ICAC score groups, respectively (p = 0.008). Use of rescue intervention, most often angioplasty and stenting, was greatest in the high ICAC score group: 3.0 % vs. 5.7 % vs. 22.2 % (p = 0.05). Functional independence at 90 days did not differ significantly among groups (41.7 % vs. 31.0 % vs. 15.4 %, p = 0.26), nor did rates of symptomatic intracranial hemorrhage (15.2 % vs. 14.3 % vs. 16.7 %, p = 0.97). CONCLUSIONS: ICAC is seen on CT in nearly three-quarters of patients with LVO-AIS. Extent of ICAC has a U-shaped association with successful reperfusion, in part due to more frequent use of rescue interventions in patients with extensive ICAC.

Reperfusion Therapy Frequency and Outcomes in Mild Ischemic Stroke in the United States.

BACKGROUND AND PURPOSE: More than half of patients with acute ischemic stroke have minor neurological deficits; however, the frequency and outcomes of reperfusion therapy in regular practice has not been well-delineated. METHODS: Analysis of US National Inpatient Sample of hospitalizations with acute ischemic stroke and mild deficits (National Institutes of Health Stroke Scale [NIHSS] score 0-5) from October 1, 2016, to December 31, 2017. Patient- and hospital-level characteristics associated with use and outcome of reperfusion therapies were analyzed. Primary outcomes included excellent discharge disposition (discharge to home without assistance); poor discharge disposition (discharge to facility or death); in-hospital mortality; and radiological intracranial hemorrhage. RESULTS: Among 179 710 acute ischemic stroke admissions with recorded NIHSS during the 15-month study period, 103 765 (57.7%) had mild strokes (47.3% women; median age, 69 [interquartile range, 59-79] years; median NIHSS score of 2 [interquartile range, 1-4]). Considering reperfusion therapies among strokes with documented NIHSS, mild deficit hospitalizations accounted for 40.0% of IVT and 10.7% of mechanical thrombectomy procedures. Characteristics associated with IVT and with mechanical thrombectomy utilization were younger age, absence of diabetes, higher NIHSS score, larger/teaching hospital status, and Western US region. Excellent discharge outcome occurred in 48.2% of all mild strokes, and in multivariable analysis, was associated with younger age, male sex, White race, lower NIHSS score, absence of diabetes, heart failure, and kidney disease, and IVT use. IVT was associated with increased likelihood of excellent outcome (odds ratio, 1.90 [95% CI, 1.71-2.13], P<0.001) despite an increased risk of intracranial hemorrhage (odds ratio, 1.41 [95% CI, 1.09-1.83], P<0.001). CONCLUSIONS: In national US practice, more than one-half of acute ischemic stroke hospitalizations had mild deficits, accounting for 4 of every 10 IVT and 1 of every 10 mechanical thrombectomy treatments, and IVT use was associated with increased discharge to home despite increased intracranial hemorrhage.

Hemorrhage Risk of Brain Arteriovenous Malformations During Pregnancy and Puerperium in a North American Cohort.

BACKGROUND AND PURPOSE: Conclusions reached in existing literature about risk of arteriovenous malformation (AVM) hemorrhage during pregnancy are controversial. This study compares the risk of hemorrhage in pregnant and nonpregnant female patients with AVM in a North American cohort. METHODS: We retrospectively reviewed female patients with AVM evaluated from 1990 to 2015. Exposure period for pregnancy and puerperium was calculated as 40 and 6 weeks, respectively, for each full-term pregnancy and 6 weeks for each abortion. Hemorrhage events and patient-years were calculated during an exposure period (pregnancy and puerperium), and a nonexposure period defined as either the interval from birth until AVM obliteration or until last follow-up after subtracting exposure period. Poisson rate ratio test was used to compare rate of hemorrhage between exposure and nonexposure periods. RESULTS: For 270 female patients with AVM, mean age was 35.0±19.6 years, and race distribution was white (n=165, 61.1%), black (n=59, 21.9%), Hispanic (n=9, 3.3%), Asian (n=6, 2.2%), and other (n=31, 11.5%). From 191 total pregnancies occurring before AVM obliteration, there were 175 (91.6%) term deliveries and 16 (8.4%) abortions. Overall annual hemorrhage rate for 149 total hemorrhages during an average of 11 097 patient-years was 1.34%. There were 140 hemorrhages in nonexposed women and 9 hemorrhages in pregnant women, translating to an annual hemorrhage rate of 1.3% in nonpregnant women versus 5.7% in pregnant women (P<0.001). Identical analysis for reproductive age patients (15-50) demonstrated a rate of 1.3% versus 7.0% (P<0.001). CONCLUSIONS: Our results conflict with those from a recent study describing no increased rate of rupture during pregnancy. This difference may reflect unique population attributes influencing brain AVM hemorrhage during pregnancy.

Clinical presentation and treatment of 26 spinal epidural arteriovenous fistulas: a single-center experience.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEDAVFs) are rarely diagnosed vascular malformations that can cause spinal cord compression and congestive myelopathy. METHODS: This is a single-center, retrospective case series of patients with SEDAVFs who underwent observation or treatment at UCLA medical center between 1993 and 2023. RESULTS: Between 1993 and 2023 a total of 26 patients at UCLA were found to have a SEDAVF. The median age at treatment was 59 years (range 4 months to 91 years). Compared with sacral, lumbar, and thoracic SEDAVFs, patients with cervical SEDAVF were younger (41 years vs 63 years, P=0.016) and more likely to be female (66.7% vs 14.3%, P=0.006). Possible triggers for development of SEDAVFs may be prior spinal surgery or trauma (n=4), turning the neck (n=1), lifting a heavy box (n=1), a prolonged period of bending over (n=1), and neurofibromatosis type 1 (n=1). Of the 22 patients treated endovascularly, 18 (82%) were angiographically cured on the first attempt without complications. One patient underwent surgical treatment alone and had a failed surgery on the first attempt, and developed a surgical site infection after the second successful attempt at treatment. Of the 16 patients with adequate clinical follow-up, 11 (69%) demonstrated early improved clinical outcome (eg, improved strength on examination, absent bruit). CONCLUSIONS: SEDAVFs are a rarely diagnosed disease that can be treated effectively and safely with endovascular embolization in most cases. Patients with sacral, lumbar, and thoracic SEDAVFs were older and more often male compared to patients with cervical SEDAVFs.

The human craniospinal venous system and its influence on postural intracranial pressure: a review.

OBJECTIVE: The cerebral and spinal venous systems have similar functions but unique anatomical and physiological properties. CSF occupies space in the cranial and spinal vaults, is continuously produced, and has many roles, including maintaining a favorable environment for CNS structures. The influence of the cerebrospinal venous system on CSF dynamics has been theorized since the 1940s. Newer studies suggest venous outflow pattern alterations in response to changes in body position. However, the relationship of postural cerebrospinal venous outflow shifts with and their influence on CSF homeostasis is not well understood. METHODS: The authors searched the published literature related to the anatomy and function of vertebral venous plexus (VVP), CSF, and positional cerebral venous flow characteristics. A comprehensive collection of literature was compiled and reviewed, and the relationship between cerebrospinal and venous system changes and alterations in body positions, with an emphasis on the craniocervical system, is discussed. RESULTS: The VVP is a network of valveless veins extending from the sacrum to the cranium that are interconnected with the cranial dural sinuses. The internal VVP occupies space within the extradural spinal canal and functions to return spinal venous blood to the heart, but it has additional properties, including the capability of bidirectional venous flow, an intraspinal dilatory capacity, and a role in cerebral venous outflow. When one rises to the upright position, CSF shifts toward the spinal canal and force vectors change, leading to reduced intracranial CSF pressure; simultaneously, cerebral venous outflow shifts from the jugular vein to the VVP outflow pathway. The venous outflow shift mechanism and its purpose are poorly understood. The authors review the known physiology of the system, identify gaps in knowledge to direct future research, and propose an interpretation of these data, concluding that position-dependent CSF and cerebrospinal venous shifts are part of a complementary positional craniospinal pressure regulation system that must be kept in balance for optimal CNS function. CONCLUSIONS: Current knowledge of the cerebrospinal venous anatomy, dynamic flow characteristics in response to gravity, and the venous system's influence on CSF suggests that the VVP plays a role in influencing CSF pressure, and the authors hypothesize that it plays a role in supporting intracranial pressure in the upright body posture. Further research is needed to better characterize the functional relationship of the VVP to CSF dynamics as well as identify potentially related disease states.

Machine learning predicts cerebral vasospasm in patients with subarachnoid haemorrhage.

BACKGROUND: Cerebral vasospasm (CV) is a feared complication which occurs after 20-40% of subarachnoid haemorrhage (SAH). It is standard practice to admit patients with SAH to intensive care for an extended period of resource-intensive monitoring. We used machine learning to predict CV requiring verapamil (CVRV) in the largest and only multi-center study to date. METHODS: Patients with SAH admitted to UCLA from 2013 to 2022 and a validation cohort from VUMC from 2018 to 2023 were included. For each patient, 172 unique intensive care unit (ICU) variables were extracted through the primary endpoint, namely first verapamil administration or no verapamil. At each institution, a light gradient boosting machine (LightGBM) was trained using five-fold cross validation to predict the primary endpoint at various hospitalization timepoints. FINDINGS: A total of 1750 patients were included from UCLA, 125 receiving verapamil. LightGBM achieved an area under the ROC (AUC) of 0.88 > 1 week in advance and ruled out 8% of non-verapamil patients with zero false negatives. Our models predicted "no CVRV" vs "CVRV within three days" vs "CVRV after three days" with AUCs = 0.88, 0.83, and 0.88, respectively. From VUMC, 1654 patients were included, 75 receiving verapamil. VUMC predictions averaged within 0.01 AUC points of UCLA predictions. INTERPRETATION: We present an accurate and early predictor of CVRV using machine learning with multi-center validation. This represents a significant step towards optimized clinical management and resource allocation in patients with SAH. FUNDING: Robert E. Freundlich is supported by National Center for Advancing Translational Sciences federal grant UL1TR002243 and National Heart, Lung, and Blood Institute federal grant K23HL148640; these funders did not play any role in this study. The National Institutes of Health supports Vanderbilt University Medical Center which indirectly supported these research efforts. Neither this study nor any other authors personally received financial support for the research presented in this manuscript. No support from pharmaceutical companies was received.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients.

OBJECTIVE: Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience. METHODS: Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization. RESULTS: The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up. CONCLUSIONS: Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Immediate procedural safety of adjunctive proximal coil occlusion in middle meningeal artery embolization for chronic subdural hematomas: Experience in 137 cases.

BACKGROUND: Endovascular embolization of the middle meningeal artery (MMA) has emerged as an adjunctive and stand-alone modality for the management of chronic subdural hematomas (cSDH). We report our experience utilizing proximal MMA coil embolization to augment cSDH devascularization in MMA embolization. METHODS: MMA embolization cases with adjunctive proximal MMA coiling were retrospectively identified from a prospectively maintained IRB-approved database of the senior authors. RESULTS: Of the 137 cases, all patients (n = 89, 100%) were symptomatic and underwent an MMA embolization procedure for cSDH. 50 of the patients underwent bilateral embolizations, with 53% (n = 72) for left-sided and 47% (n = 65) for right-sided cSDH. The anterior MMA branch was embolized in 19 (14%), posterior in 16 (12%), and both in 102 (74.5%) cases. Penetration of the liquid embolic to the contralateral MMA or into the falx was present in 38 (28%) and 31 (23%) cases, respectively, and 46 (34%) cases had ophthalmic or petrous collateral (n = 41, 30%) branches. MMA branches coiled include the primary trunk (25.5%, n = 35), primary and anterior or posterior MMA trunks (20%, n = 28), or primary with the anterior and posterior trunks (54%, n = 74). A mild ipsilateral facial nerve palsy was reported, which remained stable at discharge and follow-up. Absence of anterograde flow in the MMA occurred in 137 (100%) cases, and no cases required periprocedural rescue surgery for cSDH evacuation. The average follow-up length was 170 ± 17.9 days, cSDH was reduced by 4.24 ± 0.5(mm) and the midline shift by 1.46 ± 0.27(mm). Complete resolution was achieved in 63 (46.0%) cases. CONCLUSION: Proximal MMA coil embolization is a safe technique for providing additional embolization/occlusion of the MMA in cSDH embolization procedures. Further studies are needed to evaluate the potential added efficacy of this technique.

Use of a large-bore 088 intracranial access support catheter for delivery of large intracranial devices: case series with the TracStar LDP in 125 cases.

BACKGROUND: The delivery of neuroendovascular devices requires a robust proximal access platform. This demand has previously been met with a 6Fr long sheath (8Fr guide) that is placed in the proximal internal carotid artery (ICA) or vertebral artery segments. We share our experience with the first 0.088 inch 8Fr guide catheter designed for direct intracranial access. METHODS: We retrospectively reviewed a prospectively maintained IRB-approved institutional database of the senior authors to identify all cases where the TracStar Large Distal Platform (LDP) was positioned within the intracranial vasculature, defined as within or distal to the petrous ICA, vertebral artery (V3) segments, or transverse sinus. Technical success was defined as safe placement of the TracStar LDP within or distal to the described distal vessel segments with subsequent complication-free device implantation. RESULTS: Over the 41-month study period from January 2020 to June 2023, 125 consecutive cases were identified in whom the TracStar LDP was navigated into the intracranial vasculature for triaxial delivery of large devices, 0.027 inch microcatheter and greater, for aneurysm treatment (n=108, 86%), intracranial angioplasty/stenting (n=15, 12%), and venous sinus stenting (n=2, 1.6%). All cases used a direct select catheter technique for initial guide placement (no exchange). Posterior circulation treatments occurred in 14.4% (n=18) of cases. Technical success was achieved in 100% of cases. No vessel dissections occurred in any cases. CONCLUSION: The TracStar LDP is an 0.088 inch 8Fr guide catheter that can establish direct intracranial access with an acceptable safety profile. This can be achieved in a wide range of neurointerventional cases with a high rate of technical success.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases.

INTRODUCTION: Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. METHODS: Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. RESULTS: The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. CONCLUSION: Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Flow diversion of cerebral aneurysms in Type I osteogenesis imperfecta: A case report of the first two treatments in humans.

Osteogenesis imperfecta (OI) predisposes individuals to easy bone fracture, vessel fragility, and platelet dysfunction. We report the first known case of neurointerventional treatment with flow diversion of intracranial aneurysms in a patient with OI. A 62 year-old female with known OI Type I, history of >40 lifetime bone fractures and hypertension, underwent workup for transient ischemic attacks revealing a 4-mm right A1 segment aneurysm in 2016. Perioperative dual antiplatelet therapy was aspirin 81 mg and clopidogrel 37.5 mg daily. Tri-axial access was utilized to deploy a 3.5 × 16-mm Pipeline Flex device without complication. Two-month follow-up revealed Raymond I (O'Kelly Marotta I) obliteration of the aneurysm. Five-year follow-up revealed a de novo left-sided 3-mm A1-A2 junction aneurysm. A 4 × 12-mm Surpass Evolve was placed without complication. Six-month follow-up revealed Raymond I (O'Kelly Marotta I) obliteration of the second aneurysm. The patient remained asymptomatic at all follow-up visits.

Intracranial aneurysm wall displacement depicted by amplified Flow predicts growth.

BACKGROUND: Abnormal intracranial aneurysm (IA) wall motion has been associated with IA growth and rupture. Recently, a new image processing algorithm called amplified Flow (aFlow) has been used to successfully track IA wall motion by combining the amplification of cine and four-dimensional (4D) Flow MRI. We sought to apply aFlow to assess wall motion as a potential marker of IA growth in a paired-wise analysis of patients with growing versus stable aneurysms. METHODS: In this retrospective case-control study, 10 patients with growing IAs and a matched cohort of 10 patients with stable IAs who had baseline 4D Flow MRI were included. The aFlow was used to amplify and extract IA wall displacements from 4D Flow MRI. The associations of aFlow parameters with commonly used risk factors and morphometric features were assessed using paired-wise univariate and multivariate analyses. RESULTS: aFlow quantitative results showed significantly (P=0.035) higher wall motion displacement depicted by mean±SD 90th% values of 2.34±0.72 in growing IAs versus 1.39±0.58 in stable IAs with an area under the curve of 0.85. There was also significantly (P<0.05) higher variability of wall deformation across IA geometry in growing versus stable IAs depicted by the dispersion variables including 121-150% larger standard deviation ([Formula: see text]) and 128-161% wider interquartile range [Formula: see text]. CONCLUSIONS: aFlow-derived quantitative assessment of IA wall motion showed greater wall motion and higher variability of wall deformation in growing versus stable IAs.

Republished: Robotic assistant spinal angiography: a case report and technical considerations.

Robotic-assisted technology has shown to be promising in coronary and peripheral vascular interventions. Early case reports have also demonstrated its efficacy in neuro-interventions. However, there is no prior report demonstrating use of the robotic-assisted platform for spinal angiography. We report the feasibility of the robotic-assisted thoracic and lumbar spinal angiography.

A novel ventriculoperitoneal shunt flow sensor based on electrically induced spatial variation in cerebrospinal fluid charge density.

Introduction: Ventriculoperitoneal (VP) shunts divert cerebrospinal fluid (CSF) out of cerebral ventricles in patients with hydrocephalus or elevated intracranial pressure (ICP). Despite high failure rates, there exist limited clinically viable solutions for long-term and continuous outpatient monitoring of CSF flow rate through VP shunts. We present a novel, low-power method for sensing analog CSF flow rate through a VP shunt premised on induced spatial electrical charge variation. Methods: Two geometric variants of the proposed sensing mechanism were prototyped: linear wire (P1) and cylindrical (P2) electrodes. Normal saline was gravity-driven through P1 and a commercially available shunt system in series. True flow rates were measured using a high-precision analytical balance. Subsequently, artificial CSF was driven by a programmable syringe pump through P2. Flow rate prediction models were empirically derived and tested. Sensor response was also assessed during simulated obstruction trials. Finally, power consumption per flow measurement was measured. Results: P1 (17 mm long) and P2 (22 mm long) averaged 7.2% and 4.2% error, respectively, in flow rate measurement from 0.01 to 0.90 mL/min. Response curves exhibited an appreciably flattened profile during obstruction trials compared to non-obstructed states. P2 consumed 37.5 µJoules per flow measurement. Conclusion: We propose a novel method for accurately sensing CSF flow rate through a VP shunt and validate this method at the benchtop with normal saline and artificial CSF over a board range of flows (0.01-0.90 mL/min). The sensing element is highly power efficient, compact, insertable into existing shunt and valve assemblies, and does not alter CSF flow mechanics.

Novel endovascular transmural technique for pharmacological block of superior cervical ganglion prevents sympathetic-mediated cerebral vasospasm.

BACKGROUND: Sympathetic-mediated vasoconstriction from the superior cervical ganglion (SCG) is a significant contributor to cerebral vasospasm. Inhibition of the SCG has been shown to improve cerebral blood flow and reverse cerebral vasospasm in swine models. We evaluated the efficacy of a novel minimally invasive endovascular approach to target and pharmacologically inhibit the SCG, using a Micro-Infusion Device for transmural drug delivery. METHODS: Eight SCGs in four Yorkshire swine were surgically identified. After confirming appropriate sympathetic-mediated intracranial vasoconstriction response with SCG stimulation, an endovascular Micro-Infusion Device was used for transmural targeting of the SCG and delivery of 1.5-2 mL of 1% lidocaine-contrast mixture to the perivascular space. Digital subtraction angiography was obtained at: (1) baseline; (2) with SCG stimulation; and (3) after lidocaine delivery to the SCG using the Micro-Infusion Device with concurrent SCG stimulation. Vessel diameters were measured and compared. RESULTS: Endovascular transmural delivery of lidocaine to the SCG and carotid perivascular tissue using the Micro-Infusion Device successfully inhibited sympathetic-mediated vasoconstriction response. Measured vessel diameters after lidocaine delivery were comparable to baseline despite SCG stimulation. CONCLUSION: A novel endovascular technique of transmural delivery of lidocaine to the SCG and carotid artery perivascular tissues successfully inhibits the sympathetic input to the cerebral vasculature and modulates sympathetic-mediated cerebral vasospasm. These results suggest promising steps towards translation to potential clinical use for patients suffering from cerebral vasospasm.

Endovascular transmural access to carotid artery perivascular tissues: safety assessment of a novel technique.

BACKGROUND: Recent advances in endovascular devices have allowed access and targeting of perivascular tissues of the peripheral circulation. The perivascular tissues of the cervical and cranial circulations have many important structures of clinical significance, yet the feasibility and safety of such an approach has not been demonstrated. OBJECTIVE: To evaluate the safety of a novel endovascular transmural approach to target the perivascular tissues of the common carotid artery in swine. METHODS: A micro-infusion device was positioned in the carotid arteries of three Yorkshire pigs (six carotid arteries in total), and each carotid artery was punctured 10 times in the same location to gain access to the perivascular tissues. Digital subtraction angiography was used to evaluate vessel injury or contrast extravasation. MRI and MR angiography were used to evaluate evidence of cerebral ischemia or vessel injury. Post-mortem tissue analysis was performed to assess the level of extravascular hematoma and intravascular dissection. RESULTS: None of the tested carotid arteries showed evidence of vessel injury (dissection or perforation) or intravascular thrombosis. MRI performed after repeated puncture was negative for neck hematoma and brain ischemia. Post-mortem tissue analysis of the carotid arteries showed mild adventitial staining with blood, but without associated hematoma and without vessel dissection. CONCLUSION: Repeated puncture of the carotid artery to gain access to the perivascular tissues using a novel endovascular transmural approach is safe in a swine model. This represents a novel approach to various tissues in close proximity to the cervical and cranial vasculature.

Augmentation of flow diverter vessel wall apposition using the Comaneci device: case experience from a novel, off-label technique.

BACKGROUND: Flow diversion (FD) embolization of intracranial cerebral aneurysms is an increasingly common modality where treatment success depends on adequate vessel wall apposition of the device. This study aimed to investigate off-label use of the Comaneci device for augmenting vessel wall apposition in post-deployed flow diversion stents (FDS). METHODS: Over a 20- month period, all FD cases for the treatment of internal carotid artery (ICA) aneurysms were reviewed. Cases in which the Comaneci device was used to augment vessel wall apposition were analyzed. Data including patient demographics, case characteristics, and procedural outcomes were collected and analyzed as counts. RESULTS: From a total of 74 ICA FD cases, the Comaneci device was used to improve vessel wall apposition in 22 cases (29.7%) . Of these cases, 91% were female with a mean patient age of 64.9±11.3 years, and an average aneurysm size of 4.5±2.5 mm. Comaneci device deployment and retrieval was successful in all (100%) cases, with an average fluoroscopy time of 27.3±7.8 min, an average contrast usage of 25.8±13.2 mL, and an average radiation exposure of 915.1±320.8 mGy. Only two cases (9%) required subsequent balloon angioplasty after Comaneci deployment to improve vessel wall apposition throughout the FDS. CONCLUSION: Our experience with this technique demonstrates the feasibility of using the Comaneci device for augmentation of FDS vessel wall apposition with 100% success in the deployment and retrieval of the Comaneci device.

Endoscope-Assisted Pedicled Maxillary Artery to Middle Cerebral Artery Bypass: An Anatomic Feasibility Study.

BACKGROUND: Extracranial to intracranial bypass is used to augment and/or replace the intracranial circulation for various pathologies. The superficial temporal artery is the mainstay donor for pedicled bypasses to the anterior circulation but can be limited by its variable size, low native flow rates, and potential scalp complications. Interposition grafts such as the radial artery or greater saphenous vein are alternatives but are sometimes limited by size mismatch, length needed to reach the extracranial circulation, and loss of inherent vascular elasticity. Interposition grafts between the maxillary artery (IMA) and middle cerebral artery (MCA) address these limitations. OBJECTIVE: To explore the feasibility of harvesting the IMA through an endoscopic transnasal, transmaxillary approach to perform a direct IMA to MCA bypass. METHODS: Combined transcranial and endoscopic endonasal dissections were performed in embalmed human cadavers to harvest the IMAs for intracranial transposition and direct anastomosis to the MCA. Donor and recipient vessel calibers were measured and recorded. RESULTS: A total of 8 procedures were performed using the largest and distal-most branches of the IMA (the sphenopalatine branch and the descending palatine branch) as pedicled conduits to second division of middle cerebral artery (M2) recipients. The mean diameter of the IMA donors was 1.89 mm (SD ± 0.42 mm), and the mean diameter of the recipient M2 vessels was 1.90 mm (SD ± 0.46 mm). CONCLUSION: Endoscopic harvest of the IMA using a transnasal, transmaxillary approach is a technically feasible option offering an excellent size match to the M2 divisions of the MCA and the advantages of a relatively short, pedicled donor vessel.