Middle meningeal artery embolization for chronic subdural hematoma systematic reviews
2025
The aim of a systematic review and meta-analysis was to compare the safety and efficacy of TRA versus TFA for MMAE in cSDH patients.
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.
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).
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 1).
PubMed, Embase, and Cochrane were searched for studies reporting complications following MMAE through January 2023. A random effects model was used to calculate the pooled incidence of complications stratified based on whether studies excluded patients with comorbidities. Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was followed.
A final 34 studies containing 921 patients undergoing MMAE were included that reported 35 complications. Neurological complications were reported in 7 studies with an overall pooled incidence of 3.8% (95% confidence interval [CI]: 2.6%-5.5%). Across these studies, there was a pooled incidence of 4.9% (95% CI: 2.9%-8.0%), 3.0% (95% CI: 1.7%-5.3%), and 2.1% (95% CI: 0.4%-9.7%) in studies that did not exclude, did not mention, or excluded patients with comorbidities, respectively. Similarly, 7 studies reported cardiovascular complications with an overall pooled incidence of 3.6% (95% CI: 2.4%-5.4%), 4 studies reported infectious complications with an overall pooled incidence of 2.9% (95% CI: 1.9%-4.5%), and 3 studies reported for miscellaneous complications with an overall pooled incidence of 3.1% (95% CI: 2.0%-4.8%). Further subgroup analysis revealed the pooled incidence of cardiovascular complications was 3.2% (95% CI: 1.7%-6.1%) in studies that did not exclude patients with comorbidities, 4.1% (95% CI: 2.3%-7.1%) in studies that did not specify the exclusion of such patients, and 1.8% (95% CI: 0.2%-11.5%) in studies that excluded these patients. Similarly, the incidence of infectious complications was 3.3% (95% CI: 1.7%-6.2%), 2.7% (95% CI: 1.5%-5.0%), and 1.8% (95% CI: 0.2%-11.5%) across these groups, respectively. Miscellaneous complications were reported at 4.0% (95% CI: 2.2%-7.2%), 2.3% (95% CI: 1.1%-4.6%), and 3.1% (95% CI: 0.9%-10.1%), respectively.
The published literature suggests that MMAE is a generally well-tolerated procedure with a low risk of significant complications 2).
2024
A systematic search of PubMed, Embase Ovid, and <ext-link ext-link-type=“uri” xlink:href=“http://ClinicalTrials.gov” xmlns:xlink=“http://www.w3.org/1999/xlink”>ClinicalTrials.gov</ext-link> identified observational and randomized clinical studies comparing MMA embolization to conventional treatment for CSDH. The efficacy outcomes were hematoma recurrence and good functional outcome (as defined by a modified Rankin Scale Score [mRS] of 0-2). Safety outcomes were the rate of major complication and mortality. Heterogeneity among studies were evaluated using the I2 statistic. Analyses were conducted using Cochrane Review Manager Software, with risk ratios (RRs) and 95% confidence intervals (95% CI) presented for key outcomes. Absolute risk reduction (95% CI) of 1,000 patients was also calculated using GRADEpro software.
Results: The analysis included data from 13 studies (4 randomized clinical trials [RCTs] and 9 observational studies) with a total number of 2,960 patients (35.3% in the MMA group and 64.7% in the conventional treatment group). Compared to conventional treatment, MMA embolization decreased risk of hematoma recurrence by 59% (13 studies, RR = 0.41, 95% CI: 0.26-0.65; I2 = 49%), for an absolute effect of 116 fewer events/1,000 patients (95% CI: 69-145), with similar risk of major complications (13 studies, RR = 0.88, 95% CI: 0.67-1.15; I2 = 43%) and mortality risk (13 studies, RR = 1.05, 95% CI: 0.67-1.65). In subgroup analyses by study type, pooled results from RCTs showed similar direction effects as those from observational studies for both efficacy and safety outcomes.
Conclusion: MMA embolization in CSDH management is a safe and effective approach for CSDH 3).
A systematic review and meta-analysis provide strong evidence that MMA embolization is an effective and safe intervention for CSDH, particularly in reducing hematoma recurrence. However, the study’s moderate heterogeneity, reliance on observational data, and lack of long-term and cost-effectiveness analyses highlight areas for future research. Further large-scale, high-quality RCTs with extended follow-up periods are necessary to solidify these findings and optimize treatment guidelines for CSDH management.
PubMed, Embase, Cochrane, Web of Science, and Scopus databases were searched to August 2023. Primary outcomes were treatment failure and reoperation. Secondary outcomes were complications, mortality, length of hospital stay, 30-day readmission, and follow-up modified Rankin Scale (mRS) > 2. Additional data from our institution was included.
12 published studies and our data yielded 57,165 patients, of whom 1,065 (1.9%) received adjunct MMAE and 56,100 (98.1%) surgery alone. Compared to surgery alone, adjunct MMAE was associated with lower rates of treatment failure (OR = 0.43 [0.23-0.83], p = 0.01), reoperation (OR = 0.45 [0.22-0.90], p = 0.02), and 30-day readmission (OR = 0.50 [0.34-0.73], p < 0.001). Length of hospital stay (MD = 2.49 [-0.51, 5.49], p = 0.10) was non-significantly longer in the adjunct MMAE group. Both groups had comparable rates of treatment-related complications (OR = 0.89 [0.52-1.53], p = 0.67), mortality (OR = 1.05 [0.75-1.46], p = 0.78), and follow-up mRS > 2 (OR = 0.91 [0.39-2.12], p = 0.83).
Adjunct MMAE reduces treatment failure, reoperation, and readmission rates without increasing morbidity and mortality. MMAE may be considered as an adjunct to surgical evacuation to reduce CSDH recurrence. Randomized trials will further establish the evidence for adjunct MMAE and its role in the management of CSDH 4).
A total of 23 studies including 302,168 patients (62.5 % male, 37.5 % female) were analyzed, with most studies published between 2017 and 2024. Among these patients, 299,195 (99.0 %) were treated with conventional surgery, whereas 3113 underwent MMAE. MMAE patients showed a significantly lower recurrence rate compared to conventional surgery, with a 0.35 times lower risk of recurrence (95 % CI: 0.24-0.51, p<0.01). However, adjunctive MMAE was associated with a longer hospital stay (SMD: 2.61 [95 % CI: 2.46-2.76], p<0.01), though MMAE alone had a shorter stay compared to adjunctive MMAE. Additionally, MMAE demonstrated a lower risk of surgical rescue (0.29 times, p<0.01). While no significant difference was found in-hospital complications (RR: 1.01, 95 % CI 0.90-1.14, p=0.84) and mortality rates (RR: 0.88, 95 % CI 0.69-1.14, p=0.34).
Conclusion: MMAE stand-alone or adjunctive with conventional surgery presents a promising alternative to conventional surgery alone for chronic subdural hematomas due to lower recurrence and surgical rescue risk. Further prospective studies are needed to study the efficacy of this new approach 5)
A systematic literature review on pediatric patients undergoing MMA embolization was performed. We also report the case of successful bilateral MMA embolization for persistent subdural hematomas following resection of a juvenile pilocytic astrocytoma. Persistent bilateral subdural hematomas following resection of a large brain tumor resolved following MMA embolization in a 13-year-old male. Indications for MMA embolization in the pediatric literature included cSDH (6/13, 46.2%), treatment or preoperative embolization of arteriovenous fistula or arteriovenous malformation (3/13, 23.1%), preoperative embolization for tumor resection (1/13, 7.7%), or treatment of acute epidural hematoma (1/13, 7.7%). Embolic agents included microspheres or microparticles (2/13, 15.4%), Onyx (3/13, 23.1%), NBCA (3/13, 23.1%), or coils (4/13, 30.8%).
Whereas MMA embolization has primarily been applied in the adult population for subdural hematoma in the setting of cardiac disease and anticoagulant use, we present a novel application of MMA embolization in the management of persistent subdural hematoma following resection of a large space-occupying lesion. A systematic review of MMA embolization in pediatric patients currently shows efficacy; a multi-institutional study is warranted to further refine indications, timing, and safety of the procedure 6).
2023
Omura and Ishiguro systematically reviewed the literature according to the PRISMA guidelines using an electronic database. The search yielded 43 articles involving 2,783 patients who underwent MMAE.
The hematoma resolution, recurrence, and retreatment rates in the MMAE-alone treatment group (n = 815) were 86.7%, 6.3%, and 9.6%, respectively, whereas those in the prophylactic MMAE with combined surgery group (n = 370) were 95.6%, 4.4%, and 3.4%, respectively. The overall MMAE-related complication rate was 2.3%.
This study shows that MMAE alone is, although not immediate, as effective as evacuation surgery alone in reducing hematoma. The study also shows that combined treatment has a lower recurrence rate than evacuation surgery alone. Because MMAE is a safe procedure, it should be considered for patients with cSDH, especially those with a high risk of recurrence 7)
Chen et al. searched the Medline and Embase databases for studies reporting outcomes specific to standalone MMAE and combined MMAE and surgery. The Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess risk of bias in each included study. Patient characteristics were compared between cohorts, and rates of surgical recurrence of standalone MMAE and combined MMAE and surgery were pooled using random-effects models.
Four hundred two unique patients (156 with standalone MMAE and 246 with combined MMAE and surgery) were identified across 8 studies. Overall, the subdural thickness for the standalone MMAE group was modestly but statistically significantly smaller (16.8 vs 18.8 mm, estimated p value 0.002), and the mean follow-up time was significantly longer for the standalone MMAE group (5.4 vs 2.3 months, estimated p value < 0.001); there were no significant differences between age, sex, and anticoagulant use. The surgical recurrence rates were not significantly different between the two groups (estimated p value 0.63). Using random-effects models, the surgical recurrence rates were estimated at 6.8% (95% CI 3.5%-11.2%) and 4.6% (95% CI 2.3%-7.7%) for standalone MMAE and combined MMAE and surgery, respectively.
Standalone MMAE for cSDH may yield a low rate of surgical recurrence, which may be comparable to that of combined MMAE and surgery. However, studies in this systematic review and meta-analysis were primarily single-arm studies prone to treatment bias. Future studies are needed to further investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgical treatment for cSDH in select patients 8)
2022
Chronic subdural hematoma recurrence after evacuation occurs in approximately 10% of chronic subdural hematomas, and the various Chronic subdural hematoma surgery interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials 9).
2020
Jumah et al. conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of Middle meningeal artery embolization (MMAE) compared with conventional treatments for refractory or chronic subdural hematoma (cSDH). Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk differences were conducted recurrence, need for surgical rescue, and complications.
Eleven studies (177 patients) were included. The majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. A meta-analysis of proportions showed treatment failure to be 2.8%, the need for surgical rescue 2.7%, and embolization-related complications 1.2%. A meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I2 = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I2 = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I2 = 0) compared to conventional groups.
Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by the paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH 10).
2019
Fiorella and Arthur reviewed the potential role for the endovascular management of cSDH within the context of a discussion of the epidemiology, pathophysiology, and conventional management of this disease 11).
The goal of a study was to review the evidence on MMAE in cSDH to assess its safety, feasibility, indications and efficacy. Court et al. performed a systematic review of the literature according to PRISMA guidelines using multiple electronic databases. This search yielded a total of 18 original articles from which data were extracted. A total of 190 patients underwent MMAE from which 81.3% were symptomatic cSDH. Over half (52.3%) of the described population were undergoing antithrombotic therapy. Most (83%) procedures used polyvinyl alcohol (PVA) particles and no complications were reported regarding the embolization procedures. Although the definition of resolution varied among authors, cSDH resolution was reported in 96.8% of cases. MMAE is a feasible technique for cSDH, but the current body of evidence does not yet support its use as a standard treatment. Further studies with a higher level of evidence are necessary before MMAE can be formally recommended 12).
Three double-arm studies comparing embolization and conventional surgery groups and 6 single-arm case series were identified and analyzed. Hematoma recurrence rate was significantly lower in the embolization group compared with conventional treatment group (2.1% vs. 27.7%; odds ratio = 0.087; 95% confidence interval, 0.026-0.292; P < 0.001; I2 = 0%); surgical complication rates were similar between groups (2.1% vs. 4.4%; odds ratio = 0.563; 95% confidence interval, 0.107-2.96; P = 0.497; I2 = 27.5%). Number of patients with modified Rankin Scale score >2 in the embolization (12.5%) versus conventional treatment (9.1%) group showed no statistical difference (P = 0.689). A composite hematoma recurrence rate of 3.6% was found after summing the 6 case series. Composite recurrence and complication rates in the embolization cohorts of the double-arm studies and the case series were lower than literature values for conventional surgical treatments.
MMA embolization is a promising treatment for chronic subdural hematoma. Future randomized clinical trials are needed 13).
Fiorella and Arthur reviewed the potential role for the endovascular management of cSDH within the context of a discussion of the epidemiology, pathophysiology, and conventional management of this disease 14).