Findings Predictive of Poor Outcome in Grade 5 Subarachnoid Hemorrhage: A Cohort Study.

BACKGROUND: Most patients with World Federation of Neurological Surgeons (WFNS) grade 5 subarachnoid hemorrhage (SAH) have poor outcomes. Accurate assessment of prognosis is important for treatment decisions and conversations with families regarding goals of care. Unjustified pessimism may lead to "self-fulfilling prophecy," where withdrawal of life-sustaining measures (WLSM) is invariably followed by death. METHODS: We performed a cohort study involving consecutive patients with WFNS grade 5 SAH to identify variables with >= 90% and >= 95% positive predictive value (PPV) for poor outcome (1-year modified Rankin Score >= 4), as well as findings predictive of WLSM. RESULTS: Of 140 patients, 38 (27%) had favorable outcomes. Predictors with >= 95% PPV for poor outcome included unconfounded 72-hour Glasgow Coma Scale motor score <= 4, absence of >= 1 pupillary light reflex (PLR) at 24 hours, and intraventricular hemorrhage (IVH) score of >= 20 (volume >= 54.6 ml). Intracerebral hemorrhage (ICH) volume >= 53 ml had PPV of 92%. Variables associated with WLSM decisions included a poor motor score (p < 0.0001) and radiographic evidence of infarction (p = 0.02). CONCLUSIONS: We identified several early predictors with high PPV for poor outcome. Of these, lack of improvement in motor score during the initial 72 hours had the greatest potential for confounding from "self-fulfilling prophecy." Absence of PLR at 24 hours, IVH score >= 20, and ICH volume >= 53 ml predicted poor outcome without a statistically significant effect on WLSM decisions. More research is needed to validate prognostic variables in grade 5 SAH, especially among patients who do not undergo WLSM.

Supplementary Educational Models in Canadian Neurosurgery Residency Programs.

BACKGROUND: The proposed implementation of work hour restrictions has presented a significant challenge of maintaining the quality of resident education and ensuring adequate hands-on experience that is essential for novice surgeons. To maintain the level of resident surgical competency, revision of the apprentice model of surgical education to include supplementary educational methods, such as laboratory and virtual reality (VR) simulations, have become frequent topics of discussion. We aimed to better understand the role of supplementary educational methods in Canadian neurosurgery residency training. METHODS: An online survey was sent to program directors of all 14 Canadian neurosurgical residency programs and active resident members of the Canadian Neurosurgical Society (N=85). We asked 16 questions focusing on topics of surgeon perception, current implementation and barriers to supplementary educational models. RESULTS: Of the 99 surveys sent, 8 out of 14 (57%) program directors and 37 out of 85 (44%) residents completed the survey. Of the 14 neurosurgery residency programs across Canada, 7 reported utilizing laboratory-based teaching within their educational plan, while only 3 programs reported using VR simulation as a supplementary teaching method. The biggest barriers to implementing supplementary educational methods were resident availability, lack of resources, and cost. CONCLUSIONS: Work-hour restrictions threaten to compromise the traditional apprentice model of surgical training. The potential value of supplementary educational methods for surgical education is evident, as reported by both program directors and residents across Canada. However, availability and utilization of laboratory and VR simulations are limited by numerous factors such as time constrains and lack of resources.

Lactate storm marks cerebral metabolism following brain trauma.

Brain metabolism is thought to be maintained by neuronal-glial metabolic coupling. Glia take up glutamate from the synaptic cleft for conversion into glutamine, triggering glial glycolysis and lactate production. This lactate is shuttled into neurons and further metabolized. The origin and role of lactate in severe traumatic brain injury (TBI) remains controversial. Using a modified weight drop model of severe TBI and magnetic resonance (MR) spectroscopy with infusion of (13)C-labeled glucose, lactate, and acetate, the present study investigated the possibility that neuronal-glial metabolism is uncoupled following severe TBI. Histopathology of the model showed severe brain injury with subarachnoid and hemorrhage together with glial cell activation and positive staining for Tau at 90 min post-trauma. High resolution MR spectroscopy of brain metabolites revealed significant labeling of lactate at C-3 and C-2 irrespective of the infused substrates. Increased (13)C-labeled lactate in all study groups in the absence of ischemia implied activated astrocytic glycolysis and production of lactate with failure of neuronal uptake (i.e. a loss of glial sensing for glutamate). The early increase in extracellular lactate in severe TBI with the injured neurons rendered unable to pick it up probably contributes to a rapid progression toward irreversible injury and pan-necrosis. Hence, a method to detect and scavenge the excess extracellular lactate on site or early following severe TBI may be a potential primary therapeutic measure.

Meningioma recurrence: Time for an online prediction tool?

Background: Meningioma, the most common brain tumor, traditionally considered benign, has a relatively high risk of recurrence over a patient's lifespan. In addition, with the emergence of several clinical, radiological, and molecular variables, it is becoming evident that existing grading criteria, including Simpson's and World Health Organization classification, may not be sufficient or accurate. As web-based tools for widespread accessibility and usage become commonplace, such as those for gene identification or other cancers, it is timely for meningioma care to take advantage of evolving new markers to help advance patient care. Methods: A scoping review of the meningioma literature was undertaken using the MEDLINE and Embase databases. We reviewed original studies and review articles from September 2022 to December 2023 that provided the most updated information on the demographic, clinical, radiographic, histopathological, molecular genetics, and management of meningiomas in the adult population. Results: Our scoping review reveals a large body of meningioma literature that has evaluated the determinants for recurrence and aggressive tumor biology, including older age, female sex, genetic abnormalities such as telomerase reverse transcriptase promoter mutation, CDKN2A deletion, subtotal resection, and higher grade. Despite a large body of evidence on meningiomas, however, we noted a lack of tools to aid the clinician in decision-making. We identified the need for an online, self-updating, and machine-learning-based dynamic model that can incorporate demographic, clinical, radiographic, histopathological, and genetic variables to predict the recurrence risk of meningiomas. Conclusion: Although a challenging endeavor, a recurrence prediction tool for meningioma would provide critical information for the meningioma patient and the clinician making decisions on long-term surveillance and management of meningiomas.

Ruptured pial-pial collateral aneurysm associated with left internal carotid artery occlusion: nuances of surgical management. Illustrative case.

BACKGROUND: Carotid occlusion often leads to the formation of a collateral network. On rare occasions, due to hemodynamic influence, aneurysms can occur. Here, the authors describe a 69-year-old male presenting with intracerebral hemorrhage secondary to a ruptured aneurysm within such a network. OBSERVATIONS: The patient presented to the emergency department with an altered level of consciousness. Imaging showed a left temporal lobe hemorrhage extending into the ventricle, subdural hematoma, and evidence of contrast extravasation. Digital subtraction angiography revealed an occluded left internal carotid artery with the left middle cerebral artery territory reconstituted by flow through an external carotid artery-internal carotid artery anastomosis. The latter was formed by the superficial temporal artery-superior orbital artery, as well as pial-pial collaterals from the posterior temporal artery. Notably, a 4-mm aneurysm arising from the pial-pial collateral network was identified. Surgical intervention involved a left temporal craniectomy and aneurysm excision, with special attention paid to preserving the anastomotic flow through the superficial temporal artery. LESSONS: This case underscores the importance of recognizing and preserving collateral vascular pathways in cases of carotid occlusion with an associated aneurysm. It emphasizes the necessary balance between managing aneurysm risk and maintaining cerebral perfusion, highlighting the need for careful preoperative planning and intraoperative caution.

neuroGPT-X: toward a clinic-ready large language model.

OBJECTIVE: The objective was to assess the performance of a context-enriched large language model (LLM) compared with international neurosurgical experts on questions related to the management of vestibular schwannoma. Furthermore, another objective was to develop a chat-based platform incorporating in-text citations, references, and memory to enable accurate, relevant, and reliable information in real time. METHODS: The analysis involved 1) creating a data set through web scraping, 2) developing a chat-based platform called neuroGPT-X, 3) enlisting 8 expert neurosurgeons across international centers to independently create questions (n = 1) and to answer (n = 4) and evaluate responses (n = 3) while blinded, and 4) analyzing the evaluation results on the management of vestibular schwannoma. In the blinded phase, all answers were assessed for accuracy, coherence, relevance, thoroughness, speed, and overall rating. All experts were unblinded and provided their thoughts on the utility and limitations of the tool. In the unblinded phase, all neurosurgeons provided answers to a Likert scale survey and long-answer questions regarding the clinical utility, likelihood of use, and limitations of the tool. The tool was then evaluated on the basis of a set of 103 consensus statements on vestibular schwannoma care from the 8th Quadrennial International Conference on Vestibular Schwannoma. RESULTS: Responses from the naive and context-enriched Generative Pretrained Transformer (GPT) models were consistently rated not significantly different in terms of accuracy, coherence, relevance, thoroughness, and overall performance, and they were often rated significantly higher than expert responses. Both the naive and content-enriched GPT models provided faster responses to the standardized question set than expert neurosurgeon respondents (p < 0.01). The context-enriched GPT model agreed with 98 of the 103 (95%) consensus statements. Of interest, all expert surgeons expressed concerns about the reliability of GPT in accurately addressing the nuances and controversies surrounding the management of vestibular schwannoma. Furthermore, the authors developed neuroGPT-X, a chat-based platform designed to provide point-of-care clinical support and mitigate the limitations of human memory. neuroGPT-X incorporates features such as in-text citations and references to enable accurate, relevant, and reliable information in real time. CONCLUSIONS: The present study, with its subspecialist-level performance in generating written responses to complex neurosurgical problems for which evidence-based consensus for management is lacking, suggests that context-enriched LLMs show promise as a point-of-care medical resource. The authors anticipate that this work will be a springboard for expansion into more medical specialties, incorporating evidence-based clinical information and developing expert-level dialogue surrounding LLMs in healthcare.

Challenges and Opportunities in Awake Craniotomy for Brain Tumor Surgery in Low- and Lower-Middle-Income Countries: A Narrative Review and Perspective.

BACKGROUND: Low-income countries (LICs) and lower-middle-income countries (LMICs) are presented with unique challenges and opportunities when performing awake craniotomy (AC) for brain tumors. These circumstances arise from factors that are financial, infrastructural, educational, personnel, and sociocultural in nature. METHODS: We performed a systematic narrative review of series on AC for intra-axial brain tumors in LICs/LMICs using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, focusing on the challenges and opportunities in these settings. The PubMed, Scopus, and Web of Science databases were searched. RESULTS: After initially identifying 74 studies, inclusion-exclusion criteria were applied, leaving a total of 14 studies included in the review. These involved 409 patients who underwent AC in LICs/LMICs. These series were from India, Ghana, Nigeria, Iran, Pakistan, Morocco, the Philippines, and Egypt. The most common pathology encountered were gliomas (10-70%). Most studies (11/14, 78.5%) reported on their technique of cortical-subcortical mapping. All reported on motor mapping and 8 of these performed language mapping. The most common outcomes reported were seizure and neurologic deficits, and longest follow-up was at 1 year. Challenges noted were lack of equipment and trained personnel, need for validated tests for the local setting, and sociocultural factors. Opportunities identified were volume for training, technique innovation, and international collaboration. CONCLUSIONS: There are numerous challenges and opportunities that arise when performing AC in LICs/LMICs. A collaborative approach toward harnessing the opportunities, and seeking creative solutions to address the challenges, would provide an ideal mechanism toward advancing neurosurgical care and specialty worldwide.

Grade 3 meningioma survival and recurrence outcomes in an international multicenter cohort.

OBJECTIVE: Grade 3 meningioma represents a rare meningioma subtype, for which limited natural history data are available. The objective of this study was to identify demographics and pathologic characteristics, clinical and functional status outcomes, and prognostic factors in an international cohort of grade 3 meningioma patients. METHODS: Clinical and histopathological data were collected for patients treated at 7 sites across North America and Europe between 1991 and 2022. RESULTS: A total of 103 patients (54% female, median age 65 [IQR 52, 72] years) were included. Sixty-seven (65%) patients had de novo grade 3 lesions, whereas 29 (28%) had malignant transformations of lower-grade meningiomas. All patients underwent initial resection of their tumor. Patients were followed for a median of 46 (IQR 24, 108) months, during which time there were 65 (73%) recurrences and 50 (49%) deaths. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 66% (95% CI 56%-77%) and 37% (95% CI 28%-48%), respectively. Age ≥ 65 years and male sex were independent predictors of worse OS and PFS in multivariate regression analysis, while postoperative radiotherapy was independently associated with improved OS. Karnofsky Performance Status (KPS) remained stable relative to baseline over 5 years postdiagnosis among participants who were alive at the end of the follow-up period. CONCLUSIONS: This large multicenter study provides insight into the longitudinal outcomes of grade 3 meningioma, with respect to recurrence, survival, and functional status. This study affirms the survival benefit conferred by radiotherapy in this population and suggests good functional status outcomes for patients surviving to 5 years postoperatively.

Corrigendum: Grade 3 Meningioma Survival and Recurrence Outcomes in an International Multicenter Cohort.

[This corrects the article DOI: 10.1055/s-0044-1779888.].

Comparison of T2 and T2*-weighted MR molecular imaging of a mouse model of glioma.

BACKGROUND: Standard MRI has been used for high-grade gliomas detection, albeit with limited success as it does not provide sufficient specificity and sensitivity to detect complex tumor structure. Therefore targeted contrast agents based on iron oxide, that shorten mostly T2 relaxation time, have been recently applied. However pulse sequences for molecular imaging in animal models of gliomas have not been yet fully studied. The aim of this study was therefore to compare contrast-to-noise ratio (CNR) and explain its origin using spin-echo (SE), gradient echo (GE), GE with flow compensation (GEFC) as well as susceptibility weighted imaging (SWI) in T2 and T2* contrast-enhanced molecular MRI of glioma. METHODS: A mouse model was used. U87MGdEGFRvIII cells (U87MG), derived from a human tumor, were injected intracerebrally. A 9.4 T MRI system was used and MR imaging was performed on the 10 day after the inoculation of the tumor. The CNR was measured prior, 20 min, 2 hrs and 24 hrs post intravenous tail administration of glioma targeted paramagnetic nanoparticles (NPs) using SE, SWI, GE and GEFC pulse sequences. RESULTS: The results showed significant differences in CNR among all pulse sequences prior injection. GEFC provided higher CNR post contrast agent injection when compared to GE and SE. Post injection CNR was the highest with SWI and significantly different from any other pulse sequence. CONCLUSIONS: Molecular MR imaging using targeted contrast agents can enhance the detection of glioma cells at 9.4 T if the optimal pulse sequence is used. Hence, the use of flow compensated pulse sequences, beside SWI, should to be considered in the molecular imaging studies.

Tool-tissue force segmentation and pattern recognition for evaluating neurosurgical performance.

Surgical data quantification and comprehension expose subtle patterns in tasks and performance. Enabling surgical devices with artificial intelligence provides surgeons with personalized and objective performance evaluation: a virtual surgical assist. Here we present machine learning models developed for analyzing surgical finesse using tool-tissue interaction force data in surgical dissection obtained from a sensorized bipolar forceps. Data modeling was performed using 50 neurosurgery procedures that involved elective surgical treatment for various intracranial pathologies. The data collection was conducted by 13 surgeons of varying experience levels using sensorized bipolar forceps, SmartForceps System. The machine learning algorithm constituted design and implementation for three primary purposes, i.e., force profile segmentation for obtaining active periods of tool utilization using T-U-Net, surgical skill classification into Expert and Novice, and surgical task recognition into two primary categories of Coagulation versus non-Coagulation using FTFIT deep learning architectures. The final report to surgeon was a dashboard containing recognized segments of force application categorized into skill and task classes along with performance metrics charts compared to expert level surgeons. Operating room data recording of > 161 h containing approximately 3.6 K periods of tool operation was utilized. The modeling resulted in Weighted F1-score = 0.95 and AUC = 0.99 for force profile segmentation using T-U-Net, Weighted F1-score = 0.71 and AUC = 0.81 for surgical skill classification, and Weighted F1-score = 0.82 and AUC = 0.89 for surgical task recognition using a subset of hand-crafted features augmented to FTFIT neural network. This study delivers a novel machine learning module in a cloud, enabling an end-to-end platform for intraoperative surgical performance monitoring and evaluation. Accessed through a secure application for professional connectivity, a paradigm for data-driven learning is established.

Force Profile as Surgeon-Specific Signature.

Objective: To investigate the notion that a surgeon's force profile can be the signature of their identity and performance. Summary background data: Surgeon performance in the operating room is an understudied topic. The advent of deep learning methods paired with a sensorized surgical device presents an opportunity to incorporate quantitative insight into surgical performance and processes. Using a device called the SmartForceps System and through automated analytics, we have previously reported surgeon force profile, surgical skill, and task classification. However, an investigation of whether an individual surgeon can be identified by surgical technique has yet to be studied. Methods: In this study, we investigate multiple neural network architectures to identify the surgeon associated with their time-series tool-tissue forces using bipolar forceps data. The surgeon associated with each 10-second window of force data was labeled, and the data were randomly split into 80% for model training and validation (10% validation) and 20% for testing. Data imbalance was mitigated through subsampling from more populated classes with a random size adjustment based on 0.1% of sample counts in the respective class. An exploratory analysis of force segments was performed to investigate underlying patterns differentiating individual surgical techniques. Results: In a dataset of 2819 ten-second time segments from 89 neurosurgical cases, the best-performing model achieved a micro-average area under the curve of 0.97, a testing F1-score of 0.82, a sensitivity of 82%, and a precision of 82%. This model was a time-series ResNet model to extract features from the time-series data followed by a linearized output into the XGBoost algorithm. Furthermore, we found that convolutional neural networks outperformed long short-term memory networks in performance and speed. Using a weighted average approach, an ensemble model was able to identify an expert surgeon with 83.8% accuracy using a validation dataset. Conclusions: Our results demonstrate that each surgeon has a unique force profile amenable to identification using deep learning methods. We anticipate our models will enable a quantitative framework to provide bespoke feedback to surgeons and to track their skill progression longitudinally. Furthermore, the ability to recognize individual surgeons introduces the mechanism of correlating outcome to surgeon performance.

Tissue Acceleration as a Novel Metric for Surgical Performance During Carotid Endarterectomy.

BACKGROUND AND OBJECTIVES: Gentle tissue handling to avoid excessive motion of affected fragile vessels during surgical dissection is essential for both surgeon proficiency and patient safety during carotid endarterectomy (CEA). However, a void remains in the quantification of these aspects during surgery. The video-based measurement of tissue acceleration is presented as a novel metric for the objective assessment of surgical performance. This study aimed to evaluate whether such metrics correlate with both surgeons' skill proficiency and adverse events during CEA. METHODS: In a retrospective study including 117 patients who underwent CEA, acceleration of the carotid artery was measured during exposure through a video-based analysis. Tissue acceleration values and threshold violation error frequencies were analyzed and compared among the surgeon groups with different surgical experience (3 groups: novice , intermediate , and expert ). Multiple patient-related variables, surgeon groups, and video-based surgical performance parameters were compared between the patients with and without adverse events during CEA. RESULTS: Eleven patients (9.4%) experienced adverse events after CEA, and the rate of adverse events significantly correlated with the surgeon group. The mean maximum tissue acceleration and number of errors during surgical tasks significantly decreased from novice, to intermediate, to expert surgeons, and stepwise discriminant analysis showed that the combined use of surgical performance factors could accurately discriminate between surgeon groups. The multivariate logistic regression analysis revealed that the number of errors and vulnerable carotid plaques were associated with adverse events. CONCLUSION: Tissue acceleration profiles can be a novel metric for the objective assessment of surgical performance and the prediction of adverse events during surgery. Thus, this concept can be introduced into futuristic computer-aided surgeries for both surgical education and patient safety.

Ultrasound Elastography in Neurosurgery: Current Applications and Future Perspectives.

BACKGROUND: Similar to clinical palpation, Ultrasound elastography (USE) helps distinguish between tissues by providing information on their elasticity. While it has been widely explored and has been applied to many body organs, USE has not been studied as extensively for application in neurosurgery. The current systematic review was performed to identify articles related to the use of interoperative USE in neurosurgery. METHODS: Search included MEDLINE(R) database. Only original peer-reviewed full-text articles were included. No language or publication year restrictions were imposed. Two independent reviewers assessed the search results for relevance. The identified articles were screened by title, abstract, and full-text review. RESULTS: Seventeen articles were included in the qualitative analysis and 13 articles were related to oncology, epilepsy (n = 3), and spine (n = 1). In oncology, USE was found useful in defining tumor stiffness, aiding surgical planning, detecting residual tumors, discriminating between tumor and brain tissue, and differentiating between different tumors. In epilepsy, USE could improve the detection of epileptogenic foci, thereby enhancing the prospect of complete and safe resection. The application in spinal surgery was limited to demonstrating that a compressed spinal cord is stiffer than the decompressed one. CONCLUSIONS: USE was found to be a safe, quick, portable, and economic tool that was a useful intraoperative adjunct to provide information corresponding to a variety of neurosurgical diseases, at different stages of surgery. This review describes the current intraoperative neurosurgical applications of USE, the concept of elasticity, and different USE modalities as well as the technical challenges, limitations, and possible future implications.

Tool-Tissue Forces in Hemangioblastoma Surgery.

OBJECTIVE: Surgical resection of intracranial hemangioblastoma poses technical challenges that may be difficult to impart to trainees. Here, we introduce knowledge of tool-tissue forces in Newton (N), observed during hemangioblastoma surgery. METHODS: Seven surgeons (2 groups: trainees and mentor), with mentor (n = 1) and trainees (n = 6, PGY 1-6 including clinical fellowship), participated in 6 intracranial hemangioblastoma surgeries. Using sensorized bipolar forceps, we evaluated tool-tissue force profiles of 5 predetermined surgical tasks: 1) dissection, 2) coagulation, 3) retracting, 4) pulling, and 5) manipulating. Force profile for each trial included force duration, average, maximum, minimum, range, standard deviation (SD), and correlation coefficient. Force errors including unsuccessful trial bleeding or incomplete were compared between surgeons and with successful trials. RESULTS: Force data from 718 trials were collected. The mean (standard deviation) of force used in all surgical tasks and across all surgical levels was 0.20 ± 0.17 N. The forces exerted by trainee surgeons were significantly lower than those of the mentor (0.15 vs. 0.24; P < 0.0001). A total of 18 (4.5%) trials were unsuccessful, 4 of them being unsuccessful trial-bleeding and the rest, unsuccessful trial-incomplete. The force in unsuccessful trial-bleeding was higher than successful trials (0.3 [0.09] vs. 0.17 [0.11]; P = 0.0401). Toward the end of surgery, higher force was observed (0.17 vs. 0.20; P < 0.0001). CONCLUSIONS: The quantification of tool-tissue forces during hemangioblastoma surgery with feedback to the surgeon, could well enhance surgical training and allow avoidance of bleeding associated with high force error.

Survival After Resection of Newly-Diagnosed Intracranial Grade II Ependymomas: An Initial Multicenter Analysis and the Logistics of Intraoperative Magnetic Resonance Imaging.

OBJECTIVE: To identify factors, including the use of intraoperative magnetic resonance imaging (iMRI), impacting overall survival (OS) and progression-free survival (PFS) after resections of newly diagnosed intracranial grade II ependymomas performed across 4 different institutions. METHODS: Analyses of a multicenter mixed retrospective/prospective database assessed the impact of patient, treatment, and tumor characteristics on OS and PFS. iMRI workflow and logistics were also outlined. RESULTS: Forty-three patients were identified (mean age 25.4 years, mean follow-up 52.8 months). The mean OS was 52.8 ± 44.7 months. Univariate analyses failed to identify prognostic factors associated with OS, likely due to relatively shorter follow-up time for this less aggressive glioma subtype. The mean PFS was 43.7 ± 39.8 months. Multivariate analyses demonstrated that gross-total resection was associated with prolonged PFS compared to both subtotal resection (STR) (P = 0.005) and near-total resection (P = 0.01). Infratentorial location was associated with improved PFS compared to supratentorial location (P = 0.04). Log-rank analyses of Kaplan-Meier survival curves showed that increasing extent of resection (EOR) led to improved OS specifically for supratentorial tumors (P = 0.02) and improved PFS for all tumors (P < 0.001). Thirty cases (69.8%) utilized iMRI, of which 12 (27.9%) involved additional resection after iMRI. Of these, 8/12 (66.7%) resulted in gross-total resection, while 2/12 (16.7%) were near-total resection and 2/12 (16.7%) were subtotal resection. iMRI was not an independent prognosticator of PFS (P = 0.72). CONCLUSIONS: Greater EOR and infratentorial location were associated with increased PFS for grade II ependymomas. Greater EOR was associated with longer OS only for supratentorial tumors. A longer follow-up is needed to establish prognostic factors for this cohort, including use of iMRI.

Carotid endarterectomy versus stenting: a meta-analysis of randomized trials.

BACKGROUND: A meta-analysis of randomized controlled trials (RCTs) was conducted to update the available evidence on the safety and efficacy of carotid endarterectomy (CEA) versus carotid artery stenting (CAS) in the treatment of carotid artery stenosis. METHODS: A comprehensive search was performed of MEDLINE, EMBASE, CENTRAL, bibliographies of included articles and past systematic reviews, and abstract lists of recent scientific conferences. For each reported outcome, a Mantel-Haenszel random-effects model was used to calculate odds ratios (ORs) and 95% confidence intervals (CI). The I2 statistic was used as a measure of heterogeneity. RESULTS: Twelve RCTs enrolling 6,973 patients were included in the meta-analysis. Carotid artery stenting was associated with a significantly greater odds of periprocedural stroke (OR 1.72, 95% CI 1.20 to 2.47) and a significantly lower odds of periprocedural myocardial infarction (OR 0.47, 95% CI 0.29 to 0.78) and cranial neuropathy (OR 0.08, 95% CI, 0.04 to 0.16). The odds of periprocedural death (OR 1.11, 95% CI 0.56 to 2.18), target vessel restenosis (OR 1.95, 95% CI 0.63 to 6.06), and access-related hematoma were similar following either intervention (OR 0.60, 95% CI 0.30 to 1.21). CONCLUSIONS: In comparison with CEA, CAS is associated with a greater odds of stroke and a lower odds of myocardial infarction. While the results our meta-analysis support the continued use of CEA as the standard of care in the treatment of carotid artery stenosis, CAS is a viable alternative in patients at elevated risk of cardiac complications.

Revascularization for complex cerebral aneurysms.

BACKGROUND AND PURPOSE: Complex cerebral aneurysms may require indirect treatment with revascularization. This manuscript describes various surgical revascularization techniques together with clinical outcomes. METHODS: Thirty-two consecutive patients with complex cerebral aneurysm were managed from November 2005 to October 2008. Techniques used for revascularization were high-flow bypass, low-flow bypass, branch artery reimplantion, and primary reanastomosis. Physiologic and anatomic monitoring technologies, including electroencephalography, somatosensory evoked potential monitoring, microvascular doppler ultrasonography, and/or indocyanine green videoangiography were used intraoperatively to assess both brain physiology and vascular anatomy. Patient outcome was determined using the Glasgow Outcome Scale at discharge and at a mean of 12 months post operation (range 6-25 months). RESULTS: Two cervical carotid aneurysms (6%) were resected followed by primary reanastomosis, 21 aneurysms (66%) were trapped following saphenous vein high-flow bypasses, five (16%) were clipped after superficial temporal or occipital artery low-flow bypasses, and four (12%) middle cerebral branch arteries were reimplanted. Of the 32 patients at discharge, 29 (91%) had a Glasgow Outcome Scale of four or five, two (6%) had severe disability, and one (3%) died. CONCLUSION: Cerebral revascularization remains an effective and reliable procedure for treatment of complex cerebral aneurysms. Low morbidity and mortality rates reflect the maturity of patient selection and surgical technique in the management of these lesions.

Intra-operative MRI at 3.0 Tesla: a moveable magnet.

UNLABELLED: This paper presents the development and implementation of an intra-operative magnetic resonance imaging (ioMRI) program using a moveable 3.0 T magnet with a large working aperture. METHODS: A previously established prototype 1.5 T ioMRI program based on a ceiling-mounted moveable magnet was upgraded to 3.0 T. The upgrade included a short, 1.73 m, magnet with a large 70 cm working aperture (IMRIS, Winnipeg, Canada), whole-room radio-frequency shielding, and a fully functional MR-compatible operating room (OR) table. Between January and September 2009, 100 consecutive patients were evaluated at 3.0 T. RESULTS: The ioMRI upgrade maintained a patient-focused environment. When not needed for surgery, the magnet was moved to an adjacent room. A large aperture and streamlined OR table allowed freedom of patient positioning while maintaining access and visibility. Working at 3.0 T enabled application of advanced imaging sequences to the full spectrum of neurosurgical pathology in the ioMRI environment. The use of ioMRI continues to show unsuspected residual tumor in up to 20% of cases. There were no adverse events or technical system failures. CONCLUSION: An ioMRI program based a 3.0 T moveable magnet is feasible. By moving the magnet, the system maintains a patient-focused surgical environment and the ability to share the technology between medical disciplines.