Role of microsurgical tumor burden reduction in patients with breast cancer brain metastases considering molecular subtypes: a two-center volumetric survival analysis.

BACKGROUND: Advancements in metastatic breast cancer (BC) treatment have enhanced overall survival (OS), leading to increased rates of brain metastases (BM). This study analyzes the association between microsurgical tumor reduction and OS in patients with BCBM, considering tumor molecular subtypes and perioperative treatment approaches. METHODS: Retrospective analysis of surgically treated patients with BCBM from two tertiary brain tumor Swiss centers. The association of extent of resection (EOR), gross-total resection (GTR) achievement, and postoperative residual tumor volume (RV) with OS and intracranial progression-free survival (IC-PFS) was evaluated using Cox proportional hazard model. RESULTS: 101 patients were included in the final analysis, most patients (38%) exhibited HER2-/HR + BC molecular subtype, followed by HER2 + /HR + (25%), HER2-/HR- (21%), and HER2 + /HR- subtypes (13%). The majority received postoperative systemic treatment (75%) and radiotherapy (84%). Median OS and intracranial PFS were 22 and 8 months, respectively. The mean pre-surgery intracranial tumor volume was 26 cm3, reduced to 3 cm3 post-surgery. EOR, GTR achievement and RV were not significantly associated with OS or IC-PFS, but higher EOR and lower RV correlated with extended OS in patients without extracranial metastases. HER2-positive tumor status was associated with longer OS, extracranial metastases at BM diagnosis and symptomatic lesions with shorter OS and IC-PFS. CONCLUSIONS: Our study found that BC molecular subtypes, extracranial disease status, and BM-related symptoms were associated with OS in surgically treated patients with BCBM. Additionally, while extensive resection to minimize residual tumor volume did not significantly affect OS across the entire cohort, it appeared beneficial for patients without extracranial metastases.

Subarachnoid hemorrhage due to pituitary adenoma apoplexy-case report and review of the literature.

Pituitary apoplexy (PA) may be complicated by development of subarachnoid hemorrhage (SAH). We conducted a literature review to evaluate the rate of PA-associated tumor rupture and SAH. We conducted a systematic literature search (PubMed, Web of Science, Medline) for patients with PA-associated SAH and report a case SAH following PA. Suitable articles, case series, and case reports were selected based on predefined criteria following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We reviewed included publications for clinical, radiological, surgical, and histopathological parameters.We present the case of a patient with PA developing extensive SAH whilst on the MRI who underwent delayed transsphenoidal resection. According to our literature review, we found 55 patients with a median age of 46 years; 18 (32.7%) were female. Factors associated with PA-related SAH were hypertension, diabetes mellitus, prior trauma, anticoagulant, and/or antiplatelet therapy. The most common presenting symptoms included severe headache, nausea and/or vomiting, impaired consciousness, and meningeal irritation. Acute onset was described in almost all patients. Twenty-two of the included patients underwent resection. In patients with available outcome, 45.1% had a favorable outcome, 10 (19.6%) had persisting focal neurological deficits, 7 developed cerebral vasospasms (12.7%), and 18 (35.3%) died. Mortality greatly differed between surgically (9.1%) and non-surgically (44.8%) treated patients. PA-associated SAH is a rare condition developing predominantly in males with previously unknown macroadenomas. Timely surgery often prevents aggravation or development of severe neuro-ophthalmological defects and improves clinical outcome.

A T-cell antigen atlas for meningioma: novel options for immunotherapy.

Meningiomas are the most common primary intracranial tumors. Although most symptomatic cases can be managed by surgery and/or radiotherapy, a relevant number of patients experience an unfavorable clinical course and additional treatment options are needed. As meningiomas are often perfused by dural branches of the external carotid artery, which is located outside the blood-brain barrier, they might be an accessible target for immunotherapy. However, the landscape of naturally presented tumor antigens in meningioma is unknown. We here provide a T-cell antigen atlas for meningioma by in-depth profiling of the naturally presented immunopeptidome using LC-MS/MS. Candidate target antigens were selected based on a comparative approach using an extensive immunopeptidome data set of normal tissues. Meningioma-exclusive antigens for HLA class I and II are described here for the first time. Top-ranking targets were further functionally characterized by showing their immunogenicity through in vitro T-cell priming assays. Thus, we provide an atlas of meningioma T-cell antigens which will be publicly available for further research. In addition, we have identified novel actionable targets that warrant further investigation as an immunotherapy option for meningioma.

Impact of Long-Term Antithrombotic and Statin Therapy on the Clinical Outcome in Patients with Cavernous Malformations of the Central Nervous System: A Single-Center Case Series of 428 Patients.

INTRODUCTION: Literature regarding the safety and efficacy of antithrombotic (antiplatelet or anticoagulant) therapy and statins in patients with cavernous malformations (CMs) of the central nervous system is sparse, resulting in uncertainty about its use in clinical practice. The aim of this study was to analyze the impact of antithrombotic therapy and statins on the risk of hemorrhage and focal neurological deficit in patients with CMs. METHODS: The authors' institutional database was screened for all patients with CMs of the central nervous system treated at their institution between 2006 and 2018. Patients with radiological and/or histological diagnosis of CMs, clinical baseline characteristics, available patient's medication history, and follow-up data were included in this study. Time-to-event probability (hemorrhage or focal neurological deficit) as well as the number of events (hemorrhage or focal neurological deficit) during follow-up were assessed in patients who were categorized according to their medical treatment (antithrombotic therapy, statins, combined therapy, or no treatment). RESULTS: Four hundred twenty-eight patients with CMs were eligible and included in the final analysis. Sixty-nine (16.1%) patients were on long-term antithrombotic therapy and 46 (10.6%) on long-term statins, of whom 31 patients were on a combination of both. The probability of experiencing first hemorrhage or focal neurological deficit was less likely in patients on antiplatelet therapy (HR 0.09, 95% CI 0.021-0.39, p = 0.001), anticoagulant therapy (HR 0.12, 95% CI 0.016-0.85, p = 0.034), or the combination thereof (HR 0.12, 95% CI 0.016-0.93, p = 0.043) compared to patients with no antithrombotic treatment. The number of hemorrhages and focal neurological deficits were significantly lower in patients on antithrombotic therapy compared to patients on no treatment during follow-up. In patients on statins alone, the time-to-event probability was comparable to that of patients on no treatment (HR 0.91, 95% CI 0.438-1.91, p = 0.812), and the number of events was similar to patients on no treatment. CONCLUSION: The results of our study provide further evidence that antithrombotic therapy alone or in combination with statins in patients with CMs of the central nervous system does not increase the risk of hemorrhage or focal neurological deficit but, on the contrary, may have some benefit.

Successful weaning versus permanent cerebrospinal fluid diversion after aneurysmal subarachnoid hemorrhage: post hoc analysis of a Swiss multicenter study.

OBJECTIVE: Acute hydrocephalus is a frequent complication after aneurysmal subarachnoid hemorrhage (aSAH). Among patients needing CSF diversion, some cannot be weaned. Little is known about the comparative neurological, neuropsychological, and health-related quality-of-life (HRQOL) outcomes in patients with successful and unsuccessful CSF weaning. The authors aimed to assess outcomes of patients by comparing those with successful and unsuccessful CSF weaning; the latter was defined as occurring in patients with permanent CSF diversion at 3 months post-aSAH. METHODS: The authors included prospectively recruited alert (i.e., Glasgow Coma Scale score 13-15) patients with aSAH in this retrospective study from six Swiss neurovascular centers. Patients underwent serial neurological (National Institutes of Health Stroke Scale), neuropsychological (Montreal Cognitive Assessment), disability (modified Rankin Scale), and HRQOL (EuroQol-5D) examinations at < 72 hours, 14-28 days, and 3 months post-aSAH. RESULTS: Of 126 included patients, 54 (42.9%) developed acute hydrocephalus needing CSF diversion, of whom 37 (68.5%) could be successfully weaned and 17 (31.5%) required permanent CSF diversion. Patients with unsuccessful weaning were older (64.5 vs 50.8 years, p = 0.003) and had a higher rate of intraventricular hemorrhage (52.9% vs 24.3%, p = 0.04). Patients who succeed in restoration of physiological CSF dynamics improve on average by 2 points on the Montreal Cognitive Assessment between 48-72 hours and 14-28 days, whereas those in whom weaning fails worsen by 4 points (adjusted coefficient 6.80, 95% CI 1.57-12.04, p = 0.01). They show better neuropsychological recovery between 48-72 hours and 3 months, compared to patients in whom weaning fails (adjusted coefficient 7.60, 95% CI 3.09-12.11, p = 0.02). Patients who receive permanent CSF diversion (ventriculoperitoneal shunt) show significant neuropsychological improvement thereafter, catching up the delay in neuropsychological improvement between 14-28 days and 3 months post-aSAH. Neurological, disability, and HRQOL outcomes at 3 months were similar. CONCLUSIONS: These results show a temporary but clinically meaningful cognitive benefit in the first weeks after aSAH in successfully weaned patients. The resolution of this difference over time may be due to the positive effects of permanent CSF diversion and underlines its importance. Patients who do not show progressive neuropsychological improvement after weaning should be considered for repeat CT imaging to rule out chronic (untreated) hydrocephalus.

The BSCM score: a guideline for surgical decision-making for brainstem cavernous malformations.

Microsurgical resection of brainstem cavernous malformations (BSCMs) can be performed today with acceptable morbidity and mortality. However, in this highly eloquent location, the indication for surgery remains challenging. We aimed to elaborate a score system that may help clinicians with their choice of treatment in patients with BSCMs in this study. A single-center series of 88 consecutive BSCMs patients with 272 follow-up visits were included in this study. Univariable and multivariable generalized estimating equations (GEE) were constructed to identify the association of variables with treatment decisions. A score scale assigned points for variables that significantly contributed to surgical decision-making. Surgical treatment was recommended in 37 instances, while conservative treatment was proposed in 235 instances. The mean follow-up duration was 50.4 months, and the mean age at decision-making was 45.9 years. The mean BSCMs size was 14.3 ml. In the multivariable GEE model, patient age, lesion size, hemorrhagic event(s), mRS, and axial location were identified as significant factors for determining treatment options. With this proposed score scale (grades 0-XII), non-surgery was the first option at grades 0-III. The crossover point between surgery and non-surgery recommendations lay between grades V and VI while surgical treatment was found in favor at grades VII-X. In conclusion, the proposed BSCM operating score is a clinician-friendly tool, which may help neurosurgeons decide on the treatment for patients with BSCMs.

Distance to first symptoms measured by the 6-min walking test differentiates between treatment success and failure in patients with degenerative lumbar disorders.

PURPOSE: The smartphone-based 6-min walking test (6WT) is an established digital outcome measure in patients undergoing surgery for degenerative lumbar disorders (DLD). In addition to the 6WTs primary outcome measure, the 6-min walking distance (6WD), the patient's distance to first symptoms (DTFS) and time to first symptoms (TTFS) can be recorded. This is the first study to analyse the psychometric properties of the DTFS and TTFS. METHODS: Forty-nine consecutive patients (55 ± 15.8 years) completed the 6WT pre- and 6 weeks (W6) postoperative. DTFS and TTFS were assessed for reliability and content validity using disease-specific patient-reported outcome measures. The Zurich Claudication Questionnaire patient satisfaction subscale was used as external criterion for treatment success. Internal and external responsiveness for both measures at W6 was evaluated. RESULTS: There was a significant improvement in DTFS and TTFS from baseline to W6 (p < 0.001). Both measures demonstrated a good test-retest reliability (ß = 0.86, 95% CI 0.81-0.90 and ß = 0.83, 95% CI 0.76-0.87, both p < 0.001). The DTFS exceeded the 6WD capability to differentiate between satisfied (82%) and unsatisfied patients (18%) with an AUC of 0.75 (95% CI 0.53-0.98) vs. 0.70 (95% CI 0.52-0.90). The TTFS did not demonstrate meaningful discriminative abilities. CONCLUSION: Change in DTFS can differentiate between satisfied and unsatisfied patients after spine surgery. Digital outcome measures on the 6WT metric provide spine surgeons and researchers with a mean to assess their patient's functional disability and response to surgical treatment in DLD.

Neurosurgery resident training using blended learning concepts: course development and participant evaluation.

OBJECTIVE: Restrictions on working time and healthcare expenditures, as well as increasing subspecialization with caseload requirements per surgeon and increased quality-of-care expectations, provide limited opportunities for surgical residents to be trained in the operating room. Yet, surgical training requires goal-oriented and focused practice. As a result, training simulators are increasingly utilized. The authors designed a two-step blended course consisting of a personalized adaptive electronic learning (e-learning) module followed by simulator training. This paper reports on course development and the evaluation by the first participants. METHODS: Adaptive e-learning was curated by learning engineers based on theoretical information provided by clinicians (subject matter experts). A lumbar spine model for image-guided spinal injections was used for the simulator training. Residents were assigned to the e-learning module first; after its completion, they participated in the simulator training. Performance data were recorded for each participant's e-learning module, which was necessary to personalize the learning experience to each individual's knowledge and needs. Simulator training was organized in small groups with a 1-to-4 instructor-to-participant ratio. Structured assessments were undertaken, adapted from the Student Evaluation of Educational Quality. RESULTS: The adaptive e-learning module was curated, reviewed, and approved within 10 weeks. Eight participants have taken the course to date. The overall rating of the course is very good (4.8/5). Adaptive e-learning is well received compared with other e-learning types (8/10), but scores lower regarding usefulness, efficiency, and fun compared with the simulator training, despite improved conscious competency (32.6% ± 15.1%) and decreased subconscious incompetency (22.8% ± 10.2%). The subjective skill level improved by 20%. Asked about the estimated impact of the course, participants indicated that they had either learned something new that they plan to use in their practice (71.4%) or felt reassured in their practice (28.6%). CONCLUSIONS: The development of a blended training course combining adaptive e-learning and simulator training in a rapid manner is feasible and leads to improved skills. Simulator training is rated more valuable by surgical trainees than theoretical e-learning; the impact of this type of training on patient care needs to be further investigated.

Determining the impact of postoperative complications in neurosurgery based on simulated longitudinal smartphone app-based assessment.

BACKGROUND: Complications after neurosurgical operations can have severe impact on patient well-being, which is poorly reflected by current grading systems. The objective of this work was to develop and conduct a feasibility study of a new smartphone application that allows for the longitudinal assessment of postoperative well-being and complications. METHODS: We developed a smartphone application "Post OP Tracker" according to requirements from clinical experience and tested it on simulated patients. Participants received regular notifications through the app, inquiring them about their well-being and complications that had to be answered according to their assigned scenarios. After a 12-week period, subjects answered a questionnaire about the app's functionality, user-friendliness, and acceptability. RESULTS: A total of 13 participants (mean age 34.8, range 24-68 years, 4 (30.8%) female) volunteered in this feasibility study. Most of them had a professional background in either health care or software development. All participants downloaded, installed, and applied the app for an average of 12.9 weeks. On a scale of 1 (worst) to 4 (best), the app was rated on average 3.6 in overall satisfaction and 3.8 in acceptance. The design achieved a somewhat favorable score of 3.1. One participant (7.7%) reported major technical issues. The gathered patient data can be used to graphically display the simulated outcome and assess the impact of postoperative complications. CONCLUSIONS: This study suggests the feasibility to longitudinally gather postoperative data on subjective well-being through a smartphone application. Among potential patients, our application indicated to be functional, user-friendly, and well accepted. Using this app-based approach, further studies will enable us to classify postoperative complications according to their impact on the patient's well-being.

Mortality in Patients with Brainstem Cavernous Malformations.

OBJECTIVE: Brainstem cavernous malformations (BSCM)-associated mortality has been reported up to 20% in patients managed conservatively, whereas postoperative mortality rates range from 0 to 1.9%. Our aim was to analyze the actual risk and causes of BSCM-associated mortality in patients managed conservatively and surgically based on our own patient cohort and a systematic literature review. METHODS: Observational, retrospective single-center study encompassing all patients with BSCM that presented to our institution between 2006 and 2018. In addition, a systematic review was performed on all studies encompassing patients with BSCM managed conservatively and surgically. RESULTS: Of 118 patients, 54 were treated conservatively (961.0 person years follow-up in total). No BSCM-associated mortality was observed in our conservatively as well as surgically managed patient cohort. Our systematic literature review and analysis revealed an overall BSCM-associated mortality rate of 2.3% (95% CI: 1.6-3.3) in 22 studies comprising 1,251 patients managed conservatively and of 1.3% (95% CI: 0.9-1.7) in 99 studies comprising 3,275 patients with BSCM treated surgically. CONCLUSION: The BSCM-associated mortality rate in patients managed conservatively is almost as low as in patients treated surgically and much lower than in frequently cited reports, most probably due to the good selection nowadays in regard to surgery.

Impact of additional resection on new ischemic lesions and their clinical relevance after intraoperative 3 Tesla MRI in neuro-oncological surgery.

Intraoperative MRI (ioMRI) has become a frequently used tool to improve maximum safe resection in brain tumor surgery. The usability of intraoperatively acquired diffusion-weighted imaging sequences to predict the extent and clinical relevance of new infarcts has not yet been studied. Furthermore, the question of whether more aggressive surgery after ioMRI leads to more or larger infarcts is of crucial interest for the surgeons' operative strategy. Retrospective single-center analysis of a prospective registry of procedures from 2013 to 2019 with ioMRI was used. Infarct volumes in ioMRI/poMRI, lesion localization, mRS, and NIHSS were analyzed for each case. A total of 177 individual operations (60% male, mean age 45.5 years old) met the inclusion criteria. In 61% of the procedures, additional resection was performed after ioMRI, which resulted in a significantly higher number of new ischemic lesions postoperatively (p < .001). The development of new or enlarged ischemic areas upon additional resection could also be shown volumetrically (mean volume in ioMRI 0.39 cm3 vs. poMRI 2.97 cm3; p < .001). Despite the surgically induced new infarcts, mRS and NIHSS did not worsen significantly in cases with additional resection. Additionally, new perilesional ischemia in eloquently located tumors was not associated with an impaired neurological outcome. Additional resection after ioMRI leads to new or enlarged ischemic areas. However, these new infarcts do not necessarily result in an impaired neurological outcome, even when in eloquent brain areas.

A stereotactic frame-based drill guide-aided setting for laser interstitial thermal therapy.

BACKGROUND: Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRIgLITT) was demonstrated to be a viable neurosurgical tool. Apart from its variety of indications, different operative and technical nuances exist. In the present report, for the first time, the use and ability of a traditional Riechert-Mundinger (RM) stereotactic system combined with a novel drill guide kit for MRIgLITT are described. METHODS: A stereotactic frame-based setting was developed by combining an RM system with a drill guide kit and centering bone anchor screwing aid for application together with an MRIgLITT neuro-accessory kit and cooled laser applicator system. The apparatus was used for stereotactic biopsy and consecutive MRIgLITT with an intraoperative high-field MRI scanner in a brain tumor case. RESULTS: The feasibility of an RM stereotactic apparatus and a drill guide kit for MRIgLITT was successfully assessed. Both stereotactic biopsy and subsequent MRIgLITT in a neurooncological patient could easily and safely be performed. No technical problems or complications were observed. CONCLUSION: The combination of a traditional RM stereotactic system, a new drill guide tool, and intraoperative high-field MRI provides neurosurgeons with the opportunity to reliably confirm the diagnosis by frame-based biopsy and allows for stable and accurate real-time MRIgLITT.

Do directional deep brain stimulation leads rotate after implantation?

BACKGROUND: The two middle contacts of directional leads (d-leads) for deep brain stimulation are split into three segments, allowing current steering toward desired axial directions. To facilitate programming, their final orientation needs to be reliably determined. However, it is currently unclear whether d-leads rotate after implantation. Our objective was to assess the degree of d-lead rotation after implantation. METHODS: We retrospectively analyzed d-lead orientation on intraoperative X-rays, postoperative CT scans (latencies to surgery: 108-189 min postoperatively), and rotational fluoroscopies (4-9 days postoperatively) for a consecutive series of 32 implanted d-leads. For five d-leads, a CT scan with a mean follow-up of 57 days (range 28-182) was available. All d-leads were implanted with the marker facing anterior and the intention to hit an "iron sight" (ISi) on the X-ray, indicating anterior orientation (i.e., 0° ± 6°). RESULTS: In nine d-leads, an ISi was visible on the final X-ray; median orientation was 1.5° (range 0.5-6.0°) at the first follow-up CT, confirming anterior orientation. In d-leads without ISi or where ISi was not evaluable, the median rotation was 15.5° (9.5-35.0°) and 26.5° (5.5-62.0°), respectively. The orientation of the initial CT was comparable with the orientation determined by the postoperative rotational fluoroscopy and second CT in all d-lead groups. CONCLUSION: D-lead orientation does not change within the first week after implantation. We provide first indications that d-lead orientation remains stable for several weeks after surgery. Determination of lead orientation using marker-based X-ray alone seems too imprecise; adding the ISi method can increase determination of intraoperative orientation.

Smoking status and perioperative adverse events in patients undergoing cranial tumor surgery.

INTRODUCTION: Smoking is agreed to be a major health risk factor, but it is debated whether it has an influence on perioperative adverse events (AEs) in elective cranial tumor surgery. METHODS: We analyzed the 2013-2016 data from our prospective institutional patient registry. Consecutive patients undergoing elective microsurgical tumor surgery of a glioma or a meningioma were included. Patients were categorized as active smokers, former smokers, and non-smokers. AE were graded by the therapy-oriented Clavien-Dindo scale. Possible predictors of postoperative AE were identified with the help of a binomial logistic regression model. RESULTS: We identified 798 patients, out of which 480 were non-smokers, 193 active smokers, and 125 former smokers. The rate of AEs for active smokers (30%, 95% CI [23-37%]) was indistinguishable from the AE rate of non-smokers (32%, 95% CI [28-37%]). No difference between smoking status was found looking at all AE individually, the odds ratio of suffering from local AE and systemic AE respectively were the same between all smoking groups. The modified Rankin scale at hospital admission was a strong and significant predictor of postoperative AE (P = 0.013). CONCLUSIONS: Active smoking was not associated with an increased risk for postoperative AE, neither looking at the total number of AE nor looking at individual AE. Smoking status should therefore not be a major factor in preoperative decision making. Although not based on data of this study, doctors should always encourage patients to stop smoking due to its well-known detrimental health effect.

Repeated craniotomies for intracranial tumors: is the risk increased? Pooled analysis of two prospective, institutional registries of complications and outcomes.

PURPOSE: Deciding whether to re-operate patients with intracranial tumor recurrence or remnant is challenging, as the data on safety of repeated procedures is limited. This study set out to evaluate the risks for morbidity, mortality, and complications after repeated operations, and to compare those to primary operations. METHODS: Retrospective observational two-center study on consecutive patients undergoing microsurgical tumor resection. The data derived from independent, prospective institutional registries. The primary endpoint was morbidity at 3 months (M3), defined as significant decrease on the Karnofsky Performance Scale (KPS). Secondary endpoints were mortality, rate and severity of complications according to the Clavien-Dindo Grade (CDG). RESULTS: 463/2403 (19.3%) were repeated procedures. Morbidity at M3 occurred in n = 290 patients (12.1%). In univariable analysis, patients undergoing repeated surgery were 98% as likely as patients undergoing primary surgery to experience morbidity (OR 0.98, 95% CI 0.72-1.34, p = 0.889). In multivariable analysis adjusted for age, sex, tumor size, histology and posterior fossa location, the relationship remained stable (aOR 1.25, 95% CI 0.90-1.73, p = 0.186). Mortality was n = 10 (0.4%) at discharge and n = 95 (4.0%) at M3, without group differences. At least one complication occurred in n = 855, and the rate (35.5% vs. 35.9%, p = 0.892) and severity (CDG; p = 0.520) was similar after primary and repeated procedures. Results were reproduced in subgroup analyses for meningiomas, gliomas and cerebral metastases. CONCLUSIONS: Repeated surgery for intracranial tumors does not increase the risk of morbidity. Mortality, and both the rate and severity of complications are comparable to primary operations. This information is of value for patient counseling and the informed consent process.

Analysis of safe entry zones into the brainstem.

Intra-axial brainstem surgeries are challenging. Many experience-based "safe entry zones (SEZs)" into brainstem lesions have been proposed in the existing literature. The evidence for each one seems limited. English-language publications were retrieved using PubMed/MEDLINE. Studies that focused only on cadaveric anatomy were also included, but the clinical case number was treated as zero. The clinical evidence level was defined as "case report" when the surgical case number was ≤ 5, "limited evidence" when there were more than 5 but less than 25 cases, and "credible evidence" when a publication presented more than 25 cases. Twenty-five out of 32 publications were included, and 21 different SEZs were found for the brainstem: six SEZs were located in the midbrain, 9 SEZs in the pons, and 6 SEZs in the medulla. Case report evidence was found for 10 SEZs, and limited evidence for 7 SEZs. Four SEZs were determined to be backed by credible evidence. The proposed SEZs came from initial cadaveric anatomy studies, followed by some published clinical experience. Only a few SEZs have elevated clinical evidence. The choice of the right approach into the brainstem remains a challenge in each case.

Patterns of care: burr-hole cover application for chronic subdural hematoma trepanation.

OBJECTIVE: Skin depressions may appear as undesired effects after burr-hole trepanation for the evacuation of chronic subdural hematomas (cSDH). Placement of burr-hole covers to reconstruct skull defects can prevent skin depressions, with the potential to improve the aesthetic result and patient satisfaction. The perception of the relevance of this practice, however, appears to vary substantially among neurosurgeons. The authors aimed to identify current practice variations with regard to the application of burr-hole covers after trepanation for cSDH. METHODS: An electronic survey containing 12 questions was sent to resident and faculty neurosurgeons practicing in different parts of the world, as identified by an Internet search. All responses completed between September 2018 and December 2018 were considered. Descriptive statistics and logistic regression were used to analyze the data. RESULTS: A total of 604 responses were obtained, of which 576 (95.4%) provided complete data. The respondents' mean age was 42.4 years (SD 10.5), and 86.5% were male. The sample consisted of residents, fellows, junior/senior consultants, and department chairs from 79 countries (77.4% Europe, 11.8% Asia, 5.4% America, 3.5% Africa, and 1.9% Australasia). Skin depressions were considered a relevant issue by 31.6%, and 76.0% indicated that patients complain about skin depressions more or less frequently. Burr-hole covers are placed by 28.1% in the context of cSDH evacuation more or less frequently. The most frequent reasons for not placing a burr-hole cover were the lack of proven benefit (34.8%), followed by additional costs (21.9%), technical difficulty (19.9%), and fear of increased complications (4.9%). Most respondents (77.5%) stated that they would consider placing burr-hole covers in the future if there was evidence for superiority of the practice. The use of burr-hole covers varied substantially across countries, but a country's gross domestic product per capita was not associated with their placement. CONCLUSIONS: Only a minority of neurosurgeons place burr-hole covers after trepanation for cSDH on a regular basis, even though the majority of participants reported complaints from patients regarding postoperative skin depressions. There are significant differences in the patterns of care among countries. Class I evidence with regard to patient satisfaction and safety of burr-hole cover placement is likely to have an impact on future cSDH management.

Feasibility and safety of intraoperative BOLD functional MRI cerebrovascular reactivity to evaluate extracranial-to-intracranial bypass efficacy.

Blood oxygenation level-dependent functional MRI cerebrovascular reactivity (BOLD-CVR) is a contemporary technique to assess brain tissue hemodynamic changes after extracranial- intracranial (EC-IC) bypass flow augmentation surgery. The authors conducted a preliminary study to investigate the feasibility and safety of intraoperative 3-T MRI BOLD-CVR after EC-IC bypass flow augmentation surgery. Five consecutive patients selected for EC-IC bypass revascularization underwent an intraoperative BOLD-CVR examination to assess early hemodynamic changes after revascularization and to confirm the safety of this technique. All patients had a normal postoperative course, and none of the patients exhibited complications or radiological alterations related to prolonged anesthesia time. In addition to intraoperative flow measurements of the bypass graft, BOLD-CVR maps added information on the hemodynamic status and changes at the brain tissue level. Intraoperative BOLD-CVR is feasible and safe in patients undergoing EC-IC bypass revascularization. This technique can offer immediate hemodynamic feedback on brain tissue revascularization after bypass flow augmentation surgery.

Ultrasonic aspiration in neurosurgery: comparative analysis of complications and outcome for three commonly used models.

INTRODUCTION: Ultrasonic aspiration (UA) devices are commonly used for resecting intracranial tumors, as they allow for internal debulking of large tumors, hereby avoiding damage to adjacent brain tissue during the dissection. Little is known about their comparative safety profiles. METHODS AND MATERIALS: We analyzed data from a prospective patient registry. Procedures using one of the following UA models were included: Integra® CUSA, Söring®, and Stryker® Sonopet. The primary endpoint was morbidity at discharge, defined as significant worsening on the Karnofsky Performance Scale. Secondary endpoints included morbidity and mortality until 3 months postoperative (M3), occurrence, type, and etiology of complications. RESULTS: Of n = 1028 procedures, the CUSA was used in n = 354 (34.4 %), the Söring in n = 461 (44.8 %), and the Sonopet in n = 213 (20.7 %). There was some heterogeneity of study groups. In multivariable analysis, patients in the Söring (adjusted odds ratio (aOR) 1.29; 95 % confidence interval (CI), 0.80-2.08; p = 0.299), and Sonopet group (aOR, 0.86; 95 % CI, 0.46-1.61; p = 0.645) were as likely as patients in the CUSA group to experience discharge morbidity. At M3, patients in the Söring (aOR, 1.20; 95 % CI, 0.78-1.86; p = 0.415) and Sonopet group (aOR, 0.53; 95 % CI, 0.26-1.08; p = 0.080) were as likely as patients in the CUSA group to experience morbidity. There were also no differences for M3 morbidity in subgroup analyses for gliomas, meningiomas, and metastases. The grade (p = 0.608) and etiology (p = 0.849) of postoperative complications were similar. CONCLUSIONS: Neurosurgeons select UA types with regard to certain case-specific characteristics. The safety profiles of three commonly used UA types appear mostly similar.

Staging Hemodynamic Failure With Blood Oxygen-Level-Dependent Functional Magnetic Resonance Imaging Cerebrovascular Reactivity: A Comparison Versus Gold Standard (15O-)H2O-Positron Emission Tomography.

BACKGROUND AND PURPOSE: Increased stroke risk correlates with hemodynamic failure, which can be assessed with (15O-)H2O positron emission tomography (PET) cerebral blood flow (CBF) measurements. This gold standard technique, however, is not established for routine clinical imaging. Standardized blood oxygen-level-dependent (BOLD) functional magnetic resonance imaging+CO2 is a noninvasive and potentially widely applicable tool to assess whole-brain quantitative cerebrovascular reactivity (CVR). We examined the agreement between the 2 imaging modalities and hypothesized that quantitative CVR can be a surrogate imaging marker to assess hemodynamic failure. METHODS: Nineteen data sets of subjects with chronic cerebrovascular steno-occlusive disease (age, 60±11 years; 4 women) and unilaterally impaired perfusion reserve on Diamox-challenged (15O-)H2O PET were studied and compared with a standardized BOLD functional magnetic resonance imaging+CO2 examination within 6 weeks (8±19 days). Agreement between quantitative CBF- and CVR-based perfusion reserve was assessed. Hemodynamic failure was staged according to PET findings: stage 0: normal CBF, normal perfusion reserve; stage I: normal CBF, decreased perfusion reserve; and stage II: decreased CBF, decreased perfusion reserve. The BOLD CVR data set of the same subjects was then matched to the corresponding stage of hemodynamic failure. RESULTS: PET-based stage I versus stage II could also be clearly separated with BOLD CVR measurements (CVR for stage I 0.11 versus CVR for stage II -0.03; P<0.01). Hemispheric and middle cerebral artery territory difference analyses (ie, affected versus unaffected side) showed a significant correlation for CVR impairment in the affected hemisphere and middle cerebral artery territory (P<0.01, R2=0.47 and P=0.02, R2= 0.25, respectively). CONCLUSIONS: BOLD CVR corresponded well to CBF perfusion reserve measurements obtained with (15O-)H2O-PET, especially for detecting hemodynamic failure in the affected hemisphere and middle cerebral artery territory and for identifying hemodynamic failure stage II. BOLD CVR may, therefore, be considered for prospective studies assessing stroke risk in patients with chronic cerebrovascular steno-occlusive disease, in particular because it can potentially be implemented in routine clinical imaging.