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.

Granuloma formation as a late complication of burr-hole surgery for chronic subdural hematoma.

BACKGROUND: Surgical treatment remains the mainstream therapeutic regimen for chronic subdural hematoma (CSDH), and burr-hole craniostomy with subdural drainage is the preferable approach. Herein, we reported a case of intracranial granuloma formation as a late complication of burr-hole surgery for CSDH. CASE PRESENTATION: A 31-year-old man presented with a 1-month history of headache. Head computed tomography (CT) showed a subdural hematoma in the left frontal-temporal-parietal region with significant midline shifting. A burr-hole evacuation of the hematoma with closed-system drainage was performed. CT obtained immediately after the surgery demonstrated that the hematoma was mostly evacuated. Nine months later, he presented to us again due to intermittent headache in the left temporoparietal region. Brain magnetic resonance imaging revealed a space-occupying mass at the site of the original hematoma. A bone-flap craniotomy was performed for resecting the mass. Histopathological examination revealed a granuloma. The microbial cultivation of the resected specimen was negative. The postoperative course was uneventful, and the headache was relieved. CONCLUSION: Granuloma formation is an extremely rare late complication of burr-hole surgery for CSDH. Physicians involved in the perioperative management of CSDH should be aware of this condition, and bone-flap craniotomy may be warranted.

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.

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.

Clinical Characteristics and Prognoses of Chronic Subdural Hematoma Patients with and without Head Trauma: A Retrospective Comparative Study.

OBJECTIVE: Head trauma is considered as the main cause of chronic subdural hematoma (CSDH). However, many patients develop CSDH with no identified cause. Herein, we conduct a comparative study to investigate the differences in clinical characteristics and surgical outcomes of CSDH patients with and without a history of head trauma. METHODS: We retrospectively reviewed CSDH patients who underwent surgical treatment in our hospital between January 2013 and December 2021. Patients were categorized into a with head trauma (WHT) group and a without head trauma (WOHT) group for comparative analysis. RESULTS: A total of 219 patients were included, 119 (54.3%) cases in the WHT group and 100 (45.7%) cases in the WOHT group. More cancer patients were found in the WOHT group than in the WHT group (P = 0.045). Both at discharge and 6-month follow-up, patients in the WOHT group achieved better clinical outcomes than the WHT group cases (P = 0.025 and 0.034, respectively). Furthermore, ordered multiclass logistic regression analyses indicated that a history of head trauma (odds ratio 2.151, 95% confidence interval 1.052-4.386; P = 0.036) was a risk factor significantly related to the unfavorable outcomes at 6-month follow-ups of CSDH. However, we did not find significant differences between the 2 groups in clinical manifestations, radiological characteristics, postoperative complications, mortality, and recurrence rates. CONCLUSIONS: CSDH patients with a history of head trauma may be more susceptible to unfavorable outcomes; thus, they should be carefully evaluated and given more attention during hospitalization and after discharge.

Peptidomics insights: neutrophil extracellular traps (NETs) related to the chronic subdural hemorrhage.

Chronic subdural hemorrhage (CSDH) refers to a hematoma with an envelope between the dura mater and the arachnoid membrane and is more common among the elderly. It was reported that the dura mater, which is highly vascularized with capillary beds, precapillary arterioles and postcapillary venules play an important role in the protection of the central nervous system (CNS). Numerous evidences suggests that peptides play an important role in neuroprotection of CNS. However, whether dura mater derived endogenous peptides participate in the pathogenesis of CSDH remains undetermined. In the current study, the peptidomic profiles were performed in human dura of CSDH (three patients) and the relative control group (three non-CSDH samples) by LC-MS (liquid chromatography-mass spectrometry). The results suggested that a total of 569 peptides were differentially expressed in the dura matter of CSDH compared with relative controls, including 217 up-regulated peptides and 352 down-regulated peptides. Gene Ontology (GO) analysis demonstrated that the precursor proteins of those differentially expressed peptides were involved in the various biological processes. Interestingly, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that NETs participated in the pathogenies of CSDH. Further investigate showed that H3Cit was significantly elevated in the dural and hematoma membranes of patients with CSDH compared to patients without CSDH. Taken together, our results showed the differentially expressed peptides in human dura mater of CSDH and demonstrated that NETs formation in the dural and hematoma membranes might be involved in the pathogenesis of CSDH. It is worth noting that pharmacological inhibition of NETs may have potential therapeutic implications for CSDH.

Risk factors for recurrence of chronic subdural hematoma after surgical evacuation: a systematic review and meta-analysis.

Chronic subdural hematoma (CSDH) is a common neurosurgical condition. Surgical evacuation has remained the primary treatment despite many advancements in the endovascular field. Regardless, recurrence requiring reoperation is commonly observed during the postoperative follow-up. Herein, we aimed to investigate risk factors for recurrence after surgical evacuation. A review of MEDLINE, EMBASE, Web of Science, and Scopus was conducted using the designed search string. Studies were reviewed based on the predefined eligibility criteria. Data regarding sixty potential risk factors along with operational information were extracted for analysis. A meta-analysis using the random-effect model was conducted, and each risk factor affecting the postoperative recurrence of CSDH was then evaluated and graded. A total of 198 records met the eligibility criteria. A total number of 8523 patients with recurrent CSDH and 56,096 with non-recurrent CSDH were included in the study. The recurrence rate after surgical evacuation was 12%. Fifteen preoperative, nine radiologic, four hematoma-related, and three operative and postoperative factors were associated with recurrence. Risk factors associated with recurrence after surgical evacuation are important in neurosurgical decision-making and treatment planning. Found risk factors in this study may be used as the basis for pre-operative risk assessment to choose patients who would benefit the most from surgical evacuation.

Predictors of revision surgery after bedside subdural drain placement for chronic subdural hematomas.

BACKGROUND AND OBJECTIVE: For chronic subdural hematoma (cSDH), bedside subdural drains (SDD) provide a useful alternative to more invasive neurosurgical techniques, including evacuation through multiple burr holes or formal craniotomy. However, no scale currently exists adequately predicting SDD candidacy or treatment response. The present study sought to characterize predictors of revision surgery after initial treatment with bedside SDD for cSDH. METHODS: We conducted a retrospective case control study of cSDH patients treated with bedside SDD at a level one trauma center between 2018 and 2022. Binomial regression was used to compare SDD patients and generate odds ratios associated with revision surgery, which were compared using a binary random effects model. RESULTS: Ninety six cSDH patients were included, of whom 13 (13.5%) required a revision surgery after initial treatment failure with bedside SDD. Patients requiring revision surgery demonstrated an increased male predominance (84.6% vs. 69.9% of SDD patients not requiring revision surgery), tended to be younger (67.8 vs. 70.5 years) with a greater body mass index (28.7 vs. 25.6 kg/m2), and have a lower Glasgow Coma Scale (GCS) score on presentation of 12.5 (versus 14). Patients with an initial GCS score less than 13 (OR 11.0 95% CI 2.8 - 43.3), midline shift greater than 10 mm on CT (OR 6.5 95% CI 1.7 - 25.7), or duration of SDD placement longer than 3 days (OR 10.5 95% CI 2.6 - 41.9) demonstrated a greater likelihood of needing a revision surgery after initial treatment with bedside SDD. CONCLUSION: Among patients treated with SDD, we identified 3 independent factors predicting the need for revision surgery: GCS score, midline shift, and duration of drain placement. Craniotomy may be favored over bedside SDD in patients presenting with a GCS score less than 13 or midline shift greater than 10 mm and for SDD patients demonstrating inadequate clinical response after 3 days.

Membrane Tucking Technique using Ligature Clips with Intermembranous Placement of Oxidized Regenerated Cellulose in Multilayered Chronic Subdural Hematoma: Description of Novel Technique and our Initial Experience.

Chronic subdural hematoma (cSDH) is an encapsulated collection of blood and blood degradation products between dural border cell layers, the pathophysiology of formation and expansion of which is still debatable. It is usually seen in the elderly population, and surgical evacuation is the primary mode of treatment. The main hurdle in the treatment of cSDH is postoperative recurrences and the need for repeat operations. A few authors have classified cSDH into homogenous, gradation, separated, trabecular, and laminar types based on the internal architecture of hematoma and proposed that separated, laminar, and gradation types of cSDH have a high propensity of recurrence after surgery. A similar problem was described with multi-layered or multi-membrane cSDH. Based on the most accepted theory of formation and expansion of cSDH that suggests a complex and vicious process of membrane formation, chronic inflammation, neoangiogenesis, rebleeding from fragile capillaries, and increased fibrinolysis, we propose our theory of intermembranous placement of oxidized regenerated cellulose and membrane tucking using ligature clips to prevent recurrence in multi membranous cSDH by ceasing the ongoing cascade in hematoma's internal milieu and thus preventing recurrence and reoperation in such cases. This is the first in the world literature report describing such a technique for treating multi-layered cSDH and in our series, the reoperation and postoperative recurrence rates were 0% in patients treated by the described technique.

Dexamethasone and Statins in Patients Undergoing Primary Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Propensity-Matched Study in the TriNetX Research Network.

OBJECTIVE: Middle meningeal artery embolization (MMAE) is an effective minimally invasive option for chronic subdural hematoma (cSDH). Dexamethasone and statins have been reported to improve the resolution of cSDH and reduce its recurrence. However, only 1 study has investigated the role of statins in patients treated with MMAE, and there is no such study on dexamethasone. Thus, we used the TriNetX research network to determine whether adding dexamethasone or statin along with primary MMAE is associated with a benefit in outcomes. METHODS: We queried all primary MMAE cases for cSDH between January 1st, 2012, and July 1st, 2022, in the TriNetX research network. We included patients greater than or equal to 18 years old and separated them regarding statin and dexamethasone use around the time of MMAE. Outcomes were evaluated within 6 months and 3 years after MMAE, and analyses were performed before and after propensity score matching. RESULTS: The study included 372 patients with chronic subdural hematoma who underwent MMAE and were on dexamethasone, 339 not on dexamethasone, 391 on statins, and 278 not on statins. After propensity score matching, the dexamethasone cohorts included 250 patients each and only headache remained more prevalent in the dexamethasone cohort at both 6 months (21.2% vs. 10.0%, P = 0.001) and 3 years (23.6% vs. 12.4%, P = 0.001). After propensity score matching, the statin cohorts included 150 patients each and no differences in outcomes were found at both 6 months and 3 months after MMAE. CONCLUSIONS: Patients treated with primary MMAE and were on dexamethasone or statins had no differences in mortality and functional/provider dependence compared to those who were not on dexamethasone or statins. Patients on dexamethasone had a higher prevalence of headaches.

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.

Efficacy analysis of neuroendoscopy-assisted burr-hole evacuation for chronic subdural hematoma: a systematic review and meta-analysis.

The purpose of this study was to compare neuroendoscopy-assisted burr-hole evacuation with conventional burr-hole evacuation in the treatment of chronic subdural hematoma (CSDH), and to evaluate the curative effect of neuroendoscopy. This study follows PRISMA guidelines and uses the keywords "chronic subdural hematoma," "neuroendoscopies," "neuroendoscopy," "endoscopy," "endoscopic neurosurgery," and "neuroendoscopic surgery" to conduct an electronic search of online databases, including PubMed, Embase, Web of Science, and Cochrane Library. There were no restrictions on language or publication year. This meta-analysis involved 948 patients in six studies. The results showed that the recurrence rate in the neuroendoscopy group was significantly lower than that in the conventional burr-hole group (3.1% vs. 13.8%, P<0.001). Compared with the control group, the neuroendoscopy group had a longer operation time (P<0.001) and a shorter postoperative drainage time (P<0.001). In addition, there was no significant difference in hospital stay (P=0.14), mortality (P=0.39), postoperative morbidity (P=0.12), or 6-month neurological outcomes (P=0.32) between the two groups. It should be noted that the comparison of neurological outcomes was based on 269 patients (6/106 vs. 14/163). Compared with conventional burr-hole evacuation, neuroendoscopy-assisted burr-hole evacuation reduces the recurrence rate of CSDH and shortens the postoperative drainage time. However, the neuroendoscopy group did not have lower mortality or morbidity or better functional outcomes. In the future, randomized controlled trials are needed to further evaluate the efficacy and safety of neuroendoscopic surgery.

Nutritional and inflammatory peripheral blood markers for risk assessment of chronic subdural hematoma: a case-control study.

BACKGROUND: Some peripheral blood markers have been demonstrated to be correlated with the re-formation of chronic subdural hematoma (CSDH). The aim of this study was to identify the correlation between nutritional/inflammatory peripheral blood markers and CSDH. METHODS: 188 CSDH patients and 188 age-matched healthy controls were included in this research. The clinical characteristics and peripheral blood markers associated with nutritional or inflammatory status were obtained and analyzed. Conditional logistic regression analysis was applied to identify the potential CSDH risk factors. All the participants were divided into 3 groups based on the tertiles of change in risk factors. The Cochran-Armitage test and one way ANOVA were applied to identify the association between baseline characteristics and independent risk factors. Moreover, the net reclassification index (NRI) and integrated discrimination index (IDI) were calculated to evaluate the improvement in model performance after adding the independent risk factors in the conventional model. RESULTS: The logistic regression analysis demonstrated that the increased albumin (OR, 0.615; 95 %CI,0.489-0.773; P < 0.001) and lymphocyte count (OR, 0.141; 95 %CI,0.025-0.796; P = 0.027) were associated with lower risk of CSDH. Moreover, addition of albumin and lymphocyte to conventional risk factors significantly improved the risk prediction of CSDH(NRI: 46.47 %, P < 0.001; IDI: 30.92 %, P < 0.001; NRI: 22.45 %, P = 0.027; IDI: 1.23 %, P = 0.037, respectively) CONCLUSION: The decreased albumin and lymphocyte levels were correlated with a high risk of chronic subdural hematoma. The nutritional and inflammatory serum markers should be put great attention because these markers may play roles in finding the cause of CSDH and predicting its risk.

Acute Traumatic Subdural Hematoma in the Elderly and Associated Factors that May Influence Chronicity.

Traumatic acute subdural hematomas (TASDH) is by far the most common traumatic brain injury in adult patients with blunt trauma, who presented to the Emergency Department (ED). One of the serious sequale of TASDH is the development of Chronic Subdural Hematomas (CSD) with associated deterioration in mental status and convulsion.1,2 Studies to identify the risk factors that favors development of chronicity of TASDH are few and inconclusive. As seen in our prior initial study, there were few factors which were common in those who developed chronicity of their TASDH, and we elected to expand our pool of patients to include those admitted between the years of 2015 and 2021 with ATSDH and identify the common factors associated with development of CSD.

Significant Correlation between Structural Changes in the Net-like Appearance on Postoperative Cranial Magnetic Resonance Images and Hematoma Recurrence in Cases of Chronic Subdural Hematoma.

Organized hematoma, which exhibits a net-like appearance on imaging studies, is one of the predisposing factors for the recurrence of chronic subdural hematoma. Patients who are positive for the net-like appearance are often treated with only burr hole surgery. We investigated the relationship between postoperative structural changes in the net-like appearance and the recurrence rate of chronic subdural hematoma. Of the 949 patients with chronic subdural hematoma treated with primary burr hole surgery between January 2010 and April 2021 at our hospital, 268 who were considered positive for the net-like appearance on T2- and T2 star-weighted magnetic resonance images were extracted. We followed the structural changes in the net-like appearance postoperatively and subsequently classified the patients into three groups: decreasing type, shifting type, and no change and deterioration type. The relationship between each structural change and the recurrence rate in the three groups was investigated. Postoperative recurrence requiring surgery occurred in 3.5% of the subjects with decreasing type, 0% with shifting type, and 100% with deterioration type of the net-like appearance (P < 0.05), indicating differences in the recurrence rates according to postoperative structural changes in the magnetic resonance images (MRI) features of chronic subdural hematoma. Our results indicate that the risk of postoperative chronic subdural hematoma recurrence can be predicted by focusing on the structural changes in the postoperative net-like appearance on MRI.

Incidence of Chronic Subdural Hematoma after Mild Head Trauma in Elderly Patients with or without Pre-traumatic Conditioning of Anti-thrombotic Drugs.

Anti-thrombotic drugs may increase the risk for chronic subdural hematoma (CSDH). However, whether to continue or discontinue/counteract these drugs has not been investigated in patients with mild head trauma. CSDH incidence after mild head trauma, as well as the risk for CSDH in patients with anti-thrombotic drugs, were investigated in this study. The study included 765 consecutive elderly (>65 y.o.) patients with mild head trauma and an initial Glasgow Coma Scale (GCS) score of 14 or 15. All patients received initial CT within 24 hours after trauma and were re-examined 30 days after trauma to detect CSDH formation, repeating for every 30 days to examine symptomatic CSDH progression. Patients were divided into two groups, with anti-thrombotic drugs (n = 195) or without them (n = 263), to investigate the influence of pre-traumatic conditioning with anti-thrombotic drugs on CSDH. The whole sample was 458 out of 765 cases. The incidence of CSDH formation was 91 out of 458 cases (19.9%) after mild head trauma, with no significant difference between with and without anti-thrombotic drugs. CSDH progressed as symptomatic in 21 out of 458 cases (4.6%), with no significant difference between with and without anti-thrombotic drugs. Pre-traumatic conditioning with anti-thrombotic drugs and its continuation after trauma did not affect the incidence of formation or symptomatic progression of CSDH. This finding suggests that discontinuing and/or counteracting anti-thrombotic drugs may be unnecessary in patients with mild head trauma.

Persistent facial nerve palsy after middle meningeal artery embolization for subdural hematoma: a case report.

OBJECTIVE: To describe a case of persistent facial nerve palsy after middle meningeal artery (MMA) embolization for chronic subdural hematoma (cSDH). METHODS: A literature search was conducted for publications within the last 10 years of facial nerve palsy following cerebral circulation embolization procedures. RESULTS: With inconsistencies between previously believed pathophysiology and clinical features, other mechanisms causing cSDH such as angiogenesis and capillary formation have been proposed. MMA embolization has evolved as a therapeutic approach to reduce recurrence of subdural hematoma; however, postoperative neural complications such as cranial nerve palsies are poorly described in the literature. CONCLUSIONS: cSDH is increasingly more common and is on trajectory to become the most prevalent cranial neurosurgical condition. MMA embolization is described as a safe and minimally invasive procedure; however, as a relatively new procedure further research is needed to elucidate associated complications.

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.

Cost Comparison for Open Surgery versus Middle Meningeal Artery Embolization in Patients with Chronic Subdural Hematomas: A Propensity Score-Matched Analysis.

BACKGROUND: Chronic subdural hematoma (cSDH) can be treated with conventional surgery or middle meningeal artery embolization (MMAE). The cost profiles of open surgery versus MMAE have never been studied. Therefore, we sought to compare the costs of surgical and MMAE treatment of cSDH. METHODS: Patients treated with open surgery (2006-2019) and MMAE (2018-2020) were identified from the institutional database. Propensity score matching analysis was used to assemble a balanced group of subjects. Detailed hospitalization costs in each group were collected and compared. RESULTS: A total of 341 conventionally treated and 52 MMAE cases were identified. After propensity score matching, 33 patients were included in each group, for a total of 66 patients for analysis. Direct procedural cost was significantly greater in the MMAE group compared with the open surgery group ($38,255 ± $11,859 vs. $11,206 ± $7888; P < 0.001). Medication cost also was greater in the MMAE group ($6888 ± $6525 vs. $4291 ± $3547; P = 0.048). No significant difference was found in costs for intensive care unit care, pharmacy, therapy, laboratory values, and the emergency department. Imaging costs and other miscellaneous costs (e.g., wound care, preoperative, and postanesthesia care unit) were greater in the open surgery group (P < 0.05). Total hospitalization cost was not significantly different between the 2 groups ($60,598 ± 61,315 vs. $71,569 ± $37,813 for open surgery and MMAE respectively, P = 0.385). No significant differences in number of follow ups or total costs for follow up were found (P > 0.05). CONCLUSIONS: Open surgery and MMAE offer an overall equivalent cost-profile for cSDH treatment when matching for potential cost confounders. Direct procedural costs are greater in MMAE; however, total hospitalization costs and follow up costs are not significantly different.