Comparison of Operating Microscope and Exoscope in a Highly Challenging Experimental Setting

BACKGROUND: The use of a digital three-dimensional (3D) exoscope system in neurosurgery is increasing as an alternative to the operative microscope. The objective of this study was to compare a digital 3D exoscope system with a standard operating microscope as a neurosurgical visualization tool in a highly challenging experimental setting. METHODS: End-to-side bypass procedures, each at a depth of 9 cm, were performed in a simulation setting. The quality of the task and the depth effect, visualization, magnification, illumination, and ergonomics were evaluated. RESULTS: No major differences were noted between the microscope and the 3D exoscope in terms of the quality of the work. Working with the 3D exoscope was more time-consuming than working with the microscope. Changing the depth and focus was faster using the operative microscope. The 3D exoscope enabled higher magnification and offered better ergonomic features. CONCLUSIONS: In a highly challenging experimental setting, comparable procedural quality was found for the microscope and the 3D exoscope. Each visualization tool had advantages and disadvantages. Over time and with technologic advances, the digital 3D exoscope may become the main operative visualization system in microneurosurgery.Peer reviewe

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.Peer reviewe

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

INTRODUCTION: Intensive care management for 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 keywords, 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 standardisation 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 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 endovascular treatment 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 six 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 endovascular treatment 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 endovascular treatment and neurosurgical clipping is required-specifically focusing on both reporting and methodological quality. Different subgroup analyses and modeling could also enhance the findings

Cerebral Artery Vasoconstriction is Endothelin-1 Dependent Requiring Neurogenic and Adrenergic Crosstalk

Background: The regulation of cerebral arterial vasomotor tone involves several mechanisms. The role of sympathetic nerves and the adrenergic neurotransmitter, noradrenaline (NA), has been the subject of debate for decades. Moreover, the specific role of endothelin-1 (ET-1) in cerebral arterial vasoconstriction has not been elucidated to date. In this study, we evaluated the contribution of NA and ET-1 to cerebral artery vasoconstriction.Methods: Arterial responses of rat middle cerebral arteries, and human pial cerebral arteries to cumulative concentrations of NA and ET-1, and to Electrical Field Stimulation (EFS), were evaluated. To assess the role of NA and ET-1 when EFS was applied, experiments were performed in the presence of adrenergic, neurogenic, and endothelin-1 receptor modulators.Results: We found that vasoconstriction of cerebral arteries following EFS requires the application of exogenous NA, whereas neither EFS nor NA alone induced vasoconstriction. The observed vasoconstriction was abolished by a-adrenoreceptor antagonist, catecholamine-release inhibitor, blockade of the perivascular neurons, and by the endothelin-2 receptor antagonist (BQ123).Conclusion: Based on our results, cerebral artery vasoconstriction requires simultaneous neurogenic and adrenergic activation and is ET-1 dependent. We hypothesize that NA modulates the release of ET-1. Upon release, ET-1 binds to the ETA-receptor on smooth muscle cells inducing cerebral artery vasoconstriction.</p

Targeting Autoregulation-Guided Cerebral Perfusion Pressure after Traumatic Brain Injury (COGiTATE): A Feasibility Randomized Controlled Clinical Trial

Managing traumatic brain injury (TBI) patients with a cerebral perfusion pressure (CPP) near to the cerebral autoregulation (CA)-guided "optimal" CPP (CPPopt) value is associated with improved outcome and might be useful to individualize care, but has never been prospectively evaluated. This study evaluated the feasibility and safety of CA-guided CPP management in TBI patients requiring intracranial pressure monitoring and therapy (TBIicp patients). The CPPopt Guided Therapy: Assessment of Target Effectiveness (COGiTATE) parallel two-arm feasibility trial took place in four tertiary centers. TBIicp patients were randomized to either the Brain Trauma Foundation (BTF) guideline CPP target range (control group) or to the individualized CA-guided CPP targets (intervention group). CPP targets were guided by six times daily software-based alerts for up to 5 days. The primary feasibility end-point was the percentage of time with CPP concordant (+/- 5 mm Hg) with the set CPP targets. The main secondary safety end-point was an increase in therapeutic intensity level (TIL) between the control and intervention group. Twenty-eight patients were randomized to the control and 32 patients to the intervention group. CPP in the intervention group was in the target range for 46.5% (interquartile range, 41.2-58) of the monitored time, significantly higher than the feasibility target specified in the published protocol (36%; p < 0.001). There were no significant differences between groups for TIL or for other safety end-points. Conclusively, targeting an individual and dynamic CA-guided CPP is feasible and safe in TBIicp patients. This encourages a prospective trial powered for clinical outcomes