Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Middle meningeal artery embolization following surgical evacuation of symptomatic chronic subdural hematoma improves outcomes, interim results of a prospective randomized trial

BACKGROUND

Outcomes after surgical treatment of chronic subdural hematoma (cSDH) remain undesirable in a significant proportion of patients. We aimed to show the role of middle meningeal artery (MMA) embolization and to demonstrate its benefits.

METHODS

Thirty-five patients with symptomatic cSDH were enrolled in a prospective randomized trial following evacuation surgery. Participants were randomized to embolization or control group (expectant management following surgical evacuation without embolization). Patients were followed throughout their hospitalization and outpatient follow-ups. The main goals of this planned interim analysis were to assess neurological outcome and resource utilization.

RESULTS

The groups were comparable in terms of sex, age and follow-up retention rates. Side(s) of intervention(s) and hematoma size were similar. There was no statistical difference in neurological examination improvement at discharge, but at follow-up, we observed a decline in neurologic exam in the control group (p = 0.03). Control group participants required more re-interventions (p = 0.02) and were followed in clinic and during related readmissions for longer (p = 0.02). The number of imaging studies obtained in relation to the disease management was higher in the control group (p = 0.01).

CONCLUSIONS

Our results suggest a beneficial role for the addition of MMA embolization to surgical intervention in the treatment of symptomatic chronic subdural hematoma. Neurological outcomes were significantly better in the embolization group. This contributed to less need for follow-up, re-interventions, and imaging studies.

Safety of Postembolization Antithrombotic Therapy After Middle Meningeal Artery Embolization

BACKGROUND AND OBJECTIVES

Middle meningeal artery embolization (MMAE) for the management of chronic subdural hematoma (cSDH) has been suggested as a preferred treatment in patients where reinitiating antithrombotic (AT) therapy is necessary. In this study, we evaluate whether reinitiating AT therapy before cSDH resolution after MMAE affects radiographic and clinical resolution.

METHODS

This is a retrospective study of patients who underwent MMAE at our institution between 2018 and 2024. Clinical and radiographic findings were analyzed with standard statistical approaches. Kaplan-Meier curves for nonresolution compared AT and no-AT groups and compared AT resumption before and after 30 days after surgery.

RESULTS

In 111 MMAE procedures, the median age was 73 years, 27.9% were female, and 80.6% were White. The median follow-up was 5.1 months. Forty-six patients (41.4%) demonstrated complete resolution of their cSDH. Eleven patients (9.9%) had reoperation after MMAE. The median cSDH depth was 14.0 mm, and the median midline shift was 3.0 mm. Thirty-two patients (28.8%) resumed AT before resolution. The median time to resumption was 35.5 days. Patients in the AT group were less likely to have radiographic resolution (21.9% vs 49.4%, odds ratios = 0.2872, 95% CI = 0.1113-0.7404, P = .0103) but comparable rates of reoperation and residual symptomatic presentations. Resumption of AT therapy before or after 30 days from surgery had no effects on outcome measures on univariate analysis. Major outcomes were similar between patients receiving antiplatelet-only or anticoagulant-only medications.

CONCLUSION

Reinitiating AT therapy before cSDH resolution was associated with decreased rates of resolution, but comparable rates of reoperation and residual symptoms. Our results support the cautious reinitiation of AT therapy in patients requiring it after MMAE.

Middle Meningeal Artery Embolization Reduces the Recurrence Rate of Chronic Subdural Hematoma: A Propensity Score Matching Analysis

To evaluate the effect of middle meningeal artery embolization (MMAE) on chronic subdural hematoma (CSDH). The authors enrolled consecutive patients with CSDH who underwent burr hole craniostomy (BHC) between January 2020 and February 2023. The primary outcome was recurrence rate, defined as an increase of hematoma width on imaging compared with the immediate postoperative imaging at a 3-month follow-up. Secondary outcomes included the rate of complications and adverse prognosis. Cohorts were balanced using 1:2 propensity score matching (PSM). A total of 271 patients were eligible for this study and divided into the MMAE group (n=23) and the BHC group (n=205). Compared with the BHC group, there was more use of anticoagulant or antiplatelet medication (47.8% vs 22.4%, P=0.008), bilateral hematoma (19.5% vs 19.5%, P=0.043), and hematoma with septations (47.8% vs 21.5%, P=0.005) in the MMAE group. After PSM, 64 cases were finally successfully matched. The logistic analysis result showed that MMAE was associated with the decreased recurrence rate of CSDH in the cohort after PSM (OR 0.072, 95% CI: 0.322~0.746, P=0.028) but not with the improved clinical prognosis (OR 0.065, 95% CI: 0.533~4.786, P=0.562). MAAE has a positive therapeutic effect on reducing the recurrence rate of CSDHs as an adjunct postoperative treatment after burr hole surgery.

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.

Medical management of chronic subdural hematoma with low-dose hydrocortisone: a case series

Chronic subdural hematomas (cSDH) are often managed with a burr-hole craniostomy and drainage, but surgery is associated with elevated mortality, morbidity, and recurrence. Despite reports of steroid use for such patients, its efficacy and feasibility are still debated. We present our patient series treated with low-dose hydrocortisone. We retrospectively reviewed data from patients treated with hydrocortisone between 2017 and 2023. Demographics, clinical and radiological data were collected. Of 27 patients identified, nine required a burr-hole craniotomy for an average volume of 120.23 cm3, average midline shift of 9 mm, and neurological deficits. Eighteen met the criteria for inclusion. The mean age was 78.5 years; 13 were male. None had severe symptoms requiring urgent intervention. Except for one with a Karnofsky Performance Scale score of 70, all could maintain normal activity before treatment. The mean baseline volume was 52.6 cm3. Midline shift, present in six, averaged 6.8 mm. Patients underwent treatment for an average of 5.15 months. Nine had complete resolution within 3 months, while nine required longer treatment, including one who needed 9 months for a re-bleed after a fall. Paired t-tests indicated significant reductions in hematoma volumes at the second week (p = 0.01), first month (p < 0.0001), and third month (p < 0.0001) of treatment. No complications occurred and the post-treatment Karnofsky scores ranged from 90 to 100. Treatment for cSDH should be tailored to the patient. Low-dose hydrocortisone is safe and effective in asymptomatic patients, those with mild to moderate symptoms, and those who are either unsuitable for or decline surgical intervention.

Quantifying extent of meningioma preoperative embolization through volumetric analysis: A retrospective case series

BACKGROUND

Endovascular embolization is an adjunct to meningioma resection. Isolating the effectiveness of embolization is difficult as MR imaging is typically performed before embolization and after resection, and volumetric assessment of embolization on 2D angiographic imaging is challenging. We investigated the correlation between 2D angiographic and 3D MR measurements of meningioma devascularization following embolization.

METHODS

We implemented a protocol for postembolization, preresection MRI. Angiographic devascularization was graded according to reduction of tumor blush from 1 (partial embolization) to 4 (complete embolization with no residual circulation supply). Volumetric extent of embolization was quantified as the percent of tumor contrast enhancement lost following embolization. Tumor embolization was analyzed according to tumor location and vascular supply.

RESULTS

Thirty consecutive patients met inclusionary criteria. Grade 1 devascularization was achieved in 7% of patients, grade 2 in 43%, grade 3 in 20%, and grade 4 in 30%. Average extent of embolization was 37 ± 6%. Extent of tumor embolization was low (<25%) in 40%, moderate (25%-75%) in 40%, and high (>75%) in 20% of patients. Convexity, parasagittal/falcine and sphenoid wing tumors were found to have distinct vascular supply patterns and extent of embolization. Angiographic devascularization grade was significantly correlated with volumetric extent of tumor embolization (p < 0.001, r = 0.758).

CONCLUSION

This is the first study to implement postembolization, preoperative MRI to assess extent of embolization prior to meningioma resection. The study demonstrates that volumetric assessment of contrast reduction following embolization provides a quantitative and spatially resolved framework for assessing extent of tumor embolization.

Cost Savings on Inpatient Hospitalization for Middle Meningeal Artery Embolization in the Setting of Increased Case Volume and Low Complications Rate

BACKGROUND

Middle meningeal artery (MMA) embolization for the treatment of chronic subdural hematomas (cSDHs) is becoming increasingly prevalent. It is essential to optimize the safety and cost effectiveness of the postprocedural management. In this study, we examined our cases over time to determine the most appropriate postprocedural destination.

METHODS

This is a retrospective study of patients who underwent MMA embolization for cSDH at our institution. The study cohort was divided into 2 groups based on the year of embolization. Baseline characteristics, postprocedural complications, and length of stay were compared. Patients with shorter intensive care unit (ICU) stay were also compared to those with longer stay. Univariate statistical analysis was performed.

RESULTS

92 MMA embolizations for cSDH have been performed at our institution, of which 36 (39.1%) were done between 2019 and 2022 and 56 (60.9%) after 2023. No patients experienced stroke, cranial nerve palsy, or intraparenchymal hemorrhage after embolization. All but 5 patients were admitted to the ICU postembolization, of which 59 (64.1%) were downgraded after one day. Factors associated with a longer ICU stay included preoperative location (P = 0.002) and need for surgery (P = 0.02). Of those who came from home or nonmonitored bed, 82% were downgraded from the ICU in less than 2 days. The average cost of one night in the ICU, intermediate care, and nonmonitored unit was $3671.75, $2605.22, and $2303.81 respectively.

CONCLUSIONS

MMA embolization for cSDH is a safe procedure with low rate of procedure-related complications. In carefully selected patients, the necessity ICU admission postoperatively should be weighed against better hospital resource utilization.

Chronic subdural hematoma: What precisely are we treating?

Subdural hematoma (SDH) refers to the collection of blood between the dura matter and the arachnoid membrane. Advancements in imaging technology have enabled the categorization of SDH based on specific imaging characteristics, causative factors, and the onset of symptoms. Given that the prognosis of SDHs varies significantly and is contingent upon the size and chronicity of the hemorrhage, a comprehensive understanding of its subtypes may carry crucial treatment implications. For example, an acute SDH classically results from severe traumatic brain injury and appears as a homogenous, crescent-shaped hyperdense extra-axial collection. If not treated, over the course of 1-3 weeks, this hematoma will evolve into a sub-acute phenotype as a consequence of subdural effusion and demonstrate mixed-density hemorrhage on imaging. Chronic SDH (cSDH) becomes the end result of an untreated SDH, with neo-membranization and neo-angiogenesis from branches of the middle meningeal artery driving a mass-like growth pattern. This review article aims to elucidate the complex anatomical features of the end-stage cSDH, with a particular focus on reconceptualization of this entity based on its mass-like growth patterns, and how this is driving a shift towards endovascular treatment.

Femoral versus radial access for middle meningeal artery embolization for chronic subdural hematomas: multicenter propensity score matched study

BACKGROUND

With transradial access (TRA) being more progressively used in neuroendovascular procedures, we compared TRA with transfemoral access (TFA) in middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH).

METHODS

Consecutive patients undergoing MMAE for cSDH at 14 North American centers (2018-23) were included. TRA and TFA groups were compared using propensity score matching (PSM) controlling for: age, sex, concurrent surgery, previous surgery, hematoma thickness and side, midline shift, and pretreatment antithrombotics. The primary outcome was access site and overall complications, and procedure duration; secondary endpoints were surgical rescue, radiographic improvement, and technical success and length of stay.

RESULTS

872 patients (median age 73 years, 72.9% men) underwent 1070 MMAE procedures (54% TFA vs 46% TRA). Access site hematoma occurred in three TFA cases (0.5%; none required operative intervention) versus 0% in TRA (P=0.23), and radial-to-femoral conversion occurred in 1% of TRA cases. TRA was more used in right sided cSDH (58.4% vs 44.8%; P<0.001). Particle embolics were significantly higher in TFA while Onyx was higher in TRA (P<0.001). Following PSM, 150 matched pairs were generated. Particles were more utilized in the TFA group (53% vs 29.7%) and Onyx was more utilized in the TRA group (56.1% vs 31.5%) (P=0.001). Procedural duration was longer in the TRA group (median 68.5 min (IQR 43.1-95) vs 59 (42-84); P=0.038), and radiographic success was higher in the TFA group (87.3% vs 77.4%; P=0.036). No differences were noted in surgical rescue (8.4% vs 10.1%, P=0.35) or technical failures (2.4% vs 2%; P=0.67) between TFA and TRA. Sensitivity analysis in the standalone MMAE retained all associations but differences in procedural duration.

CONCLUSIONS

In this study, TRA offered comparable outcomes to TFA in MMAE for cSDH in terms of access related and overall complications, technical feasibility, and functional outcomes. Procedural duration was slightly longer in the TRA group, and radiographic success was higher in the TFA group, with no differences in surgical rescue rates.

Advances in pathogenic mechanisms, diagnostic methods, surgical and non-surgical treatment, and potential recurrence factors of Chronic Subdural Hematoma: A review

Chronic Subdural Hematoma (CSDH) is a common hemorrhagic disease in neurosurgery, and with the intensification of global aging, its incidence is gradually increasing. With the advancement of scientific technology, the etiological concepts and surgical treatments for CSDH have continually evolved over time. Currently, neuroscientists' understanding of CSDH is no longer confined to bridging vein rupture; exploration of various mechanisms such as angiogenesis, maturation of blood vessels, and inflammation is also underway. In-depth exploration and discovery of pathogenic mechanisms guide the updating of clinical treatment strategies and methods. For different types of CSDH, there is now a clear guidance for the targeted selection of treatment methods. However, the current treatment of CSDH cannot completely solve all problems, and the updating of treatment methods as well as the development and validation of new effective drugs remain challenges for the future. In addition, the recurrence of CSDH is a significant issue that needs to be addressed. Although we have reviewed potential recurrent factors that may be associated, the strength of this evidence is insufficient. Future research should gradually focus on validating these recurrent factors and exploring new ones, in order to optimize the existing understanding and treatment of CSDH.

Middle Meningeal Arterial Embolization Combined With Drilling in the Treatment of Acute Epidural Hematoma

OBJECTIVE

The purpose of this study was to determine the technical feasibility and safety of middle meningeal arterial (MMA) embolization combined with drilling drainage in the treatment of acute epidural hematoma (AEDH) by comparing it with traditional craniotomy in the treatment.

METHODS

One hundred seventeen patients with AEDH treated for MMA embolization combined with drilling and drainage or craniotomy hematoma removal from January 2017 to September 2020 were retrospectively analyzed and divided into a craniotomy group (n=85) and a minimally invasive group (n=32). Hematoma removal was performed in the craniotomy group, and MMA embolization combined with drilling and drainage was performed in the minimally invasive group. The general clinical data, imaging data, surgery, and follow-up of the 2 groups were compared and analyzed.

RESULTS

Compared with the craniotomy group, the residual hematoma volume in the minimally invasive group was higher than in the craniotomy group. The average postoperative drainage duration in the minimally invasive group was longer than in the craniotomy group. Compared with the craniotomy group, the minimally invasive group was associated with shorter operative time, less intraoperative bleeding, and lower rates of postoperative rebleeding. In addition, the incidence of postoperative complications and length of hospitalization in the minimally invasive group were significantly shortened.

CONCLUSION

Middle meningeal arterial embolization combined with drilling and drainage in the treatment of AEDH caused by MMA active bleeding is safe, effective, and more minimally invasive, and can be promoted and applied.

Therapeutic efficacy of drilling drainage combined with intraoperative middle meningeal artery occlusion in the management of chronic subdural hematoma: a clinical study

BACKGROUND

The bone holes in the skull during surgical drainage were accurately located at the site of the MMA. The MMA was severed, and the hematoma was removed intraoperatively; furthermore, surgical drainage removed the pathogenic factors of CSDH. This study aimed to describe and compare the results of the new treatment with those of traditional surgical drainage, and to investigate the relevance of this approach.

METHODS

From December 2021 to June 2023, 72 patients were randomly assigned to the observation group and the control group. The control group was treated with traditional surgical drainage, while the observation group was treated with DSA imaging to accurately locate the bone holes drilled in the skull on the MMA trunk before traditional surgical drainage. The MMA trunk was severed during the surgical drainage of the hematoma. The recurrence rate, time of indwelling drainage tube, complications, mRS, and other indicators of the two groups were compared, and the changes of cytokine components and imaging characteristics of the patients were collected and analyzed.

RESULTS

Overall, 27 patients with 29-side hematoma in the observation group and 45 patients with 48-side hematoma in the control group were included in the study. The recurrence rate was 0/29 in the observation group and 4/48 in the control group, indicating that the recurrence rate in the observation group was lower than in the control group (P = .048). The mean indwelling time of the drainage tube in the observation group was 2.04 ± 0.61 days, and that in the control group was 2.48 ± 0.61 days. The indwelling time of the drainage tube in the observation group was shorter than in the control group (P = .003). No surgical complications were observed in the observation group or the control group. The differences in mRS scores before and after operation between the observation group and the control group were statistically significant (P < .001). The concentrations of cytokine IL6/IL8/IL10/VEGF in the hematoma fluid of the observation and control groups were significantly higher than those in venous blood (P < .001). After intraoperative irrigation and drainage, the concentrations of cytokines (IL6/IL8/IL10/VEGF) in the subdural hematoma fluid were significantly lower than they were preoperatively. In the observation group, the number of MMA on the hematoma side (11/29) before STA development was higher than that on the non-hematoma side (1/25), and the difference was statistically significant (P = .003).

CONCLUSION

In patients with CSDH, accurately locating the MMA during surgical trepanation and drainage, severing the MMA during drainage, and properly draining the hematoma, can reduce the recurrence rate and retention time of drainage tubes, thereby significantly improving the postoperative mRS Score without increasing surgical complications.

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

BACKGROUND AND OBJECTIVES

Middle meningeal artery embolization (MMAE) has emerged as a promising modality for chronic/subacute subdural hematoma treatment; however, consensus regarding embolization technique and embolisate has not been achieved. We thus sought to compare the efficacy of distinct MMAE techniques and embolisate.

METHODS

An institutional registry was reviewed to identify patients undergoing standalone MMAE for symptomatic chronic/subacute subdural hematoma. Surgical rescue rate and time preceding 50% hematoma resolution were evaluated across 3 technical groups: aggressive penetration (AP), nonaggressive penetration with proximal coil embolization (NP-PC), and nonaggressive penetration alone (NP). Effect sizes were adjusted for demographic, neurological and radiological features through multivariable logistic and Cox regression.

RESULTS

Among 117 procedures, 33.3% achieved AP, 36.8% had NP-PC, and 29.9% had NP. The rate of surgical rescue was 2.6% after AP, 9.3% for NP-PC, and 11.4% for NP. In patients not undergoing rescue surgery, 82.4% achieved hematoma resolution ≥50% at a median imaging follow-up of 56 days; AP or NP-PC were each statistically significantly associated with enhanced hematoma resolution as compared with NP (P = .02). Similarly, sensitivity analysis within medium-size hematoma and antiplatelet/anticoagulation-at-admission subgroups revealed a superiority of resolution after AP or NP-PC. A unique, comparative secondary analysis of liquid embolisate (Onyx vs n-butyl cyanoacrylate) revealed no impact on rate of surgical rescue or hematoma resolution.

CONCLUSION

AP was associated with the lowest rate of surgical rescue, while both AP and NP-PC were associated with improved rates of hematoma resolution.

Factors associated with success of conservative therapy in chronic subdural hematoma: a single-center retrospective analysis

INTRODUCTION

Conservative therapy is a viable option for patients with chronic subdural hematoma (cSDH) who express no, or only mild symptoms. It is not clear which factors are associated with success of conservative therapy. This study aims to determine conservative therapy's success rate and to identify features possibly associated with success.

METHODS

A monocenter retrospective cohort study, including cSDH patients treated conservatively (wait-and-watch) from 2012 to 2022, was performed. The primary outcome was success of conservative therapy, defined as 'no crossover to surgery' during the follow-up period. Secondary outcomes were (1) factors associated with success, analyzed with univariate and multivariable logistic regression analyses, (2) 30-day mortality (3) time to crossover and (4) reasons for crossover.

RESULTS

We included 159 patients. Conservative therapy was successful in 96 (60%) patients. Hematoma volume (OR 0.79, 95% CI 0.69-0.92) and hypodense hematoma type (OR 3.57, 95% 1.38-9.23) were associated with success. Thirty-day mortality rate was 5% and the median duration between diagnosis and surgery was 19 days (IQR 8-39). Clinical deterioration was the most frequent reason for crossover (in 61/63 patients, 97%) and was accompanied by radiological hematoma progression in 42 patients (67%).

CONCLUSION

In this selected group of patients, conservative therapy was successful in 60%. Smaller hematoma volume and hypodense hematoma type were associated with success. As time until crossover was approximately three weeks, deploying conservative therapy as primary treatment seems safe and could be rewarding as surgical complications can be avoided. Improvement in patient selection in future cohorts remains warranted.

The Use of Middle Meningeal Artery Embolization to Treat Chronic Subdural Hematoma in the Pediatric Population: A Review of the Literature

Chronic subdural hematoma (cSDH) is rare in the pediatric population and typically arises from various causes. These include trauma (accidental, non-accidental, or birth-related injuries), coagulopathies (such as hemophilia or von Willebrand disease), vascular malformations (such as arteriovenous malformations), and complications from previous surgeries. These diverse etiologies contribute to the complexity of managing this condition. Although middle meningeal artery (MMA) embolization is proven effective in adults, limited studies have investigated its applicability in pediatrics. This study aims to assess the efficacy, safety, and outcomes of MMA embolization in the pediatric age group, guiding future research and treatment strategies. A systematic review of the literature was conducted using PubMed, Web of Science, and Embase. No restrictions were applied regarding publication status or follow-up duration. The inclusion criteria were studies that integrated MMA embolization as a treatment for cSDH in pediatric patients. Data extracted included patient sample and characteristics, cSDH etiology and characteristics, prior intervention, procedural technique and indication, and clinical and radiological outcomes. Twelve studies were included in the review, comprising a total of 14 patients. There were no randomized clinical trials or large-scale cohort studies. The included literature consisted of 11 case reports and one case series, and the results described a clinical and radiological outcome in a varied mix of patients with different characteristics and backgrounds for cSDH. No neurological complications attributed to MMA embolization were reported. Follow-up showed resolved or decreased size of cSDH in all patients except for one, who experienced hematoma expansion despite treatment. MMA embolization may be considered a primary or adjuvant treatment modality for cSDH in the pediatric population. However, further research is needed to investigate the impact of different etiologies on outcomes and to highlight long-term complications and results.

Middle Meningeal Artery Embolization in the Treatment of Acute Subdural Hematoma: A Case Series Featuring Access Through a Carotid Stent

The first objective of this case series was to describe the case of a patient with severe symptomatic left internal carotid artery stenosis after a recent stroke. Several days after stent placement by transcarotid artery revascularization, the patient developed a left-sided subdural hematoma. The patient then underwent embolization of the left middle meningeal artery (MMA) despite blocked access to the left MMA because of an internal carotid stent. The external carotid artery was accessed by passing a guiding catheter through the stent wall. We describe this method as "intrawall access." This allowed a coaxial system to deliver polyvinyl alcohol particles to the MMA for embolization. Embolization was successfully performed, with the stent integrity and blood flow through it remaining uncompromised. Overall, we demonstrated a new method of access through a previously placed internal carotid stent to gain neurointerventional access to the external carotid artery, which was jailed by a stent, for treating an acute subdural hematoma via MMA embolization. The second objective of this case series was to demonstrate the first MMA embolization in literature carried out in the acute or acute-on-subacute setting, in this case, and in four others.

Occult middle meningeal artery to middle cerebral artery anastomosis associated with prior trauma

The report describes a patient who presented with traumatic right temporoparietal calvarial fracture with chronic right subdural haematoma who underwent right middle meningeal artery embolisation with n-BCA during which direct filling of an anterior temporal branch of the middle cerebral artery was observed.

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.

Embolization of Middle Meningeal Arteries for Symptomatic Subacute Subdural Hematoma in Patients with Cancer

PURPOSE

The purpose of this study was to evaluate the technical and clinical success of middle meningeal artery (MMA) embolization performed for symptomatic subacute subdural hematoma (SDH) in patients with cancer.

METHODS

This study retrospectively included 23 consecutive patients (12 men, 11 women; median age 61 years, interquartile range: 55.5-75.5) who underwent 34 MMA angiograms for symptomatic SDH in 2022 and 2023. Median SDH thickness was 10.5 mm (7-12). Median platelet count was 117 K/mcL (54.5-218). 10 patients (43.5%, 10/23) had hematologic malignancies, seven patients (30.4%, 7/23) had surgery. Fluoroscopy time (FT), reference dose (RD), and kerma area product (Kap) were analyzed. Adverse events and outcomes were recorded.

RESULTS

The median imaging and clinical follow-up were 65 days (36.5-190.5) and 163 days (86-274), respectively. The technical success rate was 91.2% (31/34) as three MMA were not identified in two patients. Median procedure duration was 61 min (55.5-75.5). Median FT was 21.6 min (15.5-31.8); median RD was 158 mGy (96-256); and median Kap was 32.9 Gy.cm2 (20.4-45.1). No further intervention was needed. For 16 patients, SDH resolved after in median 59.5 days (50-90). For seven patients, SDH remained visible on the last imaging follow-up performed at 24 days in median (6.5-36.5). No predictive factor of failure was identified. The adverse event rate was 1/23 (4.3%). Eight patients (34.8%, 8/23) died during follow-up from progression of cancer.

CONCLUSION

MMA embolization of symptomatic SDH in patients with cancer appears safe and is associated with improvement in clinical symptoms.

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.

Grading Embolization of Middle Meningeal Artery for Chronic Subdural Hematoma

BACKGROUND AND PURPOSE

Embolization of middle meningeal artery (EMMA) is a relatively new treatment for chronic subdural hematoma (CSDH). To date, an objective method that assesses or describes the extent of EMMA for the treatment of CSDH does not exist. Recently, the concept of a novel grading scale for EMMA in patients with CSDH has emerged. However, this has not been applied to a clinical case setting and inter-rater reliability has not yet been studied. The purpose of this study was to validate the grading scale in clinical practice and to assess for inter-rater reliability.

MATERIALS AND METHODS

We retrospectively examined consecutive patients who underwent EMMA for CSDH. Patients were included if the whole head angiogram from common carotid as well as external carotid arteries before and after EMMA were available in the arterial, capillary as well as venous phases. Two independent readers, each with more than 5 years of experience in independent practice, assessed the angiograms for the grading of EMMA and assigned a score ranging between 0 and 3. The grading score between the two readers were compared using Cohen's Kappa score to assess the inter-rater reliability.

RESULTS

In 19 patients, we found that EMMA had no periprocedural morbidity and mortality. The number of cases in each EMMA grading score category are as follows: 0 n =1; 1 n =3; 2 n =1; and 3 n =10. There was substantial inter-rater reliability for the assessment of grading of EMMA (Kappa = 0.74).

CONCLUSIONS

The novel EMMA grading scheme demonstrated substantial inter-rater reliability and appears promising.

ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

Advances in chronic subdural hematoma and membrane imaging

Chronic subdural hematoma (cSDH) is projected to become the most common cranial neurosurgical disease by 2030. Despite medical and surgical management, recurrence rates remain high. Recently, middle meningeal artery embolization (MMAE) has emerged as a promising treatment; however, determinants of disease recurrence are not well understood, and developing novel radiographic biomarkers to assess hematomas and cSDH membranes remains an active area of research. In this narrative review, we summarize the current state-of-the-art for subdural hematoma and membrane imaging and discuss the potential role of MR and dual-energy CT imaging in predicting cSDH recurrence, surgical planning, and selecting patients for embolization treatment.

Middle meningeal artery embolization associated with reduced chronic subdural hematoma volume and midline shift in the acute postoperative period

BACKGROUND

Middle meningeal artery (MMA) embolization for endovascular treatment of chronic subdural hematoma (cSDH) is growing in popularity. cSDH volume and midline shift were analyzed in the immediate postoperative window after MMA embolization.

METHODS

A retrospective analysis of cSDHs managed via MMA embolization from January 1, 2018 to March 30, 2021 was performed at a large quaternary center. Pre- and postoperative cSDH volume and midline shift were quantified with CT. Postoperative CT was obtained 12 to 36 hours after embolization. Paired t-tests were used to determine significant reduction. Multivariate analysis was performed using logistic and linear regression for percent improvement from baseline volume.

RESULTS

In total, 80 patients underwent MMA embolization for 98 cSDHs during the study period. The mean (SD) initial cSDH volume was 66.54 (34.67) mL, and the mean midline shift was 3.79 (2.85) mm. There were significant reductions in mean cSDH volume (12.1 mL, 95% CI 9.32 to 14.27 mL, P<0.001) and midline shift (0.80 mm, 95% CI 0.24 to 1.36 mm, P<0.001). In the immediate postoperative period, 22% (14/65) of patients had a>30% reduction in cSDH volume. A multivariate analysis of 36 patients found that preoperative antiplatelet and anticoagulation use was significantly associated with an expansion in volume (OR 0.028, 95% CI 0.000 to 0.405, P=0.03).

CONCLUSION

MMA embolization is safe and effective for the management of cSDH and is associated with significant reductions in hematoma volume and midline shift in the immediate postoperative period.

Updates in traumatic brain injury management: brain oxygenation, middle meningeal artery embolization and new protocols

Traumatic brain injury (TBI) confers significant morbidity and mortality, and is a pathology often encountered by trauma surgeons. Several recent trials have evaluated management protocols of patients with severe TBI. The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase-II trial (BOOST-II) evaluated efficacy and feasibility of brain oxygen measurement in severe TBI. BOOST phase 3 trial (BOOST-3) and two ongoing trials look to measure functional outcomes in this population. Furthermore, middle meningeal artery embolization has now become standard therapy for adult patients with chronic subdural hematoma (SDH) and has increasing popularity in those with recurrent SDH as an alternative to surgical intervention. In this manuscript, we review the literature, ongoing trials, and discuss current updates in the management of TBI.

Middle Meningeal Artery Embolization in Acute Leukemia Patients Presenting With Subdural Hematoma

Intracerebral hemorrhage is a potentially fatal complication in patients with acute leukemia and contributing factors include thrombocytopenia and coagulopathy. Patients with acute leukemia may develop subdural hematoma (SDH) spontaneously or secondary to trauma. In patients with acute leukemia and SDH, the surgical evacuation of the hematoma causes significant morbidity and mortality. New approaches and strategies to reduce the need for surgical evacuation are needed to improve outcomes in patients with acute leukemia and intracerebral hemorrhage. We report two cases of acute SDH in patients with acute leukemia successfully treated with middle meningeal artery embolization, a minimally invasive interventional radiology technique, obviating the need for a surgical intervention. The first patient with acute promyelocytic leukemia (APL) presented with coagulopathy and developed an acute SDH after a fall. The second patient with acute myeloid leukemia presented with gum bleeding and also sustained an acute SDH after a fall. Both patients underwent middle meningeal artery embolization for treating their SDHs while actively receiving induction chemotherapy for acute leukemia. Both patients had resolution of their acute SDH and are in remission from their acute leukemia. Middle meningeal artery embolization is a very effective, and within the context of this setting, a novel, minimally invasive technique for management of SDH in acute leukemia patients, which can prevent the need for surgical interventions with its associated comorbidities and high risk of fatal outcomes in patients with acute leukemia and acute SDH.

Middle meningeal artery embolization for chronic subdural hematoma: A single-center experience and predictive modeling of outcomes

BACKGROUND

Remarkable interest is rising around middle meningeal artery embolization (MMAE) as an emerging alternative therapy for chronic subdural hematoma (cSDH). The study aims to highlight a large center experience and the variables associated with treatment failure and build experimental machine learning (ML) models for outcome prediction.

MATERIAL AND METHODS

A 2-year experience in MMAE for managing patients with chronic subdural hematoma was analyzed. Descriptive statistical analysis was conducted using imaging and clinical features of the patients and cSDH, which were subsequently used to build predictive models for the procedure outcome. The modeling evaluation metrics were the area under the ROC curve and F1-score.

RESULTS

A total of 100 cSDH of 76 patients who underwent MMAE were included with an average follow-up of 6 months. The intervention had a per procedure success rate of 92%. Thrombocytopenia had a highly significant association with treatment failure. Two patients suffered a complication related to the procedure. The best performing machine learning models in predicting MMAE failure achieved an ROC-AUC of 70%, and an F1-score of 67%, including all patients with or without surgical intervention prior to embolization, and an ROC-AUC of 82% and an F1-score of 69% when only patients who underwent upfront MMAE were included.

CONCLUSION

MMAE is a safe and minimally invasive procedure with great potential in transforming the management of cSDH and reducing the risk of surgical complications in selected patients. An ML approach with larger sample size might help better predict outcomes and highlight important predictors following MMAE in patients with cSDH.

Middle Meningeal Artery Embolization for Management of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a prevalent medical condition with potentially severe consequences if left untreated. While surgical removal has traditionally been the standard approach for treatment, middle meningeal artery (MMA) embolization has emerged as a promising minimally invasive alternative to reduce recurrences. This comprehensive review provides the general radiology community with an overview of MMA embolization as a therapeutic option for managing CSDH. The authors base their insights on existing evidence and their institutional experience. This overview encompasses the pathophysiology of CSDH as well as the potential advantages and limitations, safety profile, and potential complications of MMA embolization as compared with surgical treatment. The imaging findings seen before and after MMA, as well as insights into the procedural techniques used at the authors' institution, are described. On the basis of reports in the current literature, MMA embolization appears to be a safe and effective therapeutic option for managing CSDH, especially in patients who are unsuitable for surgery or at risk for recurrence. Nonetheless, further research is needed to validate these findings. Results from ongoing clinical trials hold promise for future validation and the establishment of scientific evidence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chatterjee in this issue.

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.

Neovascularization in Outer Membrane of Chronic Subdural Hematoma : A Rationale for Middle Meningeal Artery Embolization

OBJECTIVE

Chronic subdural hematomas (cSDHs) are generally known to result from traumatic tears of bridging veins. However, the causes of repeat spontaneous cSDHs are still unclear. We investigated the changes in vasculature in the human dura mater and outer membrane (OM) of cSDHs to elucidate the cause of their spontaneous repetition.

METHODS

The dura mater was obtained from a normal control participant and a patient with repeat spontaneous cSDHs. The pathological samples from the patient included the dura mater and OM tightly adhered to the inner dura. The samples were analyzed with a particular focus on blood and lymphatic vessels by immunohistochemistry, 3-dimensional imaging using a transparent tissue clearing technique, and electron microscopy.

RESULTS

The dural border cell (DBC) layer of the dura mater and OM were histologically indistinguishable. There were 5.9 times more blood vessels per unit volume of tissue in the DBC layer and OM in the patient than in the normal control. The DBC layer and OM contained pathological sinusoidal capillaries not observed in the normal tissue; these capillaries were connected to the middle meningeal arteries via penetrating arteries. In addition, marked lymphangiogenesis in the periosteal and meningeal layers was observed in the patient with cSDHs.

CONCLUSION

Neovascularization in the OM seemed to originate from the DBC layer; this is a potential cause of repeat spontaneous cSDHs. Embolization of the meningeal arteries to interrupt the blood supply to pathological capillaries via penetrating arteries may be an effective treatment option.

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.

Analysis of middle meningeal artery embolization for the treatment of chronic, acute on chronic, and subacute subdural hematomas

Background

Chronic subdural hematoma (cSDH) is a common sequela of traumatic brain injury. Middle meningeal artery embolization (MMAE) has shown promising results as an emerging minimally invasive alternative treatment. The purpose of this study is to examine the safety and efficacy of MMAE performed in patients with cSDH, acute-on-chronic, and subacute SDH with a traumatic etiology.

Methods

This retrospective study included cases performed at a Level II Trauma Center between January 2019 and December 2020 for MMAE of cSDHs. Data collected included patient demographic characteristics and comorbidities, SDH characteristics, complications, and efficacy outcomes. The lesion measurements were collected before the procedure, 4-6 weeks and 3-6 months post-procedure.

Results

In our patient population, 78% (39) either had lesions improve or completely resolved. The sample included 50 patients with a mean age of 74 years old. Statistically significant reductions in lesion size were found from pre- to post-procedure in the left lesions, right lesions, and midline shifts. The left lesions decreased from 13.88 ± 5.70 mm to 3.19 ± 4.89 mm at 3-6 months with P < 0.001. The right lesions decreased from 13.74 ± 5.28 mm to 4.93 ± 7.46 mm at 3-6 months with P = 0.02. Midline shifts decreased from 3.78 ± 3.98 mm to 0.48 ± 1.31 mm at 3-6 months with P = 0.02. No complications were experienced for bleeding, hematoma, worsening SDH, pseudoaneurysm, or stroke.

Conclusion

Our pilot study from a single center utilizing MMAE demonstrates that MMAE is successful without increasing treatment-related complications not only for cSDH but also in acute-on-cSDH and SDH with a subacute component.

Simple coiling of middle meningeal artery embolization for chronic subdural hematoma: An inverse probability of treatment weighting matched cohort study

BACKGROUND

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) has gained much attention in recent years. However, unintended embolization may occur when employing liquid embolic agents or particles. We present our clinical experience in simple coiling of MMAE to manage CSDH.

METHODS

Patients underwent either surgical evacuation or MMAE with simple coiling for CSDH were reviewed. Clinical and radiographic outcomes were assessed at admission, 1-month, and 6-month intervals. Two treatment groups were matched with inverse probability of treatment weighting.

RESULTS

One hundred twelve patients were included, with 27 patients in MMAE group and 87 patients in surgery group. In MMAE group, significant reductions were observed in hematoma width (admission vs. 1-month, 2.04 [1.44-2.60] cm vs. 0.62 [0.37-0.95] cm, p < 0.001). The adjusted odds ratio (aOR) of surgical rescue rate (0.77 95%CI 0.13-4.47, p = 0.77), hematoma reduction (>50%) (0.21 95%CI 0.04-1.07, p = 0.06), and midline shift improvement rate (3.22, 95%CI 0.84-12.4, p = 0.09) had no substantial disparities between two groups at 1-month follow-up. In addition, no significant difference was noted between two groups in terms of hematoma reduction (>50%) at 6-month follow-up (aOR 1.09 95%CI 0.32-3.70, p = 0.89). No procedure-related complications were found in MMA embolization group.

CONCLUSION

Simple coiling for MMA had comparable outcomes with surgical evacuation for CSDH. Our findings suggest that simple coiling can be an alternative choice for liquid agents or particles in MMA embolization for CSDH with acceptable safety.

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.

Embolization of the middle meningeal artery for the prevention of chronic subdural hematoma recurrence in high-risk patients: a randomized controlled trial-the EMPROTECT study protocol

BACKGROUND

Middle meningeal artery (MMA) embolization has been proposed as a treatment of chronic subdural hematoma (CSDH). The benefit of the procedure has yet to be demonstrated in a randomized controlled trial. We aim to assess the efficacy of MMA embolization in reducing the risk of CSDH recurrence 6 months after burr-hole surgery compared with standard medical treatment in patients at high risk of postoperative recurrence.

METHODS

The EMPROTECT trial is a multicenter open label randomized controlled trial (RCT) involving 12 French centers. Adult patients (≥18 years) operated for CSDH recurrence or for a first episode with a predefined recurrence risk factor are randomized 1:1 to receive either MMA embolization within 7 days of the burr-hole surgery (experimental group) or standard medical care (control group). The number of patients to be included is 342.

RESULTS

The primary outcome is the rate of CSDH recurrence at 6 months. Secondary outcomes include the rate of repeated surgery for a homolateral CSDH recurrence during the 6-month follow-up period, the rate of disability and dependency at 1 and 6 months, defined by a modified Rankin Scale (mRS) score ≥4, mortality at 1 and 6 months, total cumulative duration of hospital stay during the 6-month follow-up period, directly or indirectly related to the CSDH and embolization procedure-related complication rates.

CONCLUSIONS

The EMPROTECT trial is the first RCT evaluating the benefit of MMA embolization as a surgical adjunct for the prevention of CSDH recurrence. If positive, this trial will have a significant impact on patient care.

TRIAL REGISTRATION NUMBER

NCT04372147.

Particle embolic agents for embolization of middle meningeal artery in the treatment of chronic subdural hematoma: A systematic review and meta-analysis

OBJECTIVE

In this systematic review and meta-analysis, we investigated the efficacy and safety of middle meningeal artery embolization (MMAE) using particle embolic agents to treat cSDH.

METHODS

To retrieve articles investigating outcomes of patients following MMAE with particle agents and to compare their outcome with conventional treatment, Scopus, PubMed, Embase, and Web of Science were searched using relevant keywords. Original articles with more than 10 cases were included. The meta-analysis was carried out using the R studio and the random-effects model. Publication bias was assessed using Peter's test and quality assessment using NIH tools.

RESULTS

Eleven studies with 359 patients were included. The analysis revealed a pooled recurrence rate of 5% (CI: 3-8%), a need for reoperation rate of 5% (3-9%), and a peri-procedural complication rate of 4% (CI:2-9%) following MMAE with particle embolic agents. The pooled rates of decrease in size or resolution of the hematoma were 85% (CI:66-94%) and 66% (39-86%), respectively. Comparing MMAE using particulate embolysate with conventional treatments, risk ratio (RR) of 0.10 (CI:0.04-0.27) was achieved for recurrence, 0.25(CI:0.13-0.49) for reoperation, and 0.34 (CI:0.16-0.27) for peri-procedural complications. 91% of cSDH cases responded to MMAE with particles in the way they showed either down-sizing or complete resolution of the hematoma on follow-up imaging. In comparison, this rate was found to be 63% following conventional treatment.

CONCLUSION

Middle meningeal artery embolization using particle embolysates is a safe and effective technique for the treatment of cSDH, whether as a standalone intervention or in combination with conventional treatments.

Middle Meningeal Artery Embolization for Refractory Chronic Subdural Hematoma Associated with Acute Myeloid Leukemia: A Case Report

Objective

We describe a patient with leukemia-related chronic subdural hematoma (CSDH) who was successfully treated using the combination of surgical evacuation and middle meningeal artery (MMA) embolization.

Case Presentation

A 73-year-old man without apparent head trauma history was admitted to our hospital because of acute myeloid leukemia (AML). Head CT on admission revealed mild CSDH on both sides. Medical treatment options, including chemotherapy, were started. Since a decrease in platelet count and disseminated intravascular coagulation were observed on day 4, recombinant thrombomodulin was administered. As the patient exhibited signs of altered consciousness due to the enlargement of the right CSDH on day 10, we performed surgical drainage. Despite subsequent platelet transfusion and administration of goreisan, the right CSDH recurred within a short period. On day 17, we performed the second surgery and MMA embolization in one stage. The postoperative clinical course was favorable without recurrence of the hematoma. The patient eventually died on day 123 from a deterioration of his general condition.

Conclusion

Although MMA embolization has recently been recognized as an effective treatment option for recurrent CSDH, there are no published reports addressing the efficacy of MMA embolization for refractory CSDH associated with hematological malignancies. Findings from the management of this case suggest that MMA embolization can be the effective treatment option for CSDH in patients with severe hemorrhagic diathesis due to AML.

Immediate procedural safety of adjunctive proximal coil occlusion in middle meningeal artery embolization for chronic subdural hematomas: Experience in 137 cases

BACKGROUND

Endovascular embolization of the middle meningeal artery (MMA) has emerged as an adjunctive and stand-alone modality for the management of chronic subdural hematomas (cSDH). We report our experience utilizing proximal MMA coil embolization to augment cSDH devascularization in MMA embolization.

METHODS

MMA embolization cases with adjunctive proximal MMA coiling were retrospectively identified from a prospectively maintained IRB-approved database of the senior authors.

RESULTS

Of the 137 cases, all patients (n = 89, 100%) were symptomatic and underwent an MMA embolization procedure for cSDH. 50 of the patients underwent bilateral embolizations, with 53% (n = 72) for left-sided and 47% (n = 65) for right-sided cSDH. The anterior MMA branch was embolized in 19 (14%), posterior in 16 (12%), and both in 102 (74.5%) cases. Penetration of the liquid embolic to the contralateral MMA or into the falx was present in 38 (28%) and 31 (23%) cases, respectively, and 46 (34%) cases had ophthalmic or petrous collateral (n = 41, 30%) branches. MMA branches coiled include the primary trunk (25.5%, n = 35), primary and anterior or posterior MMA trunks (20%, n = 28), or primary with the anterior and posterior trunks (54%, n = 74). A mild ipsilateral facial nerve palsy was reported, which remained stable at discharge and follow-up. Absence of anterograde flow in the MMA occurred in 137 (100%) cases, and no cases required periprocedural rescue surgery for cSDH evacuation. The average follow-up length was 170 ± 17.9 days, cSDH was reduced by 4.24 ± 0.5(mm) and the midline shift by 1.46 ± 0.27(mm). Complete resolution was achieved in 63 (46.0%) cases.

CONCLUSION

Proximal MMA coil embolization is a safe technique for providing additional embolization/occlusion of the MMA in cSDH embolization procedures. Further studies are needed to evaluate the potential added efficacy of this technique.

Featured minimally invasive therapeutic approach for chronic subdural hematoma: Embolization of middle meningeal artery - A narrative review

Chronic subdural hematoma (c-SDH) is a frequent and serious neurological disease. It develops due to hemorrhage to the subdural space, mainly caused by head trauma. The middle meningeal artery (MMA) plays a critical role in the supply of blood to c-SDH. The decision on the type of treatment for c-SDH depends mainly on clinical and imaging evaluation. In cases in which patients are critically ill, the hematoma must be evacuated immediately. For this purpose, surgery is generally accepted as the mainstay of treatment. Among surgical techniques, twist-drill craniotomy, burr-hole craniotomy, and craniotomy are the three most used. The recurrence rate of c-SDH after surgery is an important problem with a rate of up to 30%. The technical success classification embolization of MMA (EMMA) has emerged as an effective and safe option for the treatment of c-SDH, especially those that recur. EMMA is commonly used as an adjunct to surgery or less frequently alone. The technical success of EMMA has been a promising minimal invasive strategy as an alternative or adjunctive therapy to surgical methods. Polyvinyl alcohol is the most widely used among various embolizing agents, including n-butyl cyanoacrylate, coil, and gelatin sponge. EMMA has been shown to prevent the formation or recurrence of c-SDH by eliminating blood flow to the subdural space. Complication rates are low. The large-scale comparative prospective will ensure efficacy and safety. This article aims to highlight the current information about EMMA in patients with c-SDH.

Peptidomics insights: neutrophil extracellular traps (NETs) related to the chronic subdural hemorrhage

Chronic subdural hemorrhage (CSDH) refers to a hematoma with an envelope between the dura mater and the arachnoid membrane and is more common among the elderly. It was reported that the dura mater, which is highly vascularized with capillary beds, precapillary arterioles and postcapillary venules play an important role in the protection of the central nervous system (CNS). Numerous evidences suggests that peptides play an important role in neuroprotection of CNS. However, whether dura mater derived endogenous peptides participate in the pathogenesis of CSDH remains undetermined. In the current study, the peptidomic profiles were performed in human dura of CSDH (three patients) and the relative control group (three non-CSDH samples) by LC-MS (liquid chromatography-mass spectrometry). The results suggested that a total of 569 peptides were differentially expressed in the dura matter of CSDH compared with relative controls, including 217 up-regulated peptides and 352 down-regulated peptides. Gene Ontology (GO) analysis demonstrated that the precursor proteins of those differentially expressed peptides were involved in the various biological processes. Interestingly, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that NETs participated in the pathogenies of CSDH. Further investigate showed that H3Cit was significantly elevated in the dural and hematoma membranes of patients with CSDH compared to patients without CSDH. Taken together, our results showed the differentially expressed peptides in human dura mater of CSDH and demonstrated that NETs formation in the dural and hematoma membranes might be involved in the pathogenesis of CSDH. It is worth noting that pharmacological inhibition of NETs may have potential therapeutic implications for CSDH.

Middle Meningeal Artery Embolization versus Surgery in Patients with Chronic Subdural Hematoma-No More Fence Sitting?

BACKGROUND

Endovascular treatment of patients with chronic subdural hematoma using middle meningeal artery (MMA) embolization could become an alternative to surgical hematoma evacuation. The aim of the study was to compare methods and identify parameters to help determine the correct treatment modality.

METHODS

We retrospectively reviewed 142 cases conducted internally; 78 were treated surgically and 64 were treated using MMA embolization. We analyzed the treatment failure rate and complications, and using a binary logistic regression model, we identified treatment failure risk factors.

RESULTS

We found a comparable treatment failure rate of 23.1% for the surgery group and 21.9% for the MMA embolization group. However, in the MMA embolization group, 11 cases showed treatment failure due to early neurological worsening with a need for concomitant surgery. We also found a recurrence of hematoma in 15.4% of cases in the surgery group and 6.3% of cases in the MMA embolization group.

CONCLUSION

Both modalities have their advantages; however, correct identification is crucial for treatment success. According to our findings, hematomas with a maximal width of <18 mm, a midline shift of <5 mm, and no acute or subacute (hyperdense) hematoma could be treated with MMA embolization. Hematomas with a maximal width of >18 mm, a midline shift of >5 mm, and no membranous segmentation could have better outcomes after surgical treatment.

Time-of-flight magnetic resonance angiography for detection of postoperative recurrence in patients with chronic subdural hematoma

PURPOSE

Chronic subdural hematoma (CSDH) is associated with postoperative recurrence. Although various factors are involved in postoperative recurrence of CSDH, blood flow, especially in the middle meningeal artery (MMA), is considered to play an important role. We investigated whether the degree of signal intensity (SI) of the MMA on time-of-flight magnetic resonance angiography (TOF MRA) and various clinical factors are involved in recurrence of CSDH.

METHODS

The maximum SI of both MMAs was measured on TOF MRA images within 1 month before or after the initial surgery.

RESULTS

In total, 185 patients (20 with and 165 without recurrence of CSDH) were included in the analysis. The SI ratio and dementia were significant predictors of recurrence of CSDH (SI ratio: odds ratio [95% confidence interval (CI)] = 1.71 [1.32, 2.22], p < 0.0001; dementia: odds ratio [95% CI] = 7.41 [1.83, 30.1], p = 0.005). The estimated regression coefficients in the final model were 6.14 for the SI ratio and 1.28 for dementia. The risk score was derived according to these regression coefficients as follows: score = 5 × SI ratio + 1 (dementia: yes). With a score of 5, the predicted probability of recurrence was 2% [95% CI 0.7, 5.7], whereas with scores of 8 and 10, the probability was 43.3% [27.0, 61.1] and 89.5% [65.7, 97.5], respectively, which increased the risk of recurrence.

CONCLUSION

Patients with an increased SI ratio of the affected MMA on TOF MRA who underwent surgery for CSDH were significantly more likely to experience recurrence.

Tonetti D, Bounajem MT, Thomas A, Ogilvy CS, Moore JM, Riina HA, Tanweer O, Levy EI, Spiotta AM, Gross BA, Jankowitz BT, Cawley CM, Khalessi AA, Pandey AS, Ringer AJ, Hanel R, Ortiz RA, Langer D, Levitt MR, Binning M, Taussky P, Kan P, Grandhi R. Radiographic and clinical outcomes with particle or liquid embolic agents for middle meningeal artery embolization of nonacute subdural hematomas

BACKGROUND

Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization.

METHODS

Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes-50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively-were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic).

RESULTS

The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78-2.18; p = 0.310), 1.09 (95% CI 0.52-2.27; p = 0.822), and 1.5 (95% CI 0.14-16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00).

CONCLUSIONS

MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

Comparative study on clinical outcomes and cost-effectiveness of chronic subdural hematomas treated by middle meningeal artery embolization and conventional treatment: a national cross-sectional study

BACKGROUND

The authors compared the efficacy and cost-effectiveness of middle meningeal artery embolization (MMAE) and conventional treatment for chronic subdural hematomas (cSDH).

METHODS

The Nationwide Readmissions Database of 9963 patients (27.2% women) with cSDH between 2016 and 2020 was analyzed. Finally, 9532 patients were included (95.7%, treated conventionally; 4.3%, treated with MMAE). Baseline demographics, comorbidities, adverse events, treatment strategies, and outcomes were compared between patients treated with MMAE and conventional treatment. After propensity score matching, the authors compared primary outcomes, including the 90-day treatment rate, functional outcome, length of hospital stays, and cost. A Markov model estimated lifetime costs and quality-adjusted life years (QALYs) associated with different treatments. The incremental cost-effectiveness ratio (ICER) was calculated to evaluate the base-case scenario. One-way, two-way, and probabilistic sensitivity analyses were performed to evaluate the uncertainty in the results.

RESULTS

After propensity score matching, MMAE had a lower 90-day retreatment rate (2.6 vs. 9.0%, P =0.001), shorter length of hospital stays (4.61±6.19 vs. 5.73±5.76 days, P =0.037), similar functional outcomes compared (favorable outcomes, 80.9 vs. 74.8%, P =0.224) but higher costs ($119 757.71±90 378.70 vs. $75 745.55±100 701.28, P <0.001) with conventional treatment. MMAE was associated with an additional cost of US$19 280.0 with additional QALY of 1.3. Its ICER was US$15199.8/QALY.

CONCLUSION

MMAE is more effective in treating cSDH than conventional treatment. Based on real-world data, though MMAE incurs higher overall costs, the Markov model showed it to be cost-effective compared to conventional treatment under the American healthcare system. These comparative and economic analyses further support the consideration of a paradigm shift in cSDH treatment.

Non-surgical management of chronic subdural hematoma: insights and future perspectives from an international survey including neurosurgeons from 90 countries worldwide

BACKGROUND

Chronic subdural hematoma (cSDH) is one of the most common neurosurgical conditions. Although surgical evacuation is still the gold standard for treatment, recent advances have led to the development of other management strategies, such as medical therapies and endovascular middle meningeal artery (MMA) embolization. Through this international survey, we investigated the global trends in cSDH management, focusing on medical and endovascular treatments.

DESIGN AND PARTICIPANTS

A 14-question, web-based, anonymous survey was distributed to neurosurgeons worldwide.

RESULTS

Most responders do not perform MMA embolization (69.5%) unless for specific indications (29.6%). These indications include residual cSDH after surgical evacuation (58.9%) or cSDH in patients on antiplatelet medications to avoid surgical evacuation (44.8%). Survey participants from teaching versus non-teaching hospitals (p = 0.002), public versus private hospitals (p = 0.022), and Europe versus other continents (p < 0.001) are the most users of MMA embolization. A large number of participants (51%) declare they use a conservative/medical approach, mainly to avoid surgery in patients with small cSDH (74.8%).

CONCLUSIONS

This survey highlights the current trends of cSDH management, focusing on conservative and MMA embolization treatment strategies. Most responders prefer a conservative approach for patients with small cSDHs not requiring surgical evacuation. However, in higher-risk scenarios such as residual hematomas after surgery or patients on antiplatelet medications, MMA embolization is regarded as a reasonable option by participants. Future studies should clarify the indications of MMA embolization, including appropriate patient selection and efficacy as a stand-alone procedure.

Standalone middle meningeal artery embolization versus middle meningeal artery embolization with concurrent surgical evacuation for chronic subdural hematomas: a multicenter propensity score matched analysis of clinical and radiographic outcomes

BACKGROUND

Middle meningeal artery embolization (MMAE) has emerged as a promising therapy for chronic subdural hematomas (cSDHs). The efficacy of standalone MMAE compared with MMAE with concurrent surgery is largely unknown.

METHODS

cSDH patients who underwent successful MMAE from 14 high volume centers with at least 30 days of follow-up were included. Clinical and radiographic variables were recorded and used to perform propensity score matching (PSM) of patients treated with standalone MMAE or MMAE with concurrent surgery. Multivariable logistic regression models were used for additional covariate adjustments. The primary outcome was recurrence requiring surgical rescue, and the secondary outcome was radiographic failure defined as <50% reduction of cSDH thickness.

RESULTS

722 MMAE procedures in 588 cSDH patients were identified. After PSM, 230 MMAE procedures remained (115 in each group). Median age was 73 years, 22.6% of patients were receiving anticoagulation medication, and 47.9% had no preoperative functional disability. Median midline shift was 4 mm and cSDH thickness was 16 mm, representing modestly sized cSDHs. Standalone MMAE and MMAE with surgery resulted in similar rates of surgical rescue (7.8% vs 13.0%, respectively, P=0.28; adjusted OR (aOR 0.73 (95% CI 0.20 to 2.40), P=0.60) and radiographic failure (15.5% vs 13.7%, respectively, P=0.84; aOR 1.08 (95% CI 0.37 to 2.19), P=0.88) with a median follow-up duration of 105 days. These results were similar across subgroup analyses and follow-up durations.

CONCLUSIONS

Standalone MMAE led to similar and durable clinical and radiographic outcomes as MMAE combined with surgery in select patients with moderately sized cSDHs and mild clinical disease.

The Utility of the 5 Factor Modified Frailty Index in Outcome Prediction for Patients with Chronic Subdural Hematoma Treated with Surgical Drainage

OBJECTIVE

Increasing frailty is a significant determinant of perioperative morbidity and mortality within neurosurgical literature. This study investigates the predictive value of the modified frailty index 5 (mFI-5) for postoperative morbidity and mortality following surgical drainage of chronic subdural hematoma (cSDH).

METHODS

A retrospective cohort study was performed on patients who underwent surgical evacuation of a cSDH. The mFI-5 score was calculated for each patient and used to stratify patients: prefrail (mFI-5<2), frail (mFI-5 = 2), and severely frail (mFI-5>2). Multivariate Cox proportional hazards (CPH) regression analysis were used to identify factors associated with our primary outcomes: overall survival and 30-day readmission. Secondary outcomes included nonhome discharge, length of stay, hematoma accumulation, development of new postoperative neurologic deficits, resolution of preoperative neurologic deficits, and a modified Rankin score >2 at discharge.

RESULTS

118 patients with a mean age of 74.4 ± 11.9 years were analyzed. All baseline demographics were similar across the 3 groups. On multivariate analysis, severely frail patients (N = 24, 20.3%) had increased rates of 30-day readmission (hazard ratio [HR] 4.3, CPH regression P value<0.001) and postoperative mortality (HR 3.1, CPH regression P value<0.01) compared to the prefrail cohort. Severely frail patients had increased rates of nonhome disposition (HR 9.6, CPH regression P value< 0.001), development of new postoperative neurologic deficits (HR 2.75, CPH regression P value = 0.03), and hematoma reaccumulation (HR 4.07, CPH regression P value = 0.004). A novel scoring system accounting for patient age and frailty was predictive of 90-day mortality (area under the curve 0.77).

CONCLUSIONS

Frailty, measured by the mFI-5, and our novel scoring system hold a predictive value regarding outcomes for patients undergoing surgical drainage of a cSDH.

Time and Influencing Factors to Chronic Subdural Hematoma Resolution After Middle Meningeal Artery Embolization

OBJECTIVE

We sought to describe the resolution time of chronic subdural hematoma (CSDH) after middle meningeal artery embolization (MMAE) and potential variables that may affect hematoma resolution.

METHODS

A retrospective analysis was performed on CSDH patients between December 2018 and December 2021. Patient characteristics, radiologic manifestations, and data of hematoma resolution were recorded. Univariate and multivariate analyses were conducted to identify predictors of CSDH resolution time.

RESULTS

A total of 53 patients were enrolled including 53 hematomas. Only 1 participant relapsed and did not require surgical evacuation. Hematoma resolution was observed in 27 (50.9%) at 4 months and 48 (90.6%) cases at the last radiologic follow-up. The median MMAE-to-resolution time was 19 weeks (interquartile range: 8-24). The burr-hole irrigation + MMAE group showed faster hematoma resolution than MMAE alone during early follow-up periods, but no significant difference was found at 6 months. Increased thickness of residual hematoma, excessive postoperative midline shift, high-density hematoma, mixed-density hematoma, separated hematoma, and anticoagulant or antiplatelet agents used were predictive of nonresolution at 4 months as determined by univariate analysis, whereas anticoagulant or antiplatelet agents used and high-density hematoma were not significant on multivariate analysis. No significant association was noted between hematoma resolution and comorbidities or other hematoma radiologic features.

CONCLUSIONS

MMAE is an effective and minimally invasive treatment for CSDH with a lower recurrence rate. The median resolution time of CSDH following MMAE was 19 weeks (interquartile range: 8-24). Burr-hole irrigation contributed to early hematoma resolution but had no significant effect at 6 months. In addition, residual hematoma thickness, postoperative midline shift, and specific type of hematoma were associated with delayed hematoma resolution at 4 months.