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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Safety of Postembolization Antithrombotic Therapy After Middle Meningeal Artery Embolization

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Factors Associated with Extended Hospitalization in Patients Who Had Adjuvant Middle Meningeal Artery Embolization After Conventional Surgery for Chronic Subdural Hematomas

BACKGROUND

This study aims to evaluate the length of stay (LOS) in patients who had adjunct middle meningeal artery embolization (MMAE) for chronic subdural hematoma after conventional surgery and determine the factors influencing the LOS in this population.

METHODS

A retrospective review of 107 cases with MMAE after conventional surgery between September 2018 and January 2024 was performed. Factors associated with prolonged LOS were identified through univariable and multivariable analyses.

RESULTS

The median LOS for MMAE after conventional surgery was 9 days (interquartile range = 6-17), with a 3-day interval between procedures (interquartile range = 2-5). Among 107 patients, 58 stayed ≤ 9 days, while 49 stayed longer. Univariable analysis showed the interval between procedures, type of surgery, MMAE sedation, and the number of complications associated with prolonged LOS. Multivariable analysis confirmed longer intervals between procedures (odds ratio [OR] = 1.52; P < 0.01), ≥2 medical complications (OR = 13.34; P = 0.01), and neurological complications (OR = 5.28; P = 0.05) were independent factors for lengthier hospitalizations. There was a trending association between general anesthesia during MMAE and prolonged LOS (P = 0.07). Subgroup analysis revealed diabetes (OR = 5.25; P = 0.01) and ≥2 medical complications (OR = 5.21; P = 0.03) correlated with a LOS over 20 days, the 75th percentile in our cohort.

CONCLUSIONS

The interval between procedures and the number of medical and neurological complications were strongly associated with prolonged LOS in patients who had adjunct MMAE after open surgery. Reducing the interval between the procedures and potentially performing both under 1 anesthetic may decrease the burden on patients and shorten their hospitalizations.

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

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

Validity of the Cost-Effectiveness of Middle Meningeal Artery Embolization Following Hematoma Evacuation for Initial Chronic Subdural Hematoma

BACKGROUND

Despite numerous articles about middle meningeal artery embolization (MMAE) highlighting its efficacy and safety for recurrent chronic subdural hematoma (CSDH), the appropriateness of adjunctive MMAE after hematoma evacuation for initial CSDH remains unclear from a cost-effectiveness perspective.

METHODS

Patients with CSDH were enrolled in this study and were prospectively divided into 2 groups: the "conventional treatment" group, which was treated with hematoma evacuation alone, and the "MMAE" group, which was treated with adjunctive MMAE after hematoma evacuation. The proportion of patients requiring retreatment, length of hospital stay, economic costs, and modified Rankin Score were compared between the 2 groups.

RESULTS

In this study, 53 cases were included, with 30 classified into the conventional treatment group and 23 classified into the MMAE group. In the conventional treatment group, the proportion of patients who required surgical retreatment was higher than that in the MMAE group (16.7% vs. 8.7%). The relative risk was 0.522 (95% confidence interval, 0.111-2.45). Although the addition of MMAE increased the cost per hospitalization by 26%, the increase in cost per patient was limited to 12%, owing to the reduction in patients who relapsed and required a second hospitalization. The increase in cost was not statistically significant. The MMAE group had a significantly higher proportion of patients with favorable outcomes (modified Rankin Score 0-2) (56.7% vs. 87.0%, P = 0.0328).

CONCLUSIONS

By minimizing the increase in hospitalization days and procedure costs, MMAE following hematoma evacuation for initial CSDH could decrease the retreatment rate and balance the total medical costs associated with MMAE.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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 Embolization for Management of Chronic Subdural Hematoma

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Preoperative Fibrinogen Levels and Function as Predictive Factors for Acute Bleeding in the Hematoma Cavity After Burr Hole Drainage in Patients with CSDH

OBJECTIVE

Burr hole drainage (BHD) is the primary surgical intervention for managing chronic subdural hematoma (CSDH). However, it can lead to postoperative complications such as acute bleeding within the hematoma cavity and hematoma recurrence. The objective of this study is to identify the risk factors for these complications and develop a predictive model for acute hematoma cavity bleeding after BHD in patients with CSDH.

METHODS

This study presents a retrospective cohort investigation conducted at a single center. The clinical dataset of 308 CSDH patients who underwent BHD at a hospital from 2016 to 2022 was analyzed to develop and assess a prognostic model.

RESULTS

The nonbleeding group exhibited a significant correlation between fibrinogen (FIB) and thrombin time (TT), whereas no correlation was observed in the bleeding group. Notably, both FIB and TT were identified as risk factors for postoperative acute bleeding within the hematoma cavity. We developed a prognostic model to predict the occurrence of postoperative acute bleeding within the hematoma cavity after BHD in patients with CSDH. The model incorporated FIB, TT, coronary artery disease, and Glasgow Coma Scale scores. The model exhibited good discrimination (area under the curve: 0.725) and calibration (Hosmer-Leeshawn goodness of fit test: P > 0.1). Furthermore, decision curve analysis demonstrated the potential clinical benefit of implementing this prediction model.

CONCLUSIONS

The predictive model developed in this study can forecast the risk of postoperative acute bleeding within the hematoma cavity, thus aiding clinicians in selecting the optimal treatment approach for patients with CSDH.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predicting the progression of chronic subdural hematoma based on skull density

Objective

The objective of this study was to investigate potential correlations between skull density and the progression of chronic subdural hematoma (CSDH).

Methods

Patients with unilateral CSDH were retrospectively enrolled between January 2018 and December 2022. Demographic and clinical characteristics, as well as hematoma and skull density (Hounsfield unit, Hu), were collected and analyzed.

Results

The study enrolled 830 patients with unilateral CSDH until the resolution of the CDSH or progressed with surgical treatment. Of the total, 488 patients (58.80%) necessitated surgical treatment. The study identified a significant correlation between the progression of CSDH and three variables: minimum skull density (MiSD), maximum skull density (MaSD), and skull density difference (SDD) (p < 0.001). Additionally, in the multivariable regression analysis, MiSD, MaSD, and SDD were independent predictors of CSDH progression. The MiSD + SDD model exhibited an accuracy of 0.88, as determined by the area under the receiver operating characteristic curve, with a sensitivity of 0.77 and specificity of 0.88. The model's accuracy was validated through additional analysis.

Conclusion

The findings suggest a significant correlation between skull density and the CSDH progression.

Middle meningeal artery embolization for chronic subdural hematoma: a systematic review

Background

Chronic subdural hematoma (cSDH) is one of the most common diseases in neurosurgery. Middle meningeal artery embolization (MMAE) is reportedly an option to prevent recurrence or avoid surgery in patients with cSDH. This study was performed to review the evidence on MMAE for cSDH and evaluate its safety, efficacy, indications, and feasibility.

Methods

We systematically reviewed the literature according to the PRISMA guidelines using an electronic database. The search yielded 43 articles involving 2,783 patients who underwent MMAE.

Results

The hematoma resolution, recurrence, and retreatment rates in the MMAE-alone treatment group (n = 815) were 86.7%, 6.3%, and 9.6%, respectively, whereas those in the prophylactic MMAE with combined surgery group (n = 370) were 95.6%, 4.4%, and 3.4%, respectively. The overall MMAE-related complication rate was 2.3%.

Conclusion

This study shows that MMAE alone is, although not immediate, as effective as evacuation surgery alone in reducing hematoma. The study also shows that combined treatment has a lower recurrence rate than evacuation surgery alone. Because MMAE is a safe procedure, it should be considered for patients with cSDH, especially those with a high risk of recurrence.

Application of deep learning models for detection of subdural hematoma: a systematic review and meta-analysis

BACKGROUND

This study aimed to investigate the application of deep learning (DL) models for the detection of subdural hematoma (SDH).

METHODS

We conducted a comprehensive search using relevant keywords. Articles extracted were original studies in which sensitivity and/or specificity were reported. Two different approaches of frequentist and Bayesian inference were applied. For quality and risk of bias assessment we used Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2).

RESULTS

We analyzed 22 articles that included 1,997,749 patients. In the first step, the frequentist method showed a pooled sensitivity of 88.8% (95% confidence interval (CI): 83.9% to 92.4%) and a specificity of 97.2% (95% CI 94.6% to 98.6%). In the second step, using Bayesian methods including 11 studies that reported sensitivity and specificity, a sensitivity rate of 86.8% (95% CI: 77.6% to 92.9%) at a specificity level of 86.9% (95% CI: 60.9% to 97.2%) was achieved. The risk of bias assessment was not remarkable using QUADAS-2.

CONCLUSION

DL models might be an appropriate tool for detecting SDHs with a reasonably high sensitivity and specificity.

Managing non-acute subdural hematoma using liquid materials: a Chinese randomized trial of middle meningeal artery treatment (MAGIC-MT)-protocol

BACKGROUND

The conventional treatments for non-acute subdural hematoma (SDH) are facing the challenge of high hematoma recurrence and progression. A novel treatment of middle meningeal artery (MMA) embolization showed the potential role in decreasing the recurrence and progression rate of SDH compared to conventional treatments in multiple cohort studies. A randomized controlled trial is warranted to determine the effectiveness and safety of MMA embolization for non-acute hematoma and whether MMA embolization is superior to conventional treatments to lower the symptomatic recurrence and progression rate of non-acute SDH.

METHODS

This is an investigator-initiated, multi-center, prospective, open-label parallel group trial with blinded outcome assessment (PROBE design) assessing superiority of MMA embolization compared to conventional treatments. A total of 722 patients are planned to be randomized 1:1 to receive MMA embolization (intervention) or conventional treatments (control). The primary outcome is the symptomatic SDH recurrence/progression rate within 90 ± 14 days post-randomization.

DISCUSSION

This trial will clarify whether MMA embolization could reduce the recurrence or progression rate of symptomatic non-acute SDH compared to conventional treatment.

TRIAL REGISTRATION

ClinicalTrials.gov. Identifier: NCT04700345, Registered on 7 January 2021.

A systematic review of middle meningeal artery embolization for minimally symptomatic chronic subdural haematomas that do not require immediate evacuation

Introduction

Embolization of the Middle Meningeal Artery (EMMA) is an emerging treatment option for patients with Chronic Subdural Haematoma (CSDH).

Questions

(1) Can EMMA change the natural history of untreated minimally symptomatic CSDH which do not require immediate evacuation? (2) What is the role of EMMA in the prevention of recurrence following surgical treatment? (3) Can the procedure be performed under local anaesthetic?

Material and methods

Systematic literature review. No randomised clinical trials available on EMMA for meta-analysis.

Results

Six unique large cohorts with more than 50 embolisations were identified (evidence: 3b-4). EMMA can control the progression of surgically naïve CSDH in 91.1-100% of the patients, in which haematoma expansion is halted, or the lesion decreases and resolves. Treatment failure requiring surgery occurs in 0-4.1% of the patients having EMMA as the primary and only treatment. Treatment failure requiring surgery goes up slightly to 6.8% if post-surgical patients are included. When EMMA is used as postsurgical adjunctive the risk of recurrence is 1.4-8.9% compared to 10-20% in surgical series. EMMA has minimal morbidity and it is feasible under local anaesthesia or slight sedation in the majority of cases.

Conclusion

There is cumulative low-quality evidence in the literature that EMMA may be able to modify the natural course of the disease. It appears effective in controlling progression of CSDHs in patients having it as a primary standing alone treatment and it reduces the risk of recurrence and the need for surgical intervention in refractory postsurgical cases or as a postsurgical adjunctive treatment with minimal morbidity (recommendation: C).

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Safety and radiologic clearance of chronic subdural hematoma after endovascular embolization using SQUID 18 in patients older than 80 years

The aim of the study was to evaluate radiographic clearance and clinical outcomes in patients over age 80 who undergo SQUID 18 embolization of the middle meningeal artery (MMA) for the management of chronic subdural hematoma (cSDH). From April 2020 to October 2021, data were obtained from patients with cSDH who underwent MMA embolization at our institution. Clinical and radiological data including pre-operative and last follow-up CT scans were analyzed. Six embolization procedures were performed in five patients using SQUID 18, a liquid embolic agent. The median age was 83 years, and three subjects were female. Two of the six cases were recurrent hematomas. MMA embolization was achieved in 100% of cases. The median diameter of the hematoma at admission was 20 mm and at last follow-up was 5.3 mm, demonstrating statistically significant radiographic clearance (P = 0.043). There were no intra or post-operative complications. Mortality was not noted during observation period. SQUID MMA embolization safely and significantly reduced the hematoma diameter and offers an alternative treatment in patients older than 80 years with cSDH.

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

BACKGROUND

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

PURPOSE

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

DATA SOURCES

We searched the literature databases from inception to March 2022.

DATA SELECTION

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

DATA ANALYSIS

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

DATA SYNTHESIS

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

LIMITATIONS

A limitation was the retrospective design of studies included.

CONCLUSIONS

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

Reduced recurrence of chronic subdural hematomas treated with open surgery followed by middle meningeal artery embolization compared to open surgery alone: a propensity score-matched analysis

OBJECTIVE

Middle meningeal artery embolization (MMAE) is an emerging endovascular treatment technique with proven promising results for chronic subdural hematomas (cSDHs). MMAE as an adjunct to open surgery is being utilized with the goal of preventing the recurrence of cSDH. However, the efficacy of MMAE following surgical evacuation of cSDH has not been clearly demonstrated. The authors sought to compare the outcomes of open surgery followed by MMAE versus open surgery alone.

METHODS

Patients who underwent surgical evacuation alone (open surgery-alone group) or MMAE along with open surgery for cSDH (adjunctive MMAE group) were identified at the authors' institution. Two balanced groups were obtained through propensity score matching. Primary outcomes included recurrence risk and reintervention rate. Secondary outcomes included decrease in hematoma size and modified Rankin Scale (mRS) score at last follow-up. Variables in the two groups were compared by use of the Mann-Whitney U-test, paired-sample t-test, and Fisher's exact test.

RESULTS

A total of 345 cases of open surgery alone and 52 cases of open surgery with adjunctive MMAE were identified. After control for subjective confounders, 146 patients treated with open surgery alone and 41 with adjunctive MMAE following open surgery with drain placement were included in the analysis. Before matching, the rebleeding risk and reintervention rate for open surgery trended higher in the open surgery alone than the open surgery plus MMAE group (14.4% vs 7.3%, p = 0.18; and 11.6% vs 4.9%, p = 0.17, respectively). No significant differences were seen in duration of radiographic or clinical follow-ups or decreases in hematoma size and mRS score at last follow-up. After one-to-one nearest neighbor propensity score matching, 26 pairs of cases were compared for outcomes. Rates of recurrence (7.7% vs 30.8%, p = 0.038) and overall reintervention (3.8% vs 23.1%, p = 0.049) after open surgery were found to be significantly lower in the adjunctive MMAE group than the open surgery-alone group. With one-to-many propensity score matching, 76 versus 37 cases were compared for open surgery alone versus adjunctive MMAE following open surgery. Similarly, the adjunctive MMAE group had significantly lower rates of recurrence (5.4% vs 19.7%, p = 0.037) and overall reintervention (2.7% vs 14.5%, p = 0.049).

CONCLUSIONS

Adjunctive MMAE following open surgery can lower the recurrence risks and reintervention rates for cSDH.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

Recurrence after evacuation occurs in approximately 10% of cSDHs, and the various surgical interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials.

Cerebral venous sinus thrombosis with an acute subdural hematoma treated with endovascular intervention: A case report

We report two cases of endovascular intervention for management of cerebral venous sinus thrombosis complicated by an acute intracranial hemorrhage during treatment with therapeutic anticoagulation. The first patient developed an acute subdural hematoma with progressive enlargement and was subsequently managed with venous sinus thrombectomy. The second patient developed an intraparenchymal and subdural hematoma and was treated with middle meningeal embolization. Anticoagulation is the primary treatment for cerebral venous sinus thrombosis but also contraindicated in an acute intracranial hemorrhage. In these cases, after endovascular intervention both patients resumed therapeutic anticoagulation without further hematoma expansion or additional invasive interventions. Both patients made an excellent neurological recovery and returned to their baseline functional independent status. Given the need for anticoagulation, endovascular intervention in the form of thrombectomy or middle meningeal artery embolization may be a viable adjuvant to anticoagulation in select patients.