Gamma Knife Radiosurgery for Cerebral Cavernous Malformations: Meta-analysis of Reconstructed Time-to-Event Data

INTRODUCTION

Cavernomas are vascular lesions with a genetic heritage that can be spotted on the central nervous system. Whenever these lesions are localized in eloquent regions, surgical resection is not recommended. In this type of situation, Gamma Knife stereotactic radiosurgery (GKRS) could be a feasible option for treating patients. Thus, we aim to explore the outcomes associated with this procedure.

METHODS

We performed a systematic review and meta-analysis of reconstructed time-to-event data based on Kaplan-Meier curves. A thorough search was conducted on PubMed, Cochrane, Web of Science and Embase databases targeting papers that provided information regarding hemorrhagic outcomes associated with GKRS through Kaplan-Meier curves.

RESULTS

After a systematic search in the specific databases, seven studies were included in this review. Notably, a total of 1071 patients had 1104 cavernomas treated by GKRS. Assessment of short-term and long-term post-procedure outcomes was performed, with the estimated overall events-free rate at 2 years being 89.8% (95% CI 87.7 - 91.5), whilst, at ten years, the estimated overall events-free rate was 71.3% (95% CI 67.2 - 75.1).

CONCLUSION

GKRS seems to be a good alternative for control of symptomatic events in early and long-term follow-up, despite the need of further investigation provided by future studies.

A light in the darkness: sodium fluorescein-assisted peripheral nerve sheath tumors resection - a comprehensive systematic review and single-arm meta-analysis

The treatment for peripheral nerve sheath tumors (PNSTs) is based on surgical excision and the primary goal is to improve symptoms whilst preserving neurological function. In order to improve this technique, surgeons may use sodium fluorescein (SF) to help visualize the neoplasm and, consequently, facilitate its removal. Aiming to assess the efficacy of this emerging surgical strategy, we conducted a systematic review and single-arm meta-analysis. We conducted a systematic search on the PubMed, Embase, and Web of Science databases, following the PRISMA guidelines. Studies without outcomes of interest, case series with less than four patients, letters, comments, technical notes, editorials, reviews, and basic research papers were excluded. The outcomes considered for this study were: the number of tumors that achieved total resection, subtotal resection, or near total resection, the approach/technique utilized by the surgeon, SF-related complications, and total complications. Five studies, with a total of 175 individuals, were included in our survey. Notably, 70% of the neoplasms presented by the patients were schwannomas. Considering extracranial lesions, we found a proportion of 96% (95% CI: 88 - 100%) in total resection, 0% (95% CI: 0-1%) in near total resection, and 4% (95% CI: 0-12%) in subtotal resection, all linked to an amount of 185 analyzed PNSTs. Furthermore, a proportion of 1% (95% CI: 0 - 2%) in SF-related complications was spotted among 183 patients. Finally, total complications analysis accounted for 11% (95% CI: 0 - 25%) among 183 individuals. We concluded that SF-assisted resection of PNSTs is a suitable and relatively safe technique, linked to minimum complications, of which the majority was not associated with the chemical compound itself. Future research is necessary to increase the number of patients available in the current literature and, therefore, enhance future analyses.

Assessing short-term and long-term security and efficacy of anterior nucleus of the thalamus deep brain stimulation for treating drug-resistant epilepsy: A systematic review and single-arm meta-analysis

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a widespread invasive procedure for treating drug-resistant epilepsy. Nonetheless, there is a persistent debate regarding the short-term and long-term efficacy and safety of ANT-DBS. Thus we conducted a systematic review and meta-analysis. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we searched PubMed, Cochrane, Embase, and Web of Science for studies treating refractory epilepsy with ANT-DBS. Short-term analysis was considered for studies with a mean follow-up of 3 years or less. The following outcomes were assessed for data extraction: procedure responders and nonresponders, increased seizure frequency, complications, and procedure-related mortality. Of 650 studies, 25 fit our inclusion criteria, involving 427 patients. Previous surgical treatments have been reported in 214 patients (50.1%) and a median average baseline seizure frequency of 64.9 monthly seizures. In the short-term analysis, we observed a proportion of 67% (95% confidence interval [CI] 54%-79%) of responders and 33% (95% CI 21%-46%) of nonresponders. In addition, 4% (95% CI 0%-9%) of the patients presented increased seizure frequency. In the long-term analysis, we observed 72% (95% CI 66%-78%) responders and 27% (95% CI 21%-34%) nonresponders. Moreover, there was a 2% (95% CI 0%-5%) increase in seizure frequency. No procedure-related mortality was reported at any follow-up. ANT-DBS effectively treats refractory epilepsy, with lasting short-term and long-term benefits. It remains safe and efficient despite complications, showing no procedure-linked fatalities, high patient responsiveness, and minimal increased seizures. Consistent results over time and low morbidity/mortality rates emphasize its worth. Further research is necessary to diminish the discrepancy among results.

Ultrasound-Guided Resection of High-Grade Gliomas: A Single-Arm Meta-Analysis

BACKGROUND

High-grade gliomas (HGGs) present a challenge in neuro-oncology, often necessitating surgical resection for optimal management. Ultrasound holds promise in achieving better gross total resection (GTR) and improving outcomes. This meta-analysis systematically evaluates literature providing robust evidence on the use of intraoperative ultrasonography (iUSG) in HGG resection.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines a comprehensive search was made across PubMed, Embase, Cochrane, and Web of Science utilized terms related to iUSG for HGG resection. The meta-analysis examined randomized trials and observational cohort studies on iUSG-guided HGG resection. GTR, subtotal resection, and postresection complications were assessed. Statistical analysis, employing R software for a single proportion analysis with confidence intervals of 95%, I2 statistics for heterogeneity, and the instrumental variables method with restricted maximum likelihood for a random effects model.

RESULTS

A total of 178 patients were included in our study. The GTR overall rate in patients with iUSG-guided resection was found to be 64% (95% confidence interval: 46%-81%). Two-dimensional ultrasound remains dominant at 80% against other options of ultrasound. Complications were reported at a 15% rate (95% confidence interval: 7%-23%).

CONCLUSIONS

Our study provided robust data on the utilization of iUSG-guided resection regarding the attainment of GTR and the complications related to resection. However, challenges such as outcome heterogeneity and limited complication reporting highlight the need for further research to optimize iUSG in HGG treatment. Long-term follow-up studies on patient survival and postsurgery quality of life will complement existing literature, guiding clinical practices in managing HGG.

Survival Impact of Combined Biguanide and Temozolomide in Glioblastoma Preclinical Models: A Systematic Review and Meta-Analysis

BACKGROUND

Glioblastoma (GBM) is an aggressive tumor known for its poor prognosis. Despite extensive research into its molecular and clinical aspects, the current management strategies have shown limited efficacy in improving survival rate. Despite some preclinical studies exploring the combination of temozolomide (TMZ) with biguanides such as metformin (MET) and others, the potential benefits of this combination remain uncertain. The aim of this study is to evaluate the overall survival (OS) in GBM murine-models treated with a combination of TMZ + biguanide compared to those treated with TMZ alone.

METHODS

We systematically searched Medline, Embase, and Lilacs databases for studies comparing TMZ + biguanide versus TMZ alone in GBM models and reporting OS data. The mean difference (MD) with 95% confidence interval and random-effects model was adopted.

RESULTS

Nine studies were included in this systematic review. The meta-analysis comprised 6 studies involving 85 rat-models, with 45 subjects undergoing combined-treatment. GBM-murine models treated with TMZ + biguanide exhibited notably superior OS rates compared to those who received TMZ alone, showing an MD of 21.0 days (6.9-35.0). Within the subgroup of orthotopic models, the OS was also significantly better in combination-therapy with an MD of 23.7 days (6.5-40.9). Similarly, in the subgroup where MET was used as biguanide therapy, TMZ + MET demonstrated a significant increase in OS, with an MD of 27.4 days (6.0-48.8). In immunocompromised models, the combination-therapy also exhibited higher survival rates, with an MD of 13 days (9.4-16.6).

CONCLUSIONS

This systematic review and meta-analysis provide compelling evidence regarding the beneficial effects of TMZ + biguanide in GBM models compared with TMZ alone, resulting in a significant improvement in OS.

A Systematic Review and Meta-Analysis on the Management and Outcome of Isolated Skull Fractures in Pediatric Patients

BACKGROUND

The impact of traumatic brain injury (TBI) on the pediatric population is profound. The aim of this study is to unveil the state of the evidence concerning acute neurosurgical intervention, hospitalizations after injury, and neuroimaging in isolated skull fractures (ISF).

MATERIALS AND METHODS

This systematic review was conducted in accordance with PRISMA guidelines. PubMed, Cochrane, Web of Science, and Embase were searched for papers until April 2023. Only ISF cases diagnosed via computed tomography were considered.

RESULTS

A total of 10,350 skull fractures from 25 studies were included, of which 7228 were ISF. For the need of acute neurosurgical intervention, the meta-analysis showed a risk of 0% (95% CI: 0-0%). For hospitalization after injury the calculated risk was 78% (95% CI: 66-89%). Finally, for the requirement of repeated neuroimaging the analysis revealed a rate of 7% (95% CI: 0-15%). No deaths were reported in any of the 25 studies.

CONCLUSIONS

Out of 7228 children with ISF, an almost negligible number required immediate neurosurgical interventions, yet a significant 74% were hospitalized for up to 72 h. Notably, the mortality was zero, and repeat neuroimaging was uncommon. This research is crucial in shedding light on the outcomes and implications of pediatric TBIs concerning ISFs.

Enhancing meningioma resection: a comprehensive study on the safety and effectiveness of Onyx™ presurgical embolization

Presurgical embolization (PE) has emerged as an interesting strategy to help turn brain tumor resection more amenable. This study aims to systematically review the safety and effectiveness of Onyx™ PE in meningioma resection. We followed Cochrane Collaboration and PRISMA for systematic review and meta-analysis, querying PUBMED, Cochrane Library, Web of Science, and Embase databases. Major complications were defined as other artery occlusion, visual deficits due to PE, or non temporary nerve damage, while minor included transitory conditions and others without clinical implications. A total of 186 patients were included, in which 120 were WHO grade I (80%), II (16%), and III (4%). Patient baseline characteristics and complications were distributed in groups without or with individual patient data analysis. Individual Patient Data Meta-Analysis (IPDMA) was performed on the last category, comprising 51 meningiomas that underwent Onyx™ PE. Among available data, 70%, 17%, and 13% were WHO grade I, II, and III, respectively. Considering all studies, tumor characteristics regarding grade underscored a certain homogeneity. Complications occurred at a rate of 9% (95% CI, 4 to 14%; I2 = 35%), with the rate of major complications significantly lower at only 1% (95% CI, 0 to 3%; I2 = 32%), whereas of minor complications was 7% (95% CI, 3 to 10%; I2 = 0%). Mean surgery blood loss was 668.7 (95% CI, 534.9 to 835.8; I2 = 0%) in IPDMA. Onyx™ PE is promising for safer surgical meningioma resection, despite limitations. Further studies are required to validate efficacy, enhance patient selection, and refine techniques.

Extracellular matrix mediated growth and differentiation in human pigment epithelial cell line 0041

Efforts to grow differentiated pigment epithelial cells have led to a characterization of the growth kinetics of spontaneously established, continuously growing, human retinal pigment epithelial (PE) cell line 0041 on several biomatrices. These substrates were prepared from (a) placental and amniotic membrane, (b) commercially available basement membrane matrix (Matrigel), (c) dishes coated with extracellular matrix secreted by endothelial cells (ECM), (d) dishes coated with collagen IV and/or laminin, (e) dishes coated with collagen I and/or fibronectin. Our findings suggest that tissue culture plastic and dishes coated with collagen IV alone promote higher cell densities, while highest plating efficiency (24 hrs) was seen on tissue culture plastic and Matrigel. The highest degree of differentiation (epithelioid appearance, apical villi and junctional complexes) was seen in cells plated on dishes coated with collagen IV and extracellular matrix secreted by endothelial cells. Cells were epithelioid and polarized on those two substrates; they expressed fine finger-shaped villi and the highest degree of cell contact (in the form of junctions). Cells grown on Matrigel looked like fibroblasts and became deeply pigmented; however, the nature of the pigment remains to be determined. Collagen IV and ECM coated dishes, therefore, are most suitable for cultures of human PE cell line 0041 because they provide higher cell densities while retaining the differentiated state. This is the first report where an established pigmented epithelial cell line has been induced to become differentiated by use of extracellular matrices and extracellular matrix components.

Replication of HIV in human fetal retinal cultures and established pigment epithelial cell lines

The ability of the human immunodeficiency virus type 1 (HIV-1) to replicate in cells derived from ocular tissue was studied. Primary retinal cultures (containing both glial and neuronal cells) were found to support the replication of HIV upon transfection with molecularly cloned proviral DNA. In addition, established retinal pigment epithelial (RPE) cell lines also produced HIV particles upon transfection. HIV released by these cell lines was able to infect and induce characteristic cytopathic effects in T4+ cells. An indicator plasmid containing the HIV long terminal repeat sequences (LTR) linked to the chloramphenicol acetyltransferase gene showed barely detectable activity in RPE cells and was transactivated by the addition of the HIV "tat" gene. Based on these observations, direct infection of ocular tissue derived cells such as RPE, fetal retinal cells, retinoblastoma cells (Y 79, WER1), choroidal endothelial cells (Chor 55) (mix culture) and corneal fibroblasts (K61) by HIV was attempted. HIV replication in these cells was not detected by reverse transcriptase, antigen and transactivation function assays.

In vitro phenotypic and functional characterization of human pigment epithelial cell lines

We have characterized human retinal pigment epithelium (HRPE) for the expression of cell surface antigens. Primary HRPE cultures, established cell lines, and freshly brushed pigment epithelial cells all express HLA-ABC but not HLA-DR antigens. However, both primary cultures and established cell lines can be induced by gamma interferon stimulation to express HLA-DR in a dose dependent manner. Only freshly brushed HRPE cells express Fc, and no cells demonstrated the presence of C3b. Our results show that HRPE cells change in culture, as reflected by the loss of Fc receptors, but retain the ability to synthesize HLA-ABC spontaneously and HLA-DR upon stimulation.

The solitary pulmonary nodule

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Massive gastrointestinal hemorrhage due to specific infections

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