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

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

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

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.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied.

METHODS

A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale.

RESULTS

Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001).

CONCLUSION

MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

Endovascular Embolization of Traumatic Vessel Injury Using N-butyl Cyanoacrylate: A Case Series

There is limited evidence of N-butyl cyanoacrylate (n-BCA) use in endovascular embolization of traumatic face and neck vessel injuries. We investigated the safety and effectiveness of n-BCA for this purpose. We retrospectively analyzed consecutive patients presenting to a Level 1 trauma center between April 2021 and July 2022. We included patients aged ≥ 18 years old with any vessel injury in the face and neck circulation requiring n-BCA embolization. The primary endpoint was n-BCA effectiveness defined as immediate control of active bleeding post-embolization. In total, 13 patients met the inclusion criteria. The median decade of life was 3 (IQR 3 - 5) with a male predominance (n = 11, 84.6%). Median Glasgow Coma Scale score on presentation was 15 (IQR 3-15). Eleven patients suffered gunshot wound injuries; two patients suffered blunt injuries. Injured vessels included facial artery (n = 6, 46.2%), buccal branch artery (n = 3, 23.1%), internal maxillary (n = 5, 38.5%), cervical internal carotid artery (n = 1, 7.7%), and vertebral artery (n = 1, 7.7%). All patients were treated with 1:2 n-BCA to ethiodol mixture with immediate extravasation control. No bleeding recurrence or need for retreatment occurred. One patient died in-hospital (7.7%). Patients were discharged to home (n = 8, 61.5%), day rehabilitation (n = 1, 7.7%), or acute rehabilitation (n = 3, 23.1%). One patient developed a right posterior cerebral artery infarct with hemorrhagic transformation. To our knowledge, this is the first study demonstrating the safety and effectiveness of n-BCA liquid embolism in traumatic vessel injuries, especially penetrating gunshot wounds.

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

Background

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

Methods

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

Results

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

Conclusion

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

In vitro comparison of middle meningeal artery embolization with Squid liquid embolic agent and Contour polyvinyl alcohol particles

BACKGROUND

Liquid embolic agents and polyvinyl alcohol (PVA) particles have been used for the embolization of the middle meningeal artery (MMA) for the treatment of chronic subdural hematomas. However, the vascular penetration and distribution of these embolic agents have not yet been compared. The current study compares distribution of a liquid embolic agent (Squid) to PVA particles (Contour) in an in vitro model of the MMA.

METHODS

MMA models were embolized with Contour PVA particles 45-150 µm, Contour PVA particles 150-250 µm, and Squid-18 liquid embolic agent (n=5 each). The models were scanned and every vascular segment with embolic agent was manually marked on the images. Embolized vascular length as a percentage of control, average embolized vascular diameter, and embolization time were compared between the groups.

RESULTS

The 150-250 µm Contour particles primarily accumulated close to the microcatheter tip, yielding proximal branch occlusions. The 45-150 µm Contour particles achieved a more distal distribution, but in a patchy segmental pattern. However, the models embolized with Squid-18 had a consistently distal, near-complete and homogenous distribution. Embolized vascular length was significantly higher (76±13% vs 5±3%, P=0.0007) and average embolized vessel diameter was significantly smaller (405±25 µm vs 775±225 µm, P=0.0006) with Squid than with Contour. Embolization time with Squid was also lower (2.8±2.4 min vs 6.4±2.7 min, P=0.09).

CONCLUSIONS

Squid-18 liquid results in a considerably more consistent, distal and homogeneous pattern of embolysate distribution than Contour PVA particles in an anatomical model of the MMA tree.

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.

Delayed Recognition, Surgical Dilemmas, and Complications: A Case Report of Acute-on-Chronic Subdural Hematoma With Ischemic Stroke

Acute-on-chronic subdural hematoma (SDH) is a new hemorrhage on a preexisting hematoma in the space between the dura mater and the arachnoid layer. Although chronic SDH is common, acute-on-chronic SDH is not. Herein, we present a case of a 70-year-old male with ischemic heart disease, diabetes mellitus, and hypertension who presented with worsening headaches for the past three days, associated with gait imbalance and dizziness. The patient was vitally stable on examination with a Glasgow Coma Scale/Score (GCS) of 15/15; his pupils were reactive bilaterally; and his neurological examination was unremarkable. Non-contrast computed tomography (CT) of the head yielded acute and chronic SDH. The patient was initially managed by embolization of the middle meningeal artery (EMMA), but one day later he developed a stroke. Hence, thrombectomy and burr hole craniotomy were performed to manage the stroke and evacuate the chronic subdural hematoma (CSDH). This paper presents this case as uncommon acute on chronic SDH presented with headache and vertigo, treated with embolization and with complications of stroke and pulmonary embolism.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effect of postoperative tranexamic acid on recurrence rate and complications in chronic subdural hematomas patients: preliminary results of a randomized controlled clinical trial

Chronic subdural hematoma (CSDH) is a frequent neurosurgical disease which mainly affects elderly patients. Tranexamic acid (TXA) has been hypothesized as an oral agent to avoid CSDH progression and/or recurrence. We performed an evaluation to determine whether the postoperative use of TXA reduces recurrence rate. A prospective, randomized, and controlled trial. Patients with unilateral or bilateral chronic subdural hematoma undergoing surgical treatment by burr-hole were randomized as to whether or not to use TXA in the postoperative period. We evaluated image and clinical recurrence of CSDH at follow up of 6 months and potential clinical and/or surgical complications impact of TXA. Twenty-six patients were randomized to the control group (52%) and twenty-four patients to the TXA group (48%). Follow-up ranged from 3 to 16 months. There were no significant difference between baseline data in groups regarding to age, gender, use of antiplatelet or anticoagulants, smoking, alcoholism, systemic arterial hypertension, diabetes mellitus, hematoma laterality, hematoma thickness, and drain use. Clinical and radiological recurrence occurred in three patients (6%), being two cases in TXA group (8.3%) and 1 in control group (3.8%). Postoperative complications occurred in two patients during follow-up (4%), being both cases in TXA group (8.3%), and none in the control group. Although TXA group had a higher recurrence rate (8.3%), there was no statistically significant difference between the two groups. Moreover, TXA group had two complications while control group had no complications. Although limited by experimental nature of study and small sample, our current data suggest that TXA should not be used as a potential agent to avoid recurrences of CSDH and might increase complication odds.

Endoscopically observed outer membrane of chronic subdural hematoma after endovascular embolization of middle meningeal artery

Background:

Embolization of the middle meningeal artery (MMA) has been established for chronic subdural hematoma (CSDH). Neuroendoscopic observation of the outer membrane of the hematoma was carried out after embolization. The treatment mechanism of embolization is discussed, focusing on the vasculature and inflammation of the membrane.

Methods:

Four patients with recurrent CSDH were included in this study. The MMA was embolized using Embosphere® particles in three patients. The outer membrane was observed with normal and narrow band images (NBIs).

Results:

The net-like vessels were not obstructed in the whole area of the outer membrane, but in a patchy fashion of embolized areas surrounded by nonembolized areas. In two patients, the nonembolized areas showed a hemorrhagic inflammatory red color. Histopathological examination confirmed hypertrophic dura with leukocyte infiltration. Dilated dural arteries and proliferated sinusoid arteries were located in the deep and superficial border cell layers. These arteries were visualized as green and brown on NBI, respectively. In the embolized area, the red membrane turned pink, indicating ischemia and subsiding inflammatory hyperemia. In the third patient, the outer membrane was white in both the nonembolized and embolized areas in endoscopic view, and the net-like vessels were sparse in both endoscopy and histology, indicating a scar inflammatory phase. The membrane transition was not observed in the patient that did not undergo embolization.

Conclusion:

Endoscopic observation revealed that embolization of the MMA blocked both the dural and sinusoidal arteries. Ischemic transformation causing the suppression of inflammation of the outer membrane is a suggested mechanism of MMA embolization.

Controversies in the Surgical Treatment of Chronic Subdural Hematoma: A Systematic Scoping Review

Chronic subdural hematoma (cSDH) is one of the most common neurosurgical entities, especially in the elderly population. Diagnosis is usually established via a head computed tomography, while an increasing number of studies are investigating biomarkers to predict the natural history of cSDH, including progression and recurrence. Surgical evacuation remains the mainstay of treatment in the overwhelming majority of cases. Nevertheless, many controversies are associated with the nuances of surgical treatment. We performed a systematic review of the literature between 2010 and 2022, aiming to identify and address the issues in cSDH surgical management where consensus is lacking. The results show ambiguous data in regard to indication, the timing and type of surgery, the duration of drainage, concomitant membranectomy and the need for embolization of the middle meningeal artery. Other aspects of surgical treatment-such as the use of drainage and its location and number of burr holes-seem to have been adequately clarified: the drainage of hematoma is strongly recommended and the outcome is considered as independent of drainage location or the number of burr holes.

[Middle meningeal artery embolization for chronic subdural hematomas]

The treatment of chronic subdural hematoma (cSDH) represents a challenge due to high recurrence rates (2-37%). One possible treatment option is middle meningeal artery (MMA) embolization as an alternative to surgery. In contrast to acute SDH, which is caused by a rupture of the bridging veins, cSDH has a different pathomechanism. Injury to the so-called dural boundary cell layer results in an intermittent or continuous cycle of cell proliferation, angiogenesis, secretion, and bleeding due to rupture of newly formed vessels within the SDH membrane. This membrane is supplied by the MMA. Embolization of the MMA leads to resorption of the cSDH. The results published so far regarding MMA embolization as sole therapy or in combination with surgical treatment are encouraging with a long-term success rate of up to 90%.

Recent Advances and Future Directions in Middle Meningeal Artery Embolization for Chronic Subdural Hematomas

PURPOSE OF REVIEW

The purpose of this review is to present a brief background on chronic subdural hematomas (cSDH), middle meningeal artery (MMA) embolization, and its role in decreasing recurrence of cSDH. A review of the most up-to-date literature should demonstrate the efficacy of this procedure.

RECENT FINDINGS

The latest data shows that MMA embolization is a safe procedure, with low complication rates and low recurrence rates. While cSDH managed with surgical evacuation can have a recurrence rate upwards of 30%, MMA embolization alone or as an adjunct to surgery decreases recurrence to less than 5% in most studies. MMA embolization can be especially useful in high-risk populations such as the elderly, patients on anti-platelet medication, and those with coagulopathies. It can also be done awake, done without general anesthesia, and is significantly less invasive than traditional surgical techniques. In reviewing the literature on MMA embolization, it is clear that there are numerous retrospective studies and systematic reviews demonstrating its safety and efficacy, and some prospective dual-arm studies that present novel information. The numerous clinical trials that are currently underway should help to further establish MMA embolization as standard of care in the management of cSDH.

Intracranial hemorrhage following drainage of chronic subdural effusion and hematoma: A case report and review of the literature

Acute intracranial hemorrhage (AIH) after drainage of chronic subdural hematoma is a rare but serious complication. An 86-year-old man with bilateral frontotemporal subdural effusion, hematoma, and cerebral hernia was admitted to our department and treated with bilateral burr hole surgery and closed-system drainage under local anesthesia. After the operation, computed tomography (CT) showed AIH in the left temporal and occipital lobe, and then a series of head CT showed that the hematoma gradually increased day by day. This patient had a medical history of hypertension, diabetes, atrial fibrillation, and taking warfarin. He was treated conservatively, but had not recovered at discharge after 1 month. We reviewed the relevant literature and analyzed the operation opportunity, causes of cerebral hemorrhage, and preventive measures in similar patients. We suppose that the coagulation abnormality and rapid fluctuations of intracranial pressure were the main causes of development of AIH in our patient. Several possible reasons such as brain shift and impaired vascular autoregulation are also associated with postoperative AIH. We must be aware of this complication and keep some preventive measures in our mind.

Expert consensus on drug treatment of chronic subdural hematoma

Chronic subdural hematoma (CSDH) is a chronic space-occupying lesion formed by blood accumulation between arachnoid and dura mater, which is usually formed in the third week after traumatic brain injury. Surgical treatment is usually the first choice for patients with CSDH having a significant space-occupying effect. Most of the patients showed good results of surgical treatment, but still some patients had a postoperative recurrence (the recurrence rate was up to 33%). Because CSDH is often seen in the elderly, patients are weak and have many basic diseases. The risk of surgical treatment is high; serious complications and even death (the death rate is up to 32%) can often occur. The overall good prognosis rate of patients aged more than 90 years is 24%. The drug treatment can provide a safe and effective treatment for elderly patients who are weak, intolerable to surgery, or failed in surgery. Low-dose and long-term use of atorvastatin (20mg/d) is suggested for continuous treatment for at least 8 weeks, while low-dose and short-term use of dexamethasone can improve the therapeutic effect of atorvastatin on CSDH. Patients should undergo CT or MRI scanning at least one time within 2 weeks after the start of drug treatment.

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.

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.

Middle meningeal artery embolization with subdural evacuating port system for primary management of chronic subdural hematomas

Optimal treatment for chronic subdural hematomas remains controversial and perioperative risks and comorbidities may affect management strategies. Minimally invasive procedures are emerging as alternatives to the standard operative treatments. We evaluate our experience with middle meningeal artery (MMA) embolization combined with Subdural Evacuating Port System (SEPS) placement as a first-line treatment for patients with cSDH. A single institution retrospective review was performed of all patients undergoing intervention. Patients were stratified by treatment with MMA embolization and SEPS placement, MMA embolization and surgery, SEPS placement only, and surgery only for cSDH from 2017 to 2020, and cohorts were compared against each other. Patients treated with MMA/SEPS were more likely to be older, be on anticoagulation, have significant comorbidities, have shorter length of stay, and less likely to have symptomatic recurrence compared to SEPS only cohort. Thus, MMA/SEPS appears to be a safe and equally effective minimally invasive treatment for cSDH patients with significant comorbidities who are poor surgical candidates.

Utilizing dual energy CT to distinguish blood from contrast leakage following middle meningeal artery embolization for chronic subdural hematomas

BACKGROUND

Recently, middle meningeal artery (MMA) embolization has emerged as a potential alternative treatment option for chronic subdural hematomas (SDH). Imaging following MMA embolization often shows high density material in the subdural space, usually representing contrast leakage through the dura or, less commonly, hemorrhage. These cannot be reliably differentiated on conventional CT. Dual energy CT (DECT) provides the ability to differentiate materials that otherwise appear similar on conventional CT such as blood and iodine.

METHODS

A retrospective review was conducted to evaluate patients who underwent MMA embolization for SDH between May 2019 and April 2020. Post-procedural head CT performed on an IQon Elite Spectral CT detector-based DECT scanner enabled two-material decomposition to separate iodine from blood. The dual energy reconstructions used included the virtual non-contrast and iodine no-water images.

RESULTS

Four representative illustrative cases were selected to highlight the ability of DECT to characterize new hyperdensity on head CT following MMA embolization as blood, contrast or a combination.

CONCLUSIONS

DECT allows objective differentiation of contrast leakage from blood following MMA embolization. This technology can obviate the need for additional follow-up scanning and prolonged patient observation, which in turn can result in reduced costs and radiation exposure to patients.

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.

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.

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.

Thirty- and 90-Day Readmissions After Treatment of Traumatic Subdural Hematoma: National Trend Analysis

OBJECTIVE

Subdural hematoma (SDH), a form of traumatic brain injury, is a common disease that requires extensive patient management and resource utilization; however, there remains a paucity of national studies examining the likelihood of readmission in this patient population. The aim of this study is to investigate differences in 30- and 90-day readmissions for treatment of traumatic SDH using a nationwide readmission database.

METHODS

The Nationwide Readmission Database years 2013-2015 were queried. Patients with a diagnosis of traumatic SDH and a primary procedure code for incision of cerebral meninges for drainage were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Patients were grouped by no readmission (Non-R), readmission within 30 days (30-R), and readmission within 31-90 days (90-R).

RESULTS

We identified a total of 14,355 patients, with 3106 (21.6%) patients encountering a readmission (30-R: n = 2193 [15.3%]; 90-R: n = 913 [6.3%]; Non-R: n = 11,249). The most prevalent 30- and 90-day diagnoses seen among the readmitted cohorts were postoperative infection (30-R: 10.5%, 90-R: 13.0%) and epilepsy (30-R: 3.7%, 90-R: 1.1%). On multivariate logistic regression analysis, Medicare, Medicaid, hypertension, diabetes, renal failure, congestive heart failure, and coagulopathy were independently associated with 30-day readmission; Medicare and rheumatoid arthritis/collagen vascular disease were independently associated with 90-day readmission.

CONCLUSIONS

In this study, we determine the relationship between readmission rates and complications associated with surgical intervention for traumatic subdural hematoma.

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.