A guide to interpreting systematic reviews and meta-analyses in neurosurgery and surgery.

INTRODUCTION: Systematic reviews (SRs) and meta-analyses (MAs) are methods of data analysis used to synthesize information presented in multiple publications on the same topic. A thorough understanding of the steps involved in conducting this type of research and approaches to data analysis is critical for appropriate understanding, interpretation, and application of the findings of these reviews. METHODS: We reviewed reference texts in clinical neuroepidemiology, neurostatistics and research methods and other previously related articles on meta-analyses (MAs) in surgery. Based on existing theories and models and our cumulative years of expertise in conducting MAs, we have synthesized and presented a detailed pragmatic approach to interpreting MAs in Neurosurgery. RESULTS: Herein we have briefly defined SRs sand MAs and related terminologies, succinctly outlined the essential steps to conduct and critically appraise SRs and MAs. A practical approach to interpreting MAs for neurosurgeons is described in details. Based on summary outcome measures, we have used hypothetical examples to illustrate the Interpretation of the three commonest types of MAs in neurosurgery: MAs of Binary Outcome Measures (Pairwise MAs), MAs of proportions and MAs of Continuous Variables. Furthermore, we have elucidated on the concepts of heterogeneity, modeling, certainty, and bias essential for the robust and transparent interpretation of MAs. The basics for the Interpretation of Forest plots, the preferred graphical display of data in MAs are summarized. Additionally, a condensation of the assessment of the overall quality of methodology and reporting of MA and the applicability of evidence to patient care is presented. CONCLUSION: There is a paucity of pragmatic guides to appraise MAs for surgeons who are non-statisticians. This article serves as a detailed guide for the interpretation of systematic reviews and meta-analyses with examples of applications for clinical neurosurgeons.

Percutaneous transluminal angioplasty and/or stenting for the treatment of basilar artery stenosis: a systematic review and meta-analysis.

PURPOSE: Basilar artery stenosis (BAS) carries high morbidity and mortality, with variable outcomes after endovascular treatments. We systematically reviewed the literature on percutaneous transluminal angioplasty and/or stenting (PTAS) for BAS. METHODS: PubMed, EMBASE, Web-of-Science, Scopus, and Cochrane were searched upon the PRISMA guidelines to include prospective/retrospective cohort studies describing PTAS for BAS. Pooled rates of intervention-related complications and outcomes were analyzed with random-effect model meta-analyses. RESULTS: We included 25 retrospective cohort studies comprising 1016 patients. All patients were symptomatic, presenting with transient ischemic attack or ischemic stroke. BAS frequently involved the middle basilar artery (51.4%), mostly classified as Mori-B (57.4%). PTAS for BAS was indicated in severe (≥ 50-70%), symptomatic BAS refractory to dual antiplatelet therapy. Patients underwent angioplasty (95.5%) and/or stenting (92.2%), preferably using Wingspan or Apollo stents. Median baseline BAS was 81% (range, 53-99%), while median post-intervention BAS was 13% (0-75%). Actuarial rates of successful intervention and "good" final outcome were 100% (95% CI: 100-100%) and 89% (95% CI: 85-93%). Intervention-related recurrent ischemic stroke occurred in 85 patients (8.3%) with actuarial rates of 5% (95% CI: 4-7%), differentiated into perforator (5.4%), in-stent (2.6%), and embolic (0.4%). Actuarial rates of intervention-related dissection, restenosis, and death were 0% (95% CI: 0-0%), 1% (95% CI: 0-1%), and 0% (95% CI: 0-2%). CONCLUSION: Elective PTAS appears to be safe and effective in selected patients with medically refractory, severe, symptomatic, and non-acute BAS. Different stent types and angioplasty-assisted procedures should be considered based on specific clinico-radiological characteristics of the lesions. Future randomized controlled trials are required to corroborate these findings.

Bilateral basal ganglia hemorrhage: a systematic review of etiologies, management strategies, and clinical outcomes.

Bilateral basal ganglia hemorrhages (BBGHs) represent rare accidents, with no clear standard of care currently defined. We reviewed the literature on BBGHs and analyzed the available conservative and surgical strategies. PubMed, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies reporting patients with BBGHs. Clinical characteristics, management, and outcomes were analyzed. We included 64 studies comprising 75 patients, 25 (33%) traumatic and 50 (67%) non-traumatic. Traumatic cases affected younger patients (mean age 35 vs. 46 years, p=0.014) and males (84% vs. 71%, p=0.27) and were characterized by higher proportion of normal blood pressures at admission (66% vs. 13%, p=0.0016) compared to non-traumatic cases. Most patients were comatose at admission (56%), with a mean Glasgow Coma Scale (GCS) score of 7 and a higher proportion of comatose patients in the traumatic than in the non-traumatic group (64% vs. 52%, p=0.28). Among the traumatic group, motor vehicle accidents and falls accounted for 79% of cases. In the non-traumatic group, hemorrhage was most associated with hypertensive or ischemic (54%) and chemical (28%) etiologies. Management was predominantly conservative (83%). Outcomes were poor in 56% of patients with mean follow-up of 8 months. Good recovery was significantly higher in the traumatic than in the non-traumatic group (48% vs. 17%, p=0.019). BBGHs are rare occurrences with dismal prognoses. Standard management follows that of current intracerebral hemorrhage guidelines with supportive care and early blood pressure management. Minimally invasive surgery is promising, though substantial evidence is required to outweigh the potentially increased risks of bilateral hematoma evacuation.

An enemy hides in the ceiling; pediatric traumatic brain injury caused by metallic ceiling fan: Case series and literature review.

Purpose: We report a series of 29 pediatric patients who sustained head injuries due to metallic ceiling fans. They all were admitted to the Emergency Department of Neurosurgery Teaching Hospital in Baghdad, Iraq, during January 2015 to January 2017. Results: Pediatric ceiling fan head injuries are characterized by four traits which distinguish them from other types of head injuries; 1- Most of them were because of climbing on or jumping from furniture between the ages of two and five. 2- Most of them sustained compound depressed skull fracture which associated with intracranial lesions and pneumocephalus. 3- The most common indication for surgical intervention was because of dirty wound which mixed with hairs. 4- These variables were statistically significantly correlated with the outcome: Level of consciousness, neurologic deficit, fracture site (occipital fracture had worse outcome), intracranial hemorrhage and surgery. Conclusion: Pediatric metallic ceiling fan head injury should be seen as a distinct type of head injury because it has special presentations, managements, and outcomes. In addition, we should start applying preventive methods to minimize its occurrence.

Mapping the circle of Trolard: A holistic view of its role in neurosurgical practice, anatomical perspectives and clinical applications.

Introduction: An anatomical structure that resembles the circle of Willis, the circle of Trolard is generated in the basal cistern and travels around the midbrain in a roundabout manner, passing adjacent to the lateral side of the cerebral peduncle. Research question: The primary objective of this article is to provide neurosurgeons with a comprehensive understanding of Trolard's circle, emphasizing its anatomical features and clinical significance. Material and methods: A comprehensive evaluation of the available literature pertaining to the venous circle of Trolard was conducted by conducting searches in the PubMed, Web of Science, and Scopus databases. In the present overview, the terminologies "venous circle of Trolard," "basal venous circle," and "basal vein of Rosenthal" were employed. Results: Upon doing a comprehensive examination of the existing literature and primary sources pertaining to the venous circle of Trolard, it was discovered that an only six studies had been conducted on this particular subject matter. We made observations regarding the anatomical characteristics of the subject and engaged in a discussion regarding their prospective applications and importance within the context of neurosurgical procedures. Discussion and conclusion: The scarcity of research on these structures is attributed to the challenges associated in studying them in vivo. Through directing focus towards these structures, our aim is to stimulate further investigation into their potential involvement in a range of neurological and neurosurgical disorders.

A case that encapsulates the challenges of being a neurosurgeon in war-torn countries: Perspectives from Iraq.

Background: The provision of healthcare services in Iraq has been negatively affected by a lack of resources, strained healthcare infrastructure, and low patient socioeconomic status. This paper describes a case of multiple intracranial aneurysms (MIAs) that highlight the challenges of practicing vascular neurosurgery in Iraq. Case Description: A 57-year-old female presented with sudden-onset severe headache, photophobia, and drowsiness and was diagnosed with subarachnoid hemorrhage in the basal cistern. Despite international guidelines recommending urgent treatment for suspected ruptured intracranial aneurysms, the patient's healthcare team in Babylon advised against a CT angiogram (CTA). The patient's family took responsibility for transferring her to a private facility for a CTA, which showed four aneurysms. Due to financial constraints, the family opted for open surgery, during which a ruptured aneurysm was found and successfully managed. The remaining two aneurysms were monitored with serial follow-up imaging. Conclusion: The case highlights the challenges of practicing vascular neurosurgery in Iraq and the impact of financial constraints on the management of MIA. It emphasizes the need for increased resources and expertise in the country's healthcare system to provide optimal care for patients with life-threatening conditions.

Developmental Venous Anomalies.

Developmental venous anomalies (DVAs) are the most common vascular malformation detected on intracranial cross-sectional imaging. They are generally benign lesions thought to drain normal parenchyma. Spontaneous hemorrhages attributed to DVAs are rare and should be ascribed to associated cerebral cavernous malformations, flow-related shunts, or venous outflow obstruction. Contrast-enhanced MRI, susceptibility-weighted imaging, and high-field MRI are ideal tools for visualizing vessel connectivity and associated lesions. DVAs are not generally considered targets for treatment. Preservation of DVAs is an established practice in the microsurgical or radiosurgical treatment of associated lesions.

A Systematic Review and Meta-Analysis of 3-Dimensional Morphometric Parameters for Cerebral Aneurysms.

BACKGROUND: Imaging modalities with increased spatial resolution have allowed for more precise quantification of cerebral aneurysm shape in 3-dimensional (3D) space. We conducted a systematic review and meta-analysis to assess the correlation of individual 3D morphometric measures with cerebral aneurysm rupture status. METHODS: Two independent reviewers performed a PRISMA (preferred reporting items of systematic reviews and meta-analysis)-guided literature search to identify articles reporting the association between 3D morphometric measures of intracranial aneurysms and rupture status. RESULTS: A total of 15,122 articles were identified. After screening, 39 studies were included. We identified 17 3D morphometric measures, with 11 eligible for the meta-analysis. The meta-analysis showed a significant association with rupture status for the following measures: nonsphericity index (standardized mean difference [SMD], 0.66; 95% confidence interval [CI], 0.53-0.79; P < 0.0001; I2 = 55.2%), undulation index (SMD, 0.55; 95% CI, 0.26-0.85; P = 0.0017; I2 = 68.1%), ellipticity index (SMD, 0.53; 95% CI, 0.29-0.77; P = 0.0005; I2 = 70.8%), volume (SMD, 0.18; 95% CI, 0.02-0.35; P = 0.0320; I2 = 82.3%), volume/ostium ratio (SMD, 0.43; 95% CI, 0.16-0.71; P = 0.0075; I2 = 90.4%), elongation (SMD, -0.94; 95% CI, -1.12 to -0.76; P = 0.0005; I2 = 0%), flatness (SMD, -0.87; 95% CI, -1.04 to -0.71; P = 0.0005; I2 = 0%), and sphericity (SMD, -0.62; 95% CI, -1.06 to -0.17; P = 0.0215; I2 = 67.9%). A significant risk of publication bias was estimated for the ellipticity index (P = 0.0360) and volume (P = 0.0030). CONCLUSIONS: Based on the results of a meta-analysis containing 39 studies, the nonsphericity index, undulation index, elongation, flatness, and sphericity demonstrated the most consistent correlation with rupture status.

Medications and "Risk" of Aneurysm Rupture Based on Presentation: Setting the Record Straight.

OBJECTIVE: Studies assessing aneurysm rupture "risk" based on comparative retrospective analyses of medications taken on presentation may be subject to presentation bias. Are patients with ruptured aneurysms simply less likely to be taking medications than those with unruptured aneurysms? METHODS: A retrospective chart review was conducted among patients with treated aneurysms from June 2016 to July 2023. A step-wise comparison of demographics, clinical characteristics (rupture status), and medications taken upon presentation was performed between ruptured and unruptured cases. RESULTS: One thousand three hundred eleven patients with intracranial aneurysms were included. The majority of patients presenting with ruptured aneurysms took no medications (68%), in contrast to 22% with unruptured aneurysms (P < 0.001). The majority of patients with unruptured aneurysms took 2-5 medications (51%), in contrast to 15% of patients with ruptured aneurysms taking 2-5 medications (P < 0.001). Twelve percent of patients with unruptured aneurysms took more than 5 medications, while only 1% with ruptured aneurysms did (P < 0.001). Thirty-five different medications were associated with unruptured presentation, including all evaluated antiplatelet agents, anti-hypertensives, antacids, pulmonary inhalers, and psychiatric medications (P < 0.05); no medications were associated with rupture on presentation. CONCLUSIONS: One cannot derive conclusions about medications and "risk" of rupture based on analyses at the time of presentation. This study identifies 35 different medications that were statistically significant and associated with an unruptured presentation; it is doubtful that each is "protective" against aneurysm rupture.

Anatomical Study of the Supratentorial Extension for the Retrolabyrinthine Presigmoid Approaches.

BACKGROUND: Supratentorial craniotomy represents the upper part of the combined trans-tentorial or the supra-infratentorial presigmoid approach. In this study, we provide qualitative and quantitative analyses for the supratentorial extension of the presigmoid retrolabyrinthine suprameatal approach (PRSA). METHODS: The infratentorial PRSA followed by the supratentorial extension craniotomy with dividing and removal of the tentorial strip were performed on both sides of 5 injected human cadaver heads (n = 10 sides). Quantitative analysis was performed for the surface area gained (surgical accessibility) by adding the supratentorial craniotomy. Qualitative analysis was performed for the parts of the brainstem, cranial nerves, and vascular structures that became accessible by adding the supratentorial craniotomy. The anatomical obstacles encountered in the added operative corridor were analyzed. RESULTS: The supratentorial extension of PRSA provides an increase in surgical accessibility of 102.65% as compared to the PRSA standalone. The mean surface area of the exposed brainstem is 197.98 (standard deviation: 76.222) and 401.209 (standard deviation: 123.96) for the infratentorial and the combined supra-infratentorial presigmoid approach, respectively. Exposure for parts of III, IV, and V cranial nerves is added after the extension, and the surface area of the outer craniotomy defect has increased by 60.32%. Parts of the basilar, anterior inferior cerebellar, and superior cerebellar arteries are accessible after the supratentorial extension. CONCLUSIONS: The supratentorial extension of PRSA allows access to the supra-trigeminal area of the pons and the lower part of the midbrain. Considering this surgical accessibility and exposure significantly assists in planning such complex approaches while targeting central skull base lesions.

Impact of Embolisate Penetration, Type, and Technique on Results After Standalone Middle Meningeal Artery Embolization for Chronic Subdural Hematoma.

BACKGROUND AND OBJECTIVES: Middle meningeal artery embolization (MMAE) has emerged as a promising modality for chronic/subacute subdural hematoma treatment; however, consensus regarding embolization technique and embolisate has not been achieved. We thus sought to compare the efficacy of distinct MMAE techniques and embolisate. METHODS: An institutional registry was reviewed to identify patients undergoing standalone MMAE for symptomatic chronic/subacute subdural hematoma. Surgical rescue rate and time preceding 50% hematoma resolution were evaluated across 3 technical groups: aggressive penetration (AP), nonaggressive penetration with proximal coil embolization (NP-PC), and nonaggressive penetration alone (NP). Effect sizes were adjusted for demographic, neurological and radiological features through multivariable logistic and Cox regression. RESULTS: Among 117 procedures, 33.3% achieved AP, 36.8% had NP-PC, and 29.9% had NP. The rate of surgical rescue was 2.6% after AP, 9.3% for NP-PC, and 11.4% for NP. In patients not undergoing rescue surgery, 82.4% achieved hematoma resolution ≥50% at a median imaging follow-up of 56 days; AP or NP-PC were each statistically significantly associated with enhanced hematoma resolution as compared with NP (P = .02). Similarly, sensitivity analysis within medium-size hematoma and antiplatelet/anticoagulation-at-admission subgroups revealed a superiority of resolution after AP or NP-PC. A unique, comparative secondary analysis of liquid embolisate (Onyx vs n-butyl cyanoacrylate) revealed no impact on rate of surgical rescue or hematoma resolution. CONCLUSION: AP was associated with the lowest rate of surgical rescue, while both AP and NP-PC were associated with improved rates of hematoma resolution.

Traumatic Cerebral Venous Sinus Thrombosis: Management and Outcomes.

BACKGROUND: Traumatic brain injury (TBI) with skull fractures parallel to or crossing venous sinuses is a recognized risk factor for traumatic cerebral venous sinus thrombosis (tCVST). Despite the recognition of this traumatic pathology in the literature, no consensus regarding management has been achieved. This study aimed to evaluate the impact of tCVST on TBI outcomes and related complications. METHODS: Patients within a prospective registry at a level I trauma center from 2014 to 2023 were reviewed to identify tCVST cases. The impact of tCVST presence on Glasgow Outcome Scale scores at 6 months, 30-day mortality, and hospital length of stay were evaluated in multivariable-adjusted analyses. RESULTS: Among 607 patients with TBI, 61 patients were identified with skull fractures extending to the vicinity of venous sinuses with dedicated venography. Twenty-eight of these 61 patients (44.3%) had tCVST. The majority (96.4%) of tCVST were located in a unilateral transverse or sigmoid sinus. Complete recanalization was observed in 28% of patients on follow-up imaging (7/25 with follow-up imaging). None of the 28 patients suffered attributable venous infarcts or thrombus propagation. In the adjusted analysis, there was no difference in the 30-day mortality or Glasgow Outcome Scale at 6 months between patients with and without tCVST. CONCLUSIONS: Unilateral tCVST follows a benign clinical course without associated increased mortality or morbidity. The management of tCVST should be distinct as compared to spontaneous CVST, likely without the need for anticoagulation.

Neurosurgery and Social Media: A Bibliometric Analysis of Scientific Production from 2004 to 2023.

BACKGROUND: Neurosurgery is a rapidly advancing surgical specialty. Social media has significantly impacted the landscape of advancements in the field of neurosurgery. Research on the subject of neurosurgery and social media plays a vital role in combating disability and mortality due to neurological diseases, especially in trauma-affected individuals by increasing cooperation and sharing of clinical experiences between neurosurgeons via social media. This study aimed to evaluate the global neurosurgery and social media research performance from 2004 to 2023. METHODS: All the data for neurosurgery and social media-related research publications from 2004 to 2023 were extracted from the Web of Science database and a comprehensive analysis was performed on the R-bibliometrix package. RESULTS: An increasing number of publications with an annual growth rate of 22.04% was observed, with >91% of total articles published in the last decade. The United States, the United Kingdom, Italy, France, Canada, and India made up of more than 67% of the global contribution. Out of 1449 authors, Chaurasia B was the most productive with 14 publications and the most globally cited document was JEAN WC, 2020 with 117 citations. The University of Cambridge was the leading institutional affiliation. World Neurosurgery was the most productive with >60 articles. CONCLUSIONS: Exploring neurosurgery on social media enhances global collaboration, utilizing dynamic platforms for real-time knowledge exchange and holds immense potential for the field's global advancement.

Flow Diverters with Surface Modification in Patients with Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diverters with surface modification (FDSM) are increasingly being used in the treatment of intracranial aneurysms (ANs). We aimed to evaluate the effectiveness and safety across different devices and antiplatelet therapies using a systematic review and meta-analysis. METHODS: A systematic review was performed to identify original studies of ≥10 patients with intracranial ANs treated with FDSM from database inception through August 2023. Primary effectiveness outcome was the rate of complete AN occlusion at follow-up ≥6 months. Safety outcomes included ischemic stroke, hemorrhage, and in-stent thrombosis, and were stratified by FDSM devices and antiplatelet therapies. Certainty of evidence was evaluated following the Grading of Recommendations, Assessment, Development, and Evaluations approach. RESULTS: Twenty-seven studies were included, yielding 2161 patients with 2373 ANs. A total of 70.5% of the ANs were located on the internal carotid artery (ICA). Total 10.3% were acutely ruptured. The complete AN occlusion rate was 72.3% at follow-up ≥6 months. Sensitivity analysis in the ICA AN cohort yielded comparable occlusion rates between Pipeline Flex Embolization Device-Shield (80.4%) and Phenox-hydrophilic polymer-coated (77.5%, P = 0.54), but a lower 66.2% rate for Flow Redirection Endoluminal Device-X (P = 0.02). The rate of in-stent thrombosis and stenosis tended to be higher in Phenox-hydrophilic polymer-coated (3.4%) and Flow Redirection Endoluminal Device-X (4.3%) versus Pipeline Flex Embolization Device-Shield (0.8%, P = 0.05). CONCLUSIONS: FDSM were safe with satisfactory effectiveness for intracranial ANs. More specific investigations are warranted to explore their performance in ANs beyond the ICA and optimal antiplatelet therapy.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review.

Background: Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies. Methods: A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed. Results: A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%). Conclusion: Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.