Efficacy of middle meningeal artery embolization in the treatment of refractory chronic subdural hematoma

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.

Direct superficial temporal artery access for middle meningeal artery embolization

Middle meningeal artery embolization has become an important option in the management of subdural hemorrhages with multiple prospective studies demonstrating efficacy and randomized controlled trial data on the way. Access to the middle meningeal artery is usually achieved via the external carotid artery to the internal maxillary artery, then the middle meningeal artery. We report a case where a patient with symptomatic left-sided chronic subdural hemorrhage also had an external carotid artery occlusion. Direct puncture of the superficial temporal artery allowed retrograde access to the internal maxillary artery and thus the middle meningeal artery. Successful embolization of the vessel with 1:9 nBCA was performed with near total resorption of the subdural collection by 1 month postprocedure.

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.

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.

Middle Meningeal Artery Embolization with Liquid Embolic Agents for Chronic Subdural Hematoma: A Systematic Review and Meta-analysis

PURPOSE

To assess the efficacy and safety of middle meningeal artery (MMA) embolization with liquid embolic agents and the outcomes of patients following this procedure.

MATERIALS AND METHODS

A review of the literature was conducted to identify studies investigating the efficacy and safety of MMA embolization with liquid embolic agents in patients with chronic subdural hematoma (cSDH) in PubMed, Scopus, Embase, and Web of Science. The keywords "liquid embolic agent," "middle meningeal artery," "cSDH," and "embolization" as well as their synonyms were used to build up the search strategy. The R statistical software and random-effects model were used for analysis. Heterogeneity was reported as I2, and publication bias was calculated using the Egger test.

RESULTS

Of 628 articles retrieved, 14 studies were eligible to be included in this study. Data of 276 patients were analyzed. n-Butyl cyanoacrylate and ethylene vinyl alcohol copolymer were the most commonly used embolic agents. This study revealed a pooled mortality rate of 0% (95% confidence interval [CI], 0.00%-100%), recurrence and failure rate of 3% (95% CI, 1%-10%), reoperation/reintervention rate of 4% (95% CI, 2%-12%), rate of size decrease of 94% (95% CI, 79%-98%), technical success rate of 100% (95% CI, 76%-100%), and adverse event rate of 1% (95% CI, 0.00%-4%).

CONCLUSIONS

With low mortality, recurrence, reoperation, and adverse event rates and a remarkable decrease in the size of hematomas, MMA embolization with liquid embolic agents may be considered a safe and effective treatment option in patients in whom surgical intervention has previously failed and as an alternative to conventional treatments.

Extensive Roles and Technical Advances of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a common pathology that typically affects the elderly in Japan, an aging society. Burr-hole irrigation is the standard treatment, but middle meningeal artery (MMA) embolization is a minimally invasive alternative. MMA embolization for CSDH has frequently been reported in recent years, and many technical innovations to improve clinical outcomes have been described. Embolic materials reaching more distally are found to avoid recurrences after MMA embolization. As a result, various studies have described the superiority of embolizing the anterior and posterior branches of the MMA, the advantages of embolic materials reaching beyond the midline, and a high degree of distal penetration using a "sugar rush technique" in which 5% soluble glucose is injected through an intermediate catheter during MMA embolization. Radiographically, reports have described the importance of a "bright falx" sign obtained by infiltrating embolic material beyond the midline and post-embolization enhancement of the dura, capsular membrane, septations, and subdural hematoma fluid as indicators of the spread of embolic materials. This review provides an overview of the current status and future challenges in MMA embolization for CSDH, focusing on technical aspects to improve clinical outcomes.

Surgical techniques for evacuation of chronic subdural hematoma: a mini-review

Chronic subdural hematoma is one of the most common neurosurgical pathologies with over 160,000 cases in the United States and Europe each year. The current standard of care involves surgically evacuating the hematoma through a cranial opening, however, varied patient risk profiles, a significant recurrence rate, and increasing financial burden have sparked innovation in the field. This mini-review provides a brief overview of currently used evacuation techniques, including emerging adjuncts such as endoscopic assistance and middle meningeal artery embolization. This review synthesizes the body of available evidence on efficacy and risk profiles for each critical aspect of surgical technique in cSDH evacuation and provides insight into trends in the field and promising new technologies.

Middle Meningeal Artery Embolization in the Management of Chronic Subdural Hematoma: a Comprehensive Review of Current Literature

PURPOSE OF REVIEW

Chronic subdural hematoma (cSDH) is a common intracranial hemorrhagic disorder with a high incidence rate among the elderly. While small, asymptomatic cSDH may resolve spontaneously, surgical intervention has been the treatment of choice for larger, symptomatic cases. Surgical evacuation of cSDH may be associated with high rates of recurrence, and even asymptomatic cSDH cases tend to progress. Over the last few years, middle meningeal artery (MMA) embolization has proven to be a safe non-invasive treatment of choice with favorable outcomes and a low recurrence rate. The ensuing paper discusses current treatment modalities for cSDH and reviews existing literature on the anatomy of MMA and its embolization as a treatment option for cSDH.

RECENT FINDINGS

Recent studies show that traumatic head injury leading to subdural hemorrhage can induce neovascularization that may initiate a cycle of recurrent subdural hematoma. Distal branches of MMA supply blood to the dural layers. Several studies have revealed that embolization of the MMA can stop the neovascularization process and blood flow. In addition, patients who underwent MMA embolization had a significantly quicker brain re-expansion and lower recurrence rate. Although the management of cSDH is still very much a dilemma, recent research findings bring MMA embolization to light as a promising treatment alternative and adjunctive therapy.

A Novel Case of Deep Temporal Artery (DTA) Embolization for Recurrent Subacute-Chronic Subdural Hematoma

Subdural hemorrhage (SDH) is a common neurological disease. In past, SDHs were managed either conservatively (non-surgically) or with surgical evacuation (burr hole versus craniotomy) depending on the severity. Surgical evacuation has major challenges including high recurrence rate, stoppage and reversal of antiplatelet or anticoagulation agents, risk of general anesthesia and surgery in elderly patients with multiple comorbidities. Given the above challenges, embolization of the distal branches of the middle meningeal artery (MMA) has recently emerged as an excellent alternate to surgical evacuation or conservative management. To the best of our knowledge, there is no literature on the embolization of the deep temporal artery (DTA) for subacute-chronic SDH. We report the first case of recurrent subdural hematoma post MMA embolization that was successfully treated with embolization of DTA.

Middle meningeal artery embolisation: The review of a new treatment for chronic subdural hematomas

Background

This is a literature review aiming to provide an update about the recent findings related to the efficacy of middle meningeal artery embolization (MMAE) in the treatment of chronic subdural hematomas (cSDHs), comparison with conventional therapy and deduction of the current recommendations and indications.

Methods

The literature is reviewed using a search through the PubMed index using keywords. Studies are then screened, skimmed, and thoroughly read. 32 studies fulfilled the inclusion criteria and are included in the study.

Results

Five indications for the application of MMA embolization (MMAE) are deducted from the literature. The usage as a preventive measure after surgical treatment of symptomatic cSDHs in patients with a high risk of recurrence and the usage as a standalone procedure has been the most common reasons for indication of this procedure. Rates of failures for the aforementioned indications have been 6.8% and 3.8%, respectively.

Conclusion

The safety of MMAE as a procedure is regarded as a general theme in the literature and can be considered for future applications. Usage of this procedure in clinical trials with more patient segregation and timeframe assessment relative to surgical intervention are recommendations of this literature review.

Chronic Subdural Hematoma after Craniotomy with Preoperative Embolization of Middle Meningeal Artery: A Case Report

Endovascular embolization of the middle meningeal artery (MMA) has been reported as an effective method for treating chronic subdural hematoma (CSDH); however, its preventive effect on CSDH following craniotomy is unknown. We present a case in which MMA embolization was ineffective in preventing CSDH following craniotomy. A 56-year-old man who complained of diplopia was diagnosed with sphenoid ridge meningioma with a 3-cm diameter. MMA embolization prior to the operation and total surgical removal of the tumor were performed. Two months postoperatively, the patient complained of headache and hemiparesis of the left side. CSDH with a 15-mm thickness and a midline shift was observed. MMA embolization before inflammation may not play a role in preventing CSDH development because MMA embolization is considered effective in CSDH because it is associated with the blood supply of neovessels that are newly formed due to inflammation. Therefore, MMA embolization might not be effective in preventing the occurrence of CSDH following craniotomy.

Onyx Versus Particles for Middle Meningeal Artery Embolization in Chronic Subdural Hematoma

BACKGROUND

Middle meningeal artery (MMA) embolization has recently emerged as a treatment option for chronic subdural hematoma (cSDH). It is considered a simple and potentially safe endovascular procedure.

OBJECTIVE

To compare between 2 different embolic agents; onyx (ethylene vinyl alcohol) and emboparticles (polyvinyl alcohol particles-PVA) for endovascular treatment of cSDH.

METHODS

A retrospective analysis of all patients who underwent MMA embolization for cSDH treatment in 2 comprehensive centers between August 2018 and December 2021. Primary outcomes were failure of embolization and need for rescue surgical evacuation.

RESULTS

Among 97 MMA embolizations, 49 (50.5%) received onyx and 48 (49.5%) received PVA. The presence of acute or subacute on cSDH was higher in the PVA group 11/49 (22.5%) vs 30/48 (62.5%), respectively, P < .001. There were no significant differences between both groups regarding failure of embolization 6/49 (12.2%) vs 12/48 (25.0%), respectively, P = .112, and need of unplanned rescue surgical evacuation 5/49 (10.2%) vs 8/48 (16.7%), respectively, P = .354. Hematoma thickness at late follow-up was significantly smaller in the PVA group 7.8 mm vs 4.6 mm, respectively; P = .017.

CONCLUSION

Both onyx and PVA as embolic agents for cSDH can be used safely and have comparable clinical and surgical outcomes.

Chronic Subdural Hematoma-Evolution of Etiology and Surgical Treatment

In this paper, I review the historical changes in the etiological concepts and surgical treatments for chronic subdural hematoma (CSDH) across the world and in Japan. I also examine future problems associated with its surgical procedures and medical costs. CSDH was first reported by Wepfer in 1657 as "delayed apoplexy." In 1857, Virchow described the famous concept of so-called "pachymeningitis hemorrhagica interna." He considered that the etiology of CSDH involved inflammation. In 1914, Trotter described the origin of CSDH as traumatic. Currently, CSDH is considered to arise with a first leak of blood from dural border cells after mild trauma. Inflammatory cells are then drawn to the border cell layer. At this point, new membranes form from activated inflammation; then, the hematoma enlarges, promoted by angiogenic factors and new capillaries. In 1883, Hulke reported successful trepanning of a patient with CSDH. Burr holes and craniotomy for removal of the hematoma were subsequently reported, and new methods were developed over the course of several decades around the world. In Japan, after the first report by Nakada in 1938, many Japanese pioneering figures of neurological surgery have studied CSDH. After Mandai reported the middle meningeal artery embolization in 2000, this method is now considered useful as an initial or second treatment for CSDH. However, the age of patients is increasing, so more minimally invasive surgeries and useful pharmacotherapies are needed. We must also consider the costs for treating CSDH, because of the increasing numbers of surgical cases.

Sequential Middle Meningeal Artery Embolization after Burr Hole Surgery for Recurrent Chronic Subdural Hematoma

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) is a novel, minimally invasive treatment. The indications and treatment practices for MMAE are variable and remain controversial. This study aimed to evaluate a strategy involving sequential MMAE after burr hole surgery for treating recurrent CSDH. We performed a retrospective analysis of data from consecutive patients who had undergone MMAE using liquid embolic agents within approximately 2 weeks after burr hole surgery for recurrent CSDH from September 2020 to March 2022. We analyzed patient characteristics, procedural details, CSDH recurrence after MMAE, surgical rescue, and complications. Six of the nine patients who underwent MMAE for CSDH recurrence were male, and the median age was 85 (range, 70-94) years. Five of the nine patients were being administered antithrombotic agents. The median duration between the burr hole surgery and MMAE procedure was 10 (range, 3-25) days. Anterior and posterior convexity branches were targeted for embolization using low-concentration N-butyl cyanoacrylate (NBCA), and the abnormal vascular networks with a cotton wool appearance disappeared after embolization in all cases. The NBCA distribution was observed by high-resolution computed tomography during the procedure; in three of nine cases, the NBCA penetrated not only the MMA but also the inner membrane. No recurrence, surgical rescue, or complications were observed in any patient during the median follow-up period of 3 months. As a minimally invasive treatment for recurrent CSDH, sequential MMAE after burr hole surgery may be a safe and effective option for preventing recurrence.

Middle meningeal artery embolization for chronic subdural hematomas. A systematic review of the literature focused on indications, technical aspects, and future possible perspectives

Background:

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical diseases that affect elderly and fragile patients and as a consequence, management can be challenging. Surgery represents the standard treatment; however, alternative options are under investigation. Middle meningeal artery (MMA) embolization is considered a minimally invasive treatment although with poor evidence. In this review, we tried to summarize the findings about MMA embolization as a treatment for a CSDH to provide a useful guidance for clinical practice and for future speculative aspects.

Methods:

Literature review on PubMed until March 2021 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. We conducted a research on PubMed with a various combinations of the keywords “CSDH” and “middle meningeal artery” and “embolization,” “refractory subdural hematoma,” and then we reviewed the references of the relevant studies as additional source of eligible articles.

Results:

Among the 35 studies eligible for this review, 22 were case series, 11 were case reports, one was a technical note, and 1 was a randomized trial. A total of 746 patients were found in the literature. Failure rate of MMA embolization was between 3.9 and 8.9% of the cases according the indication to treat CSDH (upfront vs. after surgery).

Conclusion:

The global impression deriving from the data available and the literature is that MMA embolization is a safe procedure with very low complications and with a low failure rate, both when associated with surgery or in case of a standalone treatment.

Total 1-year hospital cost of middle meningeal artery embolization compared to surgery for chronic subdural hematomas: a propensity-adjusted analysis

BACKGROUND

Middle meningeal artery (MMA) embolization results in fewer treatment failures than surgical evacuation for chronic subdural hematomas (cSDHs). We compared the total 1-year hospital cost for MMA embolization versus surgical evacuation for patients with cSDH.

METHODS

Data for patients who presented with cSDHs from January 1, 2018, through May 31, 2020, were retrospectively reviewed. Patients were grouped by initial treatment (surgery vs MMA embolization), and total hospital cost was obtained. A propensity-adjusted analysis was performed. The primary outcome was difference in mean hospital cost between treatments.

RESULTS

Of 170 patients, 48 (28%) underwent embolization and 122 (72%) underwent surgery. cSDHs were larger in the surgical (20.5 (6.7) mm) than in the embolization group (16.9 (4.6) mm; P<0.001); and index hospital length of stay was longer in the surgical group (9.8 (7.0) days) than in the embolization group (5.7 (2.4) days; P<0.001). More patients required additional hematoma treatment in the surgical cohort (16%) than in the embolization cohort (4%; P=0.03), and more required readmission in the surgical cohort (28%) than in the embolization cohort (13%; P=0.04). After propensity adjustment, MMA embolization was associated with a lower total hospital cost compared to surgery (mean difference -$32 776; 95% CI -$52 766 to -$12 787; P<0.001). A propensity-adjusted linear regression analysis found that unexpected additional treatment was the only significant contributor to total hospital cost (mean difference $96 357; 95% CI $73 886 to $118 827; P<0.001).

CONCLUSIONS

MMA embolization is associated with decreased total hospital cost compared with surgery for cSDHs. This lower cost is directly related to the decreased need for additional treatment interventions.

Middle Meningeal Artery Embolization for the Treatment of Bilateral Chronic Subdural Hematoma

Background: Bilateral chronic subdural hematoma (bCSDH) is a frequent condition commonly linked to the need for retreatment; however, the reason for this high retreatment rate remains unclear. The middle meningeal artery (MMA) was found to have a relationship with the occurrence and development of chronic subdural hematomas. This study examines a possible method to reduce bCSDH recurrence using bilateral MMA embolization combined with bilateral burr-hole drainage.

Materials and Methods: Ten patients with bCSDH who underwent bilateral MMA embolization combined with bilateral burr-hole drainage at our hospital between June 2018 and May 2020, were retrospectively analyzed. Patients' clinical information, prognoses, imaging results, as well as surgical results were documented and analyzed.

Results: Ten patients were diagnosed with bCSDH with no comorbid brain diseases. They underwent bilateral MMA embolization combined with bilateral burr-hole drainage. We embolized the MMA immediately before burr hole drainage successfully and employed angiography to validate these results. All the patients attained relief of symptoms without adverse events, and no re-expansion or relapse was reported in the follow-up computed tomography.

Conclusion: Bilateral MMA embolization combined with bilateral burr-hole drainage is an available treatment for patients with bCSDH and may have the potential for preventing recurrence.

Middle Meningeal Artery Embolization and the Treatment of a Chronic Subdural Hematoma

Chronic subdural hematoma (cSDH) is a common pathology that typically affects the elderly. It is believed to occur due to injury to the dural border cells, which creates an inflammation/proliferation reaction. Ineffective repair leads to the formation of a new external layer of cells and fragile capillaries, which damage easily and can worsen the condition. Conventionally, asymptomatic cSDH is managed by observation, and symptomatic cases are treated by surgical evacuation. Unfortunately, recurrence rates of the SDH following surgical evacuation can be high. One treatment option for SDH involves embolization of the middle meningeal artery (MMA). The MMA provides blood supply to the dura mater and feeds the membrane capillaries covering the SDH. MMA embolization blocks the blood flow to this system and can promote hematoma resolution. In this paper, we review the existing literature on MMA embolization and discuss the underlying pathophysiology of cSDH.

Surgical Management of Chronic Subdural Hematoma in Older Adults: A Systematic Review

BACKGROUND

Chronic subdural hematoma (cSDH) is a form of intracranial hemorrhage common in older adults. Optimal treatment remains controversial. We conducted a systematic review to identify surgical thresholds, characterize outcomes, and delineate critical considerations in the surgical management of older adults in order to summarize the evidence supporting the best contemporary management of cSDH.

METHODS

A systematic review exploring surgical management of cSDH among individuals aged 65 years and older was conducting by searching the PubMed, Embase, and Scopus databases for articles in English. Abstracts from articles were read and selected for full-text review according to a priori criteria. Relevant full-text articles were analyzed for bibliographic data, aim, study design, population, interventions, and outcomes.

RESULTS

Of 1473 resultant articles, 21 were included. Surgery rationale was case-by-case for symptomatic patients with cSDH. Surgery was superior to conservative management and promoted equivalent neurologic outcomes and rates of complications. Recurrence and reoperation rates in older adults were similar to younger individuals. Some studies reported higher mortality rates for older adults, while others reported no difference. Anticoagulation or antiplatelet agent use did not seem to be associated with poorer outcomes in older adults.

CONCLUSIONS

Surgery for cSDH in older adults leads to favorable neurologic outcomes without increased risk of overall complications, recurrence, or reoperation compared to younger patients. However, older adults may be at increased risk for mortality after surgery. It is important to determine use of anticoagulant or antiplatelet agents in older adults to optimally manage patients with cSDH.

History and current progress of chronic subdural hematoma

Chronic subdural hematoma (CSDH) is characterized by an encapsulated collection of old blood. Although CSDH has become the most frequent pathologic entity in daily neurosurgical practice, there are some unresolved research questions. In particular, the causes and recurrent risk factors of CSDH remain as an object of debate. The split of the dural border layer forms a few tiers of dural border cells over the arachnoid layer. Tissue plasminogen activator plays an important role as a key factor of defective coagulation. Historically, CSDH has often been treated via burr hole craniostomy using a closed drainage system. Several different operative strategies and peri-operative strategies such as the addition of burr holes, addition of cavity irrigation, position of drain, or postural position, have been described previously. Although the direction of the drainage tube, residual air, low intensity of T1-weighted images on MRI, and niveau formation have been reported as risk factors for recurrence, antiplatelet or anticoagulant drug use has not yet been verified as a risk factor. Recently, pharmaceutical strategies, including atorvastatin, significantly improved the neurological function in CSDH patients. Many case series, without randomization, have been reported; and given its promising result, several randomized clinical trials using pharmaceutical as well as operative and perioperative strategies were initiated to obtain sufficient data. In contrast, relatively fewer basic studies have achieved clinical applications in CSDH, although it is one of the most common clinical entities. Further scientific basic research may be essential for achieving a novel treatment strategy for CSDH.

To drill or not to drill, that is the question: nonsurgical treatment of chronic subdural hematoma in the elderly. A systematic review

OBJECTIVE

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical pathologies, typically affecting the elderly. Its incidence is expected to grow along with the aging population. Surgical drainage represents the treatment of choice; however, postoperative complications and the rate of recurrence are not negligible. For this reason, nonsurgical alternatives (such as middle meningeal artery embolization, steroids, or tranexamic acid administration) are gaining popularity worldwide and need to be carefully evaluated, especially in the elderly population.

METHODS

The authors performed a systematic review according to PRISMA criteria of the studies analyzing the nonsurgical strategies for CSDHs. They collected all papers in the English language published between 1990 and 2019 by searching different medical databases. The chosen keywords were "chronic subdural hematoma," "conservative treatment/management," "pharmacological treatment," "non-surgical," "tranexamic acid," "dexamethasone," "corticosteroid," "glucocorticoid," "middle meningeal artery," "endovascular treatment," and "embolization."

RESULTS

The authors ultimately collected 15 articles regarding the pharmacological management of CSDHs matching the criteria, and 14 papers included the endovascular treatment.

CONCLUSIONS

The results showed that surgery still represents the mainstay in cases of symptomatic patients with large CSDHs; however, adjuvant and alternative therapies can be effective and safe in a carefully selected population. Their inclusion in new guidelines is advisable.

Middle meningeal artery embolization for chronic subdural hematoma: a systematic review and meta-analysis

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 after MMA embolization versus conventional management for cSDH. We performed a systematic review of PubMed, Embase, Oxford Journal, Cochrane, and Google Scholar databases from April 1987 to October 2020 in accordance with PRISMA guidelines. Studies reporting outcomes after MMA embolization for ≥3 patients with cSDH were included. A meta-analysis comparing MMA embolization with conventional management was performed. The analysis comprised 20 studies with 1416 patients, including 718 and 698 patients in the MMA embolization and conventional management cohorts, respectively. The pooled recurrence, surgical rescue, and in-hospital complication rates in the MMA embolization cohort were 4.8% (95% CI 3.2% to 6.5%), 4.4% (2.8% to 5.9%), and 1.7% (0.8% to 2.6%), respectively. The pooled recurrence, surgical rescue, and in-hospital complication rates in the conventional management cohort were 21.5% (0.6% to 42.4%), 16.4% (5.9% to 27.0%), and 4.9% (2.8% to 7.1%), respectively. Compared with conservative management, MMA embolization was associated with lower rates of cSDH recurrence (OR=0.15 (95% CI 0.03 to 0.75), p=0.02) and surgical rescue (OR=0.21 (0.07 to 0.58), p=0.003). In-hospital complication rates were comparable between the two cohorts (OR=0.78 (0.34 to 1.76), p=0.55). MMA embolization is a promising minimally invasive therapy that may reduce the need for surgical intervention in appropriately selected patients with cSDH. Additional prospective studies are warranted to determine the long-term durability of MMA embolization, refine eligibility criteria, and establish this endovascular approach as a viable definitive treatment for cSDH.

Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurosurgical condition with high recurrence rates. Repeated microbleedings from fragile neo-vessels supplied by peripheral branches of the middle meningeal artery (MMA) are believed to be responsible for the growth and recurrence of CSDH. Thus, MMA embolization might be a promising method to prevent re-bleedings and recurrences. This study aims to assess the efficacy, complication rates, and mid-term outcome of MMA embolization with or without burr hole irrigation compared with burr hole irrigation alone.

METHODS

Patients diagnosed with CSDH who underwent MMA embolization and/or surgical treatment were retrospectively recruited to this single-center study. The outcome variables were defined as treatment-related complications, clinical outcome at discharge, rate of revision surgery, and CT findings during the follow-up period.

RESULTS

A total of 132 patients with CSDH were included in the study. The use of antiplatelet/anticoagulant medication was significantly higher in the combined treatment and embolization group (p<0.001). A trend towards fewer revision surgeries was found in the group of patients who received MMA embolization combined with burr hole irrigation (p=0.083). Follow-up was available for 73 patients (55.3%) with a mean follow-up period of 3.4±2.2 months. Eight patients (15.1%) of the surgery group showed hematoma re-accumulation and needed surgical rescue, whereas only one patient (5.0%) of the combined treatment group needed revision surgery. In all patients treated with only MMA embolization, complete hematoma resolution was found.

CONCLUSION

MMA embolization is a safe and efficacious minimal invasive adjuvant and/or alternative procedure for the treatment of CSDH with a reduced recurrence rate.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A National Database Study of 191 Patients in the United States

BACKGROUND

Middle meningeal artery embolization (MMAE) has been used as an effective minimally invasive treatment for chronic subdural hematoma (cSDH). The demographics and clinical outcomes after MMAE treatment for cSDH have not yet been studied using a national database.

METHODS

We queried all MMAE cases up to October 7, 2020, from the TriNetX Analytics Network. We identified patients >18 years old who underwent MMAE for treatment of cSDH. Patient demographics, baseline characteristics, comorbidities, and clinical outcomes were evaluated within 180 days after MMAE. Analyses of 180-day mortality and recurrence were performed after propensity score matching to control for baseline characteristics and comorbidities.

RESULTS

The study included 191 patients (mean age 71.2 ± 13.5 years, 73.3% male, 69.6% White, 13.6% Black/African American, and 16.8% other race). Essential hypertension (71.3%), heart disease (62.8%), type 2 diabetes mellitus (27.2%), nicotine dependence (23.6%), chronic kidney disease (19.4%), and overweight/obesity (19.4%) were among the most prevalent comorbidities. At presentation, 20.4% and 40.3% of patients were on antiplatelet and anticoagulation therapy, respectively. Outcomes within 180-day follow-up were 6.3% (1.0%-5.8% when propensity matched) for mortality (12 patients), 7.3% for craniotomy/craniectomy after MMAE (14 patients), 0.52%-5.2% for burr hole procedures (1-10 patients), and no patients with low vision/blindness.

CONCLUSIONS

MMAE is a safe and effective minimally invasive procedure for treatment of cSDH. This is the first analysis of patients undergoing MMAE for cSDH using a national database.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Multi-Center Experience of 154 Consecutive Embolizations

BACKGROUND

Middle meningeal artery (MMA) embolization has emerged as a promising treatment for chronic subdural hematoma (cSDH).

OBJECTIVE

To determine the safety and efficacy of MMA embolization.

METHODS

Consecutive patients who underwent MMA embolization for cSDH (primary treatment or recurrence after conventional surgery) at 15 centers were included. Clinical details and follow-up were collected prospectively. Primary clinical and radiographic outcomes were the proportion of patients requiring additional surgical treatment within 90 d after index treatment and proportion with > 50% cSDH thickness reduction on follow-up computed tomography imaging within 90 d. National Institute of Health Stroke Scale and modified Rankin Scale were also clinical outcomes.

RESULTS

A total of 138 patients were included (mean age: 69.8, 29% female). A total of 15 patients underwent bilateral interventions for 154 total embolizations (66.7% primary treatment). At presentation, 30.4% and 23.9% of patients were on antiplatelet and anticoagulation therapy, respectively. Median admission cSDH thickness was 14 mm. A total of 46.1% of embolizations were performed under general anesthesia, and 97.4% of procedures were successfully completed. A total of 70.2% of embolizations used particles, and 25.3% used liquid embolics with no significant outcome difference between embolization materials (P > .05). On last follow-up (mean 94.9 d), median cSDH thickness was 4 mm (71% median thickness reduction). A total of 70.8% of patients had >50% improvement on imaging (31.9% improved clinically), and 9 patients (6.5%) required further cSDH treatment. There were 16 complications with 9 (6.5%) because of continued hematoma expansion. Mortality rate was 4.4%, mostly unrelated to the index procedure but because of underlying comorbidities.

CONCLUSION

MMA embolization may provide a safe and efficacious minimally invasive alternative to conventional surgical techniques.

A propensity-adjusted comparison of middle meningeal artery embolization versus conventional therapy for chronic subdural hematomas

OBJECTIVE

Middle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis.

METHODS

A retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up.

RESULTS

A total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (15%) were treated using MMA embolization, and 196 (85%) were treated with conventional treatment. On the latest follow-up, there were no statistically significant differences between groups in the percentage of patients with worsening mRS scores. Of the 323 total cSDHs found in 231 patients, 41 (13%) were treated with MMA embolization, 159 (49%) were treated conservatively, and 123 (38%) were treated with surgical evacuation. After propensity adjustment, both surgery (OR 12, 95% CI 1.5-90; p = 0.02) and conservative therapy (OR 13, 95% CI 1.7-99; p = 0.01) were predictors of treatment failure and incomplete resolution on follow-up imaging (OR 6.1, 95% CI 2.8-13; p < 0.001 and OR 5.4, 95% CI 2.5-12; p < 0.001, respectively) when compared with MMA embolization. Additionally, MMA embolization was associated with a significant decrease in cSDH diameter on follow-up relative to conservative management (mean -8.3 mm, 95% CI -10.4 to -6.3 mm, p < 0.001).

CONCLUSIONS

This propensity-adjusted analysis suggests that MMA embolization for cSDH is associated with a greater extent of hematoma volume reduction with fewer treatment failures than conventional therapy.

Neuroanatomy of cranial dural vessels: implications for subdural hematoma embolization

Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.

Recurrence and Coniglobus Volumetric Resolution of Subacute and Chronic Subdural Hematoma Post-Middle Meningeal Artery Embolization

Objective: To study the efficacy of middle meningeal artery (MMA) embolization for the treatment of chronic subdural hematoma (SDH) and characterize its post-embolization volumetric resolution. Methods: Ten patients diagnosed with 13 cSDH underwent MMA embolization. SDH volumes were measured from time of initial discovery on imaging to pre-operative, post-operative, short-term and long-term follow-up. Time between procedure to obliteration was also measured. Volumetric analysis was done using the coniglobus formula, and recurrence rate as well as resolution timeline was defined using best-fit models. Results: Out of 10 patients, five were recurrent lesions, three were bilateral and seven unilateral cSDH. Average and median pre-operative volumes were 105.3 cc and 97.4 cc, respectively. Embolization on average was performed 21 days after discovery. Sixty percent of patients had concurrent antiplatelets or anticoagulation use. Forty percent underwent embolization treatment as the primary therapy. Recurrence was not seen in any patients treated with embolization. There were no peri- or post-operative complications. Five patients experienced complete or near-complete obliteration, while those with partial resolution showed a composite average of 75% volumetric reduction in 45 days. Post-embolization, the volumetric resolution followed an exponential decay curve over time and was independent of initial volume. Conclusion: MMA embolization contributed to a marked reduction in SDH volume post-operatively and can be used as a curative therapy for primary or recurrent chronic SDH.

Endovascular embolisation of the middle meningeal artery to treat chronic subdural haematomas: effectiveness, safety, and the current controversy. A systematic review

INTRODUCTION

Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established.

DEVELOPMENT

This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients.

CONCLUSIONS

eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

How to remove those bloody collections: Nonsurgical treatment options for chronic subdural hematoma

Chronic subdural hematoma (CSDH) is one of the most prevalent neurosurgical disorders. Patients with CSDH commonly present with altered mental status, focal neurological deficit, and/or headache. The first-line treatment for CSDH is surgical evacuation. Although the surgical procedures for CSDH have been considered relatively “straightforward,” they are not without any risk. The elderly are especially prone to show poor surgical outcomes. To make matters worse, many elderly patients are on anticoagulants and antiplatelet agents, increasing the risk of re-bleeding before and after surgery. These complications have led clinicians to search for nonsurgical alternatives. Dexamethasone should be used with caution for selected patients given its side effects. Tranexamic acid may be utilized as an adjunct therapy to surgery, but more randomized clinical trials are needed to evaluate its definitive efficacy. Interesting results of middle meningeal artery embolization (MMAE) have been reported from case studies. However, the risks associated with MMAE, including intracerebral hemorrhage, stroke, and vasospasm, have not been properly studied yet. The clinical benefits of atorvastatin and angiotensin-converting enzyme inhibitors are uncertain for CSDH. In conclusion, surgical intervention continues to be the first-line treatment while nonsurgical treatment options may be considered an adjunct therapy especially for recurrent hematoma or to reduce the volume of a hematoma.

Trephine Craniotomy versus Burr Hole Drainage for Chronic Subdural Hematoma—An Institutional Analysis of 156 Patients

Introduction Some neurosurgeons believe that doing a trephine craniotomy (TC) decreases the chance of recurrence in chronic subdural hematoma (cSDH). But this is not supported by any evidence.

Methods A retrospective analysis of patients who were operated for cSDH from 2014 to 2019 at our institute was done. Factors causing recurrence were studied.

Results A total of 156 patients were operated in the given period, among which 88 underwent TC and 68 patients underwent burr hole drainage (BHD) for evacuation of cSDH. All patients underwent two trephines or two burr holes placed according to the maximum thickness of the hematoma. Rate of recurrence in trephine group was 12.5% and in burr-hole group was 11.76% and was not statistically significant. Significant factors for recurrence included nontraumatic cSDH, anticoagulant use, presence of membranes, preoperative computed tomography (CT) showing iso- or mixed-density subdural collection and SDH volume > 60 mL. There was selection bias for the procedure. Patients with subdural membranes were preferentially taken for TC as the percentage of subdural membrane found intraoperatively was significantly greater in trephine group (51.1%) than burr-hole group (17.6%) (p value < 0.001).

When all the patients who showed membranes in CT scan were excluded, there was no statistical difference in the base line characteristics of both the groups. After excluding the patients with membranes in preoperative CT scan, there was no significant difference in recurrence rate between the two groups.

In TC group with membranes, 8 out of 45 had recurrence, whereas in burr-hole group with membranes, 8 out of 12 had recurrence. This difference was statistically significant. (p value < 0.001).

Conclusion Surgical intervention in both modalities improves patient outcome with an overall recurrence rate of 12.17%. In the absence of any identifiable membranes in preoperative CT scan, BHD is the preferred surgical intervention. We prefer TC as first choice for patients with membranes in CT scan.

Surgical Management of Trauma-Related Intracranial Hemorrhage-a Review

PURPOSE OF REVIEW

The surgical management of trauma-related intracranial hemorrhage is characterized by marked heterogeneity. Large prospective randomized trials have generally been prohibited by the ubiquity of concordant pathology, diversity of trauma systems, and paucity of clinical equipoise among providers.

RECENT FINDINGS

To date, the results of retrospective studies and surgeon preference have driven the indications, modality, extent, and timing of surgical intervention in the global neurosurgical community. With advances in our understanding of the pathophysiology of hemorrhagic TBI and the advent of novel surgical techniques, a reevaluation of surgical indication, timing, and approach is warranted. In this way, we can work to optimize surgical outcomes, achieving maximal functional recovery while minimizing surgical morbidity.

Middle meningeal artery embolization for chronic subdural hematoma: an institutional technical analysis

BACKGROUND

Recently, middle meningeal artery (MMA) embolization has emerged as a potentially safe and effective method of treating chronic subdural hematoma (cSDH).

OBJECTIVE

To report a single-center experience with MMA embolization and examines the type of embolic material used, the extent of penetration, and the number of MMA branches embolized.

METHODS

A retrospective analysis of all patients with MMA embolization from 2018 through 2019 was performed. A failed outcome was defined as either surgical rescue and/or greater than 10 mm of hematoma residual or reaccumulation following embolization.

RESULTS

Of 35 patients, surgery had failed for 9 (26%) and initial conservative treatment had failed for 6 (17%). Of 41 MMA embolizations, including those in six patients with bilateral cSDH who underwent bilateral MMA embolization, 29 (72%) were performed using ethylene vinyl alcohol copolymer (Onyx), 7 (17%) using particles, and 5 (12%) using n-butyl cyanoacrylate. Both the anterior and posterior MMA divisions were embolized in 29 cases (71%); distal penetration of these branches was achieved in 25 embolizations (61%). Twenty-six (63%) cSDHs completely resolved. Complete resolution was seen in 22 of 29 hematomas (76%) in which both anterior and posterior MMA branches were occluded versus 4 of 12 (33%) following single-branch embolization (p=0.014). Embolization of one cSDH (2%) failed.

CONCLUSION

MMA embolization of cSDHs appears to be both safe and efficacious. Furthermore, embolization of both the anterior and posterior MMA branches may be associated with increased odds of complete resolution.

Middle meningeal artery embolization treatment of nonacute subdural hematomas in the elderly: a multiinstitutional experience of 151 cases

OBJECTIVE

The incidence of already common chronic subdural hematomas (CSDHs) and other nonacute subdural hematomas (NASHs) in the elderly is expected to rise as the population ages over the coming decades. Surgical management is associated with recurrence and exposes elderly patients to perioperative and operative risks. Middle meningeal artery (MMA) embolization offers the potential for a minimally invasive, less morbid treatment in this age group. The clinical and radiographic outcomes after MMA embolization treatment for NASHs have not been adequately described in elderly patients. In this paper, the authors describe the clinical and radiographic outcomes after 151 cases of MMA embolization for NASHs among 121 elderly patients.

METHODS

In a retrospective review of a prospectively maintained database across 15 US academic centers, the authors identified patients aged ≥ 65 years who underwent MMA embolization for the treatment of NASHs between November 2017 and February 2020. Patient demographics, comorbidities, clinical and radiographic factors, treatment factors, and clinical outcomes were abstracted. Subgroup analysis was performed comparing elderly (age 65–79 years) and advanced elderly (age > 80 years) patients.

RESULTS

MMA embolization was successfully performed in 98% of NASHs (in 148 of 151 cases) in 121 patients. Seventy elderly patients underwent 87 embolization procedures, and 51 advanced elderly patients underwent 64 embolization procedures. Elderly and advanced elderly patients had similar rates of embolization for upfront (46% vs 61%), recurrent (39% vs 33%), and prophylactic (i.e., with concomitant surgical intervention; 15% vs 6%) NASH treatment. Transfemoral access was used in most patients, and the procedure time was approximately 1 hour in both groups. Particle embolization with supplemental coils was most common, used in 51% (44/87) and 44% (28/64) of attempts for the elderly and advanced elderly groups, respectively. NASH thickness decreased significantly from initial thickness to 6 weeks, with additional decrease in thickness observed in both groups at 90 days. At longest follow-up, the treated NASHs had stabilized or improved in 91% and 98% of the elderly and advanced elderly groups, respectively, with > 50% improvement seen in > 60% of patients for each group. Surgical rescue was necessary in 4.6% and 7.8% of cases, and the overall mortality was 8.6% and 3.9% for elderly and advanced elderly patients, respectively.

CONCLUSIONS

MMA embolization can be used safely and effectively as an alternative or adjunctive minimally invasive treatment for NASHs in elderly and advanced elderly patients.

Endovascular embolisation of the middle meningeal artery to treat chronic subdural haematomas: Effectiveness, safety, and the current controversy. A systematic review

INTRODUCTION

Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established.

DEVELOPMENT

This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients.

CONCLUSIONS

eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

Embolization of the middle meningeal artery in patients with chronic subdural hematoma-a systematic review and meta-analysis

BACKGROUND

Chronic subdural hematoma (CSDH) remains a neurosurgical condition with high recurrence rate after surgical treatment. The primary pathological mechanism is considered to be repeated microbleedings from fragile neo-vessels within the outer hematoma membrane. The neo-vessels are supplied from peripheral branches of the middle meningeal artery, and embolization of MMA (eMMA) has been performed to prevent re-bleeding episodes and thereby CSDH recurrence.

OBJECTIVE

To evaluate the published evidence for the effect of eMMA in patients with recurrent CSDH. Secondarily, to investigate the effect of eMMA as an alternative to surgery for primary treatment of CSDH.

METHOD

A systematic review of the literature on eMMA in patients with recurrent CSDH was conducted. PubMed, Embase, and Cochrane databases were reviewed using the search terms: Embolization, Medial Meningeal Artery, Chronic Subdural Haematoma, and Recurrence. Furthermore, the following mesh terms were used: Chronic Subdural Haematoma AND embolization AND medial meningeal artery AND recurrence. Eighteen papers were found and included. No papers were excluded. The number of patients with primary CSDH and the number of patients with recurrent CSDH treated with eMMA were listed. Furthermore, the number of recurrences in both categories was registered.

RESULTS

Eighteen papers with a total of 191 included patients diagnosed with CSDH treated with eMMA for primary and recurrent CSDH were identified. Recurrence rate for patients treated with eMMA for recurrent CSDH was found to be 2.4%, 95% CI (0.5%; 11.0%), whereas the recurrence rate for patients treated with eMMA for primary CSDH was 4.1%, 95% CI (1.4%; 11.4%).

CONCLUSION

eMMA is a minimally invasive procedure for treatment of CSDH. Although this study is limited by publication bias, it seems that this procedure may reduce recurrence rates compared with burr hole craniostomy for both primary and recurrent hematomas. A controlled study is warranted.

Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis

INTRODUCTION

Refractory or chronic subdural hematomas (cSDH) constitute a challenging entity that neurosurgeons face frequently nowadays. Middle meningeal artery embolization (MMAE) has emerged in the recent years as a promising treatment option. However, solid evidence that can dictate management guidelines is still lacking.

METHODS

We conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of MMAE compared with conventional treatments for refractory or cSDH. Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk difference were conducted recurrence, need for surgical rescue, and complications.

RESULTS

Eleven studies (177 patients) were included. Majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. Meta-analysis of proportions showed treatment failure to be 2.8%, need for surgical rescue 2.7%, and embolization-related complications 1.2%. Meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I² = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I² = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I² = 0) compared to conventional groups.

CONCLUSIONS

Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH.

Middle meningeal artery embolization as an adjuvant treatment to surgery for symptomatic chronic subdural hematoma: a pilot study assessing hematoma volume resorption

Background

Chronic subdural hematoma (CSDH) is a common condition requiring surgical treatment; however, recurrence occurs in 15% of cases at 1 year. Middle meningeal artery (MMA) embolization has recently emerged as a promising treatment to prevent CSDH recurrence.

Objective

To investigate the effect of MMA embolization on hematoma volume resorption (HVR) after surgery in symptomatic patients.

Methods

From April 2018 to October 2018, participants with CSDH requiring surgery were prospectively randomized in a pilot study, and received either surgical treatment alone (ST group) or surgery and adjuvant MMA embolization (ST+MMAE group). The primary outcome was HVR measured on the 3 month CT scan compared with the immediate pre-embolization CT scan. Secondary outcomes were clinical recurrence of CSDH and safety measures.

Results

46 patients were randomized and 41 of these achieved a 3 month follow-up . Twenty-one patients received MMA embolization. At 3 months, the HVR from postsurgical level was higher in the ST+MMAE group (mean difference 17.5 mL, 95% CI 3.87 to 31.16 mL; p=0.015). Two participants presented a CSDH recurrence (one in each group). One patient died (ST group). No MMA embolization-related adverse events were reported.

Conclusion

The addition of MMA embolization to surgery led to an increase in CSDH resorption at 3 months. One recurrence of CSDH was reported in each group, and there were no treatment-related complications.

Angiogenesis in the Septum and Inner Membrane of Refractory Chronic Subdural Hematomas: Consideration of Findings after Middle Meningeal Artery Embolization with Low-concentration n-butyl-2-cyanoacrylate

The middle meningeal artery (MMA) is suggested to play an important role in the recurrence of chronic subdural hematomas (CSDHs). However, the exact mechanisms involved in the recurrence of CSDHs still remain unknown. For recurring CSDHs, MMA embolization is performed using low-concentration n-butyl-2-cyanoacrylate (NBCA) at our hospital. We report new findings and a discussion related to the mechanism of CSDH recurrence based on the imaging findings after MMA embolization, and cases that required craniotomy due to recurrence. The study included eight patients with recurrent CSDH, defined as ipsilateral hematoma re-enlargement within 3 months, and treated with MMA embolization. MMA embolization was performed successfully in all eight patients with no complications. Of the eight patients treated, one patient required craniotomy for the evacuation of CSDHs due to hematoma re-enlargement. NBCA casts were observed in the inner membrane of CSDHs in five of the eight patients by postoperative computed tomography scans. In the case that required craniotomy, the formation of neovasculatures was observed in the inner membrane of the CSDH. Our results suggested that angiogenesis also occurs in the septum and inner membrane through the MMA and the outer membrane of the CSDH. Additionally, these neovascular vessels may be involved in the recurrence of CSDH after MMA embolization. In a future larger study, it is necessary to elucidate in detail the vascular architecture of the CSDH membrane associated with the hematoma re-enlargement, and the effectiveness of MMA embolization that embolized to these peripheral neovascular vessels.

Embolization of the Middle meningeal artery in chronic subdural hematoma - A systematic review

Chronic subdural hematomas (cSDH) are one of the most frequent reasons for consultation in neurosurgery. Multiple authors have proposed middle meningeal artery embolization (MMAE) as an option in cSDH patients to manage recurrence or avoid surgery altogether. Although many articles have been published on the matter, the current body of evidence still has to be evaluated before MMAE is integrated into clinical practice. The goal of this study was to review the evidence on MMAE in cSDH to assess its safety, feasibility, indications and efficacy. We performed a systematic review of the literature according to PRISMA guidelines using multiple electronic databases. Our search yielded a total of 18 original articles from which data were extracted. A total of 190 patients underwent MMAE from which 81.3% were symptomatic cSDH. Over half (52.3%) of the described population were undergoing antithrombotic therapy. Most (83%) procedures used polyvinyl alcohol (PVA) particles and no complications were reported regarding the embolization procedures. Although the definition of resolution varied among authors, cSDH resolution was reported in 96.8% of cases. MMAE is a feasible technique for cSDH, but the current body of evidence does not yet support its use as a standard treatment. Further studies with a higher level of evidence are necessary before MMAE can be formally recommended.

Safety and Effectiveness of Embolization for Chronic Subdural Hematoma: Systematic Review and Case Series

INTRODUCTION

Embolization of the middle meningeal artery (MMA) has emerged as a minimally invasive means of managing subdural hematoma. The purpose of this study was to systematically review the literature on the safety and effectiveness of this treatment and to share our clinical experience.

METHODS

This review was registered with PROSPERO. PubMed, CINAHL, EMBASE, and the Cochrane Library were searched using MeSH (Medical Subject Headings) terms for MMA embolization and chronic subdural hematoma (CSDH) from January 2000 to November 2018. All articles in the English language literature describing MMA embolization for CSDH were included, irrespective of study design. Consecutive patients who underwent MMA embolization at our hospital between January 2017 and June 2018 comprised our clinical experience.

RESULTS

Fifteen studies with 193 procedures were included in the review. Ninety-five cases (49.2%) involved primary MMA embolization; 88 embolizations (45.6%) for recurrent CSDH and 10 (5.2%) for prophylaxis after surgical evacuation were performed. Recurrence after MMA embolization requiring further treatment occurred in 7 cases (3.6%). All other patients had symptomatic relief with no further recurrence. No procedure-related complications were reported. Polyvinyl alcohol was the most commonly used material. Our series included 8 patients treated with Onyx. All had symptom relief and significant reduction in hematoma size; no recurrences or procedure-related complications were observed.

CONCLUSIONS

MMA embolization of CSDH is safe and effective for CSDH treatment based on a documented recurrence rate of 3.6% and lack of reported complications.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Series of 60 Cases

BACKGROUND

Chronic subdural hematoma (SDH) is a particularly challenging pathology due to high recurrence rates (2%-37%) and complex medical comorbidities that tend to afflict the patient population. Recently, there have been several case series published describing the use of middle meningeal artery (MMA) embolization as an alternative to surgery for treatment of new or recurrent chronic SDH.

OBJECTIVE

To describe our first 60 cases of MMA embolization for chronic SDH.

METHODS

MMA embolization was performed using angiography, selective microcatheterization of the MMA, and infusion of polyvinyl alcohol particles. Outcomes were assessed clinically and with interval imaging studies at 1 d, 2 wk, and 6 wk postprocedure, and additional intervals as indicated.

RESULTS

MMA embolization was performed successfully on 60 total SDHs in 49 patients. This includes upfront treatment for new (not previously treated) SDH in 42, for recurrence in 8, and prophylaxis (soon after surgical evacuation) in 10. There were 3 mortalities (unrelated to the procedure), and no procedural complications. Of the 50 nonprophylactic cases, there were 4 (8.9%) cases of recurrence requiring surgical evacuation, and 31 (68.9%) that had resolution or reduction in size >50% of SDH at longest follow-up. Overall, 41 (91.1%) were stable or decreased in size and able to avoid surgery.

CONCLUSION

MMA embolization may represent a minimally-invasive alternative to surgery for new or recurrent chronic SDH, or as prophylaxis to reduce the risk of recurrence after surgery. Given our encouraging results with a 91% long-term success rate, a large scale clinical trial is warranted.