Brain metastasis resection: the impact of fluorescence guidance (MetResect study).

OBJECTIVE: Maximal resection of brain metastases (BMs) improves both progression-free survival and overall survival (OS). Fluorescein sodium (FL) in combination with the YELLOW 560-nm filter is a safe and feasible method for visualizing residual tumor tissue during BM resection. The authors of this study aimed to show that use of FL would positively influence the volumetric extent of resection (EOR) and thus the survival outcome in patients undergoing BM resection. METHODS: Analyzing their institution's prospective brain tumor registry, the authors identified 539 consecutive patients with BMs (247 women, mean age 62.8 years) by using preoperative high-quality MR images for volumetric analysis. BMs were resected under white light (WL) in 293 patients (54.4%; WL group) and under FL guidance in 246 patients (45.6%; FL group). Sex, age, presurgical Karnofsky Performance Status (KPS), recursive partitioning analysis class, and adjuvant treatment modalities were well balanced between the two groups. Volumetric analysis was performed in a blinded fashion by quantifying pre- and postoperative tumor volume based on gadolinium-enhanced T1-weighted sequences. RESULTS: In the FL group, the postoperative tumor volume was significantly smaller (p = 0.01), and hence the quantitative EOR was significantly larger (p = 0.024) and OS was significantly longer (p = 0.0001) (log-rank testing). Multivariate Cox regression modeling showed that age, presurgical KPS, metastasis status, and FL-guided resection are independent prognostic factors for survival. CONCLUSIONS: Compared with WL resection, FL-guided BM resection increased resection quality, significantly improved EOR, and prolonged OS.

Endogenous calcitonin gene-related peptide in cerebrospinal fluid and early quality of life and mental health after good-grade spontaneous subarachnoid hemorrhage-a feasibility series.

The vasodilatory calcitonin gene-related peptide (CGRP) is excessively released after spontaneous subarachnoid hemorrhage (sSAH) and modulates psycho-behavioral function. In this pilot study, we prospectively analyzed the treatment-specific differences in the secretion of endogenous CGRP into cerebrospinal fluid (CSF) during the acute stage after good-grade sSAH and its impact on self-reported health-related quality of life (hrQoL). Twenty-six consecutive patients (f:m = 13:8; mean age 50.6 years) with good-grade sSAH were enrolled (drop out 19% (n = 5)): 35% (n = 9) underwent endovascular aneurysm occlusion, 23% (n = 6) microsurgery, and 23% (n = 6) of the patients with perimesencephalic SAH received standardized intensive medical care. An external ventricular drain was inserted within 72 h after the onset of bleeding. CSF was drawn daily from day 1-10. CGRP levels were determined via competitive enzyme immunoassay and calculated as "area under the curve" (AUC). All patients underwent a hrQoL self-report assessment (36-Item Short Form Health Survey (SF-36), ICD-10-Symptom-Rating questionnaire (ISR)) after the onset of sSAH (t1: day 11-35) and at the 6-month follow-up (t2). AUC CGRP (total mean ± SD, 5.7 ± 1.8 ng/ml/24 h) was excessively released into CSF after sSAH. AUC CGRP levels did not differ significantly when dichotomizing the aSAH (5.63 ± 1.77) and pSAH group (5.68 ± 2.08). aSAH patients revealed a higher symptom burden in the ISR supplementary item score (p = 0.021). Multiple logistic regression analyses corroborated increased mean levels of AUC CGRP in CSF at t1 as an independent prognostic factor for a significantly higher symptom burden in most ISR scores (compulsive-obsessive syndrome (OR 5.741, p = 0.018), anxiety (OR 7.748, p = 0.021), depression (OR 2.740, p = 0.005), the supplementary items (OR 2.392, p = 0.004)) and for a poorer performance in the SF-36 physical component summary score (OR 0.177, p = 0.001). In contrast, at t2, CSF AUC CGRP concentrations no longer correlated with hrQoL. To the best of our knowledge, this study is the first to correlate the levels of endogenous CSF CGRP with hrQoL outcome in good-grade sSAH patients. Excessive CGRP release into CSF may have a negative short-term impact on hrQoL and emotional health like anxiety and depression. While subacutely after sSAH, higher CSF levels of the vasodilator CGRP are supposed to be protective against vasospasm-associated cerebral ischemia, from a psychopathological point of view, our results suggest an involvement of CSF CGRP in the dysregulation of higher integrated behavior.

Intraoperative imaging of brain tumors with fluorescein: confocal laser endomicroscopy in neurosurgery. Clinical and user experience.

OBJECTIVE: Confocal laser endomicroscopy (CLE) is an established tool in basic research for tissue imaging at the level of microstructures. Miniaturization and refinement of the technology have made this modality available for operative imaging with a handheld device. Sufficient image contrast is provided by the preoperative application of fluorescein sodium. The authors report their first experiences in a clinical case series using the new confocal laser endomicroscope. METHODS: Handling, operative workflow, and visualization of the CLE were critically evaluated in 12 cases of different CNS tumors. Three different imaging positions in relation to the tumor were chosen: the tumor border (I), tumor center (II), and perilesional zone (III). Respective diagnostic sampling with H & E staining and matching intraoperative neuronavigation and microscope images are provided. RESULTS: CLE was found to be beneficial in terms of high-quality visualization of fine structures and for displaying hidden anatomical details. The handling of the device was good, and the workflow was easy. CONCLUSIONS: Handling ergonomics and image acquisition are intuitive. The endomicroscope allows excellent additional visualization of microstructures in the surgical field with a minimally invasive technique and could improve safety and clinical outcomes. The new confocal laser endomicroscope is an advanced tool with the potential to change intracranial tumor surgery. Imaging of these microstructures is novel, and research with comparative validation with traditional neuropathological assessments is needed.

Fluorescein sodium-guided resection of cerebral metastases-an update.

BACKGROUND: Cerebral metastasis (CM) is the most common malignancy affecting the brain. In patients eligible for surgery, complete tumor removal is the most important predictor of overall survival and neurological outcome. The emergence of surgical microscopes fitted with a fluorescein-specific filter have facilitated fluorescein-guided microsurgery and identification of tumor tissue. In 2012, we started evaluating fluorescein (FL) with the dedicated microscope filter in cerebral metastases (CM). After describing the treatment results of our first 30 patients, we now retrospectively report on 95 patients. METHODS: Ninety-five patients with CM of different primary cancers were included (47 women, 48 men, mean age, 60 years, range, 25-85 years); 5 mg/kg bodyweight of FL was intravenously injected at induction of anesthesia. A YELLOW 560-nm filter (Pentero 900, ZEISS Meditec, Germany) was used for microsurgical tumor resection and resection control. The extent of resection (EOR) was assessed by means of early postoperative contrast-enhanced MRI and the grade of fluorescent staining as described in the surgical reports. Furthermore, we evaluated information on neurological outcome and surgical complications as well as any adverse events. RESULTS: Ninety patients (95%) showed bright fluorescent staining that markedly enhanced tumor visibility. Five patients (5%); three with adenocarcinoma of the lung, one with melanoma of the skin, and one with renal cell carcinoma) showed insufficient FL staining. Thirteen patients (14%) showed residual tumor tissue on the postoperative MRI. Additionally, the MRI of three patients did not confirm complete resection beyond doubt. Thus, gross-total resection had been achieved in 83% (n = 79) of patients. No adverse events were registered during the postoperative course. CONCLUSIONS: FL and the YELLOW 560-nm filter are safe and feasible tools for increasing the EOR in patients with CM. Further prospective evaluation of the FL-guided technique in CM-surgery is in planning.

Fluorescein-stained confocal laser endomicroscopy versus conventional frozen section for intraoperative histopathological assessment of intracranial tumors.

BACKGROUND: The aim of this clinical trial was to compare Fluorescein-stained intraoperative confocal laser endomicroscopy (CLE) of intracranial lesions and evaluation by a neuropathologist with routine intraoperative frozen section (FS) assessment by neuropathology. METHODS: In this phase II noninferiority, prospective, multicenter, nonrandomized, off-label clinical trial (EudraCT: 2019-004512-58), patients above the age of 18 years with any intracranial lesion scheduled for elective resection were included. The diagnostic accuracies of both CLE and FS referenced with the final histopathological diagnosis were statistically compared in a noninferiority analysis, representing the primary endpoint. Secondary endpoints included the safety of the technique and time expedited for CLE and FS. RESULTS: A total of 210 patients were included by 3 participating sites between November 2020 and June 2022. Most common entities were high-grade gliomas (37.9%), metastases (24.1%), and meningiomas (22.7%). A total of 6 serious adverse events in 4 (2%) patients were recorded. For the primary endpoint, the diagnostic accuracy for CLE was inferior with 0.87 versus 0.91 for FS, resulting in a difference of 0.04 (95% confidence interval -0.10; 0.02; P = .367). The median time expedited until intraoperative diagnosis was 3 minutes for CLE and 27 minutes for FS, with a mean difference of 27.5 minutes (standard deviation 14.5; P < .001). CONCLUSIONS: CLE allowed for a safe and time-effective intraoperative histological diagnosis with a diagnostic accuracy of 87% across all intracranial entities included. The technique achieved histological assessments in real time with a 10-fold reduction of processing time compared to FS, which may invariably impact surgical strategy on the fly.

Sodium fluorescein-guided resection under the YELLOW 560 nm surgical microscope filter in malignant brain tumor surgery--a feasibility study.

OBJECTIVE: In glioma surgery, the extent of resection (EOR) is one important predictor of progression-free survival. In 2006, fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) was shown to improve the EOR in malignant gliomas. However, the use of 5-ALA is complex and causes certain side effects. Sodium fluorescein (FL) is a fluorescent dye that is used for angiography in ophthalmic surgery. FL accumulates in areas of the disturbed blood-brain barrier and can be visualized under a 560-nm wavelength fluorescent light source (YELLOW 560 nm, Carl Zeiss Meditec, Oberkochen, Germany). Here, we present the first experiences with low-dose FL and YELLOW 560 nm in 35 patients with malignant brain tumors. PATIENTS AND METHOD: A total of 200 mg of FL (3-4 mg/kg bodyweight) was administered in 35 patients during craniotomy as an off-label use between May and August 2012. We retrospectively analyzed the histology, pre-treatment, clinical parameters pre- and postoperatively and occurrence of any adverse effects. The feasibility and efficacy ('helpful,' 'not helpful') of FL under YELLOW 560 nm (demarcation of the tumor margin) was assessed by the responsible neurosurgeon (n = 5) for each surgical procedure. RESULTS: Twenty-six patients had gliomas (1 WHO grade I, 3 WHO grade II, 5 WHO grade III, 17 WHO grade IV), 5 patients had cerebral metastases, 2 had non-malignant astrogliosis and 2 had post-radiation necrosis. The fluorescence signal was detected in all patients immediately after the FL administration. FL application was classified as 'helpful' in 28 patients, implying improved visualization of the tumor margins. The intensity of the fluorescence signal seemed to be correlated to the histology and was strongly dependent on the pre-treatment status. We did not record any allergic reactions or any other adverse effects. CONCLUSION: The use of FL for the resection of brain tumors is safe and feasible. Presumably, the visualization of the tumor margin depends on the histopathology and on the pre-treatment status. A randomized evaluation of FL under the YELLOW 560 nm filter is planned to prospectively analyze the extent of resection in patients with malignant brain tumors.

Fluorescein-guided resection of newly diagnosed high-grade glioma: Impact on extent of resection and outcome.

Introduction: Maximal resection of high-grade glioma (HGG) improves progression-free survival (PFS) and overall survival (OS). Fluorescein sodium (FL) in combination with the YELLOW 560 â€‹nm filter (Carl Zeiss Meditec, Germany) is a safe and feasible method of visualizing residual tumor tissue during brain tumor resection. Research question: We hypothesized that use of FL positively influenced the volumetric extent of resection (EOR), PFS, and OS in patients undergoing resection of a newly diagnosed HGG. Materials and method: Using a prospective HGG registry, we identified 347 patients (median age 62.4 years; 141 women) with preoperative high-quality magnetic resonance images for volumetric analysis. Resection was performed under white light in n â€‹= â€‹151 (43.5%, white-light group) and under FL-guidance in n â€‹= â€‹196 (56.5%, FL group). Sex, age, presurgical Karnofsky Performance Index (KPI), O6-Methylguanin-DNA-Methyltransferase-Gene (MGMT) status, and adjuvant treatment modalities were well balanced between the groups. Volumetric analysis was performed by quantifying pre- and postoperative tumor volume based on gadolinium-enhanced T1 sequences in a blinded fashion. Results: In the FL group, postoperative tumor volume was significantly smaller (p â€‹= â€‹0.003); accordingly, quantitative EOR was significantly larger (p â€‹= â€‹0.003). Significantly more complete resections were achieved in the FL group than in the white-light group (p â€‹= â€‹0.003). The FL group showed significantly longer PFS (p â€‹= â€‹0.020) and OS (p â€‹= â€‹0.015, log rank testing). Multivariate Cox regression modelling showed age, presurgical KPI, MGMT status, and FL-guided resection to be independent prognostic factors for survival. Discussion and conclusion: Compared to white-light resection, FL-guided resection of newly diagnosed HGG significantly improved EOR and prolonged OS.

Confocal laser imaging in neurosurgery: A comprehensive review of sodium fluorescein-based CONVIVO preclinical and clinical applications.

Given the established direct correlation that exists among extent of resection and postoperative survival in brain tumors, obtaining complete resections is of primary importance. Apart from the various technological advancements that have been introduced in current clinical practice, histopathological study still remains the gold-standard for definitive diagnosis. Frozen section analysis still represents the most rapid and used intraoperative histopathological method that allows for an intraoperative differential diagnosis. Nevertheless, such technique owes some intrinsic limitations that limit its overall potential in obtaining real-time diagnosis during surgery. In this context, confocal laser technology has been suggested as a promising method to have near real-time intraoperative histological images in neurosurgery, thanks to the results of various studies performed in other non-neurosurgical fields. Still far to be routinely implemented in current neurosurgical practice, pertinent literature is growing quickly, and various reports have recently demonstrated the utility of this technology in both preclinical and clinical settings in identifying brain tumors, microvasculature, and tumor margins, when coupled to the intravenous administration of sodium fluorescein. Specifically in neurosurgery, among different available devices, the ZEISS CONVIVO system probably boasts the most recent and largest number of experimental studies assessing its usefulness, which has been confirmed for identifying brain tumors, offering a diagnosis and distinguishing between healthy and pathologic tissue, and studying brain vessels. The main objective of this systematic review is to present a state-of-the-art summary on sodium fluorescein-based preclinical and clinical applications of the ZEISS CONVIVO in neurosurgery.

Fluorescein-guided surgery for the resection of pilocytic astrocytomas: A multicentric retrospective study.

Objective: Pilocytic astrocytomas (PAs) are relatively benign tumors, usually enhancing on post-contrast MRI and often characterized by a mural nodule within a cystic component. Surgical resection represents the mainstay of treatment, and extent of resection (EOR) is associated with improved survival. In this study, we analyzed the effect of sodium fluorescein (SF) on the visualization and resection of these circumscribed astrocytic gliomas. Methods: Surgical databases at two neurosurgical departments (Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy and Department of Neurosurgery, University Medical Center Regensburg, Regensburg, Germany) were retrospectively reviewed to identify the cohort of patients with pilocytic astrocytoma who had undergone fluorescein-guided tumor resection at any of the centers between March 2016 and February 2022. SF was intravenously injected (5 mg/kg) immediately after the induction of general anesthesia. Tumors were removed using a microsurgical technique with the YELLOW 560 filter (Carl Zeiss Meditec, Oberkochen, Germany). Results: Forty-four patients (25 males and 19 females; 26 pediatric patients, mean age of 9.77 years, range 2 to 17 years; and 18 adult patients, mean age of 34.39 years, range 18 to 58 years) underwent fluorescein-guided surgery. No side effects related to SF occurred. In all tumors, contrast enhancement on preoperative MRI was correlated with intense, heterogeneous yellow fluorescence with bright fluorescent cystic fluid. Fluorescein was considered helpful in distinguishing tumors from viable tissue in all cases except three patients due to faint fluorescein enhancement. Biopsy was intended in two operations, and partial resection was intended in three operations. Gross total resection was achieved in 24 cases out of 39 patients scheduled for tumor removal (61.54%), in five cases a minimal residual volume was highlighted by postoperative MRI despite the intraoperative subjective evaluation of complete tumor removal (12.82%); in the other 10 cases, the resection was subtotal with fluorescent residual spots to avoid neurological worsening (25.64%). Conclusions: The use of SF is a valuable method for safe fluorescence-guided tumor resection. Our data showed a positive effect of fluorescein-guided surgery on intraoperative visualization during resection of Pas, suggesting a possible role in improving the extent of resection of these lesions.

Local application of BMP-2 specific plasmids in fibrin glue does not promote implant fixation.

BACKGROUND: BMP-2 is known to accelerate fracture healing and might also enhance osseointegration and implant fixation. Application of recombinant BMP-2 has a time-limited effect. Therefore, a gene transfer approach with a steady production of BMP-2 appears to be attractive. The aim of this study was to examine the effect of locally applied BMP-2 plasmids on the bone-implant integration in a non-weight bearing rabbit tibia model using a comparatively new non-viral copolymer-protected gene vector (COPROG). METHODS: Sixty rabbits were divided into 4 groups. All of them received nailing of both tibiae. The verum group had the nails inserted with the COPROG vector and BMP-2 plasmids using fibrin glue as a carrier. Controls were a group with fibrin glue only and a blank group. After 28 and 56 days, these three groups were sacrificed and one tibia was randomly chosen for biomechanical testing, while the other tibia underwent histomorphometrical examination. In a fourth group, a reporter-gene was incorporated in the fibrin glue instead of the BMP-2 formula to prove that transfection was successful. RESULTS: Implant fixation strength was significantly lower after 28 and 56 days in the verum group. Histomorphometry supported the findings after 28 days, showing less bone-implant contact.In the fourth group, successful transfection could be confirmed by detection of the reporter-gene in 20 of 22 tibiae. But, also systemic reporter-gene expression was found in heterotopic locations, showing an undesired spreading of the locally applied gene formula. CONCLUSION: Our results underline the transfecting capability of this vector and support the idea that BMP-2 might diminish osseointegration. Further studies are necessary to specify the exact mechanisms and the systemic effects.

Endoscopic Assistance in the Deep and Narrow Spaces of the Brain-Microscopic Tumor Surgery Supported by the New Micro-Inspection Tool QEVO® (Technical Note).

Introduction: To evaluate the feasibility and efficacy of the innovative micro-inspection tool QEVO® (Carl Zeiss Meditec, Oberkochen, Germany) as an endoscopic adjunct to microscopes for better visualization of the surgical field in complex deep-seated intracranial tumors in infants and adults. Materials and Methods: We retrospectively assessed the surgical videos of 25 consecutive patients with 26 complex intracranial lesions (time frame 2018-2020). Lesions were classified according to their anatomical area: 1 = sellar region (n = 6), 2 = intra-ventricular (except IV.ventricle, n = 9), 3 = IV.ventricle and rhomboid fossa (n = 4), and 4 = cerebellopontine angle (CPA) and foramen magnum (n = 7). Indications to use the QEVO® tool were divided into five "QEVO® categories": A = target localization, B = tailoring of the approach, C = looking beyond the lesion, D = resection control, and E = inspection of remote areas. Results: Overall, the most frequent indications for using the QEVO® tool were categories D (n = 19), C (n = 17), and E (n = 16). QEVO® categories B (n = 8) and A (n = 5) were mainly applied to intra-ventricular procedures (anatomical area 2). Discussion: The new micro-inspection tool QEVO® is a powerful endoscopic device to support the comprehensive visualization of complex intracranial lesions and thus instantly increases intraoperative morphological understanding. However, its use is restricted to the specific properties of the respective anatomical area.

Fluorescent tracers in neurosurgical procedures: a European survey.

BACKGROUND: In recent years several techniques have been proposed with the aim of improving tumors visualization and extent of resection and, among them, the use of photosensitive dyes is gaining great interest. Regarding the application of the two most used dyes, 5-aminolevulinic acid (5-ALA) and sodium fluorescein (SF), there is still a lack of shared and established protocols among different centers. The main objective of the present study was to evaluate the current practice of fluorescence-guided techniques in neuro-oncological surgery in Europe. METHODS: An online questionnaire consisting of 33 questions was completed by 136 European Association of Neurosurgical Societies neurosurgeons. Responses were entered into a database and subsequently analyzed. RESULTS: Data were analyzed from 136 out of 1476 active European neurosurgeons which had been contacted, with a 9,2% response rate. Based on the data from the questionnaire, Germany was the most responsive country (15% of the total respondents) and the main indication for 5-ALA and SF utilization were high-grade gliomas. 5-ALA was mainly used as defined in Gliolan® datasheet, while SF as off-label technique with a 5 mg/kg dose of injection at the end of patient intubation. Both the dyes were mainly used in adult population, more frequently by neurosurgeons with less-than 20 cases per year expertise. Mean price per patient were 817,6 € and 7,7 € for 5-ALA and SF, respectively. CONCLUSIONS: 5-ALA acid is still the preferred and more established fluorescent dye used during high-grade gliomas resection, with SF as a gaining-attention, really cheaper and more ductile alternative.

The Management of Brain Metastases-Systematic Review of Neurosurgical Aspects.

The multidisciplinary management of patients with brain metastases (BM) consists of surgical resection, different radiation treatment modalities, cytotoxic chemotherapy, and targeted molecular treatment. This review presents the current state of neurosurgical technology applied to achieve maximal resection with minimal morbidity as a treatment paradigm in patients with BM. In addition, we discuss the contribution of neurosurgical resection on functional outcome, advanced systemic treatment strategies, and enhanced understanding of the tumor biology.

Brain Metastases in Elderly Patients-The Role of Surgery in the Context of Systemic Treatment.

In patients with brain metastases (BM), advanced age is considered a negative prognostic factor. To address the potential reasons for that, we assessed 807 patients who had undergone BM resection; 315 patients aged at least 65 years (group A) were compared with 492 younger patients (group B). We analyzed the impact of the pre- and postoperative Karnofsky performance status (KPS), postoperative treatment structure and post-treatment survival. BM resection significantly improved KPS scores in both groups (p = 0.0001). Median survival after BM resection differed significantly between the groups (A: 5.81 vs. B: 8.12 months; p = 0.0015). In both groups, patients who received postoperative systemic treatment showed significantly longer overall survival (p = 0.00001). However, elderly patients less frequently received systemic treatment (p = 0.0001) and the subgroup of elderly patients receiving such therapies had a significantly higher postsurgical KPS score (p = 0.0007). In all patients receiving systemic treatment, age was no longer a negative prognostic factor. Resection of BM improves the functional status of elderly patients, thus enhancing the likeliness to receive systemic treatment, which, in turn, leads to longer overall survival. In the context of such a treatment structure, age alone is no longer a prognostic factor for survival.

A multicenter cohort study of early complications after cranioplasty: results of the German Cranial Reconstruction Registry.

OBJECTIVE: Cranioplasty (CP) is a crucial procedure after decompressive craniectomy and has a significant impact on neurological improvement. Although CP is considered a standard neurosurgical procedure, inconsistent data on surgery-related complications after CP are available. To address this topic, the authors analyzed 502 patients in a prospective multicenter database (German Cranial Reconstruction Registry) with regard to early surgery-related complications. METHODS: Early complications within 30 days, medical history, mortality rates, and neurological outcome at discharge according to the modified Rankin Scale (mRS) were evaluated. The primary endpoint was death or surgical revision within the first 30 days after CP. Independent factors for the occurrence of complications with or without surgical revision were identified using a logistic regression model. RESULTS: Traumatic brain injury (TBI) and ischemic stroke were the most common underlying diagnoses that required CP. In 230 patients (45.8%), an autologous bone flap was utilized for CP; the most common engineered materials were titanium (80 patients [15.9%]), polyetheretherketone (57 [11.4%]), and polymethylmethacrylate (57 [11.4%]). Surgical revision was necessary in 45 patients (9.0%), and the overall mortality rate was 0.8% (4 patients). The cause of death was related to ischemia in 2 patients, diffuse intraparenchymal hemorrhage in 1 patient, and cardiac complications in 1 patient. The most frequent causes of surgical revision were epidural hematoma (40.0% of all revisions), new hydrocephalus (22.0%), and subdural hematoma (13.3%). Preoperatively increased mRS score (OR 1.46, 95% CI 1.08-1.97, p = 0.014) and American Society of Anesthesiologists Physical Status Classification System score (OR 2.89, 95% CI 1.42-5.89, p = 0.003) were independent predictors of surgical revision. Ischemic stroke, as the underlying diagnosis, was associated with a minor rate of revisions compared with TBI (OR 0.18, 95% CI 0.06-0.57, p = 0.004). CONCLUSIONS: The authors have presented class II evidence-based data on surgery-related complications after CP and have identified specific preexisting risk factors. These results may provide additional guidance for optimized treatment of these patients.

Meningioma infiltrating into porous polymethylmethacrylate cranioplasty-report of a unique case.

Implantation of a cranioplasty after osteoclastic craniotomy or craniectomy is one of the most common neurosurgical procedures, and polymethylmethacrylate (PMMA) is one of the most frequently applied materials for cranioplasty. This report describes the unique case of a patient with recurrent transitional meningioma WHO I that infiltrated the PMMA cranioplasty 7 years after primary surgery. We propose to restrict the use of porous PMMA as cranioplasty after the removal of convexity meningioma.

Application of the Endoscopic Micro-Inspection Tool QEVO® in the Surgical Treatment of Anterior Circulation Aneurysms-A Technical Note and Case Series.

Introduction: The application of neuro-endoscopes in cerebral aneurysm surgery may help to avoid unintended aneurysm remnants and the accidental clipping of perforating arteries and aid the detection of blood collecting in the subdural spaces. Here, we present our experience with the novel endoscopic micro-inspection tool QEVO® (Carl Zeiss Meditec, Germany) in aneurysm surgery. Materials and Equipment: In all patients the surgical microscope KINEVO® (Carl Zeiss Meditec, Germany) and the Microinspection tool QEVO® were applied. Methods: The case series comprises 22 unruptured cerebral aneurysms of the anterior circulation. All aneurysms were treated surgically. All patients routinely underwent computed tomography and digital subtraction angiography within 10 days after surgery. Results: No aneurysm remnants, cerebral ischemic deficits, or subdural hematomas were detected. Discussion: In this technical note, we discuss the benefits and limitations of the QEVO® tool and illustrate the major paradigms by means of intraoperative photographs.

Symptomatic Postoperative Spinal Epidural Hematoma after Spinal Decompression Surgery: Prevalence, Risk Factors, and Functional Outcome.

OBJECTIVE: Postoperative spinal epidural hematoma (pSEH) with symptomatic compression of nervous structures after spinal decompression surgery is a rare complication. Delayed evacuation may result in severe neurologic impairment. We present a large single-center analysis of the prevalence, potential risk factors, and functional recovery after pSEH. METHODS: A retrospective review of our institutional database of spinal decompression surgery over 15 years yielded 6,024 consecutive patients. A total of 42 patients who had undergone surgical revision due to postoperative neurologic deterioration or intractable radiating pain and radiographically confirmed pSEH were allocated to the pSEH group. A matched 3:1 control group was formed (126 patients with the same surgical procedure, same year, same sex, and similar age). Charts, surgical reports, and radiographic data were reviewed for demographics, duration of symptoms, history of medical treatment, medication, comorbidities, radiographic extension, surgical strategy, and pre- and postoperative neurologic performance. Median follow-up was 3 months. Risk factors for pSEH, complete recovery, and recovery of neurologic symptoms were analyzed with univariable and multivariable logistic regression models. RESULTS: The prevalence of pSEH in this population was 0.69% (n = 42) with these locations: 7 of 1,284 (0.54%) cervical, 1 of 774 (0.12%) thoracic, and 34 of 3,966 (0.85%) lumbar. Use of anticoagulants (p = 0.003), pathologic coagulation values in the preoperative blood test (p = 0.034), and cigarette smoking (p = 0.003) were identified as independent risk factors of pSEH. Surgery in more than one level showed a trend toward an increased risk of pSEH. Pain as the only symptom (p = 0.0001) was a significant predictor of complete recovery. Patients symptomatic with paraplegia (p = 0.026) had a significantly higher risk of a poor neurologic outcome without full recovery of neurologic symptoms. CONCLUSION: The prevalence of pSEH was lower than previously reported incidences. Use of anticoagulants, pathologic coagulation values, and cigarette smoking were identified as independent risk factors of pSEH. Functional outcome was related to the duration between hematoma evacuation and the clinical presentation of symptomatic pSEH.

Lighting Up the Tumor-Fluorescein-Guided Resection of Gangliogliomas.

(1) Background: Gangliogliomas comprise a small number of brain tumors. They usually present as World Health Organization (WHO) grade I, and they delineate on gadolinium-enhanced MRI; the surgical goal is wide radical resection, and the course thereafter is usually benign. Fluorescein sodium (FL) tends to accumulate in areas with altered blood-brain barrier (BBB). Thus far, the results provided by prospective and retrospective studies show that the utilization of this fluorophore may be associated with better visualization and improvement of resection for several tumors of the central nervous system. In this study, we retrospectively studied the effect of fluorescein sodium on visualization and resection of gangliogliomas. (2) Methods: Surgical databases in three neurosurgical departments (Regensburg University Hospital; Besta Institute, Milano, Italy; and Liv Hospital, Istanbul, Turkey), with approval by the local ethics committee, were retrospectively reviewed to find gangliogliomas surgically removed by a fluorescein-guided technique by the aid of a dedicated filter on the surgical microscope from April 2014 to February 2020. Eighteen patients (13 women, 5 men; mean age 22.9 years, range 3 to 78 years) underwent surgical treatment for gangliogliomas during 19 operations. Fluorescein was intravenously injected (5 mg/kg) after general anesthesia induction. Tumors were removed using a microsurgical technique with the YELLOW 560 Filter (YE560) (KINEVO/PENTERO 900, Carl Zeiss Meditec, Oberkochen, Germany). (3) Results: No side effects related to fluorescein occurred. In all tumors, contrast enhancement on preoperative MRI correlated with bright yellow fluorescence during the surgical procedure (17 gangliogliomas WHO grade I, 1 ganglioglioma WHO grade II). Fluorescein was considered helpful by the operating surgeon in distinguishing tumors from viable tissue in all cases (100%). Biopsy was intended in two operations, and subtotal resection was intended in one operation. In all other operations considered preoperatively eligible, gross total resection (GTR) was achieved in 12 out of 16 (75%) instances. (4) Conclusions: The use of FL and YE560 is a readily available method for safe fluorescence-guided tumor resection, possibly visualizing tumor margins intraoperatively similar to contrast enhancement in T1-weighted MRI. Our data suggested a positive effect of fluorescein-guided surgery on intraoperative visualization and extent of resection during resection of gangliogliomas.

The World Federation of Neurosurgical Societies Young Neurosurgeons Survey (Part I): Demographics, Resources, and Education.

BACKGROUND: Providing a comprehensive and effective neurosurgical service requires adequate numbers of well-trained, resourced, and motivated neurosurgeons. The survey aims to better understand 1) the demographics of young neurosurgeons worldwide; 2) the challenges in training and resources that they face; 3) perceived barriers; and 4) needs for development. METHODS: This was a cross-sectional study in which a widely disseminated online survey (April 2018-November 2019) was used to procure a nonprobabilistic sample from current neurosurgical trainees and those within 10 years of training. Data were grouped by World Bank income classifications and analyzed using χ2 tests because of its categorical nature. RESULTS: There were 1294 respondents, with 953 completed responses included in the analysis. Of respondents, 45.2% were from high-income countries (HICs), 23.2% from upper-middle-income countries, 26.8% lower-middle-income countries, and 4.1% from low-income countries. Most respondents (79.8%) were male, a figure more pronounced in lower-income groups. Neuro-oncology was the most popular in HICs and spinal surgery in all other groups. Although access to computed tomography scanning was near universal (98.64%), magnetic resonance imaging access decreased to 66.67% in low-income countries, compared with 98.61% in HICs. Similar patterns were noted with access to operating microscopes, image guidance systems, and high-speed drills. Of respondents, 71.4% had dedicated time for neurosurgical education. CONCLUSIONS: These data confirm and quantify disparities in the equipment and training opportunities among young neurosurgeons practicing in different income groups. We hope that this study will act as a guide to further understand these differences and target resources to remedy them.