Study on prognosis of acutely ruptured intracranial aneurysms (SPARTA): a protocol for a multicentre prospective cohort study.

BACKGROUND: Ruptured intracranial aneurysms resulting in subarachnoid haemorrhage can be treated by open surgical or endovascular treatment. Despite multiple previous studies, uncertainties on the optimal treatment practice still exists. The resulting treatment variation may result in a variable, potentially worse, patient outcome. To better inform future treatment strategies, this study aims to identify the effectiveness of different treatment strategies in patients with ruptured intracranial aneurysms by investigating long-term functional outcome, complications and cost-effectiveness. An explorative analysis of the diagnostic and prognostic value of radiological imaging will also be performed. METHODS: This multi-centre observational prospective cohort study will have a follow-up of 10 years. A total of 880 adult patients with a subarachnoid haemorrhage caused by a ruptured intracranial aneurysm will be included. Calculation of sample size (N = 880) was performed to show non-inferiority of clip-reconstruction compared to endovascular treatment on 1 year outcome, assessed by using the ordinal modified Rankin Scale. The primary endpoint is the modified Rankin Scale score and mortality at 1 year after the initial subarachnoid haemorrhage. Patients will receive 'non-experimental' regular care during their hospital stay. For this study, health questionnaires and functional outcome will be assessed at baseline, before discharge and at follow-up visits. DISCUSSION: Despite the major healthcare and societal burden, the optimal treatment strategy for patients with subarachnoid haemorrhage caused by ruptured intracranial aneurysms is yet to be determined. Findings of this comparative effectiveness study, in which in-between centre variation in practice and patient outcome are investigated, will provide evidence on the effectiveness of treatment strategies, hopefully contributing to future high value treatment standardisation. TRIAL REGISTRATION NUMBER: NCT05851989 DATE OF REGISTRATION: May 10th, 2023.

3D exoscopic versus microscopic superficial temporal artery to middle cerebral artery bypass surgery for moyamoya disease - a comparative series.

PURPOSE: Superficial temporal artery to middle cerebral artery (STA-MCA) direct bypass surgery is the most common surgical procedure to treat moyamoya disease (MMD). Here, we aim to compare the performance of the 3D exoscope in bypass surgery with the gold standard operative microscope. METHODS: All direct STA-MCA bypass procedures performed at a single university hospital for MMD between 2015 and 2023 were considered for inclusion. Data were retrospectively collected from patient files and surgical video material. From 2020 onwards, bypass procedures were exclusively performed using a digital three-dimensional exoscope as visualization device. Results were compared with a microsurgical bypass control group (2015-2019). The primary endpoint was defined as total duration of surgery, duration of completing the vascular anastomosis (ischemia time), bypass patency, number of stiches to perform the anastomosis, added stiches after leakage testing of the anastomosis and the Glasgow outcome scale (GOS) at last follow-up as secondary outcome parameter. RESULTS: A total of 16 consecutive moyamoya patients underwent 21 STA-MCA bypass procedures. Thereof, six patients were operated using a microscope and ten patients using an exoscope (ORBEYE® n = 1; AEOS® n = 9). Total duration of surgery was comparable between devices (microscope: 313 min. ± 116 vs. exoscope: 279 min. ± 42; p = 0.647). Ischemia time also proved similar between groups (microscope: 43 min. ± 19 vs. exoscope: 41 min. ± 7; p = 0.701). No differences were noted in bypass patency rates. The number of stiches per anastomosis was similar between visualization devices (microscope: 17 ± 4 vs. exoscope: 17 ± 2; p = 0.887). In contrast, more additional stiches were needed in microscopic anastomoses after leakage testing the bypass (p = 0.035). CONCLUSION: Taking into account the small sample size, end-to-side bypass surgery for moyamoya disease using a foot switch-operated 3D exoscope was not associated with more complications and led to comparable clinical and radiological results as microscopic bypass surgery.

Flow diversion of ruptured intracranial aneurysms: a single-center study with a standardized antithrombotic treatment protocol.

BACKGROUND: The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol. METHODS: We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015-2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS). RESULTS: Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0-2 between the groups at 6 months. CONCLUSION: We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage.

Surgery on giant meningiomas in very old patients entails frequent postoperative intracranial hemorrhages and atypical histopathology.

PURPOSE: Surgical resection of intracranial meningiomas in patients that are 80 years old and older, i.e. very old patients, is increasingly considered. Meningiomas with a largest diameter of at least 5 cm-'giant meningiomas'-form a distinct entity, and their surgical resection is considered more difficult and prone to complications. Here, we evaluated functional outcome, morbidity and mortality, and the prognostic value of tumor size in very old patients who underwent resection of giant supratentorial meningiomas. METHODS: We retrospectively reviewed clinical and radiological data, functional performance (Karnofsky Performance Score), histopathological diagnosis and complications of very old patients who underwent surgery of a supratentorial meningioma at the Helsinki University Hospital between 2010 and 2018. RESULTS: We identified 76 very old patients, including 28 with a giant meningioma. Patients with a giant meningioma suffered from major complications more commonly than those with a non-giant meningioma (36% vs. 17%, p = 0.06), particularly from postoperative intracranial hemorrhages (ICH). At the 1-year follow-up, functional performance and mortality rate were comparable between patients with giant meningiomas and those with non-giant meningiomas. An exceptionally high rate of giant meningiomas were diagnosed as atypical meningiomas (WHO II) at an (11 out of 28 cases). CONCLUSIONS: Giant meningioma surgery entails a high complication rate in frail, very old patients. The prevention of postoperative ICH in this specific patient group is of utmost importance. An atypical histopathology was notably frequent among very old patients with a giant meningioma, which should be taken into account when planning the surgical strategy.

Discrete choice experiment on educating value-based healthcare.

INTRODUCTION: Identifying costs and values in healthcare interventions as well as the ability to measure and consider costs relative to value for patients are pivotal in clinical decision-making and medical education. This study explores residents' preferences in educating value-based healthcare (VBHC) during postgraduate medical education. Exploring residents' preferences in VBHC education, in order to understand what shapes their choices, might contribute to improved medical residency education and healthcare as a whole. METHODS: A discrete choice experiment (DCE) examined which conditions for educating VBHC are preferred by residents. DCE gives more insight into the trade-off's residents make when choosing alternatives, and which conditions for educating VBHC have the most influence on residents' preference. RESULTS: This DCE shows that residents prefer knowledge on both medical practice as well as the process of care-to be educated by an expert on VBHC together with a clinician. They prefer limited protected time to conduct VBHC initiatives (thus while at work) and desire the inclusion of VBHC in formal educational plans. CONCLUSION: When optimising graduate and postgraduate medical education curricula, these preferences should be considered to create necessary conditions for the facilitation and participation of residents in VBHC education and the set-up of VBHC initiatives.

Cerebral tumor with hemi-dural enhancement as unique presentation of multiple myeloma: A case report.

Introduction: Intracranial multiple myeloma (MM) is a rare manifestation of MM, a malignant plasma cell disorder that primarily affects bone marrow. Dural involvement in MM is even rarer and can manifest as a dural mass. We present a case of MM presenting as an intracranial dural tumor with primary hemi-dural involvement. Research question: This case report aims to investigate the clinical presentation, diagnostic challenges, and treatment approaches for intracranial multiple myeloma, with a focus on the extensive hemi-dural thickening and enhancement seen in this case. Material and methods: A 73-year-old male presented with progressive dysphasia and weakness. MRI revealed a solid left frontal mass with significant mass-effect. Hemi-dural thickening and enhancement was present along with invasion of the skull. The patient underwent surgical resection of the tumor with dural and bone reconstruction. Results: Histopathological examination confirmed MM diagnosis. Chemotherapy was started. Follow-up MRI showed complete tumor resection, but extensive hemi-dural thickening and enhancement persisted. Postoperative radiation therapy was considered. Discussion and conclusion: MM with primary dural involvement is rare and poses diagnostic challenges. Postoperative treatment involves chemotherapy, the role of surgery and radiotherapy is not established. The extensive hemi-dural thickening and enhancement observed in this case require further investigation, and a wait-and-scan policy was recommended instead of radiotherapy.

Long-Term Follow-Up of Critically Ill Patients With Traumatic Brain Injury: From Intensive Care Parameters to Patient and Caregiver-Reported Outcome.

Abstract Traumatic brain injury (TBI) is associated with a high social and financial burden due to persisting (severe) disabilities. The consequences of TBI after intensive care unit (ICU) admission are generally measured with global disability screeners such as the Glasgow Outcome Scale-Extended (GOSE), which may lack precision. To improve outcome measurement after brain injury, a comprehensive clinical outcome assessment tool called the Minimal Dataset for Acquired Brain Injury (MDS-ABI) was recently developed. The MDS-ABI covers 12 life domains (demographics, injury characteristics, comorbidity, cognitive functioning, emotional functioning, energy, mobility, self-care, communication, participation, social support, and quality of life), as well as informal caregiver capacity and strain. In this cross-sectional study, we used the MDS-ABI among formerly ICU admitted patients with TBI to explore the relationship between dichotomized severity of TBI and long-term outcome. Our objectives were to: 1) summarize demographics, clinical characteristics, and long-term outcomes of patients and their informal caregivers, and 2) compare differences between long-term outcomes in patients with mild-moderate TBI and severe TBI based on Glasgow Coma Scale (GCS) scores at admission. Participants were former patients of a Dutch university hospital (total n = 52; mild-moderate TBI n = 23; severe TBI n = 29) and their informal caregivers (n = 45). Hospital records were evaluated, and the MDS-ABI was administered during a home visit. On average 3.2 years after their TBI, 62% of the patients were cognitively impaired, 62% reported elevated fatigue, and 69% experienced restrictions in ≥2 participation domains (most frequently work or education and going out). Informal caregivers generally felt competent to provide necessary care (81%), but 31% experienced a disproportionate caregiver burden. All but four patients lived at home independently, often together with their informal caregiver (81%). Although the mild-moderate TBI group and the severe TBI group had significantly different clinical trajectories, there were no persisting differences between the groups for patient or caregiver outcomes at follow-up. As a large proportion of the patients experienced long-lasting consequences beyond global disability or independent living, clinicians should implement a multi-domain outcome set such as the MDS-AB to follow up on their patients.

Unravelling Low-Value Care Decision-Making: Residents' Perspectives on the Influence of Contextual Factors.

BACKGROUND: Several initiatives have been developed to target low-value care (i.e. waste) in decision-making with varying success. As such, decision-making is a complex process and context's influence on decisions concerning low-value care is limitedly explored. Hence, a more detailed understanding of residents' decision-making is needed to reduce future low-value care. This study explores which contextual factors residents experience to influence their decision-making concerning low-value care. Methods: We employed nominal group technique to select four low-value care vignettes. Prompted by these vignettes, we conducted individual interviews with residents. We analyzed the qualitative data thematically using an inductive-deductive approach, guided by Bronfenbrenner's social-ecological framework. This framework provided guidance to 'context' in terms of sociopolitical, environmental, organizational, interpersonal, and individual levels. RESULTS: In 2022, we interviewed 19 residents from a Dutch university medical center. We identified 33 contextual factors influencing residents' decision-making, either encouraging or discouraging low-value care. The contextual factors resided in the following levels with corresponding categories: (1) environmental and sociopolitical: society, professional medical association, and governance; (2) organizational: facility characteristics, social infrastructure, and work infrastructure; (3) interpersonal: resident-patient, resident-supervising physician, and resident-others; and (4) individual: personal attributes and work structure. CONCLUSION: This paper describes 33 contextual factors influencing residents' decision-making concerning low-value care. Residents are particularly influenced by factors related to interactions with patients and supervisors. Furthermore, organizational factors and the broader environment set margins within which residents make decisions. While acknowledging that a multi(faceted)-intervention approach targeting all contextual factors to discourage low-value care delivery may be warranted, improving communication skills in the resident-patient dynamics to recognize and explain low-value care seems a particular point of interest over which residents can exercise an influence themselves.

Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage: Location, Distribution Patterns, Infarct Load, and Effect on Outcome.

BACKGROUND AND OBJECTIVES: Delayed cerebral ischemia (DCI) is one of the main contributing factors to poor clinical outcome after aneurysmal subarachnoid hemorrhage (SAH). Unsuccessful treatment can cause irreversible brain injury in the form of DCI-related infarction. We aimed to assess the association between the location, distribution, and size of DCI-related infarction in relation to clinical outcome. METHODS: Consecutive patients with SAH treated at 2 university hospitals between 2014 and 2019 (Helsinki, Finland) and between 2006 and 2020 (Aachen, Germany) were included. Size of DCI-related infarction was quantitatively measured as absolute volume (in milliliters). In a semiquantitative fashion, infarction in 14 regions of interest (ROIs) according to a modified Alberta Stroke Program Early CT Score (ASPECTS) was noted. The association of infarction in these ROIs along predefined regions of eloquent brain, with clinical outcome, was assessed. For this purpose, 1-year outcome was measured by the Glasgow Outcome Scale (GOS) and dichotomized into favorable (GOS 4-5) and unfavorable (GOS 1-3). RESULTS: Of 1,190 consecutive patients with SAH, 155 (13%) developed DCI-related infarction. One-year outcome data were available for 148 (96%) patients. A median overall infarct volume of 103 mL (interquartile range 31-237) was measured. DCI-related infarction was significantly associated with 1-year unfavorable outcome (odds ratio [OR] 4.89, 95% CI 3.36-7.34, p < 0.001). In patients with 1-year unfavorable outcome, vascular territories more frequently affected were left middle cerebral artery (affected in 49% of patients with unfavorable outcome vs in 30% of patients with favorable outcome; p = 0.029), as well as left (44% vs 18%; p = 0.003) and right (52% vs 14%; p < 0.001) anterior cerebral artery supply areas. According to the ASPECTS model, the right M3 (OR 8.52, 95% CI 1.41-51.34, p = 0.013) and right A2 (OR 7.84, 95% CI 1.97-31.15, p = 0.003) regions were independently associated with unfavorable outcome. DISCUSSION: DCI-related infarction was associated with a 5-fold increase in the odds of unfavorable outcome, after 1 year. Ischemic lesions in specific anatomical regions are more likely to contribute to unfavorable outcome. TRIAL REGISTRATION INFORMATION: Data collection in Aachen was registered in the German Clinical Trial Register (DRKS00030505); on January 3, 2023.

3D Exoscopes in Experimental Microanastomosis: A Comparison of Different Systems.

Background: In recent years, three-dimensional exoscopes have been increasingly applied in neurosurgery. Multiple exoscopic systems are available, all offering specific features. In this study, we assessed practical and visualization performance of four different exoscopic systems in a highly challenging microsurgical procedure, and evaluated whether these affected the quality of work. Methods: We included four different exoscopes: Olympus ORBEYE, Zeiss KINEVO, Storz VITOM, and Aesculap AEOS. With each exoscope, ten experimental bypass procedures were carried out on chicken wing vessels at a depth of 3 cm. We evaluated the quality of the anastomoses, the practical considerations for the setup of the exoscopic systems, and the visualization quality by tracking the number of unnecessary movements. Results: All included exoscopes enabled us to perform the bypass procedures with mostly adequate or excellent results. Surgically, the most pronounced difference between the exoscopes was the duration of the procedure, which was mainly due to the number of unnecessary movements. Practically, the exoscopes differ highly which is important when considering which exoscope to apply. Conclusions: This is the first study comparing different exoscope systems while performing the same challenging microsurgical procedure. We found major practical differences between the exoscopes that determine the suitability of an exoscope based on the demands and conditions of the surgical procedure. Therefore, preprocedural practical training with the exoscope is required.

Late-developing posttraumatic dural arteriovenous fistula of the vertebral artery: illustrative case.

BACKGROUND: A dural arteriovenous fistula (dAVF) involving the vertebral artery (VA) is a rare vascular pathology that can result from damage to the VA, most frequently following cervical spine trauma. In most traumatic cases, the dAVF develops and manifests shortly after trauma. OBSERVATIONS: A patient was admitted after a fall from the stairs causing neck pain. Computed tomography of the cervical spine revealed a Hangman's fracture, and angiography showed a left VA dissection. The patient was treated with a cervical brace and clopidogrel. Three weeks after trauma, the patient was admitted because of bilateral leg ataxia, dizziness, and neck pain. Repeat imaging revealed increased displacement of the cervical fracture and a dAVF from the left VA with retrograde filling of the dAVF from the right VA. Embolization of the dAVF using coils proximally and distally to the dAVF was performed prior to placing a halo brace. At 6 months, all symptoms had disappeared and union of the cervical spine fracture had occurred. LESSONS: This case report emphasizes the need for follow-up angiography after traumatic VA injury resulting from cervical spine fracture and underlines important treatment considerations for successful obliteration of a dAVF of the VA.

Difference between brain temperature and core temperature in severe traumatic brain injury: a systematic review.

INTRODUCTION: Intensive care management for traumatic brain injury (TBI) patients aims to prevent secondary cerebral damage. Targeted temperature management is one option to prevent cerebral damage, as hypothermia may have protective effects. By conducting a systematic literature review we evaluated: 1) the presence of a temperature difference (gradient) between brain temperature (Tb) and core temperature (Tc) in TBI patients; and 2) clinical factors associated with reported differences. EVIDENCE ACQUISITION: The PubMed database was systematically searched using Mesh terms and key words, and Web of Sciences was assessed for additional article citations. We included studies that continuously and simultaneously measured Tb and Tc in severe TBI patients. The National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies was modified to fit the purpose of our study. Statistical data were extracted for further meta-analyses. EVIDENCE SYNTHESIS: We included 16 studies, with a total of 480 patients. Clinical heterogeneity consisted of Tb/Tc measurement site, measurement device, physiological changes, local protocols, and medical or surgical interventions. The studies have a high statistical heterogeneity (I2). The pooled mean temperature gradient between Tb and Tc was +0.14 °C (95% confidence interval: 0.03 to 0.24) and ranged from -1.29 to +1.1 °C. Patients who underwent a decompressive (hemi)craniectomy showed lower Tb values compared to Tc found in three studies. CONCLUSIONS: Studies on Tb and Tc are heterogeneous and show that, on average, Tb and Tc are not clinically significant different in TBI patients (<0.2 °C). Interpretations and interventions of the brain and central temperatures will benefit from standardization of temperature measurements.

Endovascular treatment and neurosurgical clipping in subarachnoid hemorrhage: a systematic review of economic evaluations.

INTRODUCTION: There are two treatment modalities for aneurysmal subarachnoid hemorrhage: endovascular treatment (EVT) and neurosurgical clipping. Results of economic evaluations are needed to gain insight into the relationship between clinical effectiveness and costs of these treatment modalities. This important information can inform both clinical decision-making processes and policymakers in facilitating Value-Based Healthcare. EVIDENCE ACQUISITION: Databases (PubMed, Embase, Cochrane Library, the Centre for Reviews and Dissemination, EBSCO, and Web of Science) were searched for studies published until October 2020 that had performed economic evaluations in aneurysmal subarachnoid hemorrhage patients by comparing EVT with neurosurgical clipping. The quality of reporting and methodology of these evaluations was assessed using the associated instruments (i.e. CHEERS statement and CHEC-list, respectively). EVIDENCE SYNTHESIS: A total of 6 studies met the inclusion criteria. All included studies reported both effects and costs, however five did not relate effects to costs. Only one study related effects directly to costs, thus conducted a full economic evaluation. The reporting quality scored 81% and the methodological quality scored 30%. CONCLUSIONS: The quality of published cost-effectiveness studies on the treatment of aneurysmal subarachnoid hemorrhage is poor. Six studies reported both outcomes and costs, however only one study performed a full economic evaluation comparing EVT to neurosurgical clipping. Although the reporting quality was sufficient, the methodological quality was poor. Further research that relates health-related quality of life measures to costs of EVT and neurosurgical clipping is required - specifically focusing on both reporting and methodological quality. Different subgroup analyses and modeling could also enhance the findings.

Cerebrovascular glycocalyx damage and microcirculation impairment in patients with temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is increasingly associated with blood-brain barrier dysfunction and microvascular alterations, yet the pathophysiological link is missing. An important barrier function is exerted by the glycocalyx, a gel-like layer coating the endothelium. To explore such associations, we used intraoperative videomicroscopy to quantify glycocalyx and microcirculation properties of the neocortex and hippocampus of 15 patients undergoing resective brain surgery as treatment for drug-resistant TLE, and 15 non-epileptic controls. Fluorescent lectin staining of neocortex and hippocampal tissue was used for blood vessel surface area quantification. Neocortical perfused boundary region, the thickness of the glycocalyx' impaired layer, was higher in patients (2.64 ± 0.52 µm) compared to controls (1.31 ± 0.29 µm), P < 0.01, indicative of reduced glycocalyx integrity in patients. Moreover, erythrocyte flow velocity analysis revealed an impaired ability of TLE patients to (de-)recruit capillaries in response to changing metabolic demands (R2 = 0.75, P < 0.01), indicating failure of neurovascular coupling mechanisms. Blood vessel quantification comparison between intraoperative measurements and resected tissue showed strong correlation (R2 = 0.94, P < 0.01). This is the first report on in vivo assessment of glycocalyx and microcirculation properties in TLE patients, confirming the pivotal role of cerebrovascular changes. Further assessment of the cerebral microcirculation in relation to epileptogenesis might open avenues for new therapeutic targets for drug-resistant epilepsy.

Recovery Potential of Spinal Meningioma Patients With Preoperative Loss of Walking Ability Following Surgery - A Retrospective Single-Center Study.

OBJECTIVE: Spinal meningiomas are neurosurgical rarities that manifest with progressive paraor tetraparesis. The effect of timing of surgery on the recovery after the loss of walking ability is poorly known. We studied the effect of timing of surgery on restoring walking ability in surgically-treated spinal meningioma patients. METHODS: Using electronic health records, we retrospectively identified ≥ 18-year-old patients operated on during 2010-2020. The patients were followed until 30th September 2020, death or emigration. RESULTS: We identified 108 patients (81% women) with operated spinal meningiomas. The mean age of the patients was 64 years (range, 18-94 years). A gross total resection was achieved in 101 (94%), and 21 patients (19%) suffered from perioperative complications. Of the 108 patients operated on, 49 (45%) could not walk without assistance prior to surgery. At the time of first postoperative visit (mean, 3.1 months; range, 1.3-13.1 months), 14 out of 24 patients (58%) operated on within 29 days and 8 out of 20 patients (40%) operated on later than 29 days since the loss of walking ability without assistance, were able to walk without assistance. Also, 3 out of 5 paraplegic patients who underwent surgery later than 29 days after they lost the walking ability, were able to at least walk with assistance at first postoperative visit. CONCLUSION: Early surgical treatment following the loss of walking ability restores walking ability in a substantial number of patients. However, even late surgery may restore walking ability.

Visualization and Maneuverability Features of a Robotic Arm Three-Dimensional Exoscope and Operating Microscope for Clipping an Unruptured Intracranial Aneurysm: Video Comparison and Technical Evaluation.

BACKGROUND: In recent years, three-dimensional (3D) digital exoscope systems have been developed and reported to form an adequate alternative to the conventional operating microscope. OBJECTIVE: To illustrate essential and practical features in a surgical video comparing a robotic arm 3D digital exoscope and a conventional operating microscope to clip a middle cerebral artery aneurysm. METHODS: We used a mouth switch-controlled operating microscope (OPMI PENTERO 900; Carl Zeiss Meditec AG) and robotic arm-controlled 3D digital Aeos exoscope (Aesculap Inc). We assessed the following visualization and optical features: overall visualization quality, color and contrast quality, range and quality of magnification, and adjustment of focus. In addition, we assessed maneuverability for changing surgical site within and viewing angle of the surgical field. RESULTS: We found that both modalities are suitable for this surgery and offer distinct qualities. The microscope enables faster magnification adjustment and continuous mouth switch-controlled focus adjustments. The advantages of the exoscope include the adaptation of color and contrast settings, and the surgeon can keep both hands in the surgical field while the camera pivots around its working field. CONCLUSION: The exoscope and operating microscope offer a similar high-quality visualization of, and smooth maneuvering within, the surgical field. The method of visualization and maneuvering is, however, very distinct. Therefore, a surgeon's acquaintance and experience with the specific features and how to optimally use them in surgery are of utmost importance. Further analyses of both systems are needed to evolve these tools.

Fast Transition from Open Surgery to Endovascular Treatment of Unruptured Anterior Communicating Artery Aneurysms-A Retrospective Analysis of 128 Patients.

OBJECTIVE: Anterior communicating artery aneurysms (ACoAAs) are challenging to treat both surgically and endovascularly. In this study, we evaluate the treatment-related morbidity and clinical outcome of microsurgical clipping and endovascular treatment for a consecutive series of unruptured ACoAAs while the treatment paradigm was in transition from surgical to endovascular first. METHODS: We retrospectively reviewed clinical and radiologic data of adult patients who underwent microsurgical clipping or endovascular treatment of an unruptured ACoAA at a high-volume academic neurovascular center (Helsinki University Hospital) during 2012-2019. During this period, a transition from microsurgical clipping to endovascular treatment took place. Regarding outcome, we focused on treatment-related complications, discharge-to-home rates, functional performance (modified Rankin Scale score), and obliteration rates. RESULTS: Of 128 treated ACoAAs, 81 (64%) were treated surgically and 47 (36%) endovascularly. There was no difference in major complications, intracranial hemorrhagic complications or ischemic complications, discharge-to-home rates, or functional performance between the surgically and endovascularly treated patients. With time, a decrease in major complications was observed in the surgical cases (from 29% to 17%), whereas the major complication rate increased in the endovascularly patients (from 0% to 25%). Cerebral ischemia was the most frequent complication in both groups. The risk for permanent neurologic deficit remained low in both groups (9% for endovascular and 5% for surgery). CONCLUSIONS: We did not find any major differences regarding complications and outcomes after the treatment paradigm shift from clipping to endovascular of unruptured ACoAAs. Prospective studies evaluating durability of treatments are needed to compare overall effectiveness.

Inducing oscillations in positive end-expiratory pressure improves assessment of cerebrovascular pressure reactivity in patients with traumatic brain injury.

The cerebral pressure reactivity index (PRx), through intracranial pressure (ICP) measurements, informs clinicians about the cerebral autoregulation (CA) status in adult-sedated patients with traumatic brain injury (TBI). Using PRx in clinical practice is currently limited by variability over shorter monitoring periods. We applied an innovative method to reduce the PRx variability by ventilator-induced slow (1/min) positive end-expiratory pressure (PEEP) oscillations. We hypothesized that, as seen in a previous animal model, the PRx variability would be reduced by inducing slow arterial blood pressure (ABP) and ICP oscillations without other clinically relevant physiological changes. Patients with TBI were ventilated with a static PEEP for 30 min (PRx period) followed by a 30-min period of slow [1/min (0.0167 Hz)] +5 cmH2O PEEP oscillations (induced (iPRx period). Ten patients with TBI were included. No clinical monitoring was discontinued and no additional interventions were required during the iPRx period. The PRx variability [measured as the standard deviation (SD) of PRx] decreased significantly during the iPRx period from 0.25 (0.22-0.30) to 0.14 (0.09-0.17) (P = 0.006). There was a power increase around the induced frequency (1/min) for both ABP and ICP (P = 0.002). In conclusion, 1/min PEEP-induced oscillations reduced the PRx variability in patients with TBI with ICP levels <22 mmHg. No other clinically relevant physiological changes were observed. Reduced PRx variability might improve CA-guided perfusion management by reducing the time to find "optimal" perfusion pressure targets. Larger studies with prolonged periods of PEEP-induced oscillations are required to take it to routine use.NEW & NOTEWORTHY Cerebral autoregulation assessment requires sufficient slow arterial blood pressure (ABP) waves. However, spontaneous ABP waves may be insufficient for reliable cerebral autoregulation estimations. Therefore, we applied a ventilator "sigh-function" to generate positive end-expiratory pressure oscillations that induce slow ABP waves. This method demonstrated a reduced variability of the pressure reactivity index, commonly used as continuous cerebral autoregulation measure in a traumatic brain injury population.

Elevated concentrations of macrophage migration inhibitory factor in serum and cerebral microdialysate are associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Objective: Inflammation is increasingly recognized to be involved in the pathophysiology of aneurysmal subarachnoid hemorrhage (aSAH) and may increase the susceptibility to delayed cerebral ischemia (DCI). Macrophage migration inhibitory factor (MIF) has been shown to be elevated in serum and cerebrospinal fluid (CSF) after aSAH. Here, we determined MIF levels in serum, CSF and cerebral microdialysate (MD) at different time-points after aSAH and evaluated their clinical implications. Methods: MIF levels were measured in serum, CSF and MD obtained from 30 aSAH patients during early (EPd1-4), critical (CPd5-15) and late (LPd16-21) phase after hemorrhage. For subgroup analyses, patients were stratified based on demographic and clinical data. Results: MIF levels in serum increased during CPd5-15 and decreased again during LPd16-21, while CSF levels showed little changes over time. MD levels peaked during EPd1-4, decreased during CPd5-15 and increased again during LPd16-21. Subgroup analyses revealed significantly higher serum levels in patients with aneurysms located in the anterior vs. posterior circulation during CPd5-15 (17.3 [15.1-21.1] vs. 10.0 [8.4-11.5] ng/ml, p = 0.009) and in patients with DCI vs. no DCI during CPd5-15 (17.9 [15.1-22.7] vs. 11.9 [8.9-15.9] ng/ml, p = 0.026) and LPd16-21 (17.4 [11.7-27.9] vs. 11.3 [9.2-12.2] ng/ml, p = 0.021). In addition, MIF levels in MD during CPd5-15 were significantly higher in patients with DCI vs. no DCI (3.6 [1.8-10.7] vs. 0.2 [0.1-0.7] ng/ml, p = 0.026), while CSF levels during the whole observation period were similar in all subgroups. Conclusion: Our findings in a small cohort of aSAH patients provide preliminary data on systemic, global cerebral and local cerebral MIF levels after aSAH and their clinical implications. Clinical trial registration: ClinicalTrials.gov, identifier: NCT02142166.

Brainstem intraparenchymal schwannoma: A case report and literature review.

BACKGROUND: Intracranial intraparenchymal schwannomas (IS) are rare tumors that have mainly been described in case reports. Here, we report on a case of a brainstem IS and included a comprehensive literature review. CASE DESCRIPTION: A 74-year-old man presented with progressive gait disturbances. CT- and MRI-imaging revealed a contrast-enhancing mass accompanied by a cyst in the dorsolateral pons. Hemangioblastoma was suspected and surgery was advised. During surgery, gross total resection of a non-invasive tumor was performed. Postoperative recovery was uneventful. Based on histopathological examination, the intraparenchymal brainstem tumor was diagnosed as schwannoma. CONCLUSION: Our extensive review illustrates that ISs are benign tumors that most often present in relatively young patients. Malignant cases have been described but form an extremely rare entity. Preoperative diagnosis based on radiological features is difficult but should be considered when peritumoral edema, calcifications, and cysts are noted. In benign cases, gross total resection of the lesion is curative. To adequately select this treatment and adjust the surgical strategy accordingly, it is important to include IS in the preoperative differential diagnosis when the abovementioned radiological features are present.