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.

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.

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.

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.

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.

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.

Machine Learning Predicts Cerebral Vasospasm in Subarachnoid Hemorrhage Patients.

Background: Cerebral vasospasm (CV) is a feared complication occurring in 20-40% of patients following subarachnoid hemorrhage (SAH) and is known to contribute to delayed cerebral ischemia. It is standard practice to admit SAH patients to intensive care for an extended period of vigilant, resource-intensive, clinical monitoring. We used machine learning to predict CV requiring verapamil (CVRV) in the largest and only multi-center study to date. Methods: SAH patients admitted to UCLA from 2013-2022 and a validation cohort from VUMC from 2018-2023 were included. For each patient, 172 unique intensive care unit (ICU) variables were extracted through the primary endpoint, namely first verapamil administration or ICU downgrade. At each institution, a light gradient boosting machine (LightGBM) was trained using five- fold cross validation to predict the primary endpoint at various timepoints during hospital admission. Receiver-operator curves (ROC) and precision-recall (PR) curves were generated. Results: A total of 1,750 patients were included from UCLA, 125 receiving verapamil. LightGBM achieved an area under the ROC (AUC) of 0.88 an average of over one week in advance, and successfully ruled out 8% of non-verapamil patients with zero false negatives. Minimum leukocyte count, maximum platelet count, and maximum intracranial pressure were the variables with highest predictive accuracy. 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. For external validation at VUMC, 1,654 patients were included, 75 receiving verapamil. Predictive models at VUMC performed very similarly to those at UCLA, averaging 0.01 AUC points lower. Conclusions: We present an accurate (AUC=0.88) and early (>1 week prior) predictor of CVRV using machine learning over two large cohorts of subarachnoid hemorrhage patients at separate institutions. This represents a significant step towards optimized clinical management and improved resource allocation in the intensive care setting of subarachnoid hemorrhage patients.

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.

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.

Automated assessment of ischemic core on non-contrast computed tomography: a multicenter comparative analysis with CT perfusion.

BACKGROUND: Application of machine learning (ML) algorithms has shown promising results in estimating ischemic core volumes using non-contrast CT (NCCT). OBJECTIVE: To assess the performance of the e-Stroke Suite software (Brainomix) in assessing ischemic core volumes on NCCT compared with CT perfusion (CTP) in patients with acute ischemic stroke. METHODS: In this retrospective multicenter study, patients with anterior circulation large vessel occlusions who underwent pretreatment NCCT and CTP, successful reperfusion (modified Thrombolysis in Cerbral Infarction ≥2b), and post-treatment MRI, were included from three stroke centers. Automated calculation of ischemic core volumes was obtained on NCCT scans using ML algorithm deployed by e-Stroke Suite and from CTP using Olea software (Olea Medical). Comparative analysis was performed between estimated core volumes on NCCT and CTP and against MRI calculated final infarct volume (FIV). RESULTS: A total of 111 patients were included. Estimated ischemic core volumes (mean±SD, mL) were 20.4±19.0 on NCCT and 19.9±18.6 on CTP, not significantly different (P=0.82). There was moderate (r=0.40) and significant (P<0.001) correlation between estimated core on NCCT and CTP. The mean difference between FIV and estimated core volume on NCCT and CTP was 29.9±34.6 mL and 29.6±35.0 mL, respectively (P=0.94). Correlations between FIV and estimated core volume were similar for NCCT (r=0.30, P=0.001) and CTP (r=0.36, P<0.001). CONCLUSIONS: Results show that ML-based estimated ischemic core volumes on NCCT are comparable to those obtained from concurrent CTP in magnitude and in degree of correlation with MR-assessed FIV.

Perfusion Collateral Index versus Hypoperfusion Intensity Ratio in Assessment of Collaterals in Patients with Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Perfusion-based collateral indices such as the perfusion collateral index and the hypoperfusion intensity ratio have shown promise in the assessment of collaterals in patients with acute ischemic stroke. We aimed to compare the diagnostic performance of the perfusion collateral index and the hypoperfusion intensity ratio in collateral assessment compared with angiographic collaterals and outcome measures, including final infarct volume, infarct growth, and functional independence. MATERIALS AND METHODS: Consecutive patients with acute ischemic stroke with anterior circulation proximal arterial occlusion who underwent endovascular thrombectomy and had pre- and posttreatment MRI were included. Using pretreatment MR perfusion, we calculated the perfusion collateral index and the hypoperfusion intensity ratio for each patient. The angiographic collaterals obtained from DSA were dichotomized to sufficient (American Society of Interventional and Therapeutic Neuroradiology [ASITN] scale 3-4) versus insufficient (ASITN scale 0-2). The association of collateral status determined by the perfusion collateral index and the hypoperfusion intensity ratio was assessed against angiographic collaterals and outcome measures. RESULTS: A total of 98 patients met the inclusion criteria. Perfusion collateral index values were significantly higher in patients with sufficient angiographic collaterals (P < .001), while there was no significant (P = .46) difference in hypoperfusion intensity ratio values. Among patients with good (mRS 0-2) versus poor (mRS 3-6) functional outcome, the perfusion collateral index of ≥ 62 was present in 72% versus 31% (P = .003), while the hypoperfusion intensity ratio of ≤0.4 was present in 69% versus 56% (P = .52). The perfusion collateral index and the hypoperfusion intensity ratio were both significantly predictive of final infarct volume, but only the perfusion collateral index was significantly (P = .03) associated with infarct growth. CONCLUSIONS: Results show that the perfusion collateral index outperforms the hypoperfusion intensity ratio in the assessment of collateral status, infarct growth, and determination of functional outcomes.

Proximal Internal Carotid Artery Occlusion and Extracranial-Intracranial Bypass for Treatment of Fusiform and Giant Internal Carotid Artery Aneurysms.

OBJECTIVE: To discuss the treatment of intracranial fusiform and giant internal carotid artery (ICA) aneurysms via revascularization based on our institutional experience. METHODS: An institutional review board-approved retrospective analysis was performed of patients with unruptured fusiform and giant intracranial ICA aneurysms treated from November 1991 to May 2020. All patients were evaluated for extracranial-intracranial (EC-IC) bypass and ICA occlusion. RESULTS: Thirty-eight patients were identified. Initially, patients failing preoperative balloon test occlusion were treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and concurrent proximal ICA ligation. We then treated them with STA-MCA bypass, followed by staged balloon test occlusion, and, if they passed, endovascular ICA coil occlusion. We treat all surgical medically uncomplicated patients with double-barrel STA-MCA bypass and concurrent proximal ICA ligation. The mean length of follow-up was 99 months. Symptom stability or improvement was noted in 85% of patients. Bypass graft patency was 92.1%, and all surviving patients had patent bypasses at their last angiogram. Aneurysm occlusion was complete in 90.9% of patients completing proximal ICA ligation. Three patients experienced ischemic complications and 4 patients experienced hemorrhagic complications. CONCLUSIONS: Not all fusiform intracranial ICA aneurysms require intervention, except when life-threatening rupture risk is high or symptomatic management is necessary to preserve function and quality of life. EC-IC bypass can augment the safety of proximal ICA occlusion. The rate of complete aneurysm occlusion with this treatment is 90.9%, and long-term bypass graft-related complications are rare. Perioperative stroke is a major risk, and continued evolution of treatment is required.

A Transcriptomic Comparative Study of Cranial Vasculature.

In genetic studies of cerebrovascular diseases, the optimal vessels to use as controls remain unclear. Our goal is to compare the transcriptomic profiles among 3 different types of control vessels: superficial temporal artery (STA), middle cerebral arteries (MCA), and arteries from the circle of Willis obtained from autopsies (AU). We examined the transcriptomic profiles of STA, MCA, and AU using RNAseq. We also investigated the effects of using these control groups on the results of the comparisons between aneurysms and the control arteries. Our study showed that when comparing pathological cerebral arteries to control groups, all control groups presented similar responses in the activation of immunological processes, the regulation of intracellular signaling pathways, and extracellular matrix productions, despite their intrinsic biological differences. When compared to STA, AU exhibited upregulation of stress and apoptosis genes, whereas MCA showed upregulation of genes associated with tRNA/rRNA processing. Moreover, our results suggest that the matched case-control study design, which involves control STA samples collected from the same subjects of matched aneurysm samples in our study, can improve the identification of non-inherited disease-associated genes. Given the challenges associated with obtaining fresh intracranial arteries from healthy individuals, our study suggests that using MCA, AU, or paired STA samples as controls are feasible strategies for future large-scale studies investigating cerebral vasculopathies. However, the intrinsic differences of each type of control should be taken into consideration when interpreting the results. With the limitations of each control type, it may be most optimal to use multiple tissues as controls.

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.

Robotic Diagnostic Cerebral Angiography: A Multicenter Experience of 113 Patients.

BACKGROUND: Neurointerventional robotic systems have potential to reduce occupational radiation, improve procedural precision, and allow for future remote teleoperation. A limited number of single institution case reports and series have been published outlining the safety and feasibility of robot-assisted diagnostic cerebral angiography. METHODS: This is a multicenter, retrospective case series of patients undergoing diagnostic cerebral angiography at three separate institutions - University of California, Davis (UCD); University of California, Los Angeles (UCLA); and University of California, San Francisco (UCSF). The equipment used was the CorPath GRX Robotic System (Corindus, Waltham, MA). RESULTS: A total of 113 cases were analyzed who underwent robot-assisted diagnostic cerebral angiography from September 28, 2020 to October 27, 2022. There were no significant complications related to use of the robotic system including stroke, arterial dissection, bleeding, or pseudoaneurysm formation at the access site. Using the robotic system, 88 of 113 (77.9%) cases were completed successfully without unplanned manual conversion. The principal causes for unplanned manual conversion included challenging anatomy, technical difficulty with the bedside robotic cassette, and hubbing out of the robotic system due to limited working length. For robotic operation, average fluoroscopy time was 13.2 min (interquartile range (IQR), 9.3 to 16.8 min) and average cumulative air kerma was 975.8 mGY (IQR, 350.8 to 1073.5 mGy). CONCLUSIONS: Robotic cerebral angiography with the CorPath GRX Robotic System is safe and easily learned by novice users without much prior manual experience. However, there are technical limitations such as a short working length and an inability to support 0.035" wires which may limit its widespread adoption in clinical practice.

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.

Aneurysmal subarachnoid hemorrhage in pregnancy: National trends of treatment, predictors, and outcomes.

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (aSAH) is a rare event associated with significant pregnancy-associated maternal and neonatal morbidity and mortality. The optimal treatment strategy and clinical outcome of aSAH in pregnancy remains unclear. We aimed to investigate the treatment utilizations and outcomes of aSAH in pregnant people. METHODS: Using the 2010-2018 National Inpatient Sample, we identified all birth hospitalizations of women between ages of 18 to 45 associated with subarachnoid hemorrhage and aneurysm treatment were included. Multivariate analyses were used to evaluate the effect of pregnancy state, mode of treatment of aneurysms, severity of subarachnoid hemorrhage on mortality and discharge destination of this cohort. Trends in mode of treatment utilized for aneurysmal treatment in this time interval was evaluated. RESULTS: 13,351 aSAH with treatment were identified, of which 440 were associated with pregnancy. There was no significant difference in mortality or rate of discharge to home in pregnancy related hospitalization. Worse aSAH severity, chronic hypertension, and smaller hospital size was associated with significantly higher rate of mortality from aSAH during pregnancy. Worse aSAH severity was associated with lower rate of discharge to home. Like the non-pregnant cohort, the treatment of ruptured aneurysms in pregnancy are increasingly through endovascular approaches. The mode of treatment does not change the mortality or discharge destination. CONCLUSIONS: Pregnancy does not alter mortality or the discharge destination for aSAH. Ruptured aneurysms during pregnancy are increasingly treated endovascularly. Mode of aneurysm treatment does not affect mortality or discharge destination in pregnancy.

Image-derived Metrics Quantifying Hemodynamic Instability Predicted Growth of Unruptured Intracranial Aneurysms.

Background: While image-derived predictors of intracranial aneurysm (IA) rupture have been well-explored, current understanding of IA growth is limited. Pulsatility index (PI) and wall shear stress pulsatility index (WSSPI) are important metrics measuring temporal hemodynamic instability. However, they have not been investigated in IA growth research. The present study seeks to verify reliable predictors of IA growth with comparative analyses of several important morphological and hemodynamic metrics between stable and growing cases among a group of unruptured IAs. Methods: Using 3D images, vascular models of 16 stable and 20 growing cases were constructed and verified using Geodesic techniques. With an overall mean follow-up period of 25 months, cases exhibiting a 10% or higher increase in diameter were considered growing. Patient-specific, pulsatile simulations were performed, and hemodynamic calculations were computed at 5 important regions of each aneurysm (inflow artery, aneurysm neck, body, dome, and outflow artery). Index values were compared between growing and stable IAs using ANCOVA controlling for aneurysm diameter. Stepwise multiple logistic regression and ROC analyses were conducted to investigate predictive models of IA growth. Results: Compared to stable IAs, growing IAs exhibited significantly higher intrasaccular PI, intrasaccular WSSPI, intrasaccular spatial flow rate deviation, and intrasaccular spatial wall shear stress (WSS) deviation. Stepwise logistic regression analysis revealed a significant predictive model involving PI at aneurysm body, WSSPI at inflow artery, and WSSPI at aneurysm body. Conclusions: Our results showed that high degree of hemodynamic variations within IAs is linked to growth, even after controlling for morphological parameters. Further, evaluation of PI in conjunction with WSSPI yielded a highly accurate predictive model of IA growth. Upon validation in future cohorts, these metrics may aid in early identification of IA growth and current understanding of IA remodeling mechanism.

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.