How I do it: hearing preservation in large vestibular schwannomas using vestibular nerve fiber preservation technique.

BACKGROUND: To improve hearing function after resection of large vestibular schwannomas, we describe a strategy of vestibular-nerve-fiber preservation. Anatomical considerations and stepwise dissection are described. METHOD: Steps include locating the vestibular nerve at the brainstem and identifying a dissection plane between nerve fibers and tumor capsule. Using this plane to mobilize and resect tumor reduced manipulation and maintained vascularity of underlying cochlear and facial nerves. CONCLUSION: Preservation of hearing function is feasible in large vestibular schwannomas with vestibular-nerve-fiber preservation. Reducing manipulation and ischemic injury of underlying cochlear and facial nerves thereby helped facilitate hearing preservation, even in large tumors.

Novel classification of foramen magnum meningiomas predicted by topographic position relative to neurovascular bundle.

PURPOSE: Proximity to critical neurovascular structures can create significant obstacles during surgical resection of foramen magnum meningiomas (FMMs) to the detriment of treatment outcomes. We propose a new classification that defines the tumor's relationship to neurovascular structures and assess correlation with postoperative outcomes. METHODS: In this retrospective review, 41 consecutive patients underwent primary resection of FMMs through a far lateral approach. Groups defined based on tumor-neurovascular bundle configuration included Type 1, bundle ventral to tumor; Type 2a-c, bundle superior, inferior, or splayed, respectively; Type 3, bundle dorsal; and Type 4, nerves and/or vertebral artery encased by tumor. RESULTS: The 41 patients (range 29-81 years old) had maximal tumor diameter averaging 30.1 mm (range 12.7-56 mm). Preoperatively, 17 (41%) patients had cranial nerve (CN) dysfunction, 12 (29%) had motor weakness and/or myelopathy, and 9 (22%) had sensory deficits. Tumor type was relevant to surgical outcomes: specifically, Type 4 demonstrated lower rates of gross total resection (65%) and worse immediate postoperative CN outcomes. Long-term findings showed Types 2, 3, and 4 demonstrated higher rates of permanent cranial neuropathy. Although patients with Type 4 tumors had overall higher ICU and hospital length of stay, there was no difference in tumor configuration and rates of postoperative complications or 30-day readmission. CONCLUSION: The four main types of FMMs in this proposed classification reflected a gradual increase in surgical difficulty and worse outcomes. Further studies are warranted in larger cohorts to confirm its reliability in predicting postoperative outcomes and possibly directing management decisions.

The effect of institutional case volume on post-operative outcomes after endarterectomy and stenting for symptomatic carotid stenosis.

OBJECTIVE: To investigate the effects of yearly institutional case volume for carotid endarterectomy (CEA) and stenting (CAS) among symptomatic carotid stenosis patients on the rates of postoperative stroke and inpatient mortality. MATERIALS AND METHODS: Patients with prior stroke ("symptomatic") undergoing CEA or CAS during an inpatient stay were identified from the National Inpatient Sample for years 2012-2015. The primary variable was volume of CEA or CAS performed annually by each institution. The primary outcome was a composite variable for in-hospital death or postoperative stroke. RESULTS: A total of 5,628 patients with symptomatic carotid stenosis underwent CEA, while 245 underwent CAS. In the symptomatic CEA population, 519 (9.2%) patients experienced postoperative stroke or mortality, and were more likely to be treated at centers with a lower yearly institutional volume (median 10 [IQR 5-15] versus 10 [7-20] cases, p<0.001). In the symptomatic CAS population, 32 (13.1%) patients experienced stroke or mortality, and these patients were also more likely to undergo treatment at hospitals with a lower yearly institutional volume (median 5 [IQR 5-7] versus 5 [5-10] cases, p=0.044). Thresholds for yearly institutional volume found differences in adverse outcome between 0-9, 10-29, and ≥30 cases/year (11.7% vs 8.4% vs 6.0%, p<0.001) for CEA, and differences in postoperative stroke between 0-9 and ≥10 cases/year for CAS (11.0% vs 1.4%, p=0.028). CONCLUSIONS: Hospitals performing higher volumes of CEA or CAS have fewer postoperative strokes. The threshold reported herein is ≥30 CEA procedures or ≥10 CAS procedures annually for appreciably improved outcomes.

Radiomic signatures of meningiomas using the Ki-67 proliferation index as a prognostic marker of clinical outcomes.

OBJECTIVE: The clinical behavior of meningiomas is not entirely captured by its designated WHO grade, therefore other factors must be elucidated that portend increased tumor aggressiveness and associated risk of recurrence. In this study, the authors identify multiparametric MRI radiomic signatures of meningiomas using Ki-67 as a prognostic marker of clinical outcomes independent of WHO grade. METHODS: A retrospective analysis was conducted of all resected meningiomas between 2012 and 2018. Preoperative MR images were used for high-throughput radiomic feature extraction and subsequently used to develop a machine learning algorithm to stratify meningiomas based on Ki-67 indices < 5% and ≥ 5%, independent of WHO grade. Progression-free survival (PFS) was assessed based on machine learning prediction of Ki-67 strata and compared with outcomes based on histopathological Ki-67. RESULTS: Three hundred forty-three meningiomas were included: 291 with WHO grade I, 43 with grade II, and 9 with grade III. The overall rate of recurrence was 19.8% (15.1% in grade I, 44.2% in grade II, and 77.8% in grade III) over a median follow-up of 28.5 months. Grade II and III tumors had higher Ki-67 indices than grade I tumors, albeit tumor and peritumoral edema volumes had considerable variation independent of meningioma WHO grade. Forty-six high-performing radiomic features (1 morphological, 7 intensity-based, and 38 textural) were identified and used to build a support vector machine model to stratify tumors based on a Ki-67 cutoff of 5%, with resultant areas under the curve of 0.83 (95% CI 0.78-0.89) and 0.84 (95% CI 0.75-0.94) achieved for the discovery (n = 257) and validation (n = 86) data sets, respectively. Comparison of histopathological Ki-67 versus machine learning-predicted Ki-67 showed excellent performance (overall accuracy > 80%), with classification of grade I meningiomas exhibiting the greatest accuracy. Prediction of Ki-67 by machine learning classifier revealed shorter PFS for meningiomas with Ki-67 indices ≥ 5% compared with tumors with Ki-67 < 5% (p < 0.0001, log-rank test), which corroborates divergent patient outcomes observed using histopathological Ki-67. CONCLUSIONS: The Ki-67 proliferation index may serve as a surrogate marker of increased meningioma aggressiveness independent of WHO grade. Machine learning using radiomic feature analysis may be used for the preoperative prediction of meningioma Ki-67, which provides enhanced analytical insights to help improve diagnostic classification and guide patient-specific treatment strategies.

Predictors of recurrence after surgical resection of parafalcine and parasagittal meningiomas.

PURPOSE: Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery. METHODS: This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence. RESULTS: A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10-71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan-Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60-8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16-7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38-6.96; p = 0.006) as independent factors that portend shorter time to recurrence. CONCLUSION: This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes.

Predictors of aneurysm occlusion following treatment with the WEB device: systematic review and case series.

The Woven EndoBridge (WEB) device is becoming increasingly popular for treatment of wide-neck aneurysms. As experience with this device grows, it is important to identify factors associated with occlusion following WEB treatment to guide decision making and screen patients at high risk for recurrence. The aim of this study was to identify factors associated with adequate aneurysm occlusion following WEB device treatment in the neurosurgical literature and in our case series. A systematic review of the present literature was conducted to identify studies related to the prediction of WEB device occlusion. In addition, a retrospective review of our institutional data for patients treated with the WEB device was performed. Demographics, aneurysm characteristics, procedural variables, and 6-month follow-up angiographic outcomes were recorded. Seven articles totaling 450 patients with 456 aneurysms fit our criteria. Factors in the literature associated with inadequate occlusion included larger size, increased neck width, partial intrasaccular thrombosis, irregular shape, and tobacco use. Our retrospective review identified 43 patients with 45 aneurysms. A total of 91.1% of our patients achieved adequate occlusion at a mean follow-up time of 7.32 months. Increasing degree of contrast stasis after WEB placement on the post-deployment angiogram was significantly associated with adequate occlusion on follow-up angiogram (p = 0.005) and with Raymond-Roy classification (p = 0.048), but not with retreatment (p = 0.617). In our systematic review and case series totaling 450 patients with 456 aneurysms, contrast stasis on post-deployment angiogram was identified as a predictor of adequate aneurysm occlusion, while morphological characteristics such as larger size and wide neck negatively impact occlusion.

A Machine Learning Approach to First Pass Reperfusion in Mechanical Thrombectomy: Prediction and Feature Analysis.

INTRODUCTION: Novel machine learning (ML) methods are being investigated across medicine for their predictive capabilities while boasting increased adaptability and generalizability. In our study, we compare logistic regression with machine learning for feature importance analysis and prediction in first-pass reperfusion. METHODS: We retrospectively identified cases of ischemic stroke treated with mechanical thrombectomy (MT) at our institution from 2012-2018. Significant variables used in predictive modeling were demographic characteristics, medical history, admission NIHSS, and stroke characteristics. Outcome was binarized TICI on first pass (0-2a vs 2b-3). Shapley feature importance plots were used to identify variables that strongly affected outcomes. RESULTS: Accuracy for the Random Forest and SVM models were 67.1% compared to 65.8% for the logistic regression model. Brier score was lower for the Random Forest model (0.329 vs 0.342) indicating better predictive capability. Other supervised learning models performed worse than the logistic regression model, with accuracy of 56.2% for Naïve Bayes and 61.6% for XGBoost. Shapley plots for the Random Forest model showed use of aspiration, hyperlipidemia, hypertension, use of stent retriever, and time between symptom onset and catheterization as the top five predictors of first pass reperfusion. CONCLUSION: Use of machine learning models, such as Random Forest, for the study of MT outcomes, is more accurate than logistic regression for our dataset, and identifies new factors that contribute to achieving first pass reperfusion. The benefits of machine learning, such as improved predictive capabilities, integration of new data, and generalizability, establish ML as the preferred model for studying outcomes in stroke.

Discrepancies in Stroke Distribution and Dataset Origin in Machine Learning for Stroke.

BACKGROUND: Machine learning algorithms depend on accurate and representative datasets for training in order to become valuable clinical tools that are widely generalizable to a varied population. We aim to conduct a review of machine learning uses in stroke literature to assess the geographic distribution of datasets and patient cohorts used to train these models and compare them to stroke distribution to evaluate for disparities. AIMS: 582 studies were identified on initial searching of the PubMed database. Of these studies, 106 full texts were assessed after title and abstract screening which resulted in 489 papers excluded. Of these 106 studies, 79 were excluded due to using cohorts from outside the United States or being review articles or editorials. 27 studies were thus included in this analysis. SUMMARY OF REVIEW: Of the 27 studies included, 7 (25.9%) used patient data from California, 6 (22.2%) were multicenter, 3 (11.1%) were in Massachusetts, 2 (7.4%) each in Illinois, Missouri, and New York, and 1 (3.7%) each from South Carolina, Washington, West Virginia, and Wisconsin. 1 (3.7%) study used data from Utah and Texas. These were qualitatively compared to a CDC study showing the highest distribution of stroke in Mississippi (4.3%) followed by Oklahoma (3.4%), Washington D.C. (3.4%), Louisiana (3.3%), and Alabama (3.2%) while the prevalence in California was 2.6%. CONCLUSIONS: It is clear that a strong disconnect exists between the datasets and patient cohorts used in training machine learning algorithms in clinical research and the stroke distribution in which clinical tools using these algorithms will be implemented. In order to ensure a lack of bias and increase generalizability and accuracy in future machine learning studies, datasets using a varied patient population that reflects the unequal distribution of stroke risk factors would greatly benefit the usability of these tools and ensure accuracy on a nationwide scale.

Comparison of Anesthetic Agents Dexmedetomidine and Midazolam During Mechanical Thrombectomy.

OBJECTIVES: The ideal anesthetic for mechanical thrombectomy (MT) is a subject of debate. Recent studies have supported the use of monitored anesthesia care (MAC), but few have attempted to compare MAC neuroanesthetics. Our study directly compares midazolam and dexmedetomidine (DEX) on blood pressure control during thrombectomy and functional outcomes at discharge. MATERIALS AND METHODS: We performed a retrospective review of an MT database, which consisted of 612 patients admitted between 2010-2019 to our tertiary stroke center. 193 patients who received either midazolam or DEX for MAC induction were identified. Primary and secondary outcomes were >20% maximum decrease in mean arterial pressure during MT and functional independence respectively. RESULTS: 146 patients were administered midazolam, while 47 were administered DEX. Decrease in blood pressure (BP) during MT was associated with lower rates of functional independence at last follow-up (p=0.034). When compared to midazolam, DEX had significantly higher rates of intraprocedural decrease in MAP at the following cut-offs: >20% (p<0.001), >30% (p=0.001), and >40% (p=0.006). On multivariate analysis, DEX was an independent predictor of >20% MAP decrease (OR 7.042, p<0.001). At time of discharge, NIHSS scores and functional independence (mRS 0-2) were statistically similar between DEX and midazolam. Functional independence at last known follow-up was statistically similar between DEX and midazolam (p = 0.643). CONCLUSIONS: Use of DEX during MT appears to be associated with increased blood pressure volatility when compared to midazolam. Further investigation is needed to determine the impact of MAC agents on functional independence.

Radial Artery Catheterization for Neuroendovascular Procedures.

Background and Purpose- Radial artery catheterization is an alternate route of access that has started to gain more widespread use for neuroendovascular procedures, and there have been few studies that describe its safety and efficacy. We present our institution's experience in performing neuroendovascular interventions via a transradial approach, with excellent clinical outcomes and patient satisfaction measures. Methods- We conducted a retrospective analysis and identified 223 patients who underwent 233 consecutive neuroendovascular interventions via radial artery access at our institution. The incidence of perioperative and postprocedural complications was investigated. We identified a subset of 98 patients who have undergone both transradial and transfemoral cerebral angiograms and compared clinical outcomes and patient satisfaction measures between the 2 groups. Results- The overall incidence of complications was low across all procedures performed via transradial access. Peri-procedurally, only 2 patients had symptomatic radial artery spasm, and there were no instances of iatrogenic complications (vessel dissection, stroke, and hemorrhage). In 10 cases (4.3%), the intended procedure could not be completed via a transradial approach, and, thus, femoral artery access had to be pursued instead. Ten patients complained of minor postprocedural complications, although none required therapeutic intervention. The mean procedure time was shorter for diagnostic angiograms performed via transradial versus transfemoral access (18.8±15.8 versus 39.5±31.1 minutes; P=0.025). Patients overall reported shorter recovery times with transradial access, and the majority of patients (94%) would elect to have subsequent procedures performed via this route. Conclusions- Radial artery catheterization is a safe and durable alternative to perform a wide range of neuroendovascular procedures, with a low rate of complications. On the whole, patients prefer transradial compared with transfemoral access.

A multi-institutional meningioma MRI dataset for automated multi-sequence image segmentation.

Meningiomas are the most common primary intracranial tumors and can be associated with significant morbidity and mortality. Radiologists, neurosurgeons, neuro-oncologists, and radiation oncologists rely on brain MRI for diagnosis, treatment planning, and longitudinal treatment monitoring. However, automated, objective, and quantitative tools for non-invasive assessment of meningiomas on multi-sequence MR images are not available. Here we present the BraTS Pre-operative Meningioma Dataset, as the largest multi-institutional expert annotated multilabel meningioma multi-sequence MR image dataset to date. This dataset includes 1,141 multi-sequence MR images from six sites, each with four structural MRI sequences (T2-, T2/FLAIR-, pre-contrast T1-, and post-contrast T1-weighted) accompanied by expert manually refined segmentations of three distinct meningioma sub-compartments: enhancing tumor, non-enhancing tumor, and surrounding non-enhancing T2/FLAIR hyperintensity. Basic demographic data are provided including age at time of initial imaging, sex, and CNS WHO grade. The goal of releasing this dataset is to facilitate the development of automated computational methods for meningioma segmentation and expedite their incorporation into clinical practice, ultimately targeting improvement in the care of meningioma patients.

FGF-1 delivery from multilayer alginate microbeads stimulates a rapid and persistent increase in vascular density.

In recent years, great advances have been made in the use of islet transplantation as a treatment for type I diabetes. Indeed, it is possible that stimulation of local neovascularization upon transplantation could improve functional graft outcomes. In the present study, we investigate the use of multilayered alginate microbeads to provide a sustained delivery of FGF-1, and whether this results in increased neovascularization in vivo. Multilayered alginate microbeads, loaded with either 150ng or 600ng of FGF-1 in the outer layer, were surgically implanted into rats using an omentum pouch model and compared to empty microbead implants. Rats were sacrificed at 4days, 1week, and 6weeks. Staining for CD31 showed that both conditions of FGF-1 loaded microbeads resulted in a significantly higher vessel density at all time points studied. Moreover, at 6weeks, alginate microbeads containing 600ng FGF-1 provided a greater vascular density compared to both the control group and the microbeads loaded with 150ng FGF-1. Omenta analyzed via staining for smooth muscle alpha actin showed no variation in mural cell density at either 4days or 1week. At 6weeks, however, omenta exposed to microbeads loaded with 600ng FGF-1 showed an increase in mural cell staining compared to controls. These results suggest that the sustained delivery of FGF-1 from multilayered alginate microbeads results in a rapid and persistent vascular response. An increase in the local blood supply could reduce the number of islets required for transplantation in order to achieve clinical efficacy.

Ventriculostomy Associated with Reduced Mortality in Severe Traumatic Brain Injury Compared to Parenchymal ICP Monitoring: A Propensity Score-Adjusted Analysis.

BACKGROUND: There is a lack of data on whether intracranial pressure (ICP)-guided therapy with an intraparenchymal fiberoptic monitor (IPM) or an external ventricular drain (EVD) leads to superior outcomes. Our goal is to determine the relationship between ICP-guided therapy with an EVD or IPM and mortality. METHODS: Retrospective analysis of severe traumatic brain injury cases that required IPM or EVD placement for ICP-guided therapy from January 1, 2010 to December 31, 2020. The data were obtained from the Pennsylvania Trauma Systems Foundation registry. RESULTS: A total of 2305 patients met the inclusion criteria, with 1048 (45.5%) IPM and 1257 (54.5%) EVD placed. Inpatient mortality occurred in 337 (32.2%) and 334 (26.6%) patients in the IPM and EVD cohorts, respectively (P = 0.003). Even among those treated medically only, inpatient mortality occurred in 171 (30.8%) of those with an IPM and in 100 (23.4%) of those with an EVD (P = 0.010). Multivariable logistic regression analysis showed that older age (odds ratio [OR] 1.03, P < 0.001), lower Glasgow Coma Scale (GCS) score (OR 1.16, P < 0.001), requiring surgery (OR 1.22, P = 0.049), and an IPM (OR 1.40, P = 0.001) were significant predictors of mortality. Propensity score-adjusted analysis using inverse probability of treatment weighted method revealed a 28% decrease in mortality and a 14% decrease in length of hospital stay with EVD use when adjusting for age, sex, GCS, Injury Severity Score, surgery, and Hispanic ethnicity. CONCLUSIONS: A significant mortality benefit was associated with the use of EVD compared to IPM. This mortality benefit was observed regardless of whether patients required surgery or not.

A Comparison of Outcomes Using Combined Intra- and Extradural versus Extradural-Only Repair of Tegmen Defects.

Objective Tegmen tympani or tegmen mastoideum defects involve dehiscence of the temporal bone that can be a source of cerebrospinal fluid (CSF) otorrhea. Herein, we compare a combined intra-/extradural repair strategy with an extradural-only repair as it pertains to surgical and clinical outcomes. Design A retrospective review from our institution was performed of patients with tegmen defects requiring surgical intervention. Participants Patients with tegmen defects who underwent surgery (combined transmastoid and middle fossa craniotomy) for repair of tegmen defects between 2010 and 2020 were inclined in this study. Results A total of 60 patients with 40 intra-/extradural (mean follow-up time: 1,060 ± 1,103 days) and 20 extradural-only (mean follow-up time: 519 ± 369 days) repairs were identified. No major differences in demographic factors or presenting symptoms were identified between the two cohorts. There was no difference in hospital length of stay between the two patient cohorts (mean: 4.15 vs. 4.35 days, p = 0.8). In the extradural-only repair technique, synthetic bone cement was more frequently used (100 vs. 7.5%, p < 0.01), whereas in the combined intra-/extradural repair, synthetic dural substitute was used more often (80 vs. 35%, p < 0.01), with similar successful surgical outcomes achieved. Despite disparities in the techniques and materials used for repair, there were no differences in complication rates (wound infection, seizures, and ossicular fixation), 30-day readmission rates, or persistent CSF leak between the two treatment cohorts. Conclusion The results of this study suggest no difference in clinical outcomes between combined intra-/extradural versus extradural-only repair of tegmen defects. A simplified extradural-only repair strategy can be effective, and may reduce the morbidity of intradural reconstruction (seizures, stroke, and intraparenchymal hemorrhage).

Initial Heart Rate Predicts Functional Independence in Patients With Spinal Cord Injury Requiring Surgery: A Registry-Based Study in a Mature Trauma System Over the Past 10 Years.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the ability of early vital sign abnormalities to predict functional independence in patients with SCI that required surgery. METHODS: A retrospective analysis of data extracted from the Pennsylvania Trauma Outcome Study database. Inclusion criteria were patients >18 years with a diagnosis of SCI who required urgent spine surgery in Pennsylvania from 1/1/2010-12/31/2020 and had complete records available. RESULTS: A total of 644 patients met the inclusion criteria. The mean age was 47.1 ± 14.9 years old and the mean injury severity score (ISS) was 22.3 ± 12.7 with the SCI occurring in the cervical, thoracic, and lumbar spine in 61.8%, 19.6% and 18.0%, respectively. Multivariable logistic regression analyses for predictors of functional independence at discharge showed that higher HR at the scene (OR 1.016, 95% CI 1.006-1.027, P = .002) and lower ISS score (OR .894, 95% CI .870-.920, P < .001) were significant predictors of functional independence. Similarly, higher admission HR (OR 1.015, 95% CI 1.004-1.027, P = .008) and lower ISS score (OR .880, 95% CI 0.864-.914, P < .001) were significant predictors of functional independence. Peak Youden indices showed that patients with HR at scene >70 and admission HR ≥83 were more likely to achieve functional independence. CONCLUSIONS: Early heart rate is a strong predictor of functional independence in patients with SCI. HR at scene >70 and admission HR ≥83 is associated with improved outcomes, suggesting lack of neurogenic shock.

Machine learning for outcome prediction of neurosurgical aneurysm treatment: Current methods and future directions.

INTRODUCTION: Machine learning algorithms have received increased attention in neurosurgical literature for improved accuracy over traditional predictive methods. In this review, the authors sought to assess current applications of machine learning for outcome prediction of neurosurgical treatment of intracranial aneurysms and identify areas for future research. METHODS: A PRISMA-compliant systematic review of the PubMed, MEDLINE, and EMBASE databases was conducted for all studies utilizing machine learning for outcome prediction of intracranial aneurysm treatment. Patient characteristics, machine learning methods, outcomes of interest, and accuracy metrics were recorded from included studies. RESULTS: 16 studies were ultimately included in qualitative synthesis. Studies primarily analyzed angiographic outcomes, functional outcomes, or complication prediction using clinical, radiological, or composite variables. The majority of included studies utilized supervised learning algorithms for analysis of dichotomized outcomes. CONCLUSIONS: Commonly included variables were demographics, presentation variables (including ruptured or unruptured status), and treatment used. Areas for future research include increased generalizability across institutions and for smaller datasets, as well as development of front-end tools for clinical applicability of published algorithms.

Evaluation of a Balloon Implant for Simultaneous Magnetic Nanoparticle Hyperthermia and High-Dose-Rate Brachytherapy of Brain Tumor Resection Cavities.

Previous work has reported the design of a novel thermobrachytherapy (TBT) balloon implant to deliver magnetic nanoparticle (MNP) hyperthermia and high-dose-rate (HDR) brachytherapy simultaneously after brain tumor resection, thereby maximizing their synergistic effect. This paper presents an evaluation of the robustness of the balloon device, compatibility of its heat and radiation delivery components, as well as thermal and radiation dosimetry of the TBT balloon. TBT balloon devices with 1 and 3 cm diameter were evaluated when placed in an external magnetic field with a maximal strength of 8.1 kA/m at 133 kHz. The MNP solution (nanofluid) in the balloon absorbs energy, thereby generating heat, while an HDR source travels to the center of the balloon via a catheter to deliver the radiation dose. A 3D-printed human skull model was filled with brain-tissue-equivalent gel for in-phantom heating and radiation measurements around four 3 cm balloons. For the in vivo experiments, a 1 cm diameter balloon was surgically implanted in the brains of three living pigs (40-50 kg). The durability and robustness of TBT balloon implants, as well as the compatibility of their heat and radiation delivery components, were demonstrated in laboratory studies. The presence of the nanofluid, magnetic field, and heating up to 77 °C did not affect the radiation dose significantly. Thermal mapping and 2D infrared images demonstrated spherically symmetric heating in phantom as well as in brain tissue. In vivo pig experiments showed the ability to heat well-perfused brain tissue to hyperthermic levels (≥40 °C) at a 5 mm distance from the 60 °C balloon surface.

A Comparison of Outcomes Between Transfemoral Versus Transradial Access for Carotid Stenting.

BACKGROUND: The transradial (TR) approach has emerged as an alternative to the transfemoral (TF) approach in carotid artery stenting (CAS) because of its perceived benefits in access site complications and overall patient experience. OBJECTIVE: To assess outcomes of TF vs TR approach for CAS. METHODS: This is a retrospective single-center review of patients receiving CAS through the TR or TF route between 2017 and 2022. All patients with symptomatic and asymptomatic carotid disease who underwent attempted CAS were included in our study. RESULTS: A total of 342 patients were included in this study: 232 underwent CAS through TF approach vs 110 through the TR route. On univariate analysis, the rate of overall complications was more than double for the TF vs TR cohort; however, this did not achieve statistical significance (6.5% vs 2.7%, odds ratio [OR] = 0.59 P = .36). The rate of cross-over from TR to TF was significantly higher on univariate analysis (14.6 % vs 2.6%, OR = 4.77, P = .005) and on inverse probability treatment weighting analysis (OR = 6.11, P < .001). The rate of in-stent stenosis (TR: 3.6% vs TF: 2.2%, OR = 1.71, P = .43) and strokes at follow-up (TF: 2.2% vs TR: 1.8%, OR = 0.84, P = .84) was not significantly different. Finally, median length of stay was comparable between both cohorts. CONCLUSION: The TR approach is safe, feasible, and provides similar rates of complications and high rates of successful stent deployment compared with the TF route. Neurointerventionalists adopting the radial first approach should carefully assess the preprocedural computed tomography angiography to identify patients amenable to TR approach for carotid stenting.

Clinical Outcomes After Ultra-Early Cranioplasty Using Craniectomy Contour Classification as a Patient Selection Criterion.

BACKGROUND: Although not a technically difficult operation, cranioplasty is associated with high rates of complications. The optimal timing of cranioplasty to mitigate complications remains the subject of debate. OBJECTIVE: To report outcomes between patients undergoing cranioplasty at ultra-early (0-6 weeks), intermediate (6 weeks to 6 months), and late (>6 months) time frames. We report a novel craniectomy contour classification (CCC) as a radiographic parameter to assess readiness for cranioplasty. METHODS: A single-institution retrospective analysis of patients undergoing cranioplasty was performed. Patients were stratified into ultra-early (within 6 weeks of index craniectomy), intermediate (6 weeks to 6 months), and late (>6 months) cranioplasty cohorts. We have devised CCC scores, A, B, and C, based on radiographic criteria, where A represents those with a sunken brain/flap, B with a normal parenchymal contour, and C with "full" parenchyma. RESULTS: A total of 119 patients were included. There was no significant difference in postcranioplasty complications, including return to operating room ( P = .212), seizures ( P = .556), infection ( P = .140), need for shunting ( P = .204), and deep venous thrombosis ( P = .066), between the cohorts. Univariate logistic regression revealed that ultra-early cranioplasty was significantly associated with higher rate of functional independence at >6 months (odds ratio 4.32, 95% CI 1.39-15.13, P = .015) although this did not persist when adjusting for patient selection features (odds ratio 2.90, 95% CI 0.53-19.03, P = .234). CONCLUSION: In appropriately selected patients, ultra-early cranioplasty is not associated with increased rate of postoperative complications and is a viable option. The CCC may help guide decision-making on timing of cranioplasty.

Predictors of Transfemoral Access Site Complications in Neuroendovascular Procedures: A large Single-Center Cohort Study.

OBJECTIVE: The transfemoral (TF) route has historically been the preferred access site for endovascular procedures. However, despite its widespread use, TF procedures may confer morbidity as a result of access site complications. The aim of this study is to provide the rate and predictors of TF access site complications for neuroendovascular procedures. METHODS: This is a single center retrospective study of TF neuroendovascular procedures performed between 2017 and 2022. The incidence of complications and associated risk factors were analyzed across a large cohort of patients. RESULTS: The study comprised of 2043 patients undergoing transfemoral neuroendovascular procedures. The composite rate of access site complications was 8.6 % (n = 176). These complications were divided into groin hematoma formation (n = 118, 5.78 %), retroperitoneal hematoma (n = 14, 0.69 %), pseudoaneurysm formation (n = 40, 1.96 %), and femoral artery occlusion (n = 4, 0.19 %). The cross-over to trans radial access rate was 1.1 % (n = 22). On univariate analysis, increasing age (OR=1.0, p = 0.06) coronary artery disease (OR=1.7, p = 0.05) peripheral vascular disease (OR=1.9, p = 0.07), emergent mechanical thrombectomy procedures (OR=2.1, p < 0.001) and increasing sheath size (OR=1.3, p < 0.001) were associated with higher TF access site complications. On multivariate analysis, larger sheath size was an independent risk factor for TF access site complications (OR=1.8, p = 0.02). CONCLUSION: Several pertinent factors contribute towards the incidence of TF access site complications. Factors associated with TF access site complications include patient demographics (older age) and clinical risk factors (vascular disease), as well as periprocedural factors (sheath size).