Gamma knife stereotactic radiosurgery for neurofibromatosis 2 (NF2)-associated meningiomas; a systematic review and meta-analysis

BACKGROUND

Neurofibromatosis type 2 (NF2)-related schwannomatosis is a rare genetic disorder associated with meningiomas. Stereotactic radiosurgery (SRS) has emerged as a potential non-invasive method. This study aims to synthesize the available evidence on using SRS to treat these tumors.

METHODS

PubMed/Medline, Embase, Scopus, and Web of Science were searched until March 21, 2024. This study was prepared by adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA).

RESULTS

Four studies were included comprising 101 patients with NF2-associated meningiomas treated with SRS. All included studies used gamma knife stereotactic radiosurgery (GKRS) as treatment modality. Overall survival rates remained high (100%) up to 3 years post-treatment, with slight declines at five years of 98% (95% CI: 0.95-1.01) and ten years of 68% (95% CI: 0.48-0.87). Progression-free survival rates were similarly favorable, with 95% (95% CI: 89-101%) at three years, 93% (95% CI: 86-99%) at five years, and 81% (95% CI: 51-111%) at ten years. The pooled radiation necrosis rate was 5% (95% CI: 3-7%), while the overall radiation toxicity rate was 16% (95% CI: 11-21%). Local tumor control rates were high at six months, and at 12 months, they were 100% (95% CI: 1.00-1.00).

CONCLUSION

GKRS demonstrates high efficacy and a favorable safety profile for NF2-associated meningiomas, offering a valuable treatment option for this challenging patient population.

Unmasking a Paradox: Roles of the PD-1/PD-L1 Axis in Alzheimer's Disease-Associated Neuroinflammation

Alzheimer's disease (AD) represents the most prevalent form of dementia, characterized by progressive cognitive impairment and chronic neuroinflammation. Immune checkpoint inhibitors (ICIs), including anti-programmed cell death (PD)-1 and anti-PD-L1, signify a revolutionary advancement in cancer treatment by preventing T-cell exhaustion; however, their therapeutic application in AD presents a conundrum. Hypothesis: Recent preclinical studies indicate that PD-1 inhibition in AD mouse models induces an interferon-gamma (IFN-γ)-mediated response, leading to increased recruitment of monocyte-derived macrophages into the brain, enhanced clearance of amyloid-beta (Aβ) plaques, and improved cognitive performance. Nonetheless, this therapeutic effect is counterbalanced by the potential for exacerbated neuroinflammation, as PD-1/PD-L1 blockade may potentiate pro-inflammatory T helper (Th)1 and Th17 responses. In this review, we critically discuss the pertinent pro-inflammatory and neuroprotective facets of T cell biology in the pathogenesis of AD, emphasizing the potential for modulation of the PD-1/PD-L1 axis to influence both Aβ clearance and the dynamics of neuroinflammatory processes. In summary, we determine that ICIs are promising tools for reducing AD pathology and improving cognition. However, it is essential to refine treatment protocols and carefully select patients to optimize neuroprotective effects while adequately considering inflammatory risks.

Safety and efficacy of flow redirection endoluminal device (FRED) for treatment of intracranial aneurysm; A systematic review and meta-analysis

BackgroundPrevious research has shown promising results for treating intracranial aneurysms (IAs) with a flow redirection endoluminal device (FRED). In this systematic review and meta-analysis, we aimed to assess the safety and efficacy of this device by providing pooled estimates using the data from previous studies.MethodsA systematic literature search of Web of Sciences, PubMed, Scopus, and Embase was performed until October 8th, 2023. After selecting the final articles, relevant data were extracted. Parameters relating to safety and efficacy were pooled using STATA software. Heterogeneity was assessed using I-squared and Cochran's Q. Funnel plots and Egger's regression methods were used to evaluate publication bias. Sensitivity analysis was also performed using the leave-one-out method.ResultsThe data of 37 studies were used for meta-analysis. The rates of immediate adequate occlusion and complete occlusion were 0.51 (95% CI: 0.31-0.71) and 0.34 (95% CI: 0.16-0.53), respectively, while the rates of the adequate and complete occlusion at the latest follow-up were 0.90 (95% CI: 0.84-0.94) and 0.75 (95% CI: 0.65-0.84), respectively. The periprocedural complications rate was 0.04 (95% CI: 0.03-0.06), and the overall complications rate was 0.12 (95% CI: 0.09-0.15). The rate of good functional outcome was 0.99 (95% CI: 0.99-1.00) and the successful implantation rate was 1.00 (95% CI: 1.00-1.00). There was substantial heterogeneity among the reports for most of the evaluated parameters.ConclusionFRED had high safety and efficacy in treating IAs, as evidenced by its high occlusion and low complication rates.

The safety and efficacy of NeVa mechanical thrombectomy device in acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Recent favorable cohort studies on endovascular therapy for ischemic stroke have predominantly utilized NeVa thrombectomy (NeVaTM) stent retrievers. We carried out a systematic review and meta-analysis to investigate the efficacy and safety of this second-generation stent retriever in acute ischemic stroke patients.

METHOD

We conducted the study according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The electronic databases of PubMed, Embase, and Scopus were searched until 26 November 2023 and was updated on August 1, 2024.

RESULTS

This meta-analysis systematically investigated 11 studies with a total of 805 patients suffering from ischemic stroke. The mean age of participants across the studies ranged from 65 to 77 years with a male preponderance of 50.16 %. While ten studies reported on the etiology of strokes, some studies reported the risk factors such as hypertension, dyslipidemia, diabetes, history of coronary artery disease, and previous stroke. The results of our study indicate that the all-hemorrhagic complications rate was 0.32 (95 %CI: 0.18-0.45), while the complete arterial recanalization rate was 0.76 [95 %CI: 0.49-1.04]. The overall recanalization rate was found to be 0.97 [95 %CI: 0.94-1.00]. Moreover, the postoperative hemorrhage rate was 0.28 [95 %CI: 0.14-0.41], while the repeated re-thrombosis rate was 0.01 [95 %CI: -0.01-0.03]. Lastly, the vasospasm rate was calculated to be 0.09 [95 %CI: -0.03-0.21].

CONCLUSION

NeVa™ is a safe option capable of achieving a high rate of recanalization and functional independence.

ABBREVIATIONS

PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PROSPERO, International Prospective Register of Systematic Reviews; NeVa™, NeVa Thrombectomy; ICH, Intracranial Hemorrhage; mTICI, modified Thrombolysis in Cerebral Infarction; mRS, modified Rankin Scale; ACA, Anterior Cerebral Artery; MCA, Middle Cerebral Artery; PCA, Posterior Cerebral Artery; ICA, Internal Carotid Artery; NIHSS, National Institutes of Health Stroke Scale.

Drug-eluting stent versus bare metal stent for symptomatic intracranial stenosis: a comparative systematic review and meta-analysis study

BACKGROUND

Intracranial atherosclerotic artery stenosis (ICAS) is a major cause of ischemic stroke globally and is associated with poor recanalization rates, high recurrence, and adverse functional outcomes. The use of stents has been explored as a treatment option to improve outcomes, despite concerns over procedure-related complications and in-stent restenosis (ISR). This study aimed to compare the efficacy and safety of drug-eluting stents (DES) versus bare metal stents (BMS) in treating patients with symptomatic ICAS (sICAS).

METHOD

A systematic review and meta-analysis were conducted according to PRISMA guidelines, with a comprehensive search of PubMed, Embase, and Web of Science up to March 1, 2024. Studies that reported outcomes such as technical and clinical success rates, periprocedural complications, ISR, and stroke rates were included. Statistical analysis was performed using Stata v.17.

RESULTS

A total of 44 studies involving 13,658 patients were included. DES demonstrated lower pooled rates of major stroke (3% [95% CI 2-4%]) and ISR (8% [95% CI 3-12%]) compared to BMS (5% [95% CI 3-6%] for major stroke and 19% [95% CI 14-24%] for ISR), though the difference in major stroke rate was not statistically significant. The clinical success rate was similar between DES (89% [95% CI 78-99%]) and BMS (86% [95% CI 76-97%]). Technical success rates were high and comparable for both stent types. Subgroup analyses and meta-regression identified significant factors influencing heterogeneity, including stent or wire length and diameter.

CONCLUSION

DES showed a significant advantage over BMS in reducing ISR and major stroke rates while maintaining comparable safety and technical success. These findings support the preferential use of DES in clinical practice for managing sICAS, emphasizing their role in enhancing patient outcomes through reduced restenosis and recurrent ischemic events.