Middle meningeal artery embolization: an emerging treatment for non-acute subdural hematomas

Introduction Chronic subdural hematomas (SDH) are common in older adults due to increased risks of falls, cerebral atrophy, and antithrombotic therapy, leading to higher bleeding risks. Current randomized clinical trials are evaluating the safety and efficacy of middle meningeal artery (MMA) embolization for chronic SDH. These trials, such as EMBOLISE, MAGIC‐MT, and STEM, have reported preliminary promising results using different embolic agents. This study examines the safety and efficacy of MMA embolization using liquid embolic materials and coils at a single institution, comparing outcomes with the aforementioned trials. Methods We conducted a retrospective review of 66 patients who underwent MMA embolization for subacute and chronic SDH at a single institution from February 2021 to March 2024. Data were collected from electronic medical records, including demographics, clinical data, imaging, procedural details, use of antiplatelet or anticoagulation medications, and outcomes at discharge and follow‐up. Patients aged 18 or older with subacute or chronic SDH who underwent MMA embolization were included. Follow‐up assessments were conducted at multiple intervals post‐procedure. Descriptive statistics were used for data analysis. Results The median age of the cohort was 71 years, with a predominance of males (64.71%) and African Americans (54.90%). Eighteen patients had prior SDH interventions, and 62.75% were on antithrombotic therapy before diagnosis. The median time from symptom onset to diagnosis was one day, with most SDHs being traumatic (60.78%). Elective MMA embolizations were performed in 64.71% of cases, primarily using a femoral approach. N‐butyl cyanoacrylate (n‐BCA) was used in 97.37% of procedures, and coils in 27.63%. Complications were rare, with two cases (3.92%) of MMA rupture and access site hematoma. The technical success rate was 97.37%. The median hospital stay was seven days, with most patients discharged home (70.59%). The in‐hospital mortality rate was 1.96%, with seven post‐discharge deaths unrelated to MMA embolization or SDH. The median follow‐up duration was 130 days, with two patients (3.92%) requiring repeat MMA embolization and three (5.88%) needing SDH evacuation. Compared to EMBOLISE, MAGIC‐MT, and STEM trials, our study showed a recurrence rate of 9.8% for all patients, with 6.45% in the MMA embolization alone group and 15% in the surgery with adjunctive MMA embolization group. EMBOLISE reported a 4.10% recurrence rate with surgical evacuation with adjunctive MMA embolization, MAGIC‐MT showed 1.90% recurrence with MMA embolization alone and 4.70% with surgery and adjunctive MMA embolization, and STEM found 19.10% recurrence with MMA embolization alone and 12.30% with surgery with MMA embolization. Discussion Our study suggests that selective distal embolization using n‐BCA is effective, with a low complication rate. Distal embolization may prevent cranial nerve injuries and strokes associated with proximal embolizations. The ongoing trials will provide further insights into optimal embolization sites and agents, and the timing for restarting anticoagulation. Conclusion MMA embolization using liquid embolic materials and coils is a promising treatment for subacute and chronic SDH, with low recurrence and complication rates. Comparison with current trials indicates favorable outcomes. Further research is needed to refine embolization techniques and optimize patient management strategies, potentially revolutionizing chronic SDH treatment.

To the Editor: Subdural hematoma is one of the most diagnosed neurosurgical conditions in adults with an incidence rate reported to be 13.4 per 100 000 persons per year.1,2 Although mortality rates have decreased over the past several decades due to progressive advancements in diagnostics, novel treatment strategies are required to better manage patient outcomes.3 Middle meningeal artery (MMA) embolization is one such strategy that has recently emerged to reduce postoperative recurrence. This minimally invasive technique devascularizes the subdural membranes to prevent further bleeding and has proven viable and safe, especially among nonsurgical candidates.4 Here, we investigate the trends in the rates of middle meningeal artery embolization and mortality in patients with subdural hematoma. We queried the National Inpatient Sample database from 2016 to 2020 for patients with principal diagnosis of nontraumatic subdural hematoma (SDH) using the International Classification of Disease 10th Edition (ICD10) code I62. Cases at large urban teaching hospitals were selected. The yearly rate of inpatient mortality and MMA embolization was extracted. Trends in severity, as measured using variables suggestive of clinical severity (mechanical ventilation, hydrocephalus, treatment of hydrocephalus, coma, stupor, cranial nerve palsy, paralysis/paraparesis, and aphasia), were also explored. Multivariate regression analysis was performed to analyze the association between MMA embolization and mortality when controlling for age, socioeconomic status, race, and severity. All statistical analyses were performed using Statistical Product and Service Solutions (SPSS) Statistical Software, and significance was set to P < .05 (IBM Corp. Released 2020. IBM SPSS Statistics for Windows, version 28.0., IBM Corp). All data and ICD10 codes used in this study are available on reasonable request of the corresponding author. There were 173 165 patients with a principal diagnosis of SDH at large urban teaching hospitals from 2016 to 2020. We report an overall decrease in the mortality rate in 2020 (10.5%) as compared with 2016 (10.9%) (Figure 1). The mortality rate in 2016 and 2017 averaged 11.0%, whereas the mortality rate from 2018 to 2020 averaged 10.4%. On the other hand, severity trended upward throughout the years (Figure 2). The yearly rate of craniotomy and burr hole increased slightly from 1.18% to 1.46% and 8.36% to 9.12%, respectively. Notably, the rate of MMA embolization increased more than 10-fold from 2016 (0.2%) to 2020 (2.8%) (Figure 3). Most notable increase was post-2018, depicting its recent importance and success for managing subdural hematoma. Finally, when controlling for severity and demographics, MMA embolization was found to become protective against mortality in 2020, validating the trends stated above (Figure 4).Figure 1.: Yearly trends in mortality rate.Figure 2.: Yearly trends in severity.Figure 3.: Yearly trends in the rate of MMA embolization. MMA, middle meningeal artery.Figure 4.: Relationship between MMA embolization and mortality. MMA, middle meningeal artery.Surgical evacuation through craniotomy is one of the conventional treatments for chronic subdural hematoma. However, studies cite a 30-day mortality rate of 16.5% to 18% and high rates of adverse outcomes, including prolonged mechanical ventilation, return to the operating room, and prolonged length of stay, following craniotomy for subdural hematoma evacuation.3,5 Owing to a high rate of recurrence and perioperative complications associated with open surgery, MMA embolization is emerging to be not only an adjunct but also a stand-alone treatment option for chronic subdural hematoma.6,7 In a prospective study, Ban et al7 reported MMA embolization to be a superior option than conventional treatment options. In this same study, treatment failure for MMA embolization was reported to be only 1.4% as compared with 27.5% among patients who underwent surgical drainage. As we await the results of ongoing clinical trials, our analysis supports these findings and shows an overall inverse trend among the rate of MMA embolization and mortality throughout the United States, even when controlling for severity.

Introduction Chronic subdural hematoma is a disease encountered in elderly populations with cited frequencies of 1.7‐20.6 patients per 100,000 people yielding significant morbidity and mortality (Feghali). It is associated with a 5‐30% recurrence rate despite surgical evacuation (Kan). The pathophysiology involves a complex inflammatory reaction leading to angiogenesis and continued hematoma expansion (Holl). The traditional management of cSDH has historically been neurosurgical drainage either with craniotomy, Burr holes, or craniectomy (Mehta). These treatment techniques however, have been associated with higher rates of recurrence when compared to MMA embolization (Ironside). MMA embolization is a newer technique being offered to patients for management of cSDH that has proven to be highly effective (Catapano). Several recent studies comparing MMA embolization to traditional surgical treatment are beginning to show improved clinical outcomes, hospital days, recurrence rates, and complications (Srivatsan, Ban). Methods We collected all data regarding MMA embolization for patients with cSDH between March 2019 and August 2024 admitted to a single comprehensive stroke center in Thousand Oaks, CA. Demographic data, neurologic deficits, and radiologic reports were obtained through the electronic medical record. Procedural details were noted including any periprocedural complications, as well as the need for any surgical intervention. Repeat radiologic findings were reported, in addition to pertinent events that occurred during hospitalization and disposition. Major complications reported were periprocedural stroke, perioperative bleeding requiring transfusion, catheter detachment, and vascular dissection. Minor complications included contrast allergy and groin hematoma. Results 120 patients were admitted for cSDH and treated with MMA embolization. 34% of patients were female. Comorbidities include hypertension, diabetes mellitus, atrial fibrillation in 20%, 62%, and 14%, respectively. 30% of patients were receiving antithrombotics prior to the procedure (antiplatelets and dual oral anticoagulants). 39% were right‐sided SDH, 34% left‐sided SDH, and 27% bilateral SDH. Average size was 13.8mm and 4.8mm midlife shift. 71% of patients were treated with bilateral MMA embolization and 29% were treated with unilateral MMA embolization. Decision to treat bilateral or unilateral MMA embolization depended on neurointerventionalist preference. 52% of cases required surgical evacuation as well. There were 0 major complications and 0 minor complications. Average length of stay was 12 days and 42% of patients were discharged to home. Conclusions Our single center retrospective review of MMA embolization demonstrated that the procedure is safe indicated by our low complication rates. With the increased use of antithrombotic medications in an aging population, the frequency of chronic subdural hematomas is anticipated to expand, and MMA embolization offers a safe treatment option to prevent recurrence. This project contributes to growing fund of research for MMA embolization becoming the standard of care for cSDH.

To the Editor: We read with great interest the recent publication by Paro et al1 highlighting the emergence of endovascular middle meningeal artery (MMA) embolization as a less invasive addition to the neurosurgical armamentarium to treat pediatric chronic subdural hematoma (cSDH). Based on their case report and review of 5 published cases, this technique appears to be safe and effective in the appropriately selected pediatric patient. We would like to highlight 3 considerations that will better inform us in the future which pediatric patients would benefit the most from this approach. The first consideration is pediatric age. The brain volume, cranial vault volume, and expected growth of each in an infant are vastly different to that of an adolescent. The close match of brain volume relative to the cranial volume is likely sufficient in older children and adolescents to eliminate potential space for formation of a hygroma or cSDH. In infants, if there is not a persistent mechanism for poor brain development, the brain growth may actually be a significant driver of head growth, and any contemporary mismatch that creates a potential space may be expected to resolve. This may be similar to benign natural history of extra-axial fluid of infancy.2 In these cases, MMA embolization may be less useful. These expectations for children may not hold true if there is an underlying mechanism for brain volume loss or poor brain development; this could be observed with chronic disease (as is sometimes seen in congenital cardiac disease or oncologic pathology) or severe injury (such as hypoxic injury or severe nonaccidental injury). Most of these alternative scenarios where there is an increased risk of persistent brain to cranial volume mismatch happen in infants. As such, MMA embolization may be more relevant to this age group within the pediatric demographic. The second consideration is cSDH etiology. In their paper, Paro et al1 reported that 2 of 6 cSDH cases treated by MMA embolization occurred in the setting of ruptured arachnoid cysts. It is noted that in the absence of neurological decline, resolution of these pediatric cSDHs can occur with conservative management.3 Even in the presence of symptoms, medications such as acetazolamide have been shown to promote cSDH resorption in pediatric patients after arachnoid cyst rupture.4 These reports indicate that MMA embolization should not be seen as the least invasive management option for all pediatric cSDH cases upfront. However, other etiologies such as trauma and spontaneous formation may be more amenable to MMA embolization as a lesser invasive, more permanent procedure compared with subdural taps, subdural drains, and burr hole evacuation options.5,6 The last consideration is ideal timing. It is currently unclear when MMA embolization is most effective in pediatric patients with cSDH given the natural history. Parameters to consider include hematoma size and suspicion for cSDH recurrence. We hypothesize that larger hematoma size and recurrent cSDH could be less amenable to MMA embolization. This would then question whether or not MMA embolization should be performed as first-line treatment for smaller cSDHs on initial presentation. This speculation, however, must be balanced against the potential of pediatric cSDH to self-resolve with time, as well as the need to avoid anesthetic and procedural risks as much as possible. Larger, prospective studies in the pediatric demographic are needed to better understand this. It remains challenging to understand the clinical application of MMA embolization in children when diverse populations (infants to adolescents) with different pathologies (ruptured arachnoid cyst, abusive head trauma, and unknown mechanism) are intermixed. In sum, Paro et al1 highlighted the emergence of MMA embolization to treat pediatric cSDH. There is more than likely a place in the pediatric niche for this technique, and more research is required to better identify those pediatric patients who will benefit from this intervention the most. Considerations should be given for pediatric age, cSDH etiology, and intervention timing.

Chronic subdural hematoma (CSDH) is a frequent neurosurgical disorder, particularly in elderly patients and those receiving antithrombotic therapy. Although burr-hole drainage remains the standard treatment, recurrence occurs in 10–15% of cases. Middle meningeal artery (MMA) embolization has recently emerged as a minimally invasive technique targeting the vascular pathophysiology underlying hematoma persistence and recurrence. This review summarizes the rationale, technique, embolic materials, and clinical outcomes associated with MMA embolization for recurrent CSDH, with reference to a representative clinical case from our institution. A 63-year-old female with recurrent CSDH following burr-hole drainage underwent MMA embolization using polyvinyl alcohol (PVA) particles. The literature on the pathophysiology and endovascular management of CSDH was reviewed to contextualize this case. CSDH formation is driven by fragile neocapillaries and inflammatory cascades within vascularized membranes supplied by the MMA. Embolization interrupts this pathological cycle by reducing neovascular perfusion and inflammatory activity. Recent studies report recurrence rates of 4–5% after MMA embolization substantially lower than those following surgery along with low complication rates and earlier resumption of antithrombotic therapy. In our case, complete radiological resolution was achieved without adverse events. MMA embolization represents a paradigm shift in CSDH management by directly addressing the vascular mechanisms responsible for recurrence. It offers a durable, safe, and minimally invasive alternative or adjunct to surgery, particularly valuable for elderly or high-risk patients. Further randomized controlled trials are warranted to confirm its efficacy as a first-line or adjunctive therapy.

Introduction/Purpose Middle meningeal artery (MMA) embolization has been shown to be a beneficial treatment for chronic subdural hematoma (1); however, anatomic variants of MMA can present challenges to the procedure. MMA embolization carries increased risk if there is an abnormal anastomosis between the MMA and ophthalmic artery given the risk of embolization into the ophthalmic artery and is therefore typically avoided in such cases (2). We present a case of a patient who presented with worsening chronic subdural hematoma and was found to have an ophthalmic artery that completely originated from his MMA and yet was able to undergo successful MMA embolization without complications. Materials/Methods We present a 72‐year‐old patient with a history of chronic subdural hematoma, asthma, left‐sided arachnoid cyst, hyperlipidemia, and migraines presenting for persistent severe headaches. He had a normal neurological exam. The patient had initially presented three months earlier for a ground‐level fall due to vasovagal syncope and was found to have a small right‐sided subdural hematoma. He was managed conservatively then and subsequently discharged. Interval CTH one month later showed an increased size of the SDH with a midline shift of 4mm. He subsequently re‐presented for headache (three months from the original fall), with repeat imaging showing expansion of his SDH to 2cm with 1cm midline shift. He had not had any recurrent traumatic falls and was not on any blood thinners during this time. He underwent an uncomplicated craniotomy with SDH evacuation. Results The patient subsequently underwent a digital subtraction angiography (DSA), which showed a meningio‐ophthalmic artery variant, with the ophthalmic artery fully originating from the middle meningeal artery. This variant greatly increases risk during MMA embolization given the origination of the ophthalmic artery directly and entirely from the MMA; occlusion of the MMA proximally likely results in retinal artery occlusion in this scenario. However, given the risk of re‐bleeding and re‐expansion of his cSDH, he underwent adjunctive right MMA embolization with coils placed distally to the ophthalmic‐MMA junction, confirmed on post‐embolization sequences during angiogram. He did not suffer any visual symptoms and remained with a normal neurological exam with full resolution of his headaches. Conclusion This case demonstrates the safety of MMA embolization for cSDH in a patient with a high‐risk variant, which has typically been deemed a contraindication. Using coils instead of a liquid embolization agent and embolizing distal to the ophthalmic‐MMA junction allows for safe completion of the procedure without complications. It is also unclear why this variant is more prevalent in patients with cSDH, and a causal relationship has not been established for the pathogenesis of subdural hematoma or risk of re‐bleeding

Chronic subdural hematoma (cSDH) is one of the most common diseases treated by neurosurgeons. While surgical evacuation has been the traditional way to address symptomatic lesions, there is expanding evidence of the beneficial use of middle meningeal artery (MMA) embolization as a treatment or as an adjunct for cSDH. With the current strain on healthcare resources, physicians must balance providing the best care for patients and making cost-conscious decisions. Therefore, the aim of this study was to compare the cost of surgery alone versus surgery plus MMA embolization for treatment of cSDH, and to calculate an institutional tipping point for cost benefit. This is a retrospective study of patients with symptomatic cSDH requiring surgical intervention at a single institution from May 2019 to December 2022. The patients were concurrently enrolled in a prospective randomized controlled trial. To compare the cost of surgical treatment alone versus surgical treatment plus MMA embolization, all charges related to cSDH treatment from admission to the last follow-up were categorized (procedure, radiology, pharmacy, intensive care unit bed, laboratory, floor bed, and other) and assessed. The institutional tipping point (point at which it becomes financially beneficial to add MMA embolization to surgical evacuation during the same admission) was calculated to help guide decision-making. Forty-one patients (28 male, mean age 67.9 years) were included in the analysis, and were previously randomized to surgical intervention only (n = 21) or surgical intervention plus MMA embolization (n = 20). The groups were comparable in terms of demographic and cSDH characteristics. The overall mean cost for the index admission was lower in the surgery only group (US$158,320 vs $235,263; p = 0.037). This was also true for all categories of charges. Throughout the duration of the study there were 27 admissions in the surgery only group and 20 admissions in the surgery plus MMA embolization group (p = 0.0052). When analyzing costs per patient instead of per admission, no differences were observed between treatment groups for any of the categories. Likewise, the overall mean costs related to the care of patients in either treatment group showed no statistical difference ($203,554 vs $235,263; p = 0.25). Consequently, the institutional tipping point for the addition of MMA embolization was 20.8%. MMA embolization can be considered as an adjunct to surgery in the treatment of symptomatic cSDH, decreasing the overall cost by lowering rates of readmission and repeat intervention. The tipping point formula used in this study is versatile and adaptable. It can be a useful guide to determine appropriate treatment options for patients with symptomatic cSDH according to institutional or national standards.

To the Editor: We thank Lu et al1 for their interest in our article. Middle meningeal artery (MMA) embolization is becoming increasingly used in a subset of pediatric patients, and in the short time since the submission of our manuscript, an additional 2 case reports have been published.2,3 In their letter, Lu et al1 described several important considerations that will guide the selection of appropriate pediatric candidates for MMA embolization. Age—We agree that the age of the patient is an important factor. Among pediatric patients, chronic subdural hematomas are most commonly associated with abusive head trauma, anticoagulation/antiplatelet treatment for congenital cardiac disease, and ventricular shunt overdrainage.4 As a result, pediatric chronic subdural hematomas are often identified in infants and young children. Less common etiologies include neoplastic disease and arachnoid cysts, which can affect pediatric patients of any age. Pediatric patients at the younger end of the spectrum present several unique challenges because of the small caliber of their blood vessels, as well as the importance of limiting iodinated contrast and ionizing radiation.5 Despite these challenges, MMA embolization in young patients is feasible and can be a safe option in select patients when performed by experienced providers. Five of the 8 cases that have been described in the literature involved patients who were 2 years of age or younger.2,3,6-8 Etiology—As highlighted by Lu et al,1 2 patients in our systematic review underwent MMA embolization in the setting of a ruptured arachnoid cyst.9,10 We fully agree that subdural hygromas associated with arachnoid cysts can be treated nonsurgically11 and that even a certain subset of subdural hematomas can also be observed in this setting. As such, we agree that MMA embolization may not be the optimal first-line treatment in such cases. Indeed, both patients described in the literature only underwent MMA embolization after first undergoing either burr hole drainage or subdural-to-peritoneal shunt placement, with subsequent symptomatic recurrence of the hematoma.9,10 Timing—As alluded to above, the timing of intervention is controversial. Only 2 of the patients described in the literature underwent MMA embolization as a first-line treatment.7,12 Given the small number of cases that have been reported to date, we agree that MMA embolization is far from becoming the standard of care among pediatric patients with chronic subdural hematomas. Nevertheless, it represents yet another treatment option in the neurosurgeon's armamentarium and warrants additional study to determine its optimal role. We thank Lu et al1 for pointing out these important considerations and look forward to seeing the pediatric neurosurgical community continue to study the indications, efficacy, and risks of pediatric MMA embolization.

Middle meningeal artery (MMA) embolization has been proposed as a minimally invasive treatment for chronic subdural hematoma (cSDH). The aim of this systematic review and meta-analysis is to compare outcomes...

Background: Middle meningeal artery (MMA) embolization has been increasingly applied in adult populations for the treatment of chronic subdural hematomas (cSDH). There is a paucity of literature on the indications, safety, and outcomes of MMA embolization in the pediatric population. Summary: A systematic literature review on pediatric patients undergoing MMA embolization was performed. We also report the case of successful bilateral MMA embolization for persistent subdural hematomas following resection of a juvenile pilocytic astrocytoma. Persistent bilateral subdural hematomas following resection of a large brain tumor resolved following MMA embolization in a 13-year-old male. Indications for MMA embolization in the pediatric literature included cSDH (6/13, 46.2%), treatment or preoperative embolization of arteriovenous fistula or arteriovenous malformation (3/13, 23.1%), preoperative embolization for tumor resection (1/13, 7.7%), or treatment of acute epidural hematoma (1/13, 7.7%). Embolic agents included microspheres or microparticles (2/13, 15.4%), Onyx (3/13, 23.1%), NBCA (3/13, 23.1%), or coils (4/13, 30.8%). Key Messages: Whereas MMA embolization has primarily been applied in the adult population for subdural hematoma in the setting of cardiac disease and anticoagulant use, we present a novel application of MMA embolization in the management of persistent subdural hematoma following resection of a large space-occupying lesion. A systematic review of MMA embolization in pediatric patients currently shows efficacy; a multi-institutional study is warranted to further refine indications, timing, and safety of the procedure.

Introduction/PurposeChronic subdural hematomas are frequently managed by middle meningeal artery (MMA) embolization with or without burr hole evacuation. There is limited research comparing the resolution rates of chronic subdural hematomas...

The results from studies that compare middle meningeal artery (MMA) embolization vs conventional management for patients with chronic subdural hematoma are varied. To conduct a systematic review and meta-analysis on studies that compared MMA embolization vs conventional management. 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. 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. 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.

Introduction : Chronic subdural hematoma (cSDH) is a common neurosurgical condition with a high recurrence rate. Middle meningeal artery (MMA) embolization has been shown to reduce the incidence of re‐bleeding and prevent recurrence of cSDH by devascularizing the subdural membranes and shifting the balance from continued leakage and accumulation of blood and proteinaceous material to reabsorption. We report our single center experience of MMA embolization for treatment of chronic and subacute subdural hematoma. Methods : We performed a retrospective chart review of all patients ≥18 years who underwent MMA embolization between 01/01/2020‐03/01/2021 for cSDH. We looked at the outcomes, rate of recurrence and possible complications after MMA embolization. A descriptive analysis for continuous and categorical variables was performed using SAS 9.4 version. Results : A total of 41 MMA embolizations were performed on 32 patients with a median age of 75 (Q1‐Q3 70–83). Median hematoma thickness was 12 mm. Among them, 52% patients underwent particle embolization while 48% underwent liquid embolization. One patient had recurrence on follow up imaging and required drainage with burr hole. Three patients underwent hematoma evacuation after MMA embolization without evidence of recurrence on imaging. Three cases were aborted due to high risk or difficult access. There were no procedure related complications in the whole study population. 65% patient achieved mRS 0–2 on 90 day follow up visit. There was no significant difference between particles and liquid embolizations. Conclusions : Middle meningeal artery embolization could be used as a safe and effective intervention for prevention of recurrence and improving outcomes of subacute or chronic subdural hematoma.

Objectives To describe a rare complication of acute ischemic stroke (AIS) following middle meningeal artery (MMA) embolization for recurrent traumatic subdural hematoma (SDH). This event may represent an infrequent procedure‐related complication due to distal embolization or ischemia arising from failure of collateral vessels. Introduction Traumatic and chronic SDH are common intracranial disorders in the elderly. Risk factors include cerebral atrophy, coagulopathy, and antiplatelet or anticoagulant therapy. Tearing of bridging veins is the classic mechanism; however, in chronic SDH, trauma‐induced injury to dural border cells has also been implicated. These injuries trigger inflammation, fibrosis, and angiogenesis, forming a neo‐membrane. The outer neo‐membrane is highly vascular and prone to micro bleeding and thrombosis. Therefore, in addition to surgical evacuation, adjunctive therapies such as corticosteroids and MMA embolization have emerged as promising strategies. Case Presentation A 75‐year‐old man with hypertension, diabetes mellitus, atrioventricular block s/p permanent pacemaker, and traumatic acute‐on‐chronic SDH s/p recent left frontal craniectomy and left MMA embolization presented with global aphasia and right upper motor neuron (UMN) facial weakness four days after the embolization.On neurological examination, he had global aphasia (expressive and receptive) and a right facial droop; motor and sensory examinations were otherwise intact. Non‐contrast head CT showed expected postoperative changes at the left anterofrontal convexity without enlargement of the SDH or new midline shift. CT angiography of the head and neck showed no stenosis, occlusion, or other vasculopathy. An electroencephalogram (EEG) showed no epileptiform discharges or seizure activityHe had previously been taking aspirin 81 mg daily for cardiovascular benefit but was held given risks considering the SDH, but was resumed at discharge once cleared by neurosurgery. He had been discharged previously on levetiracetam 1000 mg twice daily, which was continued. MRI Brain was deferred due to device‐related constraints including an incompatible pacemaker and the patient's preference. Device interrogation demonstrated atrial pacing without arrhythmia, including no atrial fibrillation or flutter. He remained stable during hospital course and was discharged to home with outpatient speech therapy. Discussion The patient's persistent global aphasia and right facial weakness following MMA embolization are most consistent with a clinical diagnosis of acute ischemic. The absence of arrhythmia on device interrogation, lack of significant extracranial or intracranial stenosis on CTA, and unremarkable echocardiogram make a cardioembolic or large‐vessel etiology less likely. Instead, the temporal relationship to the embolization procedure raises the possibility of procedure‐related ischemia.Potential mechanisms include distal embolization of embolic material used in the MMA embolization, unintentional migration through fragile collateral channels, or compromise of cortical collateral supply, particularly around Broca's area. Although MMA embolization has been increasingly adopted due to its favorable safety profile, reported complications have included cranial nerve palsies, scalp necrosis, and very rarely ischemic stroke. This case emphasizes that even with technically successful embolization, vigilance for delayed ischemic complications is warranted. While the diagnosis of stroke remains clinical, the case contributes to the growing awareness of rare but significant ischemic complications of MMA embolization. Recognition of these risks may inform future procedural refinements, peri‐procedural monitoring strategies, and decision‐making regarding the timing of resumption of antiplatelet therapy.

Introduction : Middle meningeal artery (MMA) anatomy has very important surgical implications during endovascular and open based skull procedures. Various anatomical origins have been identified in the literature besides its most common origin as the largest branch of the maxillary artery. It runs parallel and close contact of the lateral skull face therefore during trauma to this area is prone to rupture resulting in subdural hemorrhage(SDH). In our case report, we present its peculiar origin from anterior inferior cerebellar artery which has never been reported before. The origin of MMA may reflects the risk involved with embolization therapy for chronic SDH. Methods : A case of MMA originated form AICA. A literature review was conducted of reports of MMA origins. Results : A 35‐year‐old male with a history of alcohol abuse presented to the ED after falling down from the stairs. In the ED, the patient had multiple episodes of seizures along with respiratory distress therefore was intubated due to concern of airway protection. CT head showed bilateral SDH. Patient underwent diagnostic angiogram for possible bilateral embolization of MMA. During the procedure, the left MMA origin was seen from the AICA whereas the right MMA arising from the external carotid artery. Embolization of the left MMA was aborted. Patient remained intubated and was later transferred to a long term care facility. Conclusions : In the last 80 years, the anatomy of the MMA has been part of the discussion of various literature. Seeger et.al, highlighted the embryological changes manifested as anastomosis between Sphenomaxillary artery and lateral pontine artery resulting in origin of MMA from Basilar artery along with absence of foramen spinosum. Since 1973, multiple literature highlighted the origin of MMA including the lacrimal artery, ICA, ascending pharyngeal artery, opthalmic and occipital arteries. Recently, In 2011 Kuruvuilla et.al showed the origin of MMA from posterior inferior cerebellar artery. MMA clinical significance can be seen in multiple diseases. Older populations with chronic subdural hematomas, embolization of MMA has shown to be a less invasive and cost effective procedure. In patients with anterior and middle cranial fossa meningiomas embolization of MMA has been a crucial part of management. Similarly, understanding of its anatomy is also important while treating MMA aneurysm or pseudoaneurysms. In our case, the origin of middle meningeal artery from AICA has been significant as it supplies the posterior fossa structures and was not reported in the literature before, hence the procedure was aborted. This anatomical variant has shown us a new light upon embryological evolution and has helped us widen the horizons of our approach towards brain vasculature. This finding will help the future Interventionists to develop new ways of embolization of the MMA and understanding its anatomy.