Defining activities in neurovascular microsurgery training: entrustable professional activities for vascular neurosurgery.

BACKGROUND: Entrustable professional activities (EPAs) represent an assessment framework with an increased focus on competency-based assessment. Originally developed and adopted for undergraduate medical education, concerns over resident ability to practice effectively after graduation have led to its implementation in residency training but yet not in vascular neurosurgery. Subjective assessment of resident or fellow performance can be problematic, and thus, we aim to define core EPAs for neurosurgical vascular training. METHODS: We used a nominal group technique in a multistep interaction between a team of experienced neurovascular specialists and a medical educator to identify relevant EPAs. Panel members provided feedback on the EPAs until they reached consent. RESULTS: The process produced seven core procedural EPAs for vascular residency and fellowship training, non-complex aneurysm surgery, complex aneurysm surgery, bypass surgery, arteriovenous malformation resection, spinal dural fistula surgery, perioperative management, and clinical decision-making. CONCLUSION: These seven EPAs for vascular neurosurgical training may support and guide the neurosurgical society in the development and implementation of EPAs as an evaluation tool and incorporate entrustment decisions in their training programs.

Non-adjustable gravitational valves or adjustable valves in the treatment of hydrocephalus after aneurysmal subarachnoid hemorrhage patients?

PURPOSE: Hydrocephalus requiring permanent CSF shunting after aneurysmal subarachnoid hemorrhage (aSAH) is frequent. It is unknown which type of valve is optimal. This study evaluates if the revision rate of gravitational differential pressure valves (G-DPVs, GAV® system (B Braun)) (G-DPV) is comparable to adjustable pressure valves (Codman Medos Hakim) (APV) in the treatment of post-aSAH hydrocephalus. METHODS: The use of a gravitational differential pressure valve is placed in direct comparison with an adjustable pressure valve system. A retrospective chart review is performed to compare the revision rates for the two valve systems. RESULTS: Within the registry from Radboud University Medical Center, 641 patients with a SAH could be identified from 1 January 2013 until 1 January 2019, whereas at the Heinrich Heine University, 617 patients were identified, totaling 1258 patients who suffered from aSAH. At Radboud University Medical Center, a gravitational differential pressure valve is used, whereas at the Heinrich Heine University, an adjustable pressure valve system is used. One hundred sixty-six (13%) patients required permanent ventricular peritoneal or atrial shunting. Shunt dysfunction occurred in 36 patients: 13 patients of the 53 (25%) of the gravitational shunt cohort, and in 23 of the 113 (20%) patients with an adjustable shunt (p = 0.54). Revision was performed at a mean time of 3.2 months after implantation with the gravitational system and 8.2 months with the adjustable shunt system. Combined rates of over- and underdrainage leading to revision were 7.5% (4/53) for the gravitational and 3.5% (4/113) for the adjustable valve system (p = 0 .27). CONCLUSION: The current study does not show a benefit of a gravitational pressure valve (GAV® system) over an adjustable pressure valve (CODMAN ® HAKIM®) in the treatment of post-aSAH hydrocephalus. The overall need for revision is high and warrants further improvements in care.

Development and Internal Validation of the ARISE Prediction Models for Rebleeding After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Aneurysmal rerupture is one of the most important determents for outcome after aneurysmal subarachnoid hemorrhage and still occurs frequently because individual risk assessment is challenging given the heterogeneity in patient characteristics and aneurysm morphology. OBJECTIVE: To develop and internally validate a practical prediction model to estimate the risk of aneurysmal rerupture before aneurysm closure. METHODS: We designed a multinational cohort study of 2 prospective hospital registries and 3 retrospective observational studies to predict the risk of computed tomography confirmed rebleeding within 24 and 72 hours after ictus. We assessed predictors with Cox proportional hazard regression analysis. RESULTS: Rerupture occurred in 269 of 2075 patients. The cumulative incidence equaled 7% and 11% at 24 and 72 hours, respectively. Our base model included hypertension, World Federation of Neurosurgical Societies scale, Fisher grade, aneurysm size, and cerebrospinal fluid drainage before aneurysm closure and showed good discrimination with an optimism corrected c-statistic of 0.77. When we extend the base model with aneurysm irregularity, the optimism-corrected c-statistic increased to 0.79. CONCLUSION: Our prediction models reliably estimate the risk of aneurysm rerupture after aneurysmal subarachnoid hemorrhage using predictor variables available upon hospital admission. An online prognostic calculator is accessible at https://www.evidencio.com/models/show/2626 .

Time trends in the risk of delayed cerebral ischemia after subarachnoid hemorrhage: a meta-analysis of randomized controlled trials.

OBJECTIVE: Delayed cerebral ischemia (DCI) contributes to morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Continuous improvement in the management of these patients, such as neurocritical care and aneurysm repair, may decrease the prevalence of DCI. In this study, the authors aimed to investigate potential time trends in the prevalence of DCI in clinical studies of DCI within the last 20 years. METHODS: PubMed, Embase, and the Cochrane library were searched from 2000 to 2020. Randomized controlled trials that reported clinical (and radiological) DCI in patients with aSAH who were randomized to a control group receiving standard care were included. DCI prevalence was estimated by means of random-effects meta-analysis, and subgroup analyses were performed for the DCI sum score, Fisher grade, clinical grade on admission, and aneurysm treatment method. Time trends were evaluated by meta-regression. RESULTS: The search strategy yielded 5931 records, of which 58 randomized controlled trials were included. A total of 4424 patients in the control arm were included. The overall prevalence of DCI was 0.29 (95% CI 0.26-0.32). The event rate for prevalence of DCI among the high-quality studies was 0.30 (95% CI 0.25-0.34) and did not decrease over time (0.25% decline per year; 95% CI -2.49% to 1.99%, p = 0.819). DCI prevalence was higher in studies that included only higher clinical or Fisher grades, and in studies that included only clipping as the treatment modality. CONCLUSIONS: Overall DCI prevalence in patients with aSAH was 0.29 (95% CI 0.26-0.32) and did not decrease over time in the control groups of the included randomized controlled trials.

Proposed definition of competencies for surgical neuro-oncology training.

OBJECTIVE: The aim of this work is to define competencies and entrustable professional activities (EPAs) to be imparted within the framework of surgical neuro-oncological residency and fellowship training as well as the education of medical students. Improved and specific training in surgical neuro-oncology promotes neuro-oncological expertise, quality of surgical neuro-oncological treatment and may also contribute to further development of neuro-oncological techniques and treatment protocols. Specific curricula for a surgical neuro-oncologic education have not yet been established. METHODS: We used a consensus-building approach to propose skills, competencies and EPAs to be imparted within the framework of surgical neuro-oncological training. We developed competencies and EPAs suitable for training in surgical neuro-oncology. RESULT: In total, 70 competencies and 8 EPAs for training in surgical neuro-oncology were proposed. EPAs were defined for the management of the deteriorating patient, the management of patients with the diagnosis of a brain tumour, tumour-based resections, function-based surgical resections of brain tumours, the postoperative management of patients, the collaboration as a member of an interdisciplinary and/or -professional team and finally for the care of palliative and dying patients and their families. CONCLUSIONS AND RELEVANCE: The present work should subsequently initiate a discussion about the proposed competencies and EPAs and, together with the following discussion, contribute to the creation of new training concepts in surgical neuro-oncology.

fMRI Resting-State Connectivity between Language and Nonlanguage Areas as Defined by Intraoperative Electrocortical Stimulation in Low-Grade Glioma Patients.

BACKGROUND AND OBJECTIVES: It remains to be determined whether noninvasive functional imaging techniques can rival the clinical potential of direct electrocortical stimulation (DES). In this study, we compared the results of resting-state functional magnetic resonance imaging (rs-fMRI) to those of DES for language mapping. Our goals were twofold: (1) to replicate a previous study that demonstrated that resting-state connectivity (RSC) was significantly larger between positive DES language sites than between negative DES language sites and (2) to compare the spatial resolution of rs-fMRI to that of DES. METHODS: We conducted a retrospective study of nine low-grade glioma patients. Language sites were identified by intraoperative DES. We compared RSC values between and within groups of DES-positive and DES-negative regions of interest (ROIs). Both close-negative sites (i.e., DES-negative sites <1 cm apart from and on the same gyrus as DES-positive sites) and far-negative sites (i.e., purely randomly chosen sites not in the vicinity of the tumor or of the DES-positive sites but on the same lobe) were included. Receiver operating characteristics were used to quantify comparisons. RESULTS: Functional connectivity between all positive language sites was on average significantly higher than between all close-negative sites and between all far-negative sites. The functional connectivity between the positive language ROIs and their respective close-negative control sites was not smaller than between all positive language sites. CONCLUSION: rs-fMRI likely reflects similar neural information as detected with DES, but in its current form does not reach the spatial resolution of DES.

Evaluation of Volumetric Change of Intracerebral Hemorrhage in Patients Treated with Thrombolysis for Intraventricular Hemorrhage.

BACKGROUND: Intraventricular hemorrhage (IVH) is often caused by irruption of intracerebral hemorrhage (ICH) of basal ganglia or thalamus into the ventricular system. Instillation of recombinant tissue plasminogen activator (rtPA) via an external ventricular drainage (EVD) has been shown to effectively decrease IVH volumes while the impact of rtPA instillation on ICH volumes remains unclear. In this series, we analyzed volumetric changes of ICH in patients with and without intrathecal lysis therapy. METHODS: Between 01/2013 and 01/2019, 36 patients with IVH caused by hemorrhage of basal ganglia, thalamus or brain stem were treated with rtPA via an EVD (Group A). Initial volumes were determined in the first available computed tomography (CT) scan, final volumes in the last CT scan before discharge. During the same period, 41 patients with ICH without relevant IVH were treated without intrathecal lysis therapy at our neurocritical care unit (Group B). Serial CT scans were evaluated separately for changes in ICH volumes for both cohorts using OsiriX DICOM viewer. The Wilcoxon signed-rank test was performed for statistical analysis in not normally distributed variables. RESULTS: Median initial volume of ICH for treatment Group A was 6.5 ml and was reduced to 5.0 ml after first instillation of rtPA (p < 0.01). Twenty-six patients received a second treatment with rtPA (ICH volume reduction 4.5 to 3.3 ml, p < 0.01) and of this cohort further 16 patients underwent a third treatment (ICH volume reduction 3.0 ml to 1.5 ml, p < 0.01). Comparison of first and last CT scan in Group A confirmed an overall median percentage reduction of 91.7% (n = 36, p < 0.01) of ICH volumes and hematoma resolution in Group A was significantly more effective compared to non-rtPA group, Group B (percentage reduction = 68%) independent of initial hematoma volume in the regression analysis (p = 0.07, mean 11.1, 95%CI 7.7-14.5). There were no adverse events in Group A related to rtPA instillation. CONCLUSION: Intrathecal lysis therapy leads to a significant reduction in the intraparenchymal hematoma volume with faster clot resolution compared to the spontaneous hematoma resorption. Furthermore, intrathecal rtPA application had no adverse effect on ICH volume.

Correction to: Evaluation of Volumetric Change of Intracerebral Hemorrhage in Patients Treated with Thrombolysis for Intraventricular Hemorrhage.

The author name Kerim Beseoglu has been corrected and the details given in this correction are correct.

Proposed Definition of Experimental Secondary Ischemia for Mouse Subarachnoid Hemorrhage.

Inconsistency in outcome parameters for delayed cerebral ischemia (DCI) makes it difficult to compare results between mouse studies, in the same way inconsistency in outcome parameters in human studies has for long obstructed adequate comparison. The absence of an established definition may in part be responsible for the failed translational results. The present article proposes a standardized definition for DCI in experimental mouse models, which can be used as outcome measure in future animal studies. We used a consensus-building approach to propose a definition for "experimental secondary ischemia" (ESI) in experimental mouse subarachnoid hemorrhage that can be used as an outcome measure in preclinical studies. We propose that the outcome measure should be as follows: occurrence of focal neurological impairment or a general neurological impairment compared with a control group and that neurological impairment should occur secondarily following subarachnoid hemorrhage (SAH) induction compared with an initial assessment following SAH induction. ESI should not be used if the condition can be explained by general anesthesia or if other means of assessments sufficiently explain function impairment. If neurological impairment cannot reliably be evaluated, due to scientific setup. Verification of a significant secondary impairment of the cerebral perfusion compared with a control group is mandatory. This requires longitudinal examination in the same animal. The primary aim is that ESI should be distinguished from intervention-related ischemia or neurological deficits, in order establish a uniform definition for experimental SAH in mice that is in alignment with outcome measures in human studies.

Endovascular aneurysm closure during out of office hours is not related to complications or outcome.

PURPOSE: A possible disadvantage of endovascular occlusion outside work hours is that complex procedures might expose patients to additional risk when performed in a suboptimal setting. In this prospective cohort study, we evaluated whether treatment during out of office hours is a risk factor for per-procedural complications and clinical outcome. METHODS: We included 471 endovascular-treated, consecutive aneurysmal subarachnoid hemorrhage patients (56.6 ± 13.1, 69% female), from two prospective observational databases which were retrospectively analyzed. Primary outcome was the occurrence of per-procedural complications. Secondary outcomes were good clinical outcome (modified ranking scale ≤ 2) and death at 6-month follow-up. We determined odds ratios (OR) with 95% confidence intervals (CI) by ordered polytomous logistic regression analysis and adjusted odds ratios (aOR) for age, World Federation of Neurosurgical Societies grade, and time to treatment. RESULTS: Most patients were treated during office hours (363/471; 77.1%). Treatment during out of office hours did not result in an increased risk of per-procedural complications (OR 0.85 (95% CI 0.53-1.37; p = 0.51). Patients treated during out of office hours displayed similar odds of good clinical outcome and death after 6 months (OR 1.14, 95% CI 0.68-1.97 and 1.16 95% CI 0.56-2.29, respectively) compared to patients treated during office hours. CONCLUSION: In our study, endovascular coil embolization during out of office hours did not expose patients to an increased risk of procedural complications or affect functional outcome after 6 months.

Transcranial Doppler Ultrasound, Perfusion Computerized Tomography, and Cerebral Angiography Identify Different Pathological Entities and Supplement Each Other in the Diagnosis of Delayed Cerebral Ischemia.

INTRODUCTION: There is still controversial discussion of the value of transcranial Doppler (TCD) in predicting vasospasms in patients with aneurysmal SAH (aSAH). A newer method of predicting a delayed ischemic deficit (DCI) is CT perfusion (CTP), although it is not quite understood which kind of perfusion deficit is detected by this method since it seems to also identifying microcirculatory disturbances. We compared the TCD and CTP values with angiography and evaluated TCD and CTP changes before and after patients received intra-arterial spasmolytic therapy. MATERIAL AND METHODS: Retrospective analysis of TCD, CTP, and angiographies of N = 77 patients treated from 2013 to 2016. In 38 patients intra-arterial spasmolysis had been performed, and in these cases TCD and CTP data were compared before and after lysis. Thirty-nine patients had a pathological CTP but no angiographically seen vasospasm. RESULTS: There was no correlation between the known thresholds of mean transit time (MTT) in CTP and vasospasm or with mean velocities in TCD and vasospasm. After spasmolysis in patients with vasospasms, only the MTT showed significant improvement, whereas TCD velocities and Lindegaard index remained unaffected. CONCLUSION: TCD and CTP seem to identify different pathological entities of DCI and should be used supplementary in order to identify as many patients as possible with vasospasms after aSAH.

Meteorological factors for subarachnoid hemorrhage in the greater Düsseldorf area revisited: a machine learning approach to predict the probability of admission of patients with subarachnoid hemorrhage.

BACKGROUND: Reported data regarding the relation between the incidence of spontaneous subarachnoid hemorrhage (SAH) and weather conditions are conflicting and do so far not allow prognostic models. METHODS: Admissions for spontaneous SAH (ICD I60.*) 2009-2018 were retrieved form our hospital data base. Historical meteorological data for the nearest meteorological station, Düsseldorf Airport, was retrieved from the archive of the Deutsche Wetterdienst (DWD). Airport is in the center of our catchment area with a diameter of approximately 100 km. Pearson correlation matrix between mean daily meteorological variables and the daily admissions of one or more patients with subarachnoid hemorrhage was calculated and further analysis was done using deep learning algorithms. RESULTS: For the 10-year period from January 1, 2009 until December 31, 2018, a total of 1569 patients with SAH were admitted. No SAH was admitted on 2400 days (65.7%), 1 SAH on 979 days (26.7%), 2 cases on 233 days (6.4%), 3 SAH on 37 days (1.0%), 4 in 2 days (0.05%), and 5 cases on 1 day (0.03%). Pearson correlation matrix suggested a weak positive correlation of admissions for SAH with precipitation on the previous day and weak inverse relations with the actual mean daily temperature and the temperature change from the previous days, and weak inverse correlations with barometric pressure on the index day and the day before. Clustering with admission of multiple SAH on a given day followed a Poisson distribution and was therefore coincidental. The deep learning algorithms achieved an area under curve (AUC) score of approximately 52%. The small difference from 50% appears to reflect the size of the meteorological impact. CONCLUSION: Although in our data set a weak correlation of the probability to admit one or more cases of SAH with meteorological conditions was present during the analyzed time period, no helpful prognostic model could be deduced with current state machine learning methods. The meteorological influence on the admission of SAH appeared to be in the range of only a few percent compared with random or unknown factors.

An introduction to the pathophysiology of aneurysmal subarachnoid hemorrhage.

Pathophysiological processes following subarachnoid hemorrhage (SAH) present survivors of the initial bleeding with a high risk of morbidity and mortality during the course of the disease. As angiographic vasospasm is strongly associated with delayed cerebral ischemia (DCI) and clinical outcome, clinical trials in the last few decades focused on prevention of these angiographic spasms. Despite all efforts, no new pharmacological agents have shown to improve patient outcome. As such, it has become clear that our understanding of the pathophysiology of SAH is incomplete and we need to reevaluate our concepts on the complex pathophysiological process following SAH. Angiographic vasospasm is probably important. However, a unifying theory for the pathophysiological changes following SAH has yet not been described. Some of these changes may be causally connected or present themselves as an epiphenomenon of an associated process. A causal connection between DCI and early brain injury (EBI) would mean that future therapies should address EBI more specifically. If the mechanisms following SAH display no causal pathophysiological connection but are rather evoked by the subarachnoid blood and its degradation production, multiple treatment strategies addressing the different pathophysiological mechanisms are required. The discrepancy between experimental and clinical SAH could be one reason for unsuccessful translational results.

Volume of cerebrospinal fluid drainage as a predictor for pretreatment aneurysmal rebleeding.

OBJECTIVE Initiation of external CSF drainage has been associated with a significant increase in rebleeding probability after aneurysmal subarachnoid hemorrhage (aSAH). However, the implications for acute management are uncertain. The purpose of this study was to evaluate the role of the amount of drained CSF on aneurysmal rebleeding. METHODS Consecutive patients with aSAH were analyzed retrospectively. Radiologically confirmed cases of aneurysmal in-hospital rebleeding were identified and predictor variables for rebleeding were retrieved from hospital records. Clinical predictors were identified through multivariate analysis, and logistic regression analysis was performed to ascertain the cutoff value for the rebleeding probability. RESULTS The study included 194 patients. Eighteen cases (9.3%) of in-hospital rebleeding could be identified. Using multivariate analysis, in-hospital rebleeding was significantly associated with initiation of CSF drainage (p = 0.001) and CSF drainage volume (63 ml [interquartile range (IQR) 55-69 ml] vs 25 ml [IQR 10-35 ml], p < 0.001). Logistic regression showed that 58 ml of CSF drainage within 6 hours results in a 50% rebleeding probability. The relative risk (RR) for rebleeding after drainage of more than 60 ml in 6 hours was 5.4 times greater compared with patients with less CSF drainage (RR 5.403, 95% CI 2.481-11.767; p < 0.001, number needed to harm = 1.687). CONCLUSIONS Volume of CSF drainage was highly correlated with the probability of in-hospital aneurysmal rebleeding. These findings suggest that the rebleeding probability can be affected in acute management should the placement of an external ventricular catheter be necessary. This finding necessitates meticulous control of the amount of drained CSF and the development of a definitive treatment protocol for this group of patients.

Subarachnoid Hemorrhage in Germany Between 2010 and 2013: Estimated Incidence Rates Based on a Nationwide Hospital Discharge Registry.

BACKGROUND: Nordic countries are the primary source for nationwide data on the incidence of subarachnoid hemorrhage (SAH). Reliable estimates of national incidence rates of SAH in other countries are lacking, yet studies from Nordic countries with exceptional incidence rates are sometimes disregarded because of concerns regarding external validity. Autopsies are rarely performed for sudden deaths; therefore, estimates of the SAH incidence commonly reflect the hospital discharge rates. Our aim was to estimate the nationwide incidence of nontraumatic SAH in Germany using a national hospital discharge register. METHODS: The German federal statistical office provided the number of patients discharged from all German hospitals between 2010 and 2013 with the primary diagnosis of nontraumatic SAH (ICD code I60.0-I60.9) and corresponding age distribution. Age-standardized attack rates of nontraumatic SAH were calculated using the 2011 German demographic distribution. RESULTS: Between 2010 and 2013, the overall age-standardized incidence rate of nontraumatic SAH was 11.3 per 100,000 person-years, and it reached a maximum of 22.1 per 100,000 person-years in the oldest age group. The absolute number of SAHs was highest in the 50-55-year age group. The distribution of intracranial aneurysms displayed a propensity toward the posterior circulation with advancing age (P < 0.001), although in absolute numbers SAH originated mostly from the anterior circulation. CONCLUSIONS: Our estimate of the German nationwide attack rate suggests that the incidence of nontraumatic SAH is more homogeneous than previously assumed. Rejecting the external validity of studies from countries believed to display an exceptional incidence rates may therefore not be justified.

Increased mortality of patients with aneurysmatic subarachnoid hemorrhage caused by prolonged transport time to a high-volume neurosurgical unit.

BACKGROUND: Time has shown to be a relevant factor in the prognosis for a multitude of clinical conditions. The current analysis aimed to establish whether delayed admission to specialized care is a risk factor for increased mortality in case of high-grade aneurysmal subarachnoid hemorrhage. MATERIAL AND METHODS: Consecutive patients with aneurysmal subarachnoid hemorrhage were enrolled retrospectively if they had a World Federation of Neurological Surgeons Grading System grade of 5. Predictor variables for in-hospital mortality reflecting demographic, spatial, temporal treatment, and neurological factors were recorded from hospital medical records and emergency physicians' reports. We performed statistical analysis on the influence between the predictor variables and in-hospital mortality. RESULTS: The study included 61 patients with an average age of 58 years. The overall in-hospital mortality rate was 28% (17/61 patients). A delayed transport to specialized neurosurgical care was associated with increased in-hospital mortality. Transportation time was mainly prolonged in cases where an alternative diagnosis was made by the emergency physician. Mortality was highest in patients with cardiovascular complications of subarachnoid hemorrhage. CONCLUSION: Delayed admission to specialized care is associated with a higher mortality rate in patients with high-grade aneurysmal subarachnoid hemorrhage. Accompanying non-neurosurgical, mainly cardiac complications might be a significant factor leading to delayed admission. The emergency physician should be aware that cardiovascular abnormalities are a relevant complication and sometimes the first identified clinical feature of high-grade subarachnoid hemorrhage.