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

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.

Initial experience using middle meningeal artery embolisation for patients with recurrent and high-recurrence-risk chronic subdural haematoma

Recurrence rates following surgical management of chronic subdural haematoma (CSDH) range from 5 to 33 %. There is growing evidence which suggests middle meningeal artery embolisation (MMAe) may reduce recurrence rates when used as surgical adjunct or standalone treatment. In this study we described our experience of this new procedure in the our UK institution. Patients with recurrent CSDH or CSDH at high risk of recurrence were selected for MMAe on a case-by-case basis following MDT discussion. A departmental database was used to identify patients treated. 26 CSDH were embolised in 20 patients; 9 CSDH were de-novo and 17 were recurrent. 10/26 CSDH were treated with MMAe only. No procedural mortality, access site or thrombo-embolic complications occurred. One patient experienced symptomatic collection growth 12 h following MMAe and required surgical drainage. 15 (75 %) of patients were living at home at follow-up (mean 14 months). On imaging follow-up 15/18 showed CSDH volume reduction or resolution, 1/18 remained stable requiring no further treatment, 2/18 patients suffered recurrent CSDH requiring treatment. In both recurrent cases incomplete embolisation was noted on procedural imaging (posterior division of MMA not embolised). Persistent posterior MMA division filling was significantly associated with collection recurrence (p = 0.002). Our results suggest MMAe as a stand-alone or adjuvant therapy can be performed safely in a UK neuroscience setting and is associated with high rates of symptomatic CSDH size reduction or resolution in problematic CSDH that have either recurred or are prone to recurrence.

Chronic subdural hematoma treated with homeopathic medicine Hamamelis virginica: A case report

Chronic Subdural Hematoma is a prevalent neurosurgical disorder associated with old age, often resulting from trauma. The condition has limited scope for conservative management, and invasive techniques are frequently used as preferred treatment. Complications often arise due to comorbidities associated with old age. This case details the treatment of the condition in a 71-year-old patient who presented with seizures, hemiparesis, tremor, and disorientation. The patient had a history of a fall a few weeks prior. Initially, the condition was managed through surgery, but recurrence occurred, accompanied by concurrent neurological signs. The patient was subsequently treated with Hamamelis virginica 200CH through homeopathic approach. Following this treatment, the patient returned to his previous state within seven days. No recurrence was observed during the three-month follow-up. This case underscores a positive role of homeopathic medicines in managing neurosurgical conditions such as subdural hematoma. The positive outcomes of this study provide preliminary evidence that may eventually contribute to the design of appropriate clinical trials.

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.

Advances in chronic subdural hematoma and membrane imaging

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Middle Meningeal Artery Embolization 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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Rapid disappearance of acute subdural hematoma due to abrogated hyper-fibrinolytic activity by tranexamic acid: Case report

RATIONALE

Acute subdural hematoma (ASDH) occurs after tearing of bridging veins within the dura resulting in the accumulation of blood between the arachnoid and dura layers within 72 hours after traumatic head injury. Also, antigen fibrin D-dimer (DD) is the principal enzymatic degradation product of cross-linked fibrin by plasmin. We observed that early tranexamic acid (TXA) treatment resolved hyper-fibrinolysis and rapid disappearance ASDH.

PATIENTS CONCERNS

A 48-year-old female presented with unconsciousness for 2 hours after head trauma. Her Glasgow Coma Scale score was >8 points.

DIAGNOSIS

Computed tomography scan established ASDH with midline shift and brainstem compression and surgery was scheduled. Also, laboratory results indicated high DD spike of 34,820 μg/L and a reduction in plasma fibrinogen 1 hour after the injury.

INTERVENTION

She was treated with intravenous TXA immediately after admission.

OUTCOMES

Her DD spike decreased remarkably in 48 hours with associated rapid disappearance of ASDH thereby averting surgical intervention. She recovered fully with no long-term complications.

LESSONS

Historically, hyper-fibrinolysis is associated with poor outcome in head trauma. However, early initiation of TXA which is noninvasive treatment modality for ASDH could avert surgery and reduce cost, anesthesia, and other complications associated with surgery.

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.

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.

Middle Meningeal Artery Embolization for Subdural Hematoma: An Institutional Cohort and Propensity Score-Matched Comparison with Conventional Management

BACKGROUND

The treatment of non-acute subdural hematoma (NASDH) is challenging due to its high recurrence rates and comorbidities of mostly elderly patients. Middle meningeal artery embolization (MMAE) recently emerged as an alternative to surgery in the treatment of NASDH.

OBJECTIVE

To describe a single center's experience of MMAE with Onyx for NASDH and compare it to a surgically treated historical cohort.

METHODS

We performed a retrospective analysis of patients undergoing MMAE for NASDH from 2019 to 2021. MMAE was performed with ethylene vinyl alcohol copolymer (Onyx). Comparisons were made with a historical cohort from 2010 to 2018 who underwent surgical evacuation only, before and after propensity score matching. Outcomes were assessed clinically and radiographically.

RESULTS

We included 44 consecutive patients (55 MMAEs) who underwent MMAE, with a median follow-up of 63.5 days. Twenty-four NASDHs underwent upfront embolization, 17 adjunctive, and 14 for recurrence after prior surgical evacuation, with no significant differences in hematoma and mRS reduction between them. Two patients died during hospitalization and 2 during follow-up, unrelated to the procedure. Mean SDH thickness decreased by 48.3% ± 38.1% (P < 0.001) on last follow-up, which did not correlate with the amount of Onyx injected. Six (13.6%) patients required surgical rescue after embolization. There were no procedure-related complications. The mean modified Rankin Scale (mRS) on admission was 2.8 ± 1.5, which decreased significantly to 1 [1,4] at the last follow-up (P = 0.033). The MMAE (41 hematomas; upfront and adjunctive embolization) and Surgical Evacuation-only (461 hematomas) cohorts were balanced with propensity score mathing. Matching was successful for 41 MMAE and 41 surgical-only hematoma pairs, and only hypertension remained significantly different between the two groups, but there was no significant difference in any outcome.

CONCLUSION

MMAE for NASDH seems safe and effective in appropriately selected patients, non-inferior to surgery, and may become a minimally-invasive alternative. Given our encouraging results, large-scale clinical randomized trials are warranted.

Incidence, therapy, and outcome in the management of chronic subdural hematoma in Switzerland: a population-based multicenter cohort study

Background

Chronic subdural hematoma (cSDH) is a disease affecting mainly elderly individuals. The reported incidence ranges from 2.0/100,000 to 58 per 100,000 person-years when only considering patients who are over 70 years old, with an overall incidence of 8.2-14.0 per 100,000 persons. Due to an estimated doubling of the population above 65 years old between 2000 and 2030, cSDH will become an even more significant concern. To gain an overview of cSDH hospital admission rates, treatment, and outcome, we performed this multicenter national cohort study of patients requiring surgical treatment of cSDH.

Methods

A multicenter cohort study included patients treated in 2013 in a Swiss center accredited for residency. Demographics, medical history, symptoms, and medication were recorded. Imaging at admission was evaluated, and therapy was divided into burr hole craniostomy (BHC), twist drill craniostomy (TDC), and craniotomy. Patients' outcomes were dichotomized into good (mRS, 0-3) and poor (mRS, 4-6) outcomes. A two-sided t-test for unpaired variables was performed, while a chi-square test was performed for categorical variables, and a p-value of <0.05 was considered to be statistically significant.

Results

A total of 663 patients were included. The median age was 76 years, and the overall incidence rate was 8.2/100,000. With age, the incidence rate increased to 64.2/100,000 in patients aged 80-89 years. The most prevalent symptoms were gait disturbance in 362 (58.6%) of patients, headache in 286 (46.4%), and focal neurological deficits in 252 (40.7%). CSDH distribution was unilateral in 478 (72.1%) patients, while 185 presented a bilateral hematoma with no difference in the outcome. BHC was the most performed procedure for 758 (97.3%) evacuations. CSDH recurrence was noted in 104 patients (20.1%). A good outcome was seen in almost 81% of patients. Factors associated with poor outcomes were age, GCS and mRS on admission, and the occurrence of multiple deficits present at the diagnosis of the cSDH.

Conclusion

As the first multicenter national cohort-based study analyzing the disease burden of cSDH, our study reveals that the hospital admission rate of cSDH was 8.2/100,000, while with age, it rose to 64.2/100,000. A good outcome was seen in 81% of patients, who maintained the same quality of life as before the surgery. However, the mortality rate was 4%.

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.

Awake transradial middle meningeal artery embolization and twist drill craniostomy for chronic subdural hematomas in the elderly: case series and technical note

BACKGROUND

Due to prohibitive perioperative risk factors, optimal treatment for chronic subdural hematomas (cSDH) in the elderly remains unclear. Minimally invasive techniques are a viable option and include bedside subdural evacuation port system (SEPS), as well as prevention of recurrence with middle meningeal artery (MMA) embolization. We present a case series of elderly patients undergoing combined transradial MMA embolization and bed-side craniostomy as primary treatment for cSDH.

METHODS

Patients 70 years and older from 2019 to 2020 that underwent single setting, awake transradial MMA embolization with concurrent SEPS placement under local anesthesia were included. Those with prior treatments, interventions performed under general anesthesia, or with less than 60-day follow-up were excluded. Descriptive analyses of baseline characteristics, radiologic parameters, comorbidities, and outcome measures were completed.

RESULTS

Twenty elderly patients (mean age of 81.0 years) with multiple comorbidities underwent 28 MMA embolization+SEPS procedures as primary treatment for cSDH. Mean cSDH thickness was 1.8cm±0.6 cm with 7.3±3.9 mm midline shift. All patients tolerated the procedure well. 1/20 (5.0%) patients died within 30 days of the procedure. A majority of patients were discharged to home (12/20; 60.0%). There was an average of 3.6-month follow-up and one patient (5.0%) developed recurrence in the follow-up period requiring further intervention.

CONCLUSIONS

In select elderly patients with high perioperative risk factors, primary treatment of cSDH using awake transradial MMA embolization+SEPS placement is a minimally invasive, feasible, and safe option. Further comparative studies are warranted to evaluate efficacy of the treatment.

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.

The efficacy of postoperative middle meningeal artery embolization on chronic subdural hematoma - A multicentered randomized controlled trial

Background

Middle meningeal artery (MMA) embolization has recently emerged as a potential treatment for chronic subdural hematoma (cSDH). Numerous retrospective studies have suggested that it can potentially reduce the risk of hematoma recurrence following surgical evacuation. We have conducted a randomized controlled trial to investigate the effectiveness of postoperative MMA embolization in reducing recurrence rate, residual hematoma thickness as well as improving functional outcome.

Methods

Patients aged 18 or above were recruited. Following evacuation through burr hole or craniotomy, patients were randomly allocated to undergo either MMA embolization or standard care (monitoring). The primary outcome was symptomatic recurrence requiring redo evacuation. Secondary outcomes include residual hematoma thickness and modified Rankin Scale (mRS) at 6 weeks and 3 months.

Results

Thirty-six patients (41 cSDHs) were recruited between April 2021 and September 2022. Seventeen patients (19 cSDHs) were allocated to the embolization group and 19 patients (22 cSDHs) were in the control group. No symptomatic recurrence was observed in the treatment group while 3 control patients (15.8%) underwent repeat surgery for symptomatic recurrence, however, it was not statistically significant (P = 0.234). Furthermore, there was no significant difference in residual hematoma thickness at 6 weeks or 3 months between the two groups. All patients in the embolization group had a good functional outcome (mRS 0-1) at 3 months, which was significantly higher than the 53% observed in the control group. No complications related to MMA embolization were reported.

Conclusion

Further study with larger sample size is required to evaluate the efficacy of MMA embolization.

Usage of Tranexamic Acid for Treatment of Subdural Hematomas

The collection of blood in the subdural layer within the cranium is classified as a subdural hematoma. Prevalence of subdural hematomas is most common among older populations with the current standard of treatment being invasive surgical evacuation for patients presenting with acute subdural hematomas with a midline shift greater than 5 mm on computed tomography (CT).Tranexamic acid (TXA) has been identified as an alternative, non-invasive option to treat patients presenting with subdural hematoma who are not suitable for surgical intervention. The presenting case involves a 90-year-old female who arrived with a code stroke with the chief complaint of right lower extremity weakness. A stroke series CT panel revealed a left frontal multiloculated subdural hematoma, measuring 130 mL with mass effect and a midline shift of 7 mm. The patient was recommended a craniotomy for hematoma evacuation or access to hospice for comfort care. A second opinion resulted in the administration of TXA. After the full completion of a TXA course, the patient achieved baseline mobility. The final measurements revealed a final hematoma volume of 10 mL and a midline shift of less than 2 mm. Current literature, as well as the case described, has begun demonstrating the efficacy of the usage of TXA in the reabsorption of subdural hematomas and should encourage further exploration into society guidelines for the usage of TXA as a non-invasive alternative to treat subdural hematomas.

Republished: Resolution of an enlarging subdural haematoma after contralateral middle meningeal artery embolisation

A man in his 50s presented 1 month after an automobile accident with worsening headaches and an enlarging chronic left subdural haematoma (SDH). He underwent left middle meningeal artery (MMA) embolisation. Due to tortuosity at its origin, we were unable to catheterise the MMA distally. Only proximal coil occlusion at the origin was performed. Follow-up interval head CT showed an increase in the size of the SDH with new haemorrhage, worsening mass effect and midline shift. However, he remained neurologically intact. Contralateral embolisation of the right MMA was performed with a liquid embolic agent. His headaches improved, and a follow-up head CT 3 months later showed near-complete resolution of the SDH.

Long-Term Middle Meningeal Artery Caliber Reduction Following Trisacryl Gelatine Microsphere Embolization for the Treatment of Chronic Subdural Hematoma

PURPOSE

Middle meningeal artery (MMA) particle embolization is a promising treatment of chronic subdural hematomas (CSDH). The main purpose of this study is to measure MMA proximal caliber and assess the visibility of the two main MMA branches as a surrogate for long-term distal arterial patency following MMA CSDH embolization with trisacryl gelatine microspheres (TAGM).

METHODS

This is a single-center retrospective study. All patients having undergone MMA TAGM only embolization for CSDH treatment between 15 March 2018 and 6 June 2020 with an interpretable follow-up magnetic resonance imaging (MRI) examination and no confounding factors were included. Patients were compared with controls matched for age, sex and MRI machine. Two independent readers analyzed the MRI images.

RESULTS

In this study, 30 patients having undergone embolization procedures using TAGM of 36 MMAs were included. The follow-up MRI scans were performed after a mean delay of 14.8 ± 7.1 months (range 4.9-29.4 months). The mean diameter of TAGM embolized MMAs (1 mm; 95% confidence interval, CI 0.9-1.1) was significantly smaller than the mean diameter of paired control MMAs (1.3 mm; 95% CI 1.3-1.4) (p < 0.001). The mean proximal diameter of the embolized MMAs (0.9 mm; 95% CI 0.7-1.1) was significantly smaller than the mean diameter of the contralateral MMAs in the same patients (1.4 mm; 95% CI 1.3-1.6)(p < 0.001).

CONCLUSION

Long-term follow-up MRI demonstrated a significant impact of TAGM embolization on MMA proximal caliber as well as on the visibility of the two main MMA branches. All comparisons indicated that there was a probable lasting impact of embolization on the patency of distal branches.

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.

Clinical Outcome and Recurrence Risk of Chronic Subdural Hematoma After Surgical Drainage

Introduction Chronic subdural hematoma (CSDH) is one of the most encountered neurosurgical cases. CSDH is defined as the accumulation of liquified blood products in the space between the dura and the arachnoid. A reported incidence of 17.6/100,000/year has more than doubled in the past 25 years in parallel with an aging population. Surgical drainage remains the mainstay of treatment, yet it is challenged by variable recurrence risks. Less invasive embolization methods of the middle meningeal artery (EMMA) could reduce the recurrence risks. Before adopting a newer treatment (EMMA), it is prudent to establish the outcomes from surgical drainage. The purpose of this study is to assess the clinical outcome and recurrence risk in surgically treated CSDH patients in our center. Methods A retrospective search of our surgical database was done to identify CSDH patients undergoing surgical drainage in the year 2019-2020. Demographic and clinical details were collected, and quantitative statistical analysis was performed. Peri-procedural radiographic information and follow-ups were also included as per the standard of care. Results A total of 102 patients (mean age: 69 years; range: 21-100 years; male: 79) with CSDH underwent surgical drainage with repeat surgery in 13.7% of the patients (n=14). Peri-procedural mortality and morbidity were 11.8%(n=12) and 19.6% (n=20), respectively. Overall, among our patient population, recurrence was seen in 22.55% (n=23). The mean total hospital stay was 10.6 days. Conclusions Our retrospective cohort study showed an institutional CSDH recurrence risk of 22.55%, in keeping with what is reported in the literature. This baseline information is important for a Canadian setting and provides a basis for comparison for future Canadian trials.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma Related to Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is a connective tissue disease with vascular abnormalities involving multiple organs. The prevalence of ADPKD associated with a spontaneous subdural hematoma (SDH) is very low, with less than 10 cases reported in the literature to date. Symptomatic chronic SDH is classically treated with a twist drill, burr holes, or craniotomy. Recently, middle meningeal artery (MMA) embolization has emerged as an ancillary modality. We present the first case in the literature of a bilateral SDH in a young ADPKD patient successfully managed with MMA embolization. Moreover, we discuss the role of different treatment modalities on this subset of patients.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Chronic Subdural Hematoma-Evolution of Etiology and Surgical Treatment

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

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.

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.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

Common data elements reported on middle meningeal artery embolization in chronic subdural hematoma: an interactive systematic review of recent trials

Cross study heterogeneity has limited the evidence based evaluation of middle meningeal artery embolization (MMAE) as a treatment for chronic subdural hematoma (CSDH). Ongoing trials and prospective studies suggest that heterogeneity in upcoming publications may detract from subsequent meta-analyses and systemic reviews. This study aims to describe this data heterogeneity to promote harmonization with common data elements (CDEs) in publications. ClinicalTrials.gov and PubMed were searched for published or ongoing prospective trials of MMAE. The Nested Knowledge AutoLit living review platform was utilized to classify endpoints from randomized control trials (RCTs) and prospective cohort studies comparing MMAE with other treatments. The qualitative synthesis feature was used to determine cross study overlap of outcome related data elements. Eighteen studies were included: 12 RCTs, two non-randomized controlled studies, two prospective single arm trials, one combined prospective and retrospective controlled study, and one prospective cohort study. The most commonly reported data element was recurrence (15/18), but seven heterogenous (non-comparable) definitions were used for 'recurrence'. Mortality was reported in 10/18 studies, but no common timepoint was reported in more than four studies. Re-intervention and CSDH volume were reported in eight studies, CSDH width in seven, and no other outcome was common across more than five studies. There was significant heterogeneity in data element collection even among prospective registered trials of MMAE. Even among CDEs, variation in definition and timepoints prevented harmonization. A standardized approach based on CDEs may be necessary to facilitate future meta-analyses and evidence driven evaluation of MMAE treatment of CSDH.

Factors correlated with the postoperative recurrence of chronic subdural hematoma: An umbrella study of systematic reviews and meta-analyses

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurological disease, and the surgical evacuation of subdural collection remains the primary treatment approach for symptomatic patients. Postoperative recurrence is a serious complication, and several factors are correlated with postoperative recurrence.

METHODS

We searched Embase, Web of Science, PubMed, and Cochrane Library from their establishment to September 2020. Reports on randomized, prospective, retrospective, and overall observational studies on the management of surgical patients with CSDH were searched, and an independent reviewer performed research quality assessment. Factors that affect the postoperative recurrence of CSDH were extracted: social demographics, drugs (as the main or auxiliary treatment), surgical management, imaging, and other risk factors. We evaluated the recurrence rate of each risk factor. A random effect model was used to perform a meta-analysis, and each risk factor affecting the postoperative recurrence of CSDH was then evaluated and graded.

FINDINGS

In total, 402 studies were included in this analysis and 32 potential risk factors were evaluated. Among these, 21 were significantly associated with the postoperative recurrence of CSDH. Three risk factors (male, bilateral hematoma, and no drainage) had convincing evidence. The classification of evidence can help clinicians identify significant risk factors for the postoperative recurrence of CSDH.

INTERPRETATION

Only few associations were supported by high-quality evidence. Factors with high-quality evidence may be important for treating and preventing CSDH recurrence. Our results can be used as a basis for improving clinical treatment strategies and designing preventive methods.

FUNDING

No funding was received.

Middle Meningeal Artery Embolization as an Adjuvant Treatment for Bilateral Chronic Subdural Hematomas From Spontaneous Intracranial Hypotension: A Case Report

Middle meningeal artery embolization (MMAE) is an effective initial or adjuvant treatment for chronic subdural hematomas. However, its efficacy in the setting of spontaneous intracranial hypotension has not yet been reported. We present a case of progressive bilateral chronic subdural hematomas secondary to spontaneous intracranial hypotension that failed the initial lumbar epidural blood patch. The patient underwent surgical hematoma evacuation, with adjuvant MMAE and additional epidural blood patch, with good clinical and radiographic results. This case demonstrates the potential value of MMAE for chronic subdural hematomas secondary to spontaneous intracranial hypotension.

Efficacy and Safety of Glucocorticoids Versus Placebo as an Adjuvant Treatment to Surgery in Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurosurgical disease with a high recurrence rate, especially among the elderly. Glucocorticoids have been tested for the treatment of CSDH in observational studies and randomized clinical trials.

METHODS

We systematically searched the PubMed, Embase, and Cochrane Central Register of Controlled Trials database for randomized trials from the earliest date available to May 23, 2021 that had compared glucocorticoids and placebo as a postoperative treatment of CSDH. Trials were included if the study participants were aged ≥18 years and had had CSDH after surgery. The relative risk (RR) was used to evaluate the clinical outcomes.

RESULTS

We included 5 eligible randomized controlled trials with a total of 1251 patients. The findings showed that the use of adjuvant glucocorticoid therapy can effectively reduce the recurrence risk of CSDH compared with placebo (RR, 0.40; 95% confidence interval [CI], 0.28-0.58; P < 0.001). No significant differences were found between the glucocorticoid and placebo groups regarding favorable neurological outcomes (RR, 1; 95% CI, 0.93-1.08; P = 0.92). We found that the use of adjuvant glucocorticoids resulted in a significant increase in psychiatric symptoms (RR, 3.22; 95% CI, 1.83-5.64; P < 0.001). No significant differences were found for infection between the 2 groups (RR, 1.86; 95% CI, 0.56-6.14; P = 0.31).

CONCLUSIONS

Glucocorticoid therapy can effectively reduce the recurrence risk of CSDH after surgery without an increase in the postoperative infection rate. However, significantly increased psychiatric symptoms were reported in the glucocorticoid group.

Endovascular Treatment of Chronic Subdural Hematomas through Embolization: A Pilot Study with a Non-Adhesive Liquid Embolic Agent of Minimal Viscosity (Squid)

OBJECTIVE

Endovascular embolization using non-adhesive agents (e.g., ethylene vinyl alcohol copolymer with suspended micronized tantalum dissolved in dimethyl sulfoxide; Squid, Balt Extrusion) is an established treatment of brain arteriovenous malformations, dural arteriovenous fistulas, and hypervascular neoplasms. Middle meningeal artery (MMA) embolization is a relatively new concept for treating chronic subdural hematomas (CSDH). This study aimed to evaluate the safety and effectiveness of the use of Squid in the endovascular treatment of CSDH.

METHODS

Embolization was offered to patients with CSDH with minimal or moderate neurological deficits and patients who had previously undergone open surgery to evacuate their CSDH without a significant effect. Distal catheterization of the MMA was followed by embolization of the hematoma capsule with Squid 12 or Squid 18. Safety endpoints were ischemic or hemorrhagic stroke and any other adverse event of the endovascular procedure. Efficacy endpoints were the feasibility of the intended procedure and a ≥ 50% reduction of the maximum depth of the CSDH confirmed by follow-up computed tomography (CT) after >3 months.

RESULTS

Between November 2019 and July 2021, 10 patients (3 female and 7 male, age range 42-89 years) were enrolled. Five patients had bilateral hematomas, and five patients had previously been operated on with no significant effect and recurrent hematoma formation. The attempted embolization was technically possible in all patients. No technical or clinical complication was encountered. During a post-procedural follow-up (median 90 days), 10 patients improved clinically. A complete resolution of the CSDH was observed in 10 patients. The clinical condition of all enrolled patients during the so-far last contact was rated mRS 0 or 1.

CONCLUSION

A distal catheterization of the MMA for the endovascular embolization of CSDH with Squid allowed for the devascularization of the MMA and the dependent vessels of the hematoma capsule. This procedure resulted in a partial or complete resolution of the CSDH. Procedural complications were not encountered.

Risk of recurrence of subdural hematoma after EMMA vs surgical drainage - Systematic review and meta-analysis

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common and debilitating neurological condition whose treatments, including burr hole drainage and craniotomy, suffer from high rates of recurrence and complication. Embolization of the middle meningeal artery (EMMA) is a promising minimally invasive approach to manage CSDH in a broad set of patients.

METHODS

To evaluate the efficacy and safety of EMMA, a database search was conducted including the terms "subdural hematoma; embolization; embolized; middle meningeal" was performed and yielded a total of 260 results. Following exclusion based on predefined criteria, a total of four studies were identified and outcomes including recurrence rates and complication rates were extracted for analysis.

RESULTS

Four studies including intervention and control groups were included with a total of n = 888 patients. The relative risk of CSDH recurrence in the EMMA (3.5%) compared to control group (23.5%) was significantly reduced when EMMA was performed (risk ratio = 0.17; 95% confidence interval (CI) 0.05-0.67). In addition, rates of complication were not significantly different between patients with conventional therapy and those who received EMMA (OR = 0.77; 95 confidence interval (CI) 0.3-1.99).

CONCLUSION

Based on limited data, EMMA reduces the risk of recurrence by 20% compared to surgical treatment for CSDH.

Derivation of a Clinical Score for Prediction of Recurrence Following Evacuation of Chronic Subdural Hematoma: A Retrospective Cohort Study at a National Referral Centre

BACKGROUND

Chronic subdural hematoma (cSDH) is a common pathology, and recurrence is a common complication, which may be predicted by certain patient and radiologic factors. Empiric radiologic surveillance has been shown to convey no benefit.

METHODS

A retrospective review of a prospectively collated database was performed. Preoperative and postoperative noncontrast computed tomography scans were reviewed. Radiologic appearance, preoperative hematoma volume, patient age, presence of bilateral hematomas, maximal hematoma thickness, and therapeutic coagulopathy were assessed as predictors. Receiver operating characteristic curve analysis, logistic regression, and LASSO regression were used to select potential predictors. A multivariate model was then fitted, and a score was derived.

RESULTS

A total of 142 patients were included. Maximal hematoma thickness >12 mm (P = 0.02) and age >65 years (P = 0.01) were found to correlate with the likelihood of recurrence. Bilateral hematomas and a hyperdense or mixed density appearance were also identified on LASSO regression. Bilateral hematomas (P = 0.19), hyperdense or mixed density (P = 0.66), maximum thickness >12 mm (P = 0.01), and age >65 years (P = 0.02) were included in the multivariate model. A 6-point score was derived. A score of >3 had a sensitivity of 89% (95% confidence interval [CI] 78%-97%) and specificity of 26% (95% CI, 17%-34%) for predicting recurrence, with recurrence significantly more likely in patients with a score of 4-6 versus those with a score of 0-3 (P = 0.02).

CONCLUSIONS

Certain radiologic findings may predict the recurrence of cSDH following evacuation. The score derived may be useful in identifying patients who might benefit from routine postoperative surveillance imaging.