Perioperative prophylactic middle meningeal artery embolization for chronic subdural hematoma: a series of 44 cases

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.

Middle meningeal artery embolization: A scoping review of trends and outcomes by embolization material

Background

Chronic subdural hematomas (cSDHs), blood collections under the dural layer of the brain, are common in the elderly and frequently linked to trauma and anticoagulation. As the global elderly population increases, the incidence of cSDH is expected to rise, straining healthcare systems. Middle meningeal artery embolization is a minimally invasive alternative to surgery, which could prove especially beneficial for elderly patients with multiple comorbidities or contraindications to surgery. However, the efficacy and patient-related outcomes associated with different embolization materials remain unknown.

Methods

The authors conducted a scoping review of manuscripts published through August 2023 to assess outcomes associated with various embolization materials used in middle meningeal artery embolization for cSDH. Recurrence rates after embolization and complications were the primary outcomes.

Results

The authors analyzed a total of 25 studies, reporting 1579 embolizations in 1362 patients. Embolic materials included particles (35.7%), liquid embolisates (31.5%), coils (3.2%), and combinations of the aforementioned materials (29.6%). Recurrence rates were low (5.1%), and the most common complications were seizures and strokes. The overall mortality was 1.4%, with three procedure-related deaths.

Conclusion

With low recurrence and complication rates, middle meningeal artery embolization is a safe and effective treatment for cSDH. However, due to limitations in data availability, we were not able to link hematoma recurrence or complication rates with the type of embolization material used. To better understand the safety profiles of different materials, further large-scale studies are warranted.

Newer treatment paradigm improves outcomes in the most common neurosurgical disease of the elderly: a literature review of middle meningeal artery embolization for chronic subdural hematoma

Chronic subdural hematoma (cSDH) is one of the most prevalent neurosurgical diseases, especially in the elderly. Yet, its incidence is predicted to increase further, paralleling the growth of the geriatric population. While surgical evacuation is technically straightforward, it is associated with significant morbidity and mortality. In fact, 30% of patients are expected to have hematoma recurrence and to need repeat surgical evacuation, and 20% of patients are expected to lose independence and require long-term care. A pathophysiology more complex than originally presumed explains the disappointing results observed for decades. At its core, the formation of microcapillaries and anastomotic channels with the middle meningeal artery (MMA) perpetuates a constant cycle resulting in persistence of hematoma. The rationale behind MMA embolization is simple: to stop cSDH at its source. Over the last few years, this "newer" option has been heavily studied. It has shown tremendous potential in decreasing hematoma recurrence and improving neurological outcomes. Whether combined with surgical evacuation or performed as the only treatment, the scientific evidence to its benefits is unequivocal. Here, we aimed to review cSDH in the elderly and discuss its more recent treatment options with an emphasis on MMA embolization.

Adjunctive Middle Meningeal Artery Embolization for Subdural Hematoma

BACKGROUND

Subacute and chronic subdural hematomas are common and frequently recur after surgical evacuation. The effect of adjunctive middle meningeal artery embolization on the risk of reoperation remains unclear.

METHODS

In a prospective, multicenter, interventional, adaptive-design trial, we randomly assigned patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation to undergo middle meningeal artery embolization plus surgery (treatment group) or surgery alone (control group). The primary end point was hematoma recurrence or progression that led to repeat surgery within 90 days after the index treatment. The clinical secondary end point was deterioration of neurologic function at 90 days, which was assessed with the modified Rankin scale in a noninferiority analysis (margin for risk difference, 15 percentage points).

RESULTS

A total of 197 patients were randomly assigned to the treatment group and 203 to the control group. Surgery occurred before randomization in 136 of 400 patients (34.0%). Hematoma recurrence or progression leading to repeat surgery occurred in 8 patients (4.1%) in the treatment group, as compared with 23 patients (11.3%) in the control group (relative risk, 0.36; 95% confidence interval [CI], 0.11 to 0.80; P = 0.008). Functional deterioration occurred in 11.9% of the patients in the treatment group and in 9.8% of those in the control group (risk difference, 2.1 percentage points; 95% CI, -4.8 to 8.9). Mortality at 90 days was 5.1% in the treatment group and 3.0% in the control group. By 30 days, serious adverse events related to the embolization procedure had occurred in 4 patients (2.0%) in the treatment group, including disabling stroke in 2 patients; no additional events had occurred by 180 days.

CONCLUSIONS

Among patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation, middle meningeal artery embolization plus surgery was associated with a lower risk of hematoma recurrence or progression leading to reoperation than surgery alone. Further study is needed to evaluate the safety of middle meningeal artery embolization in the management of subdural hematoma. (Funded by Medtronic; EMBOLISE ClinicalTrials.gov number, NCT04402632.).

Transradial approach for middle meningeal artery embolization is a safe alternative to transfemoral approach in patients with chronic subdural hematoma: A single-center retrospective comparative study

BACKGROUND

Transradial approach (TRA) has been increasingly utilized in various neuroendovascular interventions as a safe alternative to the transfemoral approach (TFA). As middle meningeal artery (MMA) embolization emerges as an effective therapy for treating chronic subdural hematomas (cSDH), some studies have explored using TRA. In this study, we compared procedural times and post-operative outcomes between those with TRA and TFA.

METHODS

This is a single-institution retrospective study of patients undergoing MMA embolization for cSDH. The cohort was divided into the TRA and TFA subgroups. Baseline characteristics, procedural times, and immediate outcomes were compared. Univariate analysis was performed.

RESULTS

We performed 62 MMA embolizations for treatment of cSDH, of which 37 (59.7 %) were performed transradial and 25 (40.3 %) were performed transfemoral. Those who underwent TRA were significantly younger than those who had TFA (p = 0.02). For patients who underwent unilateral MMA embolization, those with TRA had significantly shorter duration of procedure compared to the TRF group (p = 0.01). This difference was not observed in the bilateral MMA embolization subgroup. Only three patients had access site complications, and all were in the TFA group. There was no significant difference in length of hospital stay.

CONCLUSION

As MMA embolization for cSDH becomes more prevalent, efforts to optimize the safety and efficacy of the technical aspects become critical. In this study we demonstrate that TRA is a safe and efficient alternative to traditional TFA in those undergoing unilateral MMA embolization.

Comparison of adjunctive middle meningeal artery embolization using embosphere particles versus surgical drainage alone for the treatment of chronic subdural hematoma: A prospective study

BACKGROUND

Middle meningeal artery embolization (MMAE) has emerged as a primary and adjunctive therapy for chronic subdural hematoma (CSDH) in addition to conventional treatment. However, there is a scarcity of data that explicitly compares the effectiveness of adjunctive MMAE to surgical drainage alone (SDA), as well as the use of Embosphere particles. The objective of this study was to assess the safety and efficacy of adjunctive MMAE in the treatment of symptomatic CSDH compared to SDA.

METHODS

This prospective study included 43 patients with 52 CSDH sides, treated at a single institution between 2022 and 2023. The primary outcome was postoperative hematoma volume at 14, 30, 90, and 180 days after surgical drainage, which was analyzed using the generalized estimating equation. The secondary outcomes were the complications and recurrence/reoperation rate. Adjunctive MMAE was performed within 7 days following the surgery, utilizing Embosphere as the embolic material.

RESULTS

The patients were assigned to either the adjunctive MMAE group (n = 20, 26 CSDH sides) or the SDA group (n = 23, 26 CSDH sides). The adjunctive MMAE group demonstrated a more significant reduction in hematoma volume (p = 0.007) and maximal hematoma thickness (p = 0.016) at all follow-up intervals. A trend towards lower recurrence and reoperation rates was observed with adjunctive MMAE; particularly, none of the patients in the adjunctive MMAE group experienced a recurrence of CSDH, compared to 19.2 % in the SDA group (p = 0.051). One procedural-related complication (3.8 %) in the adjunctive MMAE group.

CONCLUSION

Our results suggested that adjunctive MMAE, compared to SDA, may enhance hematoma resolution and reduce the need for reoperation due to recurrence.

Transradial versus transfemoral access for middle meningeal artery embolization: Choice of the access route considering delirium in the elderly

Background

Treatment of chronic subdural hematoma (CSDH) with middle meningeal artery embolization (MMAE) is becoming well established. Transradial artery access (TRA) is considered less invasive than transfemoral artery access (TFA) and is increasingly indicated in the field of endovascular therapy. Therefore, this study focused on postoperative delirium and compared access routes.

Methods

This is a single-center and retrospective study. The strategy was to perform MMAE for CSDH with symptomatic recurrence at our hospital. Cases from July 2018 to September 2022, when MMAE was introduced in our hospital, were included in this study. Patients were divided into TRA and TFA groups and were compared descriptively for patient background, procedure duration, and incidence of postoperative delirium.

Results

Twenty-five patients underwent MMAE, of whom 12 (48%) were treated with TRA. The overall median age was 82 years, with no clear differences between the TRA and TFA groups in the presence or absence of preexisting dementia or antithrombotic therapy. Delirium requiring medication tended to be lower in the TRA group: 2/12 (16.7%) in the TRA group versus 6/13 (46.2%) in the TFA group, and the mean procedure time for patients undergoing bilateral MMAE was 151 min (interquartile range [IQR]: 140-173 min) in the TRA group versus 174 min (IQR: 137-205 min) in the TFA group.

Conclusion

TRA was associated with an overall shorter procedure time than TFA. MMAE through TRA tended to have a lower incidence of delirium. MMAE through TRA may be useful in recurrent CSDH with a high elderly population.

Preoperative middle meningeal artery embolization in the treatment of organized chronic subdural hematoma

Organized chronic subdural hematoma is a rare form of chronic subdural hematoma. The optimal treatment method is still controversial. Preoperative middle meningeal artery embolization and craniotomy are effective methods for chronic subdural hematoma. However, there are not many reports investigating the effectiveness of these methods in treating organized chronic subdural hematoma. We report the case of a 61-year-old male patient who had a twist-drill craniostomy to treat a left hemisphere subdural hematoma. After surgery, there was a recurrence on the same side in the form of an organized subdural hematoma. The patient received preoperative left middle meningeal artery embolization. After 3 months of follow-up, a small portion of the hematoma remained, causing pressure and slightly shifting the midline to the right by 6.5 mm, and the patient no longer had clinical symptoms.

The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/μL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

Initial experience using middle meningeal artery embolisation for patients with recurrent and high-recurrence-risk chronic subdural haematoma

Recurrence rates following surgical management of chronic subdural haematoma (CSDH) range from 5 to 33 %. There is growing evidence which suggests middle meningeal artery embolisation (MMAe) may reduce recurrence rates when used as surgical adjunct or standalone treatment. In this study we described our experience of this new procedure in the our UK institution. Patients with recurrent CSDH or CSDH at high risk of recurrence were selected for MMAe on a case-by-case basis following MDT discussion. A departmental database was used to identify patients treated. 26 CSDH were embolised in 20 patients; 9 CSDH were de-novo and 17 were recurrent. 10/26 CSDH were treated with MMAe only. No procedural mortality, access site or thrombo-embolic complications occurred. One patient experienced symptomatic collection growth 12 h following MMAe and required surgical drainage. 15 (75 %) of patients were living at home at follow-up (mean 14 months). On imaging follow-up 15/18 showed CSDH volume reduction or resolution, 1/18 remained stable requiring no further treatment, 2/18 patients suffered recurrent CSDH requiring treatment. In both recurrent cases incomplete embolisation was noted on procedural imaging (posterior division of MMA not embolised). Persistent posterior MMA division filling was significantly associated with collection recurrence (p = 0.002). Our results suggest MMAe as a stand-alone or adjuvant therapy can be performed safely in a UK neuroscience setting and is associated with high rates of symptomatic CSDH size reduction or resolution in problematic CSDH that have either recurred or are prone to recurrence.

Middle meningeal artery embolization for the treatment of unilateral large chronic subdural hematoma patients with significant midline shift: A single-center experience

BACKGROUND

The amount of midline shift (MLS) considered safe for middle meningeal artery embolization (MMAE) in patients with chronic subdural hematoma (CSDH) has not been established. Whether MMAE could be used as upfront treatment for unilateral large CSDH patients with significant MLS (>1 cm) has not been reported.

OBJECTIVE

To investigate the efficacy and safety of MMAE in unilateral large CSDH patients with MLS > 1 cm.

METHODS

Eleven carefully selected CSDH patients with mild or moderate symptoms and significant MLS > 1 cm from 1 May 2021 to 31 August 2022 were included in the study. All patients were treated with MMAE using polyvinyl alcohol (PVA) particles. Outcomes were assessed clinically and with interval imaging studies at follow-up.

RESULTS

All 19 MMAs (unilateral embolization in three patients and bilateral embolization in eight patients) were successfully embolized. All 11 patients were followed for subsequent months, and there was no recurrence and enlargement of CSDH. Procedural adverse events, mortality, or complications were not observed. The average time to achieve a 50% reduction in MLS was approximately four weeks, while it took approximately eight weeks to achieve a 50% reduction in maximal volume. All 11 patients showed improvement in their neurological symptoms at three days post-operation, including four hemiplegic patients.

CONCLUSIONS

MMAE may demonstrate safety in carefully selected CSDH patients with significant midline shift (MLS > 1 cm), particularly in those who are not suitable for surgery, thus providing a potential alternative approach.

Safety and efficacy comparison of embolic agents for middle meningeal artery embolization for chronic subdural hematoma

OBJECTIVE

To perform a systematic review and meta-analysis evaluating the efficacy of middle meningeal artery embolization in terms of both clinical and radiographic outcomes, when performed with different embolic agents.

METHODS

A systematic literature review and meta-analysis was performed to evaluate the impact of embolic agents on outcomes for middle meningeal artery (MMA) embolization. The use of polyvinyl alcohol (PVA) with or without (±) coils, N-butyl cyanoacrylate (n-BCA) ± coils, and Onyx alone were separately evaluated. Primary outcome measures were recurrence, the need for surgical rescue and in-hospital periprocedural complications.

RESULTS

Thirty-one studies were identified with a total of 1,134 patients, with 786 receiving PVA, 167 receiving n-BCA, and 181 patients receiving Onyx. There was no difference in the recurrence rate (5.5% for PVA, 4.5% for n-BCA, and 6.5% for Onyx, with P=0.71) or need for surgical rescue (5.0% for PVA, 4.0% for n-BCA, and 6.9% for Onyx, with P=0.89) based on the embolic agent. Procedural complications also did not differ between embolic agents (1.8% for PVA, 3.6% for n-BCA, and 1.6% for Onyx, with P=0.48).

CONCLUSIONS

Rates of recurrence, need for surgical rescue, and periprocedural complication following MMA embolization are not impacted by the type of embolic agent utilized. Ongoing clinical trials may be used to further investigate these findings.

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study

BACKGROUND AND OBJECTIVES

The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE.

METHODS

Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes.

RESULTS

Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations.

CONCLUSION

We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Automated Preoperative and Postoperative Volume Estimates Risk of Retreatment in Chronic Subdural Hematoma: A Retrospective, Multicenter Study

BACKGROUND AND OBJECTIVES

Several neurosurgical pathologies, ranging from glioblastoma to hemorrhagic stroke, use volume thresholds to guide treatment decisions. For chronic subdural hematoma (cSDH), with a risk of retreatment of 10%-30%, the relationship between preoperative and postoperative cSDH volume and retreatment is not well understood. We investigated the potential link between preoperative and postoperative cSDH volumes and retreatment.

METHODS

We performed a retrospective chart review of patients operated for unilateral cSDH from 4 level 1 trauma centers, February 2009-August 2021. We used a 3-dimensional deep learning, automated segmentation pipeline to calculate preoperative and postoperative cSDH volumes. To identify volume thresholds, we constructed a receiver operating curve with preoperative and postoperative volumes to predict cSDH retreatment rates and selected the threshold with the highest Youden index. Then, we developed a light gradient boosting machine to predict the risk of cSDH recurrence.

RESULTS

We identified 538 patients with unilateral cSDH, of whom 62 (12%) underwent surgical retreatment within 6 months of the index surgery. cSDH retreatment was associated with higher preoperative (122 vs 103 mL; P < .001) and postoperative (62 vs 35 mL; P < .001) volumes. Patients with >140 mL preoperative volume had nearly triple the risk of cSDH recurrence compared with those below 140 mL, while a postoperative volume >46 mL led to an increased risk for retreatment (22% vs 6%; P < .001). On multivariate modeling, our model had an area under the receiver operating curve of 0.76 (95% CI: 0.60-0.93) for predicting retreatment. The most important features were preoperative and postoperative volume, platelet count, and age.

CONCLUSION

Larger preoperative and postoperative cSDH volumes increase the risk of retreatment. Volume thresholds may allow identification of patients at high risk of cSDH retreatment who would benefit from adjunct treatments. Machine learning algorithm can quickly provide accurate estimates of preoperative and postoperative volumes.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: An Analysis of 35 Consecutive Patients

INTRODUCTION

There is sufficient scientific literature that demonstrates favorable outcomes using the minimally invasive technique of middle meningeal artery embolization (MMAE) for the treatment of chronic subdural hematomas (cSDH). The authors evaluate the outcomes of 35 consecutive patients treated with MMAE, both with and without adjuvant surgical drainage (ASD), in an attempt to identify variables that may affect the outcome of patients treated with MMAE for cSDH.

METHODS

A multivariate retrospective analysis was performed on patients who received MMAE for cSDH, including age, size of cSDH, ASD, presence of unilateral or bilateral collections, and use of anticoagulants.

RESULTS

Twenty patients underwent MMAE with planned ASD, while 15 patients had MMAE only; these groups had an average cSDH size reduction (measured at its greatest width) of 74% and 69% of cSDH, respectively. Of the 15 patients who were initially treated only with MMAE, three (20%) required a rescue craniotomy. Twenty patients (57%) who had initially presented while receiving oral anticoagulants had an average of 71% size reduction with ASD compared to 74% reduction in those without ASD. Patients not using anticoagulants had an 84% and 78% average reduction in size, respectively. Twelve patients presented with bilateral cSDH; patients who received ASD had an average size reduction of 58%; those without ASD had 63%. Patients with unilateral cSDH had 85% and 83% reduction in size, respectively.

CONCLUSION

Middle meningeal artery embolization, with or without ASD, can be a useful alternative or adjunct to standard surgical treatment for cSDH. Our study found that only three of 35 patients (9%) treated with this method required any further surgical intervention. No patient who received ASD had a recurrence of their cSDH. Further investigation, including prospective randomized studies, would be useful to better identify which patients can benefit and variables that impact the outcome of patients undergoing MMAE.

Middle meningeal artery embolization combined with surgical evacuation for chronic subdural hematoma: A single-center experience of 75 cases

BACKGROUND

Chronic subdural hematoma (cSDH) is a challenging and common neurosurgical condition. Our goal is to demonstrate that middle meningeal artery (MMA) embolization combined with surgical evacuation can be a promising adjuvant option for treatment of cSDHs and prevent recurrence in symptomatic patients who require surgical treatment.

METHOD

We retrospectively collected data from patients who underwent MMA embolization using polyvinyl alcohol particles and surgical evacuation with burr hole or craniotomy in a single center for the treatment of new and recurrent cSDHs. The primary outcome was recurrence of cSDH requiring surgical rescue during follow up, and secondary outcomes were defined as >50% decrease in the maximum width of cSDHs on the longest follow-up computed tomography (CT) scan, complications following procedure, and improvement in modified Rankin scale (mRS) score.

RESULTS

A total of 51 patients successfully underwent 72 MMA embolization procedures (96% of the total 75 cases in the cohort) combined with surgical evacuation. Seventy cases (93.3%) achieved at least 50% reduction in the size of the cSDHs on the last CT imaging. A surgical evacuation was required in five cases (6.7%) due to cSDH recurrence during the follow-up period. There were three complications (6.0%) related to embolization procedure. Forty patients (78.4%) showed improvement in mRS score. There was one mortality (2%) regardless of the embolization and evacuation.

CONCLUSIONS

Our study demonstrates the safety and efficacy of adjunct MMA embolization in significantly reducing size and recurrence of cSDHs.

Middle Meningeal Artery Embolization Versus Conventional Management for Patients With Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis

BACKGROUND

The results from studies that compare middle meningeal artery (MMA) embolization vs conventional management for patients with chronic subdural hematoma are varied.

OBJECTIVE

To conduct a systematic review and meta-analysis on studies that compared MMA embolization vs conventional management.

METHODS

Medline, PubMed, and Embase databases were searched. Primary outcomes were treatment failure and surgical rescue; secondary outcomes were complications, follow-up modified Rankin scale > 2, mortality, complete hematoma resolution, and length of hospital stay (day). The certainty of the evidence was determined using the GRADE approach.

RESULTS

Nine studies yielding 1523 patients were enrolled, of which 337 (22.2%) and 1186 (77.8%) patients received MMA embolization and conventional management, respectively. MMA embolization was superior to conventional management for treatment failure (relative risk [RR] = 0.34 [0.14-0.82], P = .02), surgical rescue (RR = 0.33 [0.14-0.77], P = .01), and complete hematoma resolution (RR = 2.01 [1.10-3.68], P = .02). There was no difference between the 2 groups for complications (RR = 0.93 [0.63-1.37], P = .72), follow-up modified Rankin scale >2 (RR = 0.78 [0.449-1.25], P = .31), mortality (RR = 1.05 [0.51-2.14], P = .89), and length of hospital stay (mean difference = -0.57 [-2.55, 1.41], P = .57). For MMA embolization, the number needed to treat for treatment failure, surgical rescue, and complete hematoma resolution was 7, 9, and 3, respectively. The certainty of the evidence was moderate to high for primary outcomes and low to moderate for secondary outcomes.

CONCLUSION

MMA embolization decreases treatment failure and the need for surgical rescue without furthering the risk of morbidity and mortality. The authors recommend considering MMA embolization in the chronic subdural hematoma management.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Predictors of Clinical and Radiographic Failure from 636 Embolizations

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.

Embolic Agent Choice in Middle Meningeal Artery Embolization as Primary or Adjunct Treatment for Chronic Subdural Hematoma: A Systematic Review and Meta-analysis

BACKGROUND

Middle meningeal artery embolization is an emerging treatment option for chronic subdural hematomas.

PURPOSE

Our aim was to assess outcomes following middle meningeal artery embolization by different techniques, including in comparison with traditional surgical methods.

DATA SOURCES

We searched the literature databases from inception to March 2022.

DATA SELECTION

We selected studies reporting outcomes after middle meningeal artery embolization as a primary or adjunctive treatment for chronic subdural hematoma.

DATA ANALYSIS

We analyzed the risk of recurrence of chronic subdural hematoma, reoperation for recurrence or residual hematoma, complications, and radiologic and clinical outcomes using random effects modeling. Additional analyses were performed on the basis of whether middle meningeal artery embolization was used as the primary or adjunct treatment and by embolic agent type.

DATA SYNTHESIS

Twenty-two studies were included with 382 patients with middle meningeal artery embolization and 1373 surgical patients. The rate of subdural hematoma recurrence was 4.1%. Fifty (4.2%) patients underwent a reoperation for a recurrent or residual subdural hematoma. Thirty-six (2.6%) experienced postoperative complications. The rates of good radiologic and clinical outcomes were 83.1% and 73.3%, respectively. Middle meningeal artery embolization was significantly associated with decreased odds of subdural hematoma reoperation (OR = 0.48; 95% CI, 23.4-99.1; P = .047) compared with surgery. The lowest rates of subdural hematoma radiologic recurrence, reoperation, and complications were observed among patients receiving embolization with Onyx, whereas good overall clinical outcome occurred most commonly with combined polyvinyl alcohol and coils.

LIMITATIONS

A limitation was the retrospective design of studies included.

CONCLUSIONS

Middle meningeal artery embolization is safe and effective, either as a primary or adjunctive treatment. Treatment using Onyx seems to yield lower rates of recurrence, rescue operation, and complications whereas particles and coils produce good overall clinical outcomes.

Middle Meningeal Artery Embolization for the Management of Chronic Subdural Hematomas: A New-Old Treatment

Chronic subdural hematoma (cSDH) is defined as a subdural collection of blood on CT imaging that tends to persist and gradually increase in volume over time, with components that are hypodense or isodense compared to the brain. There are no proven guidelines for the management of patients with cSDH. Surgical approaches included burr hole, twist drill hole, and craniotomy-based evacuations. Outcomes after surgical removal is generally favorable, but cSDH tends to recur after the initial evacuation.Middle meningeal artery (MMA) embolization has been gaining increasing popularity among the treatments of cSDH. This is largely due to a growing population of patients with cSDH who are refractory to other treatments or in patients who present with multiple comorbidities or who are taking antiplatelet and anticoagulant medications. The goal of middle meningeal artery (MMA) embolization is to devascularize subdural membranes associated with SDH so that the balance between continued leakage and reabsorption is shifted toward reabsorption.We discuss our clinical and technical approach to cSDH treated with perioperative embolization of the MMA.

Management of Chronic Subdural Hematoma: A Systematic Review and Component Network Meta-analysis of 455 Studies With 103 645 Cases

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurosurgical condition with a high risk of recurrence after treatment.

OBJECTIVE

To assess and compare the risk of recurrence, morbidity, and mortality across various treatments for CSDH.

METHODS

A systematic review and meta-analysis was performed. PubMed/MEDLINE, EMBASE, SCOPUS, and Web of Science were searched from January 01, 2000, to July 07, 2021. The primary outcome was recurrence, and secondary outcomes were morbidity and mortality. Component network meta-analyses (CNMAs) were performed for surgical and medical treatments, assessing recurrence and morbidity. Incremental risk ratios (iRRs) with 95% CIs were estimated for each component.

RESULTS

In total, 12 526 citations were identified, and 455 studies with 103 645 cases were included. Recurrence occurred in 11 491/93 525 (10.8%, 95% CI 10.2-11.5, 418 studies) cases after surgery. The use of a postoperative drain (iRR 0.53, 95% CI 0.44-0.63) and middle meningeal artery embolization (iRR 0.19, 95% CI 0.05-0.83) reduced recurrence in the surgical CNMA. In the pharmacological CNMA, corticosteroids (iRR 0.47, 95% CI 0.36-0.61) and surgical intervention (iRR 0.11, 95% CI 0.07-0.15) were associated with lower risk. Corticosteroids were associated with increased morbidity (iRR 1.34, 95% CI 1.05-1.70). The risk of morbidity was equivalent across surgical treatments.

CONCLUSION

Recurrence after evacuation occurs in approximately 10% of cSDHs, and the various surgical 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.

Subdural evacuation port system and middle meningeal artery embolization for chronic subdural hematoma: a multicenter experience

OBJECTIVE

Middle meningeal artery (MMA) embolization and the Subdural Evacuation Port System (SEPS) are minimally invasive treatment paradigms for chronic subdural hematoma (cSDH). Although SEPS offers acute decompression of local mass effect from a cSDH, MMA embolization has been shown to reduce the rate of cSDH recurrence. In combination, these procedures present a potentially safer strategy to a challenging pathology. The authors present a multi-institutional retrospective case series that assessed the safety, efficacy, and complications of SEPS and MMA embolization for cSDH.

METHODS

A retrospective review was performed of patients who underwent SEPS placement and MMA embolization for cSDH between 2018 and 2021 at three institutions.

RESULTS

One hundred patients with 136 cSDHs and a median age of 73 years underwent both SEPS placement and MMA embolization. Initial Glasgow Coma Scale scores were between 14 and 15 in 81% of patients and between 9 and 13 in 14%. The median initial midline shift (MLS) was 7 mm, with subdural hematoma (SDH) in the left hemisphere (lh) in 30% of patients, right hemisphere (rh) in 34%, and bilateral hemispheres in 36%. Follow-up was available for 86 patients: 93.4% demonstrated decreased MLS, and all patients with lhSDH and rhSDH demonstrated progressive decrease in SDH size. The overall complication rate was 4%, including 1 case of facial palsy and 3 cases of iatrogenic acute SDH. Two subjects (2%) required craniotomy for hematoma evacuation. The rate of good functional outcomes, with modified Rankin Scale (mRS) score < 2, was 89% on final follow-up and the overall mortality rate was 2%. A good mRS score on admission was associated with increased odds of functional improvement at follow-up (p < 0.001).

CONCLUSIONS

SEPS placement with MMA embolization for cSDH can be done safely and effectively reduces cSDH size with minimal perioperative morbidity.

Surgical Treatment of Bilateral Chronic Subdural Hematoma

Background

Chronic subdural hematoma (CSDH) is one of the common clinical intracranial hemorrhagic disorders, accounting for 16%-20% of bilateral CSDH. At present, the surgical treatment of bilateral CSDH mainly includes drilling drainage and neuroendoscopic assistance. The main objective of this paper was to compare the effects of two surgical methods on CSDH.

Methods

153 patients who were diagnosed with CSDH were included in this study. 79 patients were treated with bilateral drilling drainage, and the other 74 patients were treated with neuroendoscope-assisted drainage. The clinical data of the two groups were compared, and the surgical indexes, neurological function, cure rate, and recurrence rate of the two groups were compared. The operation indexes of patients include operation time, postoperative hematoma volume, hospital stay, extubation time, misplacement of drainage tube, recurrence, and hematoma clearance rate.

Results

All patients underwent CT  examination one day after operation. The CT  imaging detection of the two groups was generally good. The cranial CT was reexamined before discharge. The bilateral hematoma disappeared in 114 patients, the unilateral hematoma disappeared in 29 patients, a small amount of compensatory crescent very low-density shadow subdural effusion was observed on the other side, and a small amount of compensatory crescent very low-density shadow subdural effusion was observed on both sides in 10 patients. There was no space occupying effect and intracranial gas disappeared. Compared with neuroendoscopic assisted drainage, the operation time of drilling drainage patients was significantly shorter. The extubation time, drainage tube dislocation, recurrence rate, postoperative hematoma volume, and hematoma clearance rate of patients receiving neuroendoscopic assisted drainage were significantly better than those receiving drilling drainage. The Markwalder score and hospital stay between the two groups were not significant.

Conclusions

Drilling drainage and neuroendoscopic assisted surgery have good therapeutic effects on bilateral CSDH. The operation time of drilling drainage is shorter. Neuroendoscopic assisted surgery has more advantages in extubation time, misplacement of drainage tube, recurrence, postoperative hematoma volume, and hematoma clearance rate.

Trans-cell Approach through Closed-cell Stent for Middle Meningeal Artery Embolization in Recurrent Chronic Subdural Hematoma

We report a case of recurrent chronic subdural hematoma (CSDH) treated using the trans-cell approach through a closed-cell stent for middle meningeal artery embolization (MMAE). A 77-year-old man with acute ischemic stroke due to anterior circulation tandem occlusion was treated with intracranial thrombectomy and carotid artery stenting using a closed-cell stent 5 years ago. He experienced head trauma after a fall, which then developed into a CSDH. Burr hole surgery was performed twice, followed by MMAE considering the high possibility of recurrence due to antiplatelet therapy and brain atrophy after ischemic stroke. A distal access catheter was inserted into the external carotid artery through the closed-cell stent, and a microcatheter was navigated in the middle meningeal artery. The anterior and posterior convexity branches were embolized with 16.7% N-butyl cyanoacrylate. The postoperative course was favorable, and CT at 3-month follow-up showed a decrease in the hematoma. Even after the placement of the closed-cell stent, endovascular treatment of the external carotid artery is possible and can be a therapeutic option using the trans-cell approach.

Endovascular Treatment of Chronic Subdural Hematomas through Embolization: A Pilot Study with a Non-Adhesive Liquid Embolic Agent of Minimal Viscosity (Squid)

OBJECTIVE

Endovascular embolization using non-adhesive agents (e.g., ethylene vinyl alcohol copolymer with suspended micronized tantalum dissolved in dimethyl sulfoxide; Squid, Balt Extrusion) is an established treatment of brain arteriovenous malformations, dural arteriovenous fistulas, and hypervascular neoplasms. Middle meningeal artery (MMA) embolization is a relatively new concept for treating chronic subdural hematomas (CSDH). This study aimed to evaluate the safety and effectiveness of the use of Squid in the endovascular treatment of CSDH.

METHODS

Embolization was offered to patients with CSDH with minimal or moderate neurological deficits and patients who had previously undergone open surgery to evacuate their CSDH without a significant effect. Distal catheterization of the MMA was followed by embolization of the hematoma capsule with Squid 12 or Squid 18. Safety endpoints were ischemic or hemorrhagic stroke and any other adverse event of the endovascular procedure. Efficacy endpoints were the feasibility of the intended procedure and a ≥ 50% reduction of the maximum depth of the CSDH confirmed by follow-up computed tomography (CT) after >3 months.

RESULTS

Between November 2019 and July 2021, 10 patients (3 female and 7 male, age range 42-89 years) were enrolled. Five patients had bilateral hematomas, and five patients had previously been operated on with no significant effect and recurrent hematoma formation. The attempted embolization was technically possible in all patients. No technical or clinical complication was encountered. During a post-procedural follow-up (median 90 days), 10 patients improved clinically. A complete resolution of the CSDH was observed in 10 patients. The clinical condition of all enrolled patients during the so-far last contact was rated mRS 0 or 1.

CONCLUSION

A distal catheterization of the MMA for the endovascular embolization of CSDH with Squid allowed for the devascularization of the MMA and the dependent vessels of the hematoma capsule. This procedure resulted in a partial or complete resolution of the CSDH. Procedural complications were not encountered.