Middle Meningeal Artery Embolization for Nonacute Subdural Hematoma

Diplopia after middle meningeal artery embolization for chronic subdural hematoma: A case report

BACKGROUND

Middle meningeal artery embolization (MMAE) is emerging as a promising treatment for chronic subdural hematoma (CSDH), serving both as an adjunct to surgery and as a primary therapeutic option depending on patient presentation. Due to its low recurrence rate and minimal complications, MMAE has gained increasing acceptance among clinicians in recent years. This report presents a case of diplopia following MMAE due to the presence of a potential anastomotic artery, aiming to enhance awareness of this complication.

CASE SUMMARY

A 60-year-old male patient presented with a headache following head trauma, and cranial computed tomography revealed a left-sided CSDH. The patient underwent left MMAE; however, polyvinyl alcohol particles inadvertently flowed into the lacrimal artery through an anastomotic artery, resulting in diplopia due to impaired abduction of the left eye. The diplopia resolved by postoperative day 40. The patient’s headache resolved by postoperative day 7, and the hematoma completely resolved by postoperative day 108.

CONCLUSION

Potential anastomotic arteries in the middle meningeal artery (MMA) can lead to serious complications. Superselective angiography of the MMA or its branches prior to embolization is essential. Performing embolization distal to potential anastomotic sites can reduce risks, and the presence of an anastomosis may warrant coil embolization or termination of the procedure.

Middle meningeal artery embolization for chronic subdural hematoma: meta-analysis of three randomized controlled trials and review of ongoing trials

BACKGROUND

Middle Meningeal Artery Embolization (MMAE) has been proposed as adjunct and stand-alone treatment for Chronic Subdural Hematoma (CSDH). We aimed to meta-analyze three recently published randomized controlled trials, to reliably estimate the effect of MMAE. We also carried out a systematic review of ongoing trials and their key outcomes.

METHODS

A PRISMA-compliant meta-analysis was conducted (PROSPERO ID CRD42024618816). Three published RCTs (MAGIC-MT, EMBOLISE, and STEM) assessing MMAE in CSDH were included. Trial primary outcomes were pooled for analysis using random effects models. Primary and secondary outcomes (recurrence/surgical rescue, functional outcome) were obtained, stratified by treatment group (undergoing surgery, and nonsurgical management). A descriptive review of trials in public registries was also conducted (search date 30th November 2024).

RESULTS

In total, 1432 patients were included from three trials in meta-analysis. Overall, MMAE reduced symptomatic progression or recurrence, but was not statistically significant (RR 0.50, 95% CI 0.23-1.06, P = 0.058). For the group undergoing surgery, MMAE was not associated with reduced recurrence (RR 0.60, 95% CI 0.19-1.88, P = 0.194). For nonsurgical management, MMAE reduced progression (RR 0.36, 95% CI 0.22-0.60, P < 0.001). MMAE did not influence functional outcome (RR 1.01, 95% CI 0.97-1.04, P = 0.790). From the literature search, there are twenty-one registered trials. Nineteen studies include arms assessing MMAE as an adjunct to surgery, eleven compare MMAE to observation, and four with surgery. The most common primary outcome is recurrence (47.8%, N = 11), either radiologically, or requiring a second surgery. Inclusion criteria, embolization agents, primary and secondary outcomes differed significantly between studies.

CONCLUSIONS

In this meta-analysis of three randomized controlled trials, the use of MMAE in patients undergoing surgery did not appear to significantly reduce recurrence or improve functional outcomes, but did reduce progression in nonsurgical cohorts. Further studies assessing these cohorts are ongoing.

Imaging and Clinical Outcomes Six Months After Middle Meningeal Artery Embolization with Squid for Chronic Subdural Hematoma: A Prospective Study

Background: Chronic subdural hematoma (CSDH) is a common condition in older adults with rising rates of incidence. While burr hole drainage remains the standard treatment, it is associated with significant recurrence and complications. This study assesses MMA embolization with Squid, both as a standalone procedure and as an adjunct to surgery. Methods: Our prospective registry included 101 patients with 134 CSDH cases treated at two tertiary care centers from December 2020 to January 2024. Patients were divided into two groups: embolization alone and embolization combined with surgery. Demographic, clinical, radiological, and procedural data were collected. Follow-up imaging was conducted at 1, 3, and 6 months. Treatment failure was defined as rescue surgery, hematoma thickness ≥ 10 mm, midline shift > 3 mm at 6 months, or procedure-related death. Results: Fifty-two patients (51.5%) underwent combined treatment, and forty-nine (48.5%) received embolization alone. Most were men (68.3%) and the median age was 82 years. Combined-treatment patients had larger hematomas and more symptoms. Procedures were performed under general anesthesia in 72.3% of patients, with radial and femoral access used equally frequently, and 32.7% underwent bilateral embolization. Patients' hematoma thickness in follow-up imaging showed a significant decrease (p = 0.000), reaching a median of 0 mm at six months, with no significant difference between groups. Complications occurred in 5.9%, and treatment failure in 4%. Mortality was higher in the embolization-only group, likely reflecting greater rates of comorbidities. Conclusions: This study supports the use of MMA embolization with Squid as a safe and effective treatment for CSDH. Comparable procedural and radiological outcomes in both groups suggest embolization alone may suffice in select patients, offering a less invasive alternative.

Standalone Middle Meningeal Artery Embolization Versus Conservative Management for Nontraumatic Subdural Hematoma

BACKGROUND

Recent randomized control trials have demonstrated the efficacy and safety of middle meningeal artery embolization (MMAE) as an adjunct to conventional management for patients with nonacute subdural hematoma (SDH); however, a large majority of trial participants received surgical evacuation as part of the standard of care. Thus, the efficacy and safety of standalone MMAE compared with conservative management (CM) for patients with nonsurgical SDH are unclear.

METHODS

This was a retrospective cohort study of the 2019 to 2021 Nationwide Readmissions Database in the United States. Patients with nonsurgical nontraumatic SDH were identified, and MMAE patients were matched with similar CM patients using propensity scores calculated from demographics, comorbidities, and initial hospitalization outcomes. Patients were followed up to 300 days. The primary end point was composite surgical rescue or death, and secondary end points included surgical rescue and all-cause mortality by 180 days.

RESULTS

A total of 24 465 patients with nonsurgical nontraumatic SDH were identified; 2228 (9.1%) underwent MMAE. After propensity score matching, 6675 patients remained in the CM group and 2217 in the MMAE group. At 180 days, MMAE patients had a significantly lower risk of surgery or death compared with CM (8.2% versus 10.9%; relative risk, 0.75 [95% CI, 0.59-0.96]; P=0.022) and lower risk of death (1.1% versus 3.0%; relative risk, 0.38 [95% CI, 0.17-0.86]; P=0.020). Rates of surgical rescue among MMAE and CM patients at 180 days were similar (7.1% versus 8.4%; relative risk, 0.85 [95% CI, 0.63-1.14]; P=0.27). Time-to-event analyses for the entire 300-day study follow-up period confirmed that while MMAE was associated with a lower cumulative risk of all-cause mortality (hazard ratio, 0.55 [95% CI, 0.35-0.87]; P=0.010), it was not associated with a different risk of surgical rescue (hazard ratio, 1.00 [95% CI, 0.76-1.31]; P=1.00).

CONCLUSIONS

Standalone MMAE may be beneficial for patients with nonsurgical nontraumatic SDH by reducing the long-term risk of all-cause mortality.

Middle Meningeal Artery Embolisation for Chronic Subdural Haematoma-Time for a Paradigm Shift?

Chronic subdural haematoma (CSDH) is a common condition and surgical intervention is the mainstay of treatment. Recurrence rates are high and this patient cohort is frequently elderly, comorbid, or both. Middle meningeal artery (MMA) embolisation has emerged as a technique to manage CSDH, either as an adjunct or as a stand-alone procedure. Three recently published trials have added to the evidence in favour of this technique. MMA embolisation seems set to become commonplace but more evidence is needed to understand in which cases it should be considered.

Comparative analysis of Onyx, squid, and n-BCA in middle meningeal artery embolization for chronic subdural hematoma: a meta-analysis of randomized controlled trials

BACKGROUND

Selection of an embolic agent for middle meningeal artery embolization (MMAE) in a chronic subdural hematoma (cSDH) is a subject of debate and is limited to observational data. We report the first meta-analysis that exclusively assessed randomized controlled trials (RCTs) to address this gap.

METHODS

A systematic review and meta-analysis was conducted, incorporating all available RCTs that compared MMAE plus standard of care (SOC) versus SOC alone for cSDH usingeither Onyx, n-BCA, and Squid as embolic agent for embolization. Primary outcomes were the rate of hematoma recurrence/progression and the need for reoperation. Secondary outcomes included serious adverse events (SAE), all-cause mortality, functional independence (defined as a Modified Rankin Scale (mRS) score of 0-2), and the rate of successful embolization. To assess heterogeneity, a fixed-effect or random-effects model was applied, depending on statistical significance (I²>50%, P < 0.1).

RESULTS

Four RCTs, with 894 patients in the MMAE plus SOC group and 914 patients in the SOC alone group, were identified and met our standard for analysis. Results revealed significant superiority of n-BCA compared to Onyx and Squid in lower all-cause mortality at last follow-up. There was no significant difference in using Onyx, Squid, and n-BCA in recurrence at the last follow-up (P = 0.36), reoperation at the last follow-up (P = 0.55), and successful embolization (P = 0.52), and 90-day functional independence (P = 0.076) between trials. Additionally, further analysis on safety outcomes showed no significant difference between embolic agents in SAE at last follow-up (P = 0.78), embolization-related complications (P = 0.087), new onset ischemic stroke (P = 0.98), and deep venous thrombosis (P = 0.94).

CONCLUSION

This meta-analysis of RCTs suggests that while n-BCA is associated with lower all-cause mortality compared to Onyx and Squid in MMAE for cSDH, all three embolic agents demonstrate comparable efficacy and safety.

Adjunctive middle meningeal artery embolization for chronic subdural hematoma: A systematic review and meta-analysis of clinical trials

BACKGROUND

Chronic subdural hematoma (cSDH) is a common neurosurgical condition with high recurrence rates, particularly in elderly patients. The pathophysiology involves complex mechanisms of angiogenesis, fibrinolysis, and inflammation, leading to progressive hemorrhage and fluid accumulation.

AIM

To systematically review and meta-analyze the clinical benefits and safety of middle meningeal artery embolization (MMAE) as an adjunctive treatment to usual care for cSDH.

METHODS

A comprehensive literature search was conducted across four electronic databases following PRISMA guidelines. Four clinical trials were included, involving 1680 patients with cSDH. Meta-analysis was performed using the Mantel-Haenszel method to calculate risk ratios and 95 % confidence intervals for key outcomes, including recurrence, mortality, functional outcomes, and complications.

RESULTS

MMAE plus usual care significantly reduced cSDH recurrence (Risk Ratio 0.56, 95 % CI [0.39 to 0.80], P = 0.001) and mortality (Risk Ratio [RR] 0.53, 95 % CI [0.31 to 0.91], P = 0.02) compared to usual care alone. No statistically significant differences were observed in functional outcomes (mRS 0-2 at 90 days), serious adverse events, or major disabling stroke between the two groups.

CONCLUSION

MMAE as an adjunctive treatment shows promising results in reducing cSDH recurrence and mortality without increasing procedural risks, suggesting potential benefits in managing this challenging neurosurgical condition.

Adjunct middle meningeal artery embolization versus surgery alone for chronic subdural hematoma: A meta-analysis and trial sequential analysis of randomized controlled trials

INTRODUCTION

Middle meningeal artery embolization (MMAE) has been studied as an adjunct to surgical evacuation for chronic subdural hematoma (cSDH). Previous meta-analyses comparing MMAE with conventional treatment for cSDH included both observational and randomized studies. To provide a more robust assessment, we performed a meta-analysis of randomized controlled trials to evaluate the outcomes of adjunct MMAE compared to surgical treatment alone.

METHODS

We searched PubMed, EMBASE, and Cochrane CENTRAL databases for studies comparing adjunct middle meningeal artery embolization to surgical treatment alone until December 2024. The outcomes assessed were treatment failure, reoperation, complications, mortality, functional outcome, and length of hospital stay. Statistical analysis was performed via R software (version 4.3.2). Heterogeneity was assessed with I2 statistics. The risk of bias was assessed using the Cochrane Risk of Bias Tool for Randomized Trials.

RESULTS

We included 6 studies with 1,422 patients, of whom 700 (49.2 %) received adjunct middle meningeal artery embolization. The mean age ranged from 64.2 to 77.4 years in the embolization group and from 70 to 74.4 years in the surgery-only group. Among the patients, 435 (54.5 %) had previous known head trauma, and 315 (22.1 %) were on antiplatelets or anticoagulants. The follow-up ranged from 90 to 180 days. Adjunct middle meningeal artery embolization reduced the occurrence of treatment failure compared to surgical treatment alone (RR 0.482; 95 % CI 0.328 to 0.708; p < 0.001; I2 = 0 %) and reoperation (RR 0.333; 95 % CI 0.212 to 0.521; p < 0.001; I2 = 0 %), however, didńt reduce the occurrence of any cause mortality (RR 0.970; 95 % CI 0.400 to 2.353; p = 0.946; I2 = 39.6 %), functional dependence at the last follow-up (RR 1.000; 95 % CI 0.726 to 1.377; p = 0.705; I2 = 0 %), or the length of stay (MD 0.576; 95 % CI -0.085 to 1.238; p = 0.088; I2 = 0 %). Furthermore, no differences were found regarding complications secondary to the surgical procedure (RR 0.902; 95 % CI 0.688 to 1.182; p = 0.455; I2 = 0 %), and the occurrence of embolization-related complication was low (RR 0.013; 95 % CI 0.006 to 0.027; I2 = 0 %). Trial sequential analysis judged the sample size sufficient for treatment failure and reoperation but suggested that further trials are needed to prove differences in surgical-related complications.

CONCLUSION

Our results confirm that middle meningeal artery embolization significantly reduces recurrence and reoperation rates compared to surgery alone, with low adverse event rates. However, the impact on functional outcomes and mortality remains uncertain, warranting further studies to clarify its long-term benefits.

Twist-drill craniostomy with pressure-controlled fibrinolytic irrigation therapy reduces recurrence of chronic subdural hematomas: initial experience in 16 cases

BACKGROUND

Chronic subdural hematoma (cSDH) is prevalent in the elderly, frail, and those on antithrombotic therapy, often resulting in significant morbidity and mortality. Recurrence and reoperation rates are substantial concerns. Emerging evidence suggests that irrigation, drainage, and possibly fibrinolytic therapy, may improve reoperation rates.

OBJECTIVE

To explore safety and efficacy of twist-drill craniostomy (TDC) with pressure-controlled fibrinolytic irrigation therapy (TDC-FIT) in reducing recurrence rates of cSDH compared to conventional TDC with subdural passive drainage.

METHODS

A retrospective study included 314 patients treated with TDC and 16 patients treated with TDC-FIT between January 2021, and March 2024. The primary endpoint was the reoperation rate due to symptomatic recurrence or persistence of cSDH at 6 months. Secondary endpoints included hematoma resolution, perioperative complications, and the impact of antithrombotic therapy and preoperative membrane formation.

RESULTS

Reoperation was required in 107 (34.1 %) TDC patients and in one (6.3 %) TDC-FIT patient (P = .026). Hematoma membranes (OR 2.6, 95 % CI 1.6-4.3, P < .001) and dual antithrombotic therapy (OR 10.3, 95 % CI 1.1-93.3, P = .041) were significantly associated with reoperation in the TDC cohort. TDC-FIT showed superior hematoma resolution with a similar complication profile and functional outcome. TDC-FIT patients had a significantly lower reoperation rate despite a higher presence of hematoma membranes (75 % vs. 34.7 %, P = .002).

CONCLUSION

Preliminary data on TDC-FIT suggests improved reoperation rate and membranous hematoma resolution with comparable safety profiles to conventional TDC. Further prospective studies are needed to validate these findings in larger cohorts.

Prognostic significance of frailty in chronic subdural hematoma: implications for treatment selection in the era of middle meningeal artery embolization

PURPOSE

Middle meningeal artery embolization (MMAE) as a standalone or adjunctive therapy has emerged as an efficacious and safe treatment for chronic/subacute subdural hematoma (csaSDH). The objective of this study is to compare the prognostic significance of frailty in csaSDH patients treated with MMAE alone or with craniotomy/burr hole (CBH).

METHODS

Hospitalization records were identified in the National Inpatient Sample (2016-2020) and the cohort was stratified by increasing frailty thresholds, quantified by the Risk Analysis Index (RAI). Effect sizes of frailty tiers for poor outcome (defined as non-routine discharge disposition) produced from multivariable logistic regression models and discrimination (c-statistic) were evaluated separately in the MMAE only and CBH sub-cohorts.

RESULTS

This analysis identified 13,390 csaSDH hospitalizations, of which 595 (5%) documented treatment with MMAE only. Although all frailty tiers of the categorical RAI were significantly associated with poor outcome in the CBH cohort, lower effect sizes were observed in the MMAE cohort. Discrimination of RAI for poor outcome was significantly greater in the CBH cohort compared to the MMAE only cohort.

CONCLUSION

In comparison to surgical evacuation, frailty demonstrated lower effect sizes and worse discrimination for poor outcomes in patients treated with MMAE, suggesting that frail patients may be more likely to achieve better outcomes following this less invasive therapy. MMAE may be considered as a first-line or standalone treatment in certain patients.

Enhancing Outcomes in Subdural Hematoma: The Role of Middle Meningeal Artery Embolization

Chronic subdural hematoma (cSDH) is a prevalent neurosurgical condition with increasing incidence, especially among the elderly. The pathophysiology of cSDH is multifactorial, involving inflammation, fibrinolysis, and angiogenesis, with fragile neovascularization contributing to recurrent microbleeding and hematoma persistence. While burr-hole evacuation remains a standard surgical approach, recurrence rates remain high, necessitating adjunctive strategies such as subdural drain placement, subdural-peritoneal shunting, and pharmacologic interventions. Middle meningeal artery embolization (MMAE) has emerged as a promising adjunctive therapy for cSDH by targeting the abnormal neovascularization of the dura and within the hematoma's outer membrane. In this meta-analysis, we pooled data from 4 recent clinical trials (EMBOLISE, STEM, MAGIC-MT, and MEMBRANE) to evaluate MMAE's efficacy and safety. Our results demonstrate that MMAE plus usual care significantly reduces recurrence or residual cSDH compared with standard care alone (RR = 0.56, P = 0.001), and is associated with lower mortality (RR = 0.54, P = 0.03). No significant differences were observed in functional outcomes, serious adverse events, or major disabling stroke. These findings highlight MMAE as an effective adjunct in cSDH management. Future studies should aim to further assess long-term outcomes and cost-effectiveness, as well as refine the optimal patient selection criteria for MMAE.

Embolization of Middle Meningeal Artery in Patients with Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis of Randomized-Controlled Clinical Trials

Background: Chronic subdural hematoma (cSDH) is a common neurosurgical condition, particularly among elderly patients. Middle meningeal artery (MMA) embolization has emerged as a minimally invasive adjunctive treatment aimed at reducing recurrence. However, its comparative efficacy and safety remain under investigation. Methods: In this systematic review and meta-analysis, randomized-controlled clinical trial (RCT) data evaluating MMA embolization combined with best medical therapy (BMT) versus BMT alone in adult patients with symptomatic cSDH were pooled. The primary efficacy outcome was recurrence or progression of hematoma at follow-up. Secondary efficacy outcomes included good functional outcome [modified Rankin Scale (mRS) score ≤ 2], independent ambulation (mRS score ≤ 3), and hematoma thickness at follow-up. The primary safety outcome was all-cause mortality. Procedure-related complications were assessed as a secondary safety outcome. Results: Six RCTs were included, comprising 760 patients treated with MMA embolization and 788 patients treated with BMT alone. MMA embolization significantly reduced recurrence compared to BMT alone (RR: 0.50; 95% CI: 0.37-0.69; six studies; I2 = 0%; number-needed-to-treat = 13). No significant differences were observed in good functional outcome (RR: 1.01; 95% CI: 0.97-1.05; three studies; I2 = 0%), independent ambulation (RR: 1.01; 95% CI: 0.99-1.04; three studies; I2 = 0%), or hematoma thickness at follow-up (SMD: -0.1; 95% CI: -0.3 to 0; four studies; I2 = 42%). All-cause mortality was similar between the two groups (RR: 1.01; 95% CI: 0.42-2.40; five studies; I2 = 44%). The pooled rate of procedure-related adverse events in the MMA embolization-group was 1% (95% CI: 0-3%; two studies; I2 = 35%). Conclusions: MMA embolization significantly reduced cSDH recurrence when used as an adjunct to BMT. However, it did not demonstrate a significant impact on functional outcomes or mortality in this meta-analysis. Further research is needed to identify patient subgroups that benefit most from MMA embolization and to evaluate its impact on cognitive function and quality of life using longer follow-up periods.

Middle meningeal artery embolization for chronic subdural hematoma: a meta-analysis of randomized controlled trials with trial sequential analysis

Middle meningeal artery embolization (MMAE) has gained attention as an innovative approach for chronic subdural hematoma (cSDH). It can be utilized either as a standalone treatment or as an adjunct to surgical evacuation, with the primary goal of reducing the risk of cSDH recurrence. Therefore, we aim to investigate the efficacy and safety of MMAE in cSDH patients. Databases were systematically searched for randomized controlled trials (RCTs) reporting the use of MMAE in cSDH patients. All statistical analyses were performed using Review Manager 5.4.1. We employed risk ratio (RR) and Mean Differences (MD) with 95% confidence intervals (CIs) as the measure of effect size using a random-effects model. We included seven RCTs (1,623 patients; mean age, 72.7 ± 10.9 [MMAE group] and 72.3 ± 11.0 [usual-care group] years; 74.9% [MMAE] and 77.3% [usual-care] were male). MMAE significantly reduced recurrence (RR 0.47, 95% CI: 0.34 to 0.65, p < 0.001). No statistically significant differences were observed in good (RR 1.01, 95% CI: 0.97 to 1.05, p = 0.77) and favorable functional outcome (RR 1.01, 95% CI: 0.96 to 1.07, p = 0.69). Hematoma volume was only significantly reduced in the adjunctive MMAE subgroup analysis (MD -6.49, 95% CI: -12.21 to -0.78, p = 0.03). No statistically significant differences were observed in adverse events (RR 0.97, 95% CI: 0.68 to 1.39, p = 0.885), serious adverse events (RR 0.78, 95% CI: 0.59 to 1.04, p = 0.09), and mortality (RR 0.98, 95% CI: 0.42 to 2.30, p = 0.97). MMAE significantly reduced recurrence risk compared to usual care, with benefits observed in adjunctive MMAE, including lower reoperation rates and reduced hematoma volume at 90 days. Functional outcomes at 90 days were not significantly different between groups. Similarly, adverse events and mortality rates were comparable between groups Clinical trial number: Not applicable.

2024 middle meningeal artery embolization trials: A comprehensive review of past, recent, and ongoing trials

Background and objectivesMiddle meningeal artery embolization (MMAE) has become a pivotal intervention in managing chronic subdural hematomas (cSDHs). This systematic review synthesizes past, recent, and ongoing clinical trials to assess MMAE's role in cSDH treatment.MethodsA systematic review was conducted using PRISMA guidelines, incorporating PubMed, ClinicalTrials.gov, and reverse bibliography searches to identify clinical trials evaluating MMAE for cSDH. Inclusion criteria included randomized and nonrandomized trials reporting outcomes, such as recurrence rates and procedural safety. Case reports, retrospective reviews, and opinion pieces were excluded.ResultsSeven published and 15 ongoing trials were identified. Landmark randomized controlled trials (RCTs), including EMBOLISE, STEM, and MAGIC-MT, demonstrated reductions in hematoma recurrence and surgical rescues with MMAE, establishing its role as both an adjunctive and standalone therapy. Ongoing trials, such as EMPROTECT and CHESS, investigate diverse embolic agents, procedural strategies, and patient populations to optimize MMAE outcomes. However, challenges remain, including variability in patient selection criteria, embolic materials, and endpoints.ConclusionMMAE is an innovative and minimally invasive approach that has reshaped cSDH management. Evidence supports its efficacy and safety as an adjunct to surgery and a potential standalone therapy for select patients. Future research should focus on long-term outcomes, subgroup analyses, and standardization of protocols to further refine its application and integration into clinical practice.

Efficacy and safety of middle meningeal artery embolization for nonacute subdural hematoma

BACKGROUND

This study aims to synthesise data from randomized controlled trials (RCTs) to evaluate the efficacy and safety of middle meningeal artery embolization (MMAE) in the treatment of nonacute subdural hematoma (SDH).

METHODS

We systematically searched electronic databases for RCTs comparing the efficacy and safety of MMAE with conventional treatment (usual care with or without surgery) for nonacute SDH. The primary efficacy outcome was treatment failure. Secondary efficacy outcomes included changes in hematoma volume, thickness, and functional independence. The primary safety outcome was severe adverse events, and the secondary safety outcome was mortality. Pooled analyses were conducted using risk ratios (RRs) and their 95% confidence intervals (CIs) with random effects model. Trial sequential analysis (TSA) employed to assess the robustness of the evidence.

RESULTS

Six RCTs with 1481 patients were included in the final analysis. Compared to conventional treatment groups, the proportion of treatment failure were lower in the adjunctive MMAE group (RR 0.48, [95% CI 0.34-0.68]), with TSA suggesting sufficient evidence. There was no significant difference in the risk of severe adverse events between the MMAE and conventional treatment groups (RR 0.85, [95% CI 0.63-1.15]). No significant differences were found in secondary outcomes. Further analysis showed that MMAE plus surgery also significantly reduced the proportion of treatment failure compared to surgery alone (RR 0.55, [95% CI 0.34-0.91]), without increasing severe adverse events. In the TSA, the cumulative z-line crossed the boundary for effect.

CONCLUSIONS

MMAE significantly reduces the risk of treatment failure in patients with nonacute SDH, without increasing the incidence of severe adverse events.

Transradial versus transfemoral access in middle meningeal artery embolization for chronic subdural hematoma: A systematic review and meta-analysis

BACKGROUND

Chronic subdural hematoma (cSDH) is increasingly prevalent in the elderly and traditionally treated with surgical interventions. Middle meningeal artery embolization (MMAE) has emerged as an adjunctive therapy to reduce recurrence rates. Transfemoral access (TFA) is the conventional route for neuroendovascular procedures, but transradial access (TRA) offers potential advantages, including reduced access-site complications, earlier ambulation, and shorter hospital stays.

OBJECTIVE

The aim of this systematic review and meta-analysis was to compare the safety and efficacy of TRA versus TFA for MMAE in cSDH patients.

METHODS

This study followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and involved a comprehensive search of four databases to identify studies comparing TRA and TFA in MMAE. Outcomes included hematoma recurrence, hospital length of stay, procedural duration, access-site complications, and overall complications.

RESULTS

Four studies met the inclusion criteria. There were no significant differences between TRA and TFA in hematoma recurrence (Relative Risk (RR) 0.65, 95 % Confidence Interval [CI] 0.09-4.85), hospital length of stay (Mean Difference [MD] 0.10 days, 95 % CI -0.11-0.31), procedural duration (MD 0.04 h, 95 % CI -0.49-0.56), access-site complications (RR 0.24, 95 % CI 0.04-1.40), or overall complications (RR 0.76, 95 % CI 0.33-1.75).

CONCLUSION

TRA demonstrates comparable safety and efficacy to TFA for MMAE in cSDH patients. Although current evidence is limited to observational studies, these findings support the feasibility of TRA as an access route. Future large-scale studies are necessary to validate these results and optimize procedural strategies.

Nontraumatic Intracranial Hemorrhage and Risk of Incident Dementia in US Medicare Beneficiaries

BACKGROUND

To study the risk of incident dementia after a nontraumatic intracranial hemorrhage in a diverse US population and evaluate whether this risk is different for the subtypes of intracranial hemorrhage.

METHODS

We performed a retrospective cohort study using both inpatient and outpatient claims data on a 5% sample of Medicare beneficiaries per year between January 1, 2008 and December 31, 2018. The exposure was a new diagnosis of nontraumatic intracranial hemorrhage, defined as a composite of intracerebral hemorrhage, subarachnoid hemorrhage, and subdural hemorrhage. The outcome was a first-ever diagnosis of dementia. The exposure and outcomes were identified using validated International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification diagnosis codes. We excluded patients who had prevalent intracranial hemorrhage or dementia to ensure that only incident cases were counted in our analyses. In the primary analysis, we used Cox regression to study the risk of dementia after intracranial hemorrhage, after adjusting for demographics and comorbidities. In secondary analyses, the risks of dementia in different subtypes of intracranial hemorrhage were studied.

RESULTS

Among 2.1 million patients, 14 775 had a diagnosis of intracranial hemorrhage with an incidence rate of 1.2 (95% CI, 1.1-1.2) per 1000 person-years. Incident dementia was diagnosed in 2527 (17.1%) of the 14 775 patients with intracranial hemorrhage and in 260 691 (12.8%) of the 2 033 190 patients without intracranial hemorrhage. During a median follow-up of 5.6 (interquartile range, 3.0-9.0) years, the incidence rate of dementia was 8.6 (95% CI, 8.1-8.9) per 100 person-years among patients with intracranial hemorrhage and 2.2 (95% CI, 2.0-2.4) per 100 person-years among patients without intracranial hemorrhage. In an adjusted Cox regression analysis, intracranial hemorrhage was associated with an increased risk of incident dementia (hazard ratio, 2.0 [95% CI, 1.9-2.2]). In secondary analyses, a higher risk of incident dementia was observed with intracerebral hemorrhage (hazard ratio, 2.4 [95% CI, 2.2-2.5]), subarachnoid hemorrhage (hazard ratio, 1.99 [95% CI, 1.7-2.2]), and subdural hemorrhage (hazard ratio, 1.6 [95% CI, 1.4-1.7]).

CONCLUSIONS

In a large, heterogeneous cohort of elderly US participants, we found that intracranial hemorrhage was independently associated with a 2-fold increased risk of incident dementia. This elevated risk was consistently observed across subtypes of intracranial hemorrhage.

Order and Timing of Middle Meningeal Artery Embolization as a Perioperative Adjunct to Surgical Evacuation for Chronic Subdural Hematomas: A Multicenter Study

Background Chronic subdural hematoma (cSDH) is a common neurosurgical condition, and middle meningeal artery embolization (MMAE) has emerged as a minimally invasive adjunct to surgery, but optimal timing remains unclear. Purpose To investigate radiographic and clinical outcomes of patients with cSDH undergoing MMAE as an adjunct to surgical evacuation, focusing on order and timing of MMAE relative to surgery. Materials and Methods This multicenter, retrospective study included consecutive patients undergoing MMAE adjunct to surgery for cSDH at 10 U.S. centers from September 2018 to September 2023. Clinical and radiographic characteristics and outcomes were examined in MMAE before or after surgery. Primary outcomes included recurrence requiring reoperation and technical success of MMAE. Secondary outcomes included radiographic success, rate of change in hematoma thickness, and functional outcome. Propensity score matching (PSM) balanced baseline characteristics. χ2 and Mann-Whitney U tests were used. Results Of the 266 MMAE procedures included in the study (237 patients; median age, 73 years [IQR, 65-80 years]; 175 [73.8%] male), 85 (32.0%) were performed before surgery and 181 (68.0%) were performed after surgery. After PSM, no evidence of differences was found in reoperation (8% [four of 48] vs 4% [four of 93]; P = .90) or technical success (100% [48 of 48] vs 98% [91 of 93]; P = .31) between groups. Similarly, no evidence of differences was observed between MMAE performed within 2 days or 3-7 days after surgery in PSM analysis in reoperation (6% [three of 52] vs 8% [three of 37], respectively; P = .67) or procedural success (98% [51 of 52] vs 100% [37 of 37], respectively; P = .40). The unmatched analysis for order and timing was underpowered to detect differences in reoperation below 11.6% and 14.6%, respectively, and in technical success below 8.5% and 11.3%, respectively, and the matched analyses were more underpowered. Conclusion The cohort did not show statistically significant differences in technical success or reoperation rates based on the timing and order of MMAE relative to surgical evacuation, although larger studies are needed to confirm these observations and rule out smaller, clinically meaningful differences. © RSNA, 2025 Supplemental material is available for this article.

Single-session middle meningeal artery embolization and surgical evacuation for chronic subdural hematoma

BACKGROUND

The aim of this study was to evaluate the preliminary experience of a combined middle meningeal artery embolization (MMAE) and burr hole evacuation approach for chronic subdural hematoma (cSDH) under a single anesthesia session.

METHODS

We performed a retrospective review of all patients who underwent MMAE and burr hole surgery during the same admission at a single major academic institution between 2019 and 2024. Patients were dichotomized by those with both procedures performed under a single anesthesia session (combined) or two separate sessions (separate). Baseline demographics, comorbidities, and complications were compared. The primary outcomes were in-hospital and 90-day complication and reoperation rates.

RESULTS

103 patients were included in the study (median age 74 (67-81) years), with 33.9% in the combined cohort. Demographics, comorbidities, and radiographic characteristics were similar between the cohorts. While cumulative procedure times were similar (separate 85 (71-110) min vs combined 96 (82-127) min), total anesthesia time was significantly longer for patients with separate procedures (separate 225 (193-264) min vs combined 165 (145-183) min, P<0.001). There were no differences in the rates of access site complications, reoperation, stroke, or mortality between the cohorts. The combined cohort trended to have shorter length of stay (separate 6 (5-8) days vs combined 5 (4-7) days, P=0.058). There were no differences in complication or reoperation rates within 90 days.

CONCLUSION

The results of this study suggest that MMAE performed under a single anesthesia session with burr hole evacuation surgery is a safe and potentially resource-efficient approach for the management of cSDH.

Best practice in the use of middle meningeal artery embolisation for chronic subdural haematoma

Chronic subdural haematoma (cSDH) is a common neurosurgical disorder in older people and projected to become the most common cranial neurosurgical pathology by 2030. Incidence of cSDH has risen in recent years as a consequence of improved access to brain imaging, and the increased prescribing of antithrombotic medication for both primary and secondary prevention of vascular disease. Chronic SDH typically presents with an insidious onset of broad-ranging symptoms including impaired cognition, gait, balance and mobility, often with headache. It progresses to more fulminant symptoms of hemiplegia, dysphasia and eventually coma. Although the established standard of care for clearly symptomatic cSDH is burr hole trephination, Middle Meningeal Artery Embolisation (MMAE) has emerged as a minimally invasive treatment option for some patients with cSDH. This is a rapidly evolving field: recently published randomised control trials have provided an evidence-base supporting the use of MMAE not only as an adjunct to burr hole trephination, but also in patients in whom trephination is contraindicated, or in patients with mild symptomatology who are not considered appropriate for immediate burr hole trephination. This article provides practical, real-world guidance on current best practice based on our experience and the published evidence available to date. We use case studies and treatment algorithms from the UK's highest volume MMAE centre to illustrate collaborative care pathways for patients with cSDH between neurosurgery, interventional neuroradiology and trauma geriatricians.

Embolization of middle meningeal artery (EMMA) for non-acute subdural hematoma: Insight from recent randomized trials and meta-analysis

Embolization of the middle meningeal artery (EMMA) has emerged as a promising treatment for non-acute subdural hematoma (NASDH), either as an adjunct to surgical drainage or as a primary intervention in patients not undergoing surgery. Recent randomized controlled trials (RCTs) have investigated the efficacy of EMMA using dimethyl sulfoxide (DMSO)-based agents like ONYX and SQUID. The EMBOLISE trial demonstrated a significant reduction in hematoma recurrence with adjunctive EMMA, while the STEM trial showed similar benefits at 180 days. Conversely, the MAGIC MT trial found no significant difference in recurrence rates with EMMA. A meta-analysis of these trials confirmed EMMA's safety, with no significant increase in serious adverse events. The analysis indicated a modest overall benefit in reducing NASDH recurrence (risk difference -0.09, P = 0.02), though results were largely driven by the STEM trial. The benefit of adjunctive EMMA was less clear, with no significant effect found. Primary EMMA showed marginal benefit but with considerable variability. Factors such as primary outcome, trial design, patient demographics, and surgical biases complicate the interpretation of these findings. While the safety of EMMA is supported, its clinical efficacy remains inconclusive. Further trials, including patient-level meta-analyses, are needed to refine the role of EMMA in NASDH management and address existing gaps in the literature.

A Scoping Review of the Methodologies and Reporting Standards in Recent Applications of Artificial Intelligence in Radiomics for Chronic Subdural Hematoma Imaging

Chronic subdural hematoma (cSDH) is the accumulation of blood in the subdural space, primarily affecting older adults. Radiomics is a rapidly emerging field that integrates artificial intelligence (AI) with imaging to improve diagnostic precision and prognostic predictions, including hematoma expansion and recurrence. However, the heterogeneous study designs, endpoints, and reporting standards limit its clinical application. This scoping review queried PubMed for studies published before or on December 25, 2024, using terms related to cSDH and AI-based imaging analysis. Inclusion criteria required primary research applying AI to cSDH imaging and reporting prognostic endpoints such as recurrence, expansion, or treatment response. Extracted data included methodological variables, imaging modalities, endpoints of interest, and performance metrics. Most studies used computed tomography (CT) imaging for analysis, with hematoma recurrence being the most frequently evaluated endpoint of interest. However, there was wide inconsistency in the reporting of model performance metrics. Thus, radiomics offers opportunities to improve outcome prediction and treatment planning in cSDH. Future work should focus on defining clinically meaningful endpoints, standardizing metrics, and validating models prospectively to facilitate integration into practice.

Antithrombotic resumption after middle meningeal artery embolization or surgery for chronic subdural hematoma: a systematic review and meta-analysis

BACKGROUND

The periprocedural management of antithrombotic medications in patients with chronic subdural hematoma (cSDH) after middle meningeal artery embolization (MMAE) or surgical evacuation is uncertain.

METHODS

A systematic review was conducted across Medline, Embase, and Web of Science databases. We pooled proportions and risk ratios (RRs) for the meta-analysis with the corresponding 95% CIs. Systemic and intracranial (including recurrence) bleeding complications and thromboembolic events were evaluated.

RESULTS

Of the 16 included studies with 4606 patients, 1784 were receiving antithrombotic medications. Antithrombotic therapy was resumed in 1231 patients (69.0%). Bleeding complications were similar between patients in whom antithrombotic therapy was resumed (14.1%, 95% CI 9.7% to 20.2%) and in those in whom it was discontinued (15.4%, 95% CI 7.4% to 29.3%). After MMAE, patients had similar rates of bleeding events (12.1%, 95% CI 4.9% to 27.0%) to patients with overall treated cSDH, and recurrence (RR 2.28, 95% CI 0.46 to 11.37) and reoperation (RR 1.07, 95% CI 0.40 to 2.917) risks were similar between the resumed and discontinued groups. Thromboembolic complications were significantly higher in the discontinued group (12.6%, 95% CI 6.5% to 23.0%) than in the resumption group (3.5%, 95% CI 1.8% to 6.9%). Earlier resumption (1 week to 1 month) was associated with a lower thromboembolic risk without increasing bleeding complications.

CONCLUSIONS

Post-procedural antithrombotic resumption may reduce thromboembolic events without significantly increasing bleeding risk. Early resumption of antithrombotics post-MMAE appears to be safe, although further data are required to confirm this observation. Future studies should aim to better define patient characteristics influencing decision-making in this context.

Middle meningeal artery embolization for chronic subdural hematoma in a young patient with antiphospholipid syndrome: A case report

Chronic subdural hematoma is a common condition in neurosurgical practice. It is usually treated by burr-hole surgery. Patients with coagulopathies such as antiphospholipid syndrome, are at increased risk of complications, and careful consideration of the patient's specific risk of both bleeding and thromboembolic complications must guide medical management. We present the case of a 34-year-old who presented to the neurosurgical department with a chronic subdural hematoma. She had a medical history of triple-positive antiphospholipid syndrome, lupus, and mechanical aortic valve replacement due to Libman-Sacks endocarditis. It was considered of high risk to proceed with traditional burr-hole surgery, so instead embolization of the middle meningeal artery was performed. Postoperatively the patient gradually improved, and a scan at 6 months showed complete regression of the hematoma. She later presented with a contralateral subdural hematoma, which was also successfully treated with middle meningeal artery embolization. Unfortunately, she suffered from an intracerebral hemorrhage shortly afterward, which was treated conservatively by careful management of her anticoagulant therapy. She has now made a full recovery at 4 months follow-up.

Improved healthcare utilization and economic outcomes of chronic subdural hematoma treatment with middle meningeal artery embolization compared to conventional surgical drainage

BACKGROUND

Middle meningeal artery embolization (MMAE) emerges as an alternative to conventional surgical drainage (CSD) for chronic subdural hematomas (cSDH). Several studies have suggested that MMAE improves the cost efficacy of cSDH treatment. However, further comprehensive analyses of the outcomes and healthcare costs of MMAE are necessary.

METHODS

Merative MarketScan Research Database from 2017-2022 was used to compare demographics, reoperation rates, complications, healthcare utilization, and payments of patients being treated with CSD, CSD and adjunctive MMAE, or standalone MMAE for cSDH or nontraumatic subdural hemorrhage.

RESULTS

From 2017-2022, there were 2108 patients who underwent CSD (n = 2015), or CSD+MMAE (n = 23) or MMAE only (n = 70). The median age of the surgical group was 61 years (IQR 53-73 years), the surgery plus MMAE was 67 years (56-77 years) and the MMAE group was 65 years (55-77 years). Median hospital days were significantly longer for the CSD (6 (IQR 5-7) days) and CSD + MMAE (7 (IQR 6-7) days) groups compared to MMAE only (0 days(IQR 0-1)(p < 0.0001). Median index hospitalization payments were significantly higher for the CSD+MMAE group ($74,568) compared to both CSD ($39,658) (p = 0.003) and MMAE groups ($22,286) (p < 0.0001). The total median payments at six-month follow-up for the CSD group were higher compared to CSD+MMAE ($11494 vs $7300, p = 0.0017) but not compared to MMAE only ($10,680, p = 0.08).

CONCLUSIONS

The reduced complications, infection rate, hospital utilization, and costs observed in this study support MMAE as a promising treatment option in the arsenal for cSDH management.

Association between postoperative thromboembolic and hemorrhagic complications and clinical outcomes after surgery for chronic subdural hematoma in patients with anticoagulation therapy for atrial fibrillation

PURPOSE

A substantial proportion of patients undergoing surgery for chronic subdural hematoma (CSDH) use anticoagulation medication due to atrial fibrillation (AF). We assessed the risk of postoperative thromboembolic and hemorrhagic complications in CSDH surgery patients with a history of anticoagulation for AF and their association with outcome.

METHODS

This posthoc analysis of a nationwide multicenter randomized controlled trial conducted during 2020-2022 included CSDH patients undergoing surgery with a history of preoperative anticoagulation use for AF. We assessed the incidence of thromboembolic and hemorrhagic complications and their associations with functional outcomes and mortality.

RESULTS

Of 589 patients, 128 patients (median age 83 years, 24% females) were on anticoagulation medication due to AF. The incidences of postoperative thromboembolic and hemorrhagic complications were 8% and 6%, respectively. A significantly higher proportion of patients with a thromboembolic complication had unfavorable functional outcome (70% vs. 21%, p < 0.001) and higher mortality (50% vs. 14%) than those without. After adjusting for risk factors, a thromboembolic complication was independently associated with a higher risk for unfavorable outcome (OR 16.8, 95% CI 3.0-94.2) and death (OR 11.1, 95% CI 2.4-52.0). Similarly, hemorrhagic complications associated independently with unfavorable outcome, although the effect size was smaller than for thromboembolic complications.

CONCLUSION

The risk for thromboembolic complications seemed to be slightly higher than the risk for postoperative hemorrhagic complications after CSDH surgery in patients with a history of preoperative anticoagulation medication use due to AF. The occurrence of a thromboembolic complication was detrimental for patient prognosis, underscoring the importance of strategies to prevent thromboembolic events. There is an urgent need for a trial assessing the optimal timing of restarting anticoagulation medication after CSDH surgery.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04203550.