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

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

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

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.

Middle meningeal artery embolization for chronic subdural hematoma: A single-center experience and predictive modeling of outcomes

BACKGROUND

Remarkable interest is rising around middle meningeal artery embolization (MMAE) as an emerging alternative therapy for chronic subdural hematoma (cSDH). The study aims to highlight a large center experience and the variables associated with treatment failure and build experimental machine learning (ML) models for outcome prediction.

MATERIAL AND METHODS

A 2-year experience in MMAE for managing patients with chronic subdural hematoma was analyzed. Descriptive statistical analysis was conducted using imaging and clinical features of the patients and cSDH, which were subsequently used to build predictive models for the procedure outcome. The modeling evaluation metrics were the area under the ROC curve and F1-score.

RESULTS

A total of 100 cSDH of 76 patients who underwent MMAE were included with an average follow-up of 6 months. The intervention had a per procedure success rate of 92%. Thrombocytopenia had a highly significant association with treatment failure. Two patients suffered a complication related to the procedure. The best performing machine learning models in predicting MMAE failure achieved an ROC-AUC of 70%, and an F1-score of 67%, including all patients with or without surgical intervention prior to embolization, and an ROC-AUC of 82% and an F1-score of 69% when only patients who underwent upfront MMAE were included.

CONCLUSION

MMAE is a safe and minimally invasive procedure with great potential in transforming the management of cSDH and reducing the risk of surgical complications in selected patients. An ML approach with larger sample size might help better predict outcomes and highlight important predictors following MMAE in patients with cSDH.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Tonetti D, Bounajem MT, Thomas A, Ogilvy CS, Moore JM, Riina HA, Tanweer O, Levy EI, Spiotta AM, Gross BA, Jankowitz BT, Cawley CM, Khalessi AA, Pandey AS, Ringer AJ, Hanel R, Ortiz RA, Langer D, Levitt MR, Binning M, Taussky P, Kan P, Grandhi R. Radiographic and clinical outcomes with particle or liquid embolic agents for middle meningeal artery embolization of nonacute subdural hematomas

BACKGROUND

Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization.

METHODS

Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes-50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively-were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic).

RESULTS

The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78-2.18; p = 0.310), 1.09 (95% CI 0.52-2.27; p = 0.822), and 1.5 (95% CI 0.14-16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00).

CONCLUSIONS

MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

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.

Comparative outcomes of middle meningeal artery embolization with statins versus embolization alone in the treatment of chronic subdural hematoma: a systematic review and meta-analysis

Chronic subdural hematoma (cSDH) is common among the elderly, with surgical evacuation as a prevalent treatment, facing recurrence rates up to 30%. Recently, middle meningeal artery embolization (MMAE) has emerged as a promising approach, offering reduced treatment failures and recurrence rates. Additionally, statins, known for their anti-inflammatory properties, have been considered as a potential adjunctive or sole treatment for cSDH. However, the combination of MMAE with statins remains understudied. This systematic review and meta-analysis aims to evaluate the comparative outcomes of MMAE with statins versus MMAE alone in the treatment of cSDH. A comprehensive systematic search of the PubMed, Web of Science, and SCOPUS databases was conducted. Inclusion criteria were: studies published in English between the dates of inception of each database and August 2023, studies comparing the treatment of cSDH with either MMAE + statin or MMAE alone were included. Main outcome measures were complete resolution of the hematoma at follow-up and the recurrence rates. Two studies comprising 715 patients were included; 408 patients underwent MMAE + statin; and 307 underwent MMAE alone. MMAE + statin was not significantly superior to MMAE alone in achieving complete resolution of the hematoma at follow-up (RR: 0.99; CI: 0.91 to 1.07, P = 0.84), nor was it a significant difference in rates of recurrence (RR: 1.35; CI: 0.83 to 2.17, P = 0.21) between the two groups. MMAE + statin did not demonstrate significant superiority over MMAE alone for achieving complete resolution and decreasing the recurrence rates in cSDH patients. Further research with larger, randomized studies may be required to fully elucidate the potential synergistic effects of MMAE and statins in this patient population.

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.

Volumetric resolution of chronic subdural hematomas treated with surgical evacuation versus middle meningeal artery embolization during immediate, early, and late follow up: propensity-score matched cohorts

BACKGROUND

Literature on volumetric resolution and recurrence over time between surgical evacuation alone (SEA) and standalone middle meningeal artery embolization (MMAE) in comparable chronic subdural hematoma (cSDH) patients is limited.

METHODS

A retrospective database analysis of cSDH patients managed with either SEA or MMAE was conducted. Propensity-score matching was performed for axial and coronal lengths, maximum diameter, and midline shift. Volumetric measurements at multiple time intervals and recurrence were compared between the groups.

RESULTS

48 matched hematoma pairs in patients with similar demographics, comorbidities, medications, and symptoms were obtained. Median volume was significantly lower at 24 hours in the SEA group (12.6 mL vs 52.7 mL, p<0.001) but not at remaining intervals. Median volume reduction was significantly greater in the SEA group at 24 hours (39.1 mL vs 8.8 mL in the MMAE group, p<0.001) and at 3-12 weeks (50.8 mL vs 23.7 mL, p<0.001), but not at remaining intervals. The SEA group had a significantly greater median hematoma resolution rate at 24 hours (39.1 mL/day vs 8.8 mL/day, p<0.001) and 3-12 weeks (1 mL/day vs 0.4 mL/day, p<0.001), but not at remaining intervals. Near-complete resolution at 3-12 weeks and 12-60 weeks was not significantly different between groups. Overall, the recurrence rate was significantly higher in the SEA group (22.9% vs 4.2%, p=0.01).

CONCLUSIONS

In comparable cSDH patients, SEA resulted in better volumetric outcomes in immediate postoperative and early follow-up periods, as expected. However, this difference was not significant at more distant follow-up intervals. Furthermore, surgical patients experienced a significantly higher rate of recurrence.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Lidocaine for headache prevention during chronic subdural hematoma embolization

BACKGROUND

Middle meningeal artery embolization (MMAE) for the management of chronic subdural hematomas (CSDH) with ethylene vinyl alcohol (EVOH) causes an evident patient discomfort due to meningeal nociceptors stimulation. The aim of this study was to assess safety and efficacy of intra-arterial lidocaine (IAL) before MMAE of CSDH with EVOH.

METHODS

We analyzed all consecutive patients with bilateral CSDH undergoing MMAE with EVOH. We used a monolateral IAL injection, with casual allocation. We assessed the headache felt by patients during embolization with the visual analog scale (VAS) and compared scores obtained after embolization of both sides. We followed the STROBE guidelines for case-control studies. Paired t-test and χ2 test were used to compare the distribution of variables in IAL vs control group.

RESULTS

Between September 2021 and March 2023, 32 patients underwent bilateral MMAE with EVOH for a CSDH. Lidocaine treatment resulted in a substantially lower VAS score compared to the control group (median 3 vs 7, p < 0.001), with no substantial side effect. Compliance also benefited from lidocaine administration.

CONCLUSIONS

In patients with CSDH undergoing MMAE, IAL seems to reduce pain sensation associated with EVOH injection and to increase patients' compliance during treatment.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Intra-arterial lidocaine therapy via the middle meningeal artery for migraine headache: Theory, current practice and future directions

Recent developments in neurointerventional research have seen the emergence of the middle meningeal artery (MMA) as an effective conduit for intra-arterial (IA) therapy for a number of pathologies. Here, we review the anatomical, pathophysiological and experimental basis for utilisation of the MMA for IA treatment of migraine headache. We explore the in-human case literature for the treatment of headaches with IA lidocaine and discuss considerations and challenges for future research.

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.

Liquid embolic agents for middle meningeal artery embolization in chronic subdural hematoma: Institutional experience with systematic review and meta-analysis

INTRODUCTION

Chronic subdural hematoma (CSDH) is associated with high recurrence rates. Middle meningeal artery embolization (MMAE) has emerged as a promising treatment option. In this systematic review and meta-analysis, we aimed to assess the safety and efficacy of MMAE for CSDH using liquid embolic agents and compare them with particles.

METHODS

We systematically reviewed all studies describing MMAE for CSDH with liquid embolic agents, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Additionally, we included a cohort of patients from our institution using liquid and particle embolic agents. Data were analyzed using random-effects proportions and comparisons meta-analysis, and statistical heterogeneity was assessed.

RESULTS

A total of 18 studies with 507 cases of MMAE with liquid embolic agents (including our institutional experience) were included in the analysis. The success rate was 99% (95% confidence interval [CI]: 98-⁠100%), all complications rate was 1% (95% CI: 0-⁠5%), major complications rate was 0% (95% CI: 0-⁠0%), and mortality rate was 1% (95% CI: 0-⁠6%). The rate of hematoma size reduction was 97% (95% CI: 73-⁠100%), complete resolution 64% (95% CI: 33-⁠87%), radiographic recurrence 3% (95% CI: 1-⁠7%), and reoperation 3% (95% CI: 1-⁠7%). No significant differences in outcomes were found between liquid and particle embolic agents. Sensitivity analyses revealed that liquid embolic agents were associated with lower reoperation rates in upfront MMAE (risk ratio 0.13, 95% CI: 0.02-⁠0.95).

CONCLUSION

MMAE with liquid embolic agents is safe and effective for the treatment of CSDH. Outcomes are comparable to particles, but liquids were associated with a decreased risk of reoperation in upfront MMAE. However, further studies are needed to support our findings.

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.

Use of Novel Automated Active Irrigation With Drainage Versus Passive Drainage Alone for Chronic Subdural Hematoma-A Propensity Score-Matched Comparative Study With Volumetric Analysis

BACKGROUND

Passive drainage post-surgical evacuation of symptomatic chronic subdural hematoma (cSDH) is currently standard of care. High rates of infection, drain occlusion, and recurrence are associated complications.

OBJECTIVE

To explore the use of a novel double-lumen active automated irrigation and aspiration system, IRRAflow (IRRAS), for patients with cSDH and compared procedural and clinical outcomes against passive drainage alone with propensity score matching (PSM) and volumetric analysis.

METHODS

A prospectively maintained database was retrospectively searched for consecutive patients presenting with cSDH. One-to-one PSM of covariates (including baseline comorbidities and presentation hematoma volume) in active and passive irrigation groups was performed to adjust for treatment selection bias. Rates of hematoma clearance, catheter-related occlusion, and infection; number of revisions; and length of hospital stay were recorded.

RESULTS

This study included 55 patients: active continuous irrigation-drainage-21 (21 post-PSM) and passive drainage-34 (21 post-PSM). For PSM groups, a significantly higher rate of hematoma clearance was obtained in the active irrigation-drainage group (0.5 ± 0.4 vs 0.4 ± 0.5 mL/day) and in the passive drainage group; odds ratio (OR) = 1.291 (CI: 1.062-1.570, P = .002) and a significantly lower rate of catheter-related infections (OR = 0.051; CI: 0.004-0.697, P = .039). A nonsignificantly lower hematoma expansion rate at discharge was noted in the active irrigation-drainage group (4.8% vs 23.8%; OR = 0.127; P = .186). No statistical difference in all-cause in-hospital mortality or discharge Glasgow Coma Scale score was observed between groups.

CONCLUSION

Active and automated continuous irrigation plus drainage after cSDH surgical evacuation resulted in faster hematoma clearance and led to favorable clinical outcomes and low complication and revision rates compared with passive irrigation.

Outcomes of Particle versus Liquid Embolic Materials Used in Middle Meningeal Artery Embolization for the Treatment of Chronic Subdural Hematoma

BACKGROUND

Early evidence suggests that middle meningeal artery (MMA) embolization is an efficacious minimally invasive neuroendovascular technique for the management of chronic subdural hematoma (cSDH). Particle and liquid embolic materials are commonly used to embolize the MMA; however, studies comparing the safety and outcomes between these 2 materials are limited.

METHODS

Patients ≥18 years old who had MMA embolization for cSDH between July 15, 2020 and May 1, 2022 were retrospectively identified from a single-center database. The primary safety, radiation dosage, fluoroscopy time, and radiographic and clinical outcomes were compared between particle and liquid embolization.

RESULTS

In a cohort of 116, 48 (41.38%) were treated with liquid embolic material and 68 (58.62%) were treated with particle. The median age of the cohort was 73 years in the particle group and 73.5 years in the liquid embolic group. There was no significant difference in radiation dose or duration among both groups. There was no reported mortality associated with the procedure. One patient experienced nondisabling ischemic stroke in the particle group. Based on imaging follow-up, 3 patients in the particle group and 1 in the liquid embolic group had asymptomatic recurrence. One patient in each group had symptomatic recurrence requiring hematoma evacuation. The index median size of hematoma was 12 mm in the particle group and 11 mm in the liquid embolic group. At approximately 1 month follow-up, the median size of hematoma reduced to 6 mm in both groups.

CONCLUSIONS

Our series shows that liquid embolic and particle embolization are equally safe and effective among patients undergoing MMA embolization for management of cSDH.

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

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

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.

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

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

Clinical efficacy of minimally invasive puncture and drainage versus trepanation and drainage for chronic subdural hematoma: Systematic review and meta-analysis

BACKGROUND

This study aimed to evaluate the clinical efficacy of minimally invasive puncture and drainage (MIPD) versus trepanation and drainage in the treatment of chronic subdural hematoma (CSDH).

METHODS

PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, and Wanfang database were searched for studies on the treatment of CSDH by MIPD and trepanation and drainage. By reading the title, abstract and full text, and screening according to the inclusion and exclusion criteria, the qualified articles were confirmed. Subsequently, the literature quality was evaluated based on the Cochrane Handbook for Systematic Reviews of Interventions, and the data of the research subjects and the primary outcome measures were extracted for meta-analysis with RevMan 5.1 software.

RESULTS

Ten articles were included, with a total of 1000 patients. According to the meta-analysis, the 2 groups showed no statistical difference in CSDH recurrence rate (P > .05). The operation time, intraoperative blood loss, and incidence of postoperative adverse reactions were lower and the cure rate was higher in the MIPD group compared with trepanation and drainage group (all P < .05). By drawing the funnel plot of the outcome measures with heterogeneity, it can be seen that the distribution on both sides of the funnel was basically symmetrical, suggesting a low deviation possibility of the analysis results and reliable reference significance of our findings.

CONCLUSION

Compared with trepanation and drainage, MIPD has better clinical effects and higher safety in treating CSDH and can effectively reduce surgery-induced damage, which is worth popularizing in clinical practice.

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 Outcomes After Nonoperative Management of Large Acute Traumatic Subdural Hematomas in Older Patients: A Propensity-Scored Retrospective Analysis

BACKGROUND

Large (≥1 cm) acute traumatic subdural hematomas (aSDHs) are neurosurgical emergencies. Elderly patients with asymptomatic large aSDHs may benefit from conservative management.

OBJECTIVE

To investigate inpatient mortality after conservative management of large aSDHs.

METHODS

Single-center retrospective review of adult patients with traumatic brain injury from 2018 to 2021 revealed 45 large aSDHs that met inclusion criteria. Inpatient outcomes included mortality, length of stay, and discharge disposition. Follow-up data included rate of surgery for chronic SDH progression. Patients with large aSDHs were 2:1 propensity score-matched to patients with small (<1 cm) aSDHs based on age, Injury Severity Scale, Glasgow Coma Scale, and Rotterdam computed tomography scale.

RESULTS

Median age (78 years), sex (male 52%), and race (Caucasian 91%) were similar between both groups. Inpatient outcomes including length of stay ( P = .32), mortality ( P = .37), and discharge home ( P = .28) were similar between those with small and large aSDHs. On multivariate logistic regression (odds ratio [95% CI]), increased in-hospital mortality was predicted by Injury Severity Scale (1.3 [1.0-1.6]), Rotterdam computed tomography scale 3 to 4 (99.5 [2.1-4754.0), parafalcine (28.3 [1.7-461.7]), tentorial location (196.7 [2.9-13 325.6]), or presence of an intracranial contusion (52.8 [4.0-690.1]). Patients with large aSDHs trended toward higher progression on follow-up computed tomography of the head (36% vs 16%; P = .225) and higher rates of chronic SDH surgery (25% vs 7%; P = .110).

CONCLUSION

In conservatively managed patients with minimal symptoms and mass effect on computed tomography of the head, increasing SDH size did not contribute to worsened in-hospital mortality or length of stay. Patients with large aSDHs may undergo an initial course of nonoperative management if symptoms and the degree of mass effect are mild.

Embolization as adjunctive treatment to achieve complete cure of ruptured arachnoid cyst associated with chronic subdural hematoma

INTRODUCTION

Chronic Subdural Hematoma (CSDH) is a rare but classical evolutive complication of arachnoid cysts (AC). Its management has rarely been evaluated to date. Several approaches have been proposed including conservative and surgical treatments. Endovascular treatment in such CSDH subtype remains poorly reported.

CASE PRESENTATION

We present here an original case of a 16 years-old-boy suffering from ruptured AC responsible for CSDH successfully treated with embolization.

CONCLUSION

Endovascular approach may be considered in the treatment of CSDH related to arachnoid cyst rupture.

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.

Predictors of Subsequent Intervention After Middle Meningeal Artery Embolization for Treatment of Subdural Hematoma: A Nationwide Analysis

BACKGROUND

Middle meningeal artery (MMA) embolization has recently emerged as an effective technique to treat subdural hematomas (SDHs). Studies to date have been limited, largely, to single-center studies with limited follow-up and have not assessed subsequent surgical interventions and factors associated with these interventions.

OBJECTIVE

To evaluate rates of retreatment for SDH after MMA embolization and patient-specific factors that may be important predictors for these interventions.

METHODS

Using an all-payer claims database, Mariner, patients who underwent MMA embolization between January 2010 and October 2020 after the diagnosis of SDH were identified. Rates of post-MMA embolization surgical interventions, including craniotomy and burr hole drainage, were accessed within 5 years following. Patient-specific contributors to the rates of these interventions were studied using Gaussian logistic regression models.

RESULTS

A total of 322 patients were included. Of this cohort, 55 (17.1%) required subsequent intervention within 5 years, with 36 (11.2%) receiving burr hole evacuation and 19 (5.9%) receiving craniotomy. Factor Xa inhibitor use was independently associated with subsequent interventions after MMA embolization procedures (odds ratio: 1.20 [95% CI: 1.02-1.40]). Of the other patient factors evaluated, including age, sex, comorbidity status, and use of vitamin K antagonists, antiplatelets, and factor Xa inhibitors, none were found to be significantly associated with future interventions.

CONCLUSION

Although previous literature has shown MMA embolization to be safe and successful in preventing recurrent SDH, patients undergoing this procedure still carry a risk of future interventions. Patients taking factor Xa inhibitors are at especially high risk of subsequent intervention after MMA embolization.

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.

Rescue of inadvertent superior sagittal sinus occlusion during middle meningeal artery embolization

Middle meningeal artery embolization is increasingly becoming popular in the treatment of chronic subdural hematomas. The safety and efficacy of the procedure has previously been demonstrated in the literature; however, complications do arise from time to time. Here we present the case of an elderly gentleman who experienced inadvertent embolization of the superior sagittal sinus through an occult arteriovenous fistula between the middle meningeal artery and the superior sagittal sinus. Multiple rescue techniques including aspiration and stent retriever thrombectomy were performed with restoration of venous flow and an overall optimal result.

Middle meningeal artery embolization for treatment of chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (cSDH) is caused by rupture of bridging intracranial veins located in the subdural space. Predominantly, cSDH is a disease of older adults and other predisposing risk factors include minor head trauma, cerebral atrophy, antiplatelet and anticoagulation therapies, arterial hypertension, cerebrovascular atherosclerosis, diabetes mellitus, cerebrospinal fluid loss, and excessive alcohol consumption. The incidence of cSDH is rising worldwide due to an aging population and the increased use of anticoagulant or antiplatelet medications. Clinical manifestations are varied, with altered mental status and focal neurologic deficits among the most common.

METHODOLOGICAL INNOVATIONS

Treatment strategies depend on the symptomatology and extent of hematoma. In general, conservative treatment is sought for patients who are asymptomatic or have only mild symptoms, whereas symptomatic patients are often treated surgically. However, the recurrence rate of cSDH may be as high as 30%. In recent years, middle meningeal artery embolization has emerged as a complementary option to surgery aimed at decreasing the recurrence rate after excision as well as an alternative therapeutic approach to surgical therapy in certain circumstances.

CONCLUSION

Embolization of the middle meningeal artery appears to be a promising treatment for patients with cSDH, both before and after surgical excision.

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

Background:

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

Methods:

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

Results:

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

Conclusion:

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

The Effect of Statins on the Recurrence of Chronic Subdural Hematomas: A Systematic Review and Meta-Analysis

BACKGROUND

Statins have been proposed to improve the resolution of chronic subdural hematoma (cSDH), with conflicting results likely due to underpowered analysis or confounding factors, such as the use of antithrombotic medication. We performed a systematic literature review and meta-analysis to better elucidate the effect of statin therapy on cSDH recurrence.

METHODS

We performed a comprehensive search of PubMed, MEDLINE, and Embase databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were included if the number of recurrences requiring surgical evacuation or leading to neurological deterioration was reported and could be extracted separately for patients who did or did not receive statin therapy.

RESULTS

Seven studies were included, comprising 1359 cSDH patients (statin therapy, 449 vs. non-statin therapy, 910). Age was not different between groups (P = 0.548). The proportion of men was significantly different (statin, 80.1% vs. non-statin, 74.7%; P = 0.02). Use of antithrombotic medication was significantly higher (P = 0.005) in the statin group (11.7%) than in the non-statin group (7.3%). The statin group had a non-significant lower odds of recurrence (odds ratio 0.80, 95% confidence interval 0.35-1.81). In an exploratory data analysis of 4 studies without a difference between groups in antithrombotic medication use, the statin group had significantly lower odds of recurrence (odds ratio 0.29, 95% confidence interval 0.17-0.50).

CONCLUSIONS

Overall, we found that statin use did not result in lower odds of cSDH recurrence, likely due to a dilution caused by the higher rate of patients on antithrombotic medications in the statin group.

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 pediatric chronic subdural hematoma under anticoagulant therapy with ventricular assist device: a case report

INTRODUCTION

Recently, the efficacy of middle meningeal artery (MMA) embolization for chronic subdural hematoma (cSDH) in the elderly has been reported. However, no previous reports of MMA embolization for cSDH in children with ventricular assist devices (VAD) have been published. Here, we report a case of MMA embolization for cSDH in a child with VAD.

CASE

A 15-month-old female was diagnosed with dilated cardiomyopathy at 7 months old. Soon, a VAD was inserted, and anticoagulant and antiplatelet therapy was started. Bilateral cSDH was observed at 15 months, and, 2 months later, an acute exacerbation of the right cSDH necessitated intracerebral hemorrhage removal. Afterwards, increased intracranial pressure occurred due to a contralateral subdural hematoma but, 4 months after intracerebral hemorrhage removal, CT showed new hemorrhaging in the left cSDH. MMA embolization was then conducted to prevent rebleeding in the hematoma. Selective angiography of the left MMA demonstrated stains of hematoma capsules from the frontal and parietal branches, which were embolized using liquid embolic material. During the procedure, the material migrated into the intracranial vessels via an undetected transdural anastomosis. Postoperatively, no new neurological abnormalities, including hemiparesis, were observed. Two months later, CT showed a decrease in hematoma size.

CONCLUSION

MMA embolization for cSDH in pediatric patients with VAD may be effective, if vigilance is maintained against transdural anastomoses.

The "Bright Falx" Sign-Midline Embolic Penetration Is Associated With Faster Resolution of Chronic Subdural Hematoma After Middle Meningeal Artery Embolization: A Case Series

BACKGROUND

Chronic subdural hematomas (CSDHs) are common in the elderly population and patients taking antiplatelet/anticoagulation medications. Middle meningeal artery (MMA) embolization has become an adjunctive treatment to observation and surgery. Despite many embolization techniques, best practices for optimal CSDH resolution remain unknown.

OBJECTIVE

To report a retrospective case series of MMA embolization for CSDHs regarding rate of hematoma improvement and the significance of distal embolic penetration into the falx.

METHODS

Retrospective chart review was performed on all patients who underwent MMA embolization for CSDHs between January 2017 and June 2021. Patient demographics, clinical presentation, anticoagulant use, and radiographic features were collected. Pre-embolization and postembolization computed tomography scans were analyzed for volumetric changes and assessed for midline penetration of embolic material in the falx.

RESULTS

MMA embolization was performed in 37 patients and 53 hemispheres. Older patients took longer to obtain complete resolution of CSDHs (r = 0.47, P = .03). Patients with larger pre-embolization (r = 0.57, P = .007) and postembolization (r = 0.56, P = .008) CSDH volumes took longer to completely resolve. Patients who had n-butyl cyanoacrylate embolization with midline penetration, as evidenced by the "bright falx" sign, had faster improvement rates than those who did not (5.64 cm3/d vs 1.2 cm3/d, P = .02).

CONCLUSION

Distal penetration of embolic material, particularly n-butyl cyanoacrylate, into the falx may lead to more rapid improvement of CSDH.

Middle meningeal artery embolization before craniotomy for infected organizing chronic subdural hematoma: A case report and review of the literature

Background:

Organizing chronic subdural hematoma (OSDH) is intractable and its radical treatment remains controversial. Middle meningeal artery embolization has emerged as an adjunctive treatment to craniotomy for OSDH.

Case Description:

The patient is an 86-year-old man. He had been taking warfarin for atrial fibrillation and was referred to the department for the treatment of bilateral chronic subdural hematoma (CSDH), which was found on head computed tomography after a fall. Bilateral burr hole drainages were performed, but his hematomas were organized, so the hematomas could not be drained sufficiently. The patient was discharged from the hospital without any neurological symptoms. Two months later, the patient presented with persistent fever and headache and had recurrent bilateral CSDHs. The hematoma on the right side was larger. Based on the initial intraoperative findings, OSDH was suspected, and craniotomy was performed on the right hematoma. Propionibacterium acnes were detected in the hematoma culture, and antimicrobial therapy was started postoperatively. Since the right hematoma recurred on the 7^th postoperative day, bilateral middle meningeal artery (MMA) embolization with 20% n-butyl-2-cyanoacrylate was performed, followed by craniotomy for the left hematoma and drainage for the right recurrent hematoma. Antimicrobials were administered for 2 weeks after the last operations. Six months after the operations, both bilateral hematomas had almost disappeared.

Conclusion:

Craniotomy is effective for the treatment of infected OSDH, and MMA embolization is useful to reduce the risk of bleeding complications in the perioperative period, and may also reduce the recurrence 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.

The effect of antithrombotic therapy on the recurrence and outcome of chronic subdural hematoma after burr-hole craniostomy in a population-based cohort

PURPOSE

To study the effect of antithrombotic therapy (ATT) on the outcome of operatively treated chronic subdural hematomas (CSDH).

METHODS

A retrospective population-based cohort study from Eastern Finland including all adult patients who underwent a burr-hole craniostomy (BHC) for CSDH during 2016 and 2017. The follow-up time for recurrence was 6 months and for mortality 3 years.

RESULTS

A total of 301 CSDH patients were included in the study. ATT (antithrombotic therapy; antiplatelet or anticoagulant medication) was used by 164 patients (54.5%) at the time of diagnosis. The hematoma was bilateral in 102 patients (33.9%). Forty-seven patients (15.8%) encountered hematoma recurrence. Bilateral CSDHs required reoperations more often than unilateral hematomas (12.6% vs. 22.0%; p = 0.036) regardless of the primary operation (uni- or bilateral). A bivariate logistic regression analysis showed that bilateral hematoma (OR 1.918; 95% CI 1.013-3.630; p = 0.045) and male gender (OR 2.363; 95% CI 1.089-5.128; p = 0.030) independently predicted hematoma recurrence. The overall three-year mortality was 27.9%. The use of ATT was not associated with CSDH recurrence, and the length of the temporary postoperative ATT discontinuation did not correlate with the rate of thromboembolic events.

CONCLUSIONS

ATT did not affect CSDH recurrence in our study population, and the duration of the temporary postoperative ATT discontinuation was not associated with the rate of thromboembolic complications. Male gender and bilateral hematomas were more frequently associated with recurrences.

Radiographic clearance of chronic subdural hematomas after middle meningeal artery embolization

BACKGROUND

Few reports discuss variables associated with improved outcomes after middle meningeal artery (MMA) embolization for chronic subdural hematomas (cSDHs). We analyzed radiographic evidence of cSDH clearance after MMA embolization to elucidate optimal techniques, hematoma clearance rates, and suitable length of follow-up.

METHODS

Patients who underwent MMA embolization for cSDH from January 1, 2018 through December 31, 2020 were analyzed. Patient characteristics, demographics, and technical procedural details were examined. Outcomes for cSDHs analyzed included complete or near-complete resolution at 30, 90, and 180 days following embolization. A multivariable logistic regression analysis identified variables predictive of rapid clearance and resolution of hematomas at 90 days.

RESULTS

The study cohort comprised 66 patients with 84 treated cSDHs. The mean (SD) cSDH size differed significantly at 30-day (8.8 (4.3) mm), 90-day (3.4 (3.0) mm), and 180-day (1.0 (1.7) mm) follow-up (p<0.001). More cSDHs had complete or near-complete resolution at 180 days (92%, 67/73) than at 90 (63%, 45/72) and 30 days (18%, 15/84) post-embolization (p<0.001). Only distal embolysate penetration was independently associated with rapid clearance (OR 3.9, 95% CI 1.4 to 11.1; p=0.01) and resolution of cSDHs at 90 days (OR 5.0, 95% CI 1.7 to 14.6; p=0.003).

CONCLUSION

Although 63% of cSDHs with MMA embolization had complete or near-complete resolution by 90 days post-procedure, 92% reached this stage by 180 days. Therefore, 90-day follow-up may be insufficient to determine the effectiveness of MMA embolization for cSDHs, particularly compared with surgical evacuation alone. Also, distal MMA penetration may be associated with more rapid hematoma clearance.

[Middle meningeal artery embolization for chronic subdural haematoma. Case series and literature review]

Middle meningeal artery embolization as primary method for treatment of chronic subdural hematomas became more popular in past decade. There are few large case series (>150 patients) and literature reviews characterizing advantages and drawbacks of endovascular treatment and technical features of surgeries. In this manuscript, the authors report 11 patients with chronic subdural hematoma scheduled for middle meningeal artery embolization and review the literature data on this issue.

History and current progress of chronic subdural hematoma

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.