Endovascular Treatment for Complex Vascular Pathologies in the Pediatric Population: Experience from a Center with Dual-Trained Neurosurgeons.

OBJECTIVE: Endovascular treatment of complex vascular pathologies in the pediatric population is often performed by non-pediatric subspecialists with adaptation of equipment and techniques developed for adult patients. We aimed to report our center's experience with safety and outcomes of endovascular treatments for pediatric vascular pathologies. METHODS: We performed a retrospective review of our endovascular database. All patients ≤18 years who underwent endovascular treatment between January 1, 2004 and December 1, 2022 were included. RESULTS: During the study time frame, 118 cerebral angiograms were performed for interventional purposes in 55 patients. Of these patients, 8(14.5%) had intracranial aneurysms, 21(38.2%) had intracranial arteriovenous malformations (AVMs), 6(10.9%) had tumors, 5(9.1%) had arterial occlusions (n=3) or dissections (n=2), 8(14.5%) had vein of Galen malformations, and 7(12.7%) had other cerebrovascular conditions. Of the total 118 procedures, access-site complications occurred in 2(1.7%), intraprocedural complications occurred in 3(2.5%), and transient neurological deficits were observed after 2(1.7%). Treatment-related mortality occurred in 1(1.8%) patient. CONCLUSIONS: Neurointervention in pediatric patients was safe and effective in our experience.

A propensity score-matched comparative study of balloon guide catheters versus conventional guide catheters for concurrent mechanical thrombectomy with carotid stenting in tandem strokes: comparison of first pass effect, symptomatic intracranial hemorrhage, and 90-day functional outcomes.

BACKGROUND: Extensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting. OBJECTIVE: In view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study. METHODS: Patients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes. RESULTS: Concurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0-2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067). CONCLUSION: BGCs used for concurrent MT-carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.

Residual In-Stent Carotid Stenosis and Cigarette Smoking are Independent Predictors of Carotid Restenosis After Carotid Artery Stenting-Results from 738 Carotid Artery Stenting Procedures at a Single Center.

BACKGROUND AND OBJECTIVES: Carotid artery stenting (CAS) has become a viable alternative to carotid endarterectomy for the management of carotid stenosis. Our aim was to determine the rate of radiographic restenosis after CAS and clinical, radiographic, and procedural predictors of in-stent restenosis. METHODS: Our single-center, prospectively maintained database was retrospectively reviewed for CAS procedures performed in symptomatic and asymptomatic patients over 12 years (2010-2022). Baseline demographic data, procedural characteristics, and preprocedural and postprocedural radiographic and clinical details were noted. Baseline characteristics of patients with and without carotid restenosis were compared using the χ2 test for categorical variables and the Student t-test for continuous variables. Univariate and multivariate analyses were performed to determine risk factors associated with restenosis, defined as >70% on digital subtraction angiography. RESULTS: A total of 1017 consecutive CAS procedures were performed in 905 patients during the 12-year period, with 738 in 632 patients included in our study. Our cohort's overall restenosis rate was 17%, with a 14% restenosis rate at 2 years. On multivariate regression analysis, former or current smoking status (odds ratio [OR] = 2.3, 95% CI 1.2-4.1), plaque irregularity (OR 0.55, 95% CI 0.33-0.91), moderate (50.1%-75%) contralateral stenosis (OR 3.2, 95% CI 1.4-7.2), severe (75.1%-99.9%) contralateral stenosis (OR 2.8, 95% CI 1.3-6.0), and residual (>70%) in-stent stenosis after initial stenting (OR 433, 95% CI 80-2346) were significantly associated with carotid restenosis. Area under the curve for the multivariate regression model analysis was 0.78. Patients with <28.6% initial (residual) in-stent stenosis (45/517 cases) had a 9% restenosis rate, whereas those with >28.6% initial in-stent stenosis (77/221 cases) had a 35% restenosis rate. CONCLUSION: In this large, single-center study of carotid artery stenosis treated with CAS, residual in-stent carotid stenosis of approximately 30% and smoking status were independent predictors for restenosis. Maximizing treatment of initial stenosis and smoking cessation education are important steps in preventing future carotid restenosis.

Cerebral emboli detection and autonomous neuromonitoring using robotic transcranial Doppler with artificial intelligence for transcatheter aortic valve replacement with and without embolic protection devices: a pilot study.

BACKGROUND: Periprocedural ischemic stroke remains a serious complication in patients undergoing transcatheter aortic valve replacement (TAVR). We used a novel robotic transcranial Doppler (TCD) system equipped with artificial intelligence (AI) for real-time continuous intraoperative neuromonitoring during TAVR to establish the safety and potential validity of this tool in detecting cerebral emboli, report the quantity and distribution of high intensity transient signals (HITS) with and without cerebral protection, and correlate HITS occurrence with various procedural steps. METHODS: Consecutive patients undergoing TAVR procedures during which the robotic system was used between October 2021 and May 2022 were prospectively enrolled in this pilot study. The robotic TCD system included autonomous adjustment of the TCD probes and AI-assisted post-processing of HITS and other cerebral flow parameters. Basic demographics and procedural details were recorded. Continuous variables were analyzed by a two-sample Mann-Whitney t-test and categorical variables by a χ2 or Fisher test. RESULTS: Thirty-one patients were prospectively enrolled (mean age 79.9±7.6 years; 16 men (51.6%)). Mean aortic valve stenotic area was 0.7 cm2 and mean aortic-ventricular gradient was 43 mmHg (IQR 31.5-50 mmHg). Cerebral protection was used in 16 cases (51.6%). Significantly fewer emboli were observed in the protection group than in the non-protection group (mean 470.38 vs 693.33; p=0.01). Emboli counts during valve positioning and implantation were significantly different in the protection and non-protection groups (mean 249.92 and 387.5, respectively; p=0.01). One (4%) transient ischemic attack occurred post-procedurally in the non-protection group. CONCLUSION: We describe a novel real-time intraoperative neuromonitoring tool used in patients undergoing TAVR. Significantly fewer HITS were detected with protection. Valve positioning-implantation was the most significant stage for intraprocedural HITS.

The first endovascular rat glioma model for pre-clinical evaluation of intra-arterial therapeutics.

BACKGROUND: Several translational animal models have been described assessing intra-arterial (IA) treatments for malignant gliomas. We describe the first endovascular animal model that allows testing of IA drug delivery as a first-line treatment, which is difficult to do in actual patients. We report a unique protocol for vascular access and IA delivery in the rat model that, unlike prior reports, does not require direct puncture and opening of proximal cerebrovasculature which carries risk of ischemia in the animal brain post-delivery. METHODS: Wistar rats underwent left femoral artery catherization with a Balt Magic 1.2F catheter or Marathon Flow directed 1.5F Microcatheter with an Asahi Chikai 0.008 micro-guidewire which was navigated to the left internal carotid artery under x-ray. 25% mannitol was administered to test blood brain barrier breakdown (BBBB). Additional rats were implanted with C6 glioma cells in the left frontal lobe. C6 Glioma-Implanted Rats (C6GRs) were monitored for overall survival and tumor growth. Tumor volumes from MRI images were calculated utilizing 3D slicer. Additional rats underwent femoral artery catheterization with Bevacizumab, carboplatin, or irinotecan injected into the left internal carotid artery to test feasibility and safety. RESULTS: A successful endovascular access and BBBB protocol was established. BBBB was confirmed with positive Evans blue staining. 10 rats were successfully implanted with C6 gliomas with confirmed growths on MRI. Overall survival was 19.75 ± 2.21 days. 5 rats were utilized for the development of our femoral catheterization protocol and BBBB testing. With regards to IA chemotherapy dosage testing, control rats tolerated targeted 10 mg/kg of bevascizumab, 2.4 mg/kg of carboplatin, and 15 mg/kg of irinotecan IA ICA injections without any complications. CONCLUSIONS: We present the first endovascular IA rat glioma model that allows selective catheterization of the intracranial vasculature and assessment of IA therapies for gliomas without need for access and sacrifice of proximal cerebrovasculature.

The abscopal effect: inducing immunogenicity in the treatment of brain metastases secondary to lung cancer and melanoma.

PURPOSE: The phenomenon of radiation therapy (RT) causing regression of targeted lesions as well as lesions outside of the radiation field is known as the abscopal effect and is thought to be mediated by immunologic causes. This phenomena has been described following whole brain radiation (WBRT) and stereotactic radiosurgery (SRS) of brain metastasis (BM) in advanced melanoma and non-small-cell lung cancer (NSCLC). We systematically reviewed the available literature to identify which radiation modality and immunotherapy (IT) combination may elicit the abscopal effect, the optimal timing of RT and IT, and potential adverse effects inherent to the combination of RT and IT. METHODS: Using PRISMA guidelines, a search of PubMed, Medline, and Web of Science was conducted to identify studies demonstrating the abscopal effect during treatment of NSCLC or melanoma with BM. RESULTS: 598 cases of irradiated BM of melanoma or NSCLC in 18 studies met inclusion criteria. The most commonly administered ITs included PD-1 or CTLA-4 immune checkpoint inhibitors (ICI), with RT most commonly administered within 3 months of ICI. Synergy between ICI and RT was described in 16 studies including evidence of higher tumor response within and outside of the irradiated field. In the 12 papers (n = 232 patients) that reported objective response rate (ORR) in patients with BM treated with RT and concurrent systemic IT, the non-weighted mean ORR was 49.4%; in the 5 papers (n = 110 patients) that reported ORR for treatment with RT or IT alone, the non-weighted mean ORR was 27.8%. No studies found evidence of significantly increased toxicity in patients receiving RT and ICI. CONCLUSION: The combination of RT and ICIs may enhance ICI efficacy and induce more durable responses via the abscopal effect in patients with brain metastases of melanoma or NSCLC.

A look at the global impact of COVID-19 pandemic on neurosurgical services and residency training.

Background: The COVID-19 pandemic has left an indelible effect on healthcare delivery and education system, including residency training. Particularly, neurosurgical departments worldwide had to adapt their operating model to the constantly changing pandemic landscape. This review aimed to quantify the reduction in neurosurgical operative volume and describe the impact of these trends on neurosurgical residency training. Methods: We performed a comprehensive search of PubMed and EMBASE between December 2019 and October 2022 to identify studies comparing pre-pandemic and pandemic neurosurgical caseloads as well as articles detailing the impact of COVID-19 on neurosurgery residency training. Statistical analysis of quantitative data was presented as pooled odds ratio (OR) and 95% confidence intervals (CI). Results: A total of 49 studies met the inclusion criteria, of which 12 (24.5%) were survey-based. The case volume of elective surgeries and non-elective procedures decreased by 70.4% (OR=0.296, 95%CI 0.210-0.418) and 68.2% (OR=0.318, 95%CI 0.193-0.525), respectively. A significant decrease was also observed in functional (OR=0.542, 95%CI 0.394-0.746), spine (OR=0.545, 95%CI 0.409-0.725), and skull base surgery (OR=0.545, 95%CI 0.409-0.725), whereas the caseloads for tumor (OR=1.029, 95%CI 0.838-1.263), trauma (OR=1.021, 95%CI 0.846-1.232), vascular (OR=1.001, 95%CI 0.870-1.152), and pediatric neurosurgery (OR=0.589, 95%CI 0.344-1.010) remained relatively the same between pre-pandemic and pandemic periods. The reduction in caseloads had caused concerns among residents and program directors in regard to the diminished clinical exposure, financial constraints, and mental well-being. Some positives highlighted were rapid adaptation to virtual educational platforms and increasing time for self-learning and research activities. Conclusion: While COVID-19 has brought about significant disruptions in neurosurgical practice and training, this unprecedented challenge has opened the door for technological advances and collaboration that broaden the accessibility of resources and reduce the worldwide gap in neurosurgical education.

Volumetric resolution of chronic subdural hematomas treated with surgical evacuation versus middle meningeal artery embolization during immediate, early, and late follow up: propensity-score matched cohorts.

BACKGROUND: Literature on volumetric resolution and recurrence over time between surgical evacuation alone (SEA) and standalone middle meningeal artery embolization (MMAE) in comparable chronic subdural hematoma (cSDH) patients is limited. METHODS: A retrospective database analysis of cSDH patients managed with either SEA or MMAE was conducted. Propensity-score matching was performed for axial and coronal lengths, maximum diameter, and midline shift. Volumetric measurements at multiple time intervals and recurrence were compared between the groups. RESULTS: 48 matched hematoma pairs in patients with similar demographics, comorbidities, medications, and symptoms were obtained. Median volume was significantly lower at 24 hours in the SEA group (12.6 mL vs 52.7 mL, p<0.001) but not at remaining intervals. Median volume reduction was significantly greater in the SEA group at 24 hours (39.1 mL vs 8.8 mL in the MMAE group, p<0.001) and at 3-12 weeks (50.8 mL vs 23.7 mL, p<0.001), but not at remaining intervals. The SEA group had a significantly greater median hematoma resolution rate at 24 hours (39.1 mL/day vs 8.8 mL/day, p<0.001) and 3-12 weeks (1 mL/day vs 0.4 mL/day, p<0.001), but not at remaining intervals. Near-complete resolution at 3-12 weeks and 12-60 weeks was not significantly different between groups. Overall, the recurrence rate was significantly higher in the SEA group (22.9% vs 4.2%, p=0.01). CONCLUSIONS: In comparable cSDH patients, SEA resulted in better volumetric outcomes in immediate postoperative and early follow-up periods, as expected. However, this difference was not significant at more distant follow-up intervals. Furthermore, surgical patients experienced a significantly higher rate of recurrence.