Increased mRNA Expression of VEGF within the Hematoma and Imbalance of Angiopoietin-1 and -2 mRNA within the Neomembranes of Chronic Subdural Hematoma

Vitamin D accelerates the subdural hematoma clearance through improving the meningeal lymphatic vessel function

Subdural hematoma (SDH) drains into the extracranial lymphatic system through the meningeal lymphatic vessels (mLVs) but the formation of SDH impairs mLVs. Because vitamin D (Vit D) can protect the endothelial cells, we hypothesized that Vit D may enhance the SDH clearance. SDH was induced in Sprague-Dawley rats and treated with Vit D or vehicle. Hematoma volume in each group was measured by H&E staining and hemoglobin quantification. Evans blue (EB) quantification and red blood cells injection were used to evaluated the drainage of mLVs. Western blot analysis and immunofluorescence were conducted to assess the expression of lymphatic protein markers. We also examined the inflammatory factors levels in subdural space by ELISA. Vit D treatment significantly reduced SDH volume and improved the drainage of SDH to cervical lymph nodes. The structure of mLVs in SDH rats were protected by Vit D, and the expressions of LYVE1, PROX1, FOXC2, and VE-cadherin were increased after Vit D treatment. The TNF-α, IL-6, and IL-8 levels were reduced in Vit D group. In vitro, Vit D also increased the VE-cadherin expression levels under inflammation. Vit D protects the structure of mLVs and enhances the absorption of SDH, partly by the anti-inflammatory effect of Vit D.

Effects of Angiotensin-Converting Enzyme Inhibition on the Recurrence and Internal Structure of Chronic Subdural Hematomas

Background/Objectives: Chronic subdural hematoma (cSDH) is a common disease of growing significance due to the increasing use of antithrombotic drugs and population aging. There exists conflicting observational evidence that previous treatment with angiotensin-converting enzyme (ACE) inhibitors reduces the rate of cSDH recurrence. This study assesses the hypothesis that ACE inhibitors may affect recurrence rates by altering hematoma membrane formation. Methods: All patients with chronic subdural hematoma who were operated upon in a single university hospital between 2015 and 2020 were considered for inclusion. Hematomas were classified according to their structural appearance in computed tomography (CT) imaging into one of eight subtypes. Patients' own medication, prior to hospitalization for cSDH treatment, was noted, and the use of ACI-inhibitors was identified. Results: Of the included 398 patients, 142 (35.9%) were treated with ACE inhibitors before admission for cSDH treatment. Of these, 115 patients (81.0%) received ramipril, 13 received patients lisinopril (11.3%), and 11 patients (9.6%) received enalapril. Reflecting cardiovascular comorbidity, patients on ACE inhibitors were more often simultaneously treated with antithrombotics (63.4% vs. 42.6%; p ≤ 0.001). Hematomas with homogenous hypodense (OR 11.739, 95%CI 2.570 to 53.612; p = 0.001), homogenous isodense (OR 12.204, 95%CI 2.669 to 55.798; p < 0.001), and homogenous hyperdense (OR 9.472, 95%CI 1.718 to 52.217; p < 0.001) architectures, as well as the prior use of ACE inhibitors (OR 2.026, 95%CI 1.214 to 3.384; p = 0.007), were independently associated with cSDH recurrence. Conclusions: Once corrected for hematoma architecture, type of surgery, and use of antithrombotic medication, preoperative use of ACE inhibitors was associated with a twofold increase in the likelihood of hematoma recurrence.

Urokinase Plasminogen Activator Receptor: An Important Focal Player in Chronic Subdural Hematoma?

Chronic subdural hematoma (CSDH) development involves inflammatory, angiogenetic, and fibrinolytic mechanisms, several components of which are now unraveled through intensive research. The urokinase plasminogen activator receptor (uPAR) is part of the plasminogen activator system and possesses inflammatory, angiogenetic, and fibrinolytic capabilities. As a first, this study aims to identify uPAR in the hematoma fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH and, if present, to investigate if the uPAR level at the time of surgery may be a predictor for later developing recurrent CSDH. uPAR expression in the hematoma membrane and dura mater was analyzed using immunohistochemistry and presented as the H-score of the positive immunostaining. The uPAR levels in the hematoma fluid and systemic blood were determined using a multiplex antibody bead kit (Luminex). Samples were collected at the time of the first CSDH surgery, and in the case of recurrent CSDH within 90 days, the samples were again collected at reoperation. A comparison of uPAR expression between the hematoma membrane and dura mater, as well as uPAR levels in systemic blood and hematoma fluid, was performed using the Wilcoxon rank sum test. We included 112 patients, 26 of whom had recurrent CSDH. The median hematoma uPAR level was 22,125 (14,845-33,237) and significantly higher than the median systemic blood level of 789 pg/L (465-2,088) (p < 0.001). Similarly, the uPAR level of the hematoma membrane was 14.3 (7.54-44.8) and significantly higher than the dural uPAR level of 0.81 (0.3-1.98) (p < 0.001). For the first time, we identified uPAR in the subdural fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH. The high expression of uPAR in the subdural fluid and hematoma membrane indicates that the mechanisms of CSDH are predominantly in the subdural fluid collection and surrounding hematoma membrane.

Middle Meningeal Artery Embolization in the Treatment of Acute Subdural Hematoma: A Case Series Featuring Access Through a Carotid Stent

The first objective of this case series was to describe the case of a patient with severe symptomatic left internal carotid artery stenosis after a recent stroke. Several days after stent placement by transcarotid artery revascularization, the patient developed a left-sided subdural hematoma. The patient then underwent embolization of the left middle meningeal artery (MMA) despite blocked access to the left MMA because of an internal carotid stent. The external carotid artery was accessed by passing a guiding catheter through the stent wall. We describe this method as "intrawall access." This allowed a coaxial system to deliver polyvinyl alcohol particles to the MMA for embolization. Embolization was successfully performed, with the stent integrity and blood flow through it remaining uncompromised. Overall, we demonstrated a new method of access through a previously placed internal carotid stent to gain neurointerventional access to the external carotid artery, which was jailed by a stent, for treating an acute subdural hematoma via MMA embolization. The second objective of this case series was to demonstrate the first MMA embolization in literature carried out in the acute or acute-on-subacute setting, in this case, and in four others.

Effectiveness of tranexamic acid on chronic subdural hematoma recurrence: a meta-analysis and systematic review

Objectives

Our objective was to compare the effectiveness of TXA in improving recurrence in patients with chronic subdural hematoma (CSDH).

Methods

Eligible randomized controlled trials (RCTs), prospective trials and retrospective cohort studies were searched in PubMed, Cochrane Library, Embase, and CNKI from database inception to December 2023. After the available studies following inclusion and exclusion criteria were screened, the main outcome measures were strictly extracted. Reman v5.4. was used to assess the overall recurrence rate. A random-effects model was used to assess pooled ORs, with the Mantel-Haenszel estimation method applied. Cochran Q (Chi-square) test and I2 statistics were used to assess inter-study heterogeneity. Funnel plots were used to evaluate publication bias.

Results

From the 141 articles found during initial citation screening, 9 literatures were ultimately included in our study. Our NMA results illustrated that patients with newly diagnosed Chronic subdural hematoma revealed a significantly improved recurrence rate when patients were treated with Tranexamic acid (OR: 0.33; 95% CI 0.26-0.41; p < 0.00001) compared with standard neurosurgical treatment. There was no significant difference in the incidence rates of thrombosis (OR: 0.84; 95% CI 0.63-1.12; p = 0.23) and mortality (OR: 1.0; 95% CI 0.57-11.76; p = 0.99), Occurrence of myocardial infarction was significantly less frequent in TXA users than in nonusers (OR: 0.18; 95% CI 0.04-0.82; p = 0.03).

Conclusion

TXA can effectively improve the recurrence rate of CDSH. It provides a high level of evidence-based medicine for clinical treatment. In addition, multicenter randomized controlled trials, with dose adjustments, are still needed to determine whether TXA intervention improves neurological function or prognosis.

Impact of antithrombotic agents on outcomes in patients requiring surgery for chronic subdural haematoma: a systematic review and meta-analysis

A chronic subdural haematoma (CSDH) is a collection of aged blood between the dura and the brain, typically treated with surgical evacuation. Many patients with CSDH have comorbidities requiring the use of antithrombotic medications. The optimal management of these medications in the context of CSDH remains unknown, as the risk of recurrence must be carefully weighed against the risk of vaso-occlusive events. To better understand these risks and inform the development of clinical practice guidelines, we conducted a systematic review and meta-analysis. A systematic review was conducted in accordance with the PRISMA guidelines, searching Medline and Embase databases. The study was registered with PROSPERO (CRD42023397061). A total of 44 studies were included, encompassing 1 prospective cohort study and 43 retrospective cohort studies. Pooled odds ratios (ORs) were calculated for CSDH recurrence and vaso-occlusive events in patients taking anticoagulant or antiplatelet medications compared to patients not receiving antithrombotic therapy. GRADE was used to assess the quality of evidence. In patients on anticoagulant therapy at CSDH diagnosis, the pooled OR for CSDH recurrence was 1.41 (95% CI 1.11 to 1.79; I2 = 28%). For patients on antiplatelet therapy, the pooled OR was 1.31 (95% CI 1.08 to 1.58; I2 = 32%). Patients taking antithrombotic medications had a significantly higher risk of vaso-occlusive events, with a pooled OR of 3.74 (95% CI 2.12 to 6.60; I2 = 0%). There was insufficient evidence to assess the impact of time to recommence antithrombotic medication on CSDH outcomes. We found that baseline antithrombotic use is associated with the risk of CSDH recurrence and vaso-occlusive events following surgical evacuation. The evidence base is of low quality, and decisions regarding antithrombotic therapy should be individualised for each patient. Further high-quality, prospective studies or registry-based designs are needed to better inform clinical decision-making and establish evidence-based guidelines.

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.

Platelet-derived Growth Factor Activates Pericytes in the Microvessels of Chronic Subdural Hematoma Outer Membranes

Angiogenesis is one of the growth mechanisms of chronic subdural hematoma (CSDH). Pericytes have been implicated in the capillary sprouting during angiogenesis and are involved in brain ischemia and diabetic retinopathy. This study examined the pericyte expressions in CSDH outer membranes obtained during trepanation surgery. Eight samples of CSDH outer membranes and 35 samples of CSDH fluid were included. NG2, N-cadherin, VE-cadherin, Tie-2, endothelial nitric oxide synthase (eNOS), platelet-derived growth factor (PDGF) receptor-β (PDGFR-β), a well-known marker of pericytes, phosphorylated PDGFR-β at Tyr751, and β-actin expressions, were examined using western blot analysis. PDGFR-β, N-cadherin, and Tie-2 expression levels were also examined using immunohistochemistry. The concentrations of PDGF-BB in CSDH fluid samples were measured using enzyme-linked immunosorbent assay kits. NG2, N-cadherin, VE-cadherin, Tie-2, eNOS, PDGFR-β, and eNOS expressions in CSDH outer membranes were confirmed in all cases. Furthermore, phosphorylated PDGFR-β at Tyr751 was also detected. In addition, PDGFR-β, N-cadherin, and Tie-2 expressions were localized to the endothelial cells of the vessels within CSDH outer membranes by immunohistochemistry. The concentration of PDGF-BB in CSDH fluids was significantly higher than that in cerebrospinal fluid. These findings indicate that PDGF activates pericytes in the microvessels of CSDH outer membranes and suggest that pericytes are crucial in CSDH angiogenesis through the PDGF/PDGFR-β signaling pathway.

Featured minimally invasive therapeutic approach for chronic subdural hematoma: Embolization of middle meningeal artery - A narrative review

Chronic subdural hematoma (c-SDH) is a frequent and serious neurological disease. It develops due to hemorrhage to the subdural space, mainly caused by head trauma. The middle meningeal artery (MMA) plays a critical role in the supply of blood to c-SDH. The decision on the type of treatment for c-SDH depends mainly on clinical and imaging evaluation. In cases in which patients are critically ill, the hematoma must be evacuated immediately. For this purpose, surgery is generally accepted as the mainstay of treatment. Among surgical techniques, twist-drill craniotomy, burr-hole craniotomy, and craniotomy are the three most used. The recurrence rate of c-SDH after surgery is an important problem with a rate of up to 30%. The technical success classification embolization of MMA (EMMA) has emerged as an effective and safe option for the treatment of c-SDH, especially those that recur. EMMA is commonly used as an adjunct to surgery or less frequently alone. The technical success of EMMA has been a promising minimal invasive strategy as an alternative or adjunctive therapy to surgical methods. Polyvinyl alcohol is the most widely used among various embolizing agents, including n-butyl cyanoacrylate, coil, and gelatin sponge. EMMA has been shown to prevent the formation or recurrence of c-SDH by eliminating blood flow to the subdural space. Complication rates are low. The large-scale comparative prospective will ensure efficacy and safety. This article aims to highlight the current information about EMMA in patients with c-SDH.

Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization

BACKGROUND

Liquid embolic agents (LEAs) such as ethylene vinyl alcohol (EVOH) are utilized for middle meningeal artery embolization (MMAE) for chronic subdural hematomas (cSDH). LEAs may be advantageous for MMAE as they are permanent and can penetrate the microvasculature of the subdural membranes. LEA surface area (SA) can quantify this penetration. The segmentation of LEA SA is not described in the literature and may be of interest in refining MMAE technique.

METHODS

We retrospectively collected computerized tomography (CT) scans from 74 patients (with 95 cSDH) who underwent first-line MMAE with EVOH. Non-contrast head CTs were acquired pre-embolization, immediately post-embolization and at 1-, 3-, and 6 month follow-up. A 3D-Slicer was used to segment hematoma volumes and the liquid embolic cast. We hypothesized that greater LEA SA would be correlated with greater improvements in cSDH volumetric resolution.

RESULTS

There was significant resolution in cSDH volumes over the follow-up period compared to preoperative volume (p<0.0001). The LEA SA was significantly correlated with the rate of cSDH resolution at 3 months (R2=0.08, p=0.03), and 6 months (R2=0.14, p=0.01).

CONCLUSIONS

The correlation of LEA surface area with hematoma resolution at 3-months and 6-months suggests greater LEA penetration may improve radiographic outcomes. This study uniquely provides a quantitative radiological perspective on the effect of LEA penetration on cSDH resolution.

Quantitative DECT of Iodine in Chronic Subdural Hematoma as Surrogate of Membrane Exudation: A Pilot Feasibility Study

OBJECTIVE

We explore the feasibility to estimate the exudation from chronic subdural hematoma (CSDH) membranes, by using dual-energy computed tomography (DECT) quantification of iodine leak and test if the derived quantitative variables and membrane morphology correlates with hematoma volume, internal architecture (homogeneous, laminar, separated, and trabecular types), and fractional hyperdense hematoma at presentation.

METHODS

In this retrospective study, consecutive CSDH patients with postcontrast DECT head images from January 2020 and June 2021 were analyzed. Predictor variables derived from DECT were correlated with outcome variables followed by mixed-effects regression analysis.

RESULTS

The study included 36 patients with 50 observations (mean age, 72.6 years; standard deviation, 11.6 years); 31 were men. Dual-energy CT variables that correlated with hematoma volume were external membrane volume (ρ, 0.37; P = 0.008) and iodine concentration (ρ, -0.29; P = 0.04). Variables that correlated with separated type of hematoma were total iodine leak (median [Q 1 , Q 3 ], 68.3 mg [48.5, 88.9] vs 38.8 mg [15.5, 62.9]; P = 0.001) and iodine leak per unit membrane volume (median [Q 1 , Q 3 ], 16.47 mg/mL [10.19, 20.65] vs 8.68 mg/mL [5.72, 11.41]; P = 0.002). Membrane grade was the only variable that correlated with fractional hyperdense hematoma (ρ, 0.28; P = 0.05). Regression analysis showed total iodine leak as the strongest predictor of separated type hematoma (odds ratio [95% confidence interval], 1.06 per mg [1.01, 1.1]).

CONCLUSIONS

Dual-energy CT demonstrates iodine leak from CSDH membranes. The variables derived from DECT correlated with hematoma volume, internal architecture, and fractional hyperdense hematoma.

Endoscopic Treatment of Chronic Subdural Hematoma Combined with Inner Subdural Hygroma

OBJECTIVE

A chronic subdural hematoma (CSDH) is a collection of bloody fluid located in the subdural space and encapsulated by neo-membranes. An inner subdural hygroma (ISH) is observed between the inner membrane of a CSDH and the brain surface. We present six cases of CSDH combined with ISH treated via endoscopy.

METHODS

Between 2011 and 2022, among the 107 patients diagnosed with CSDH in our institute, six patients were identified as presenting with CSDH combined with ISH and were included in this study. Preoperative computerized tomography (CT) and magnetic resonance imaging (MRI) were performed simultaneously, and endoscopic surgery for aspiration of the hematoma was performed in all cases of CSDH combined with ISH.

RESULTS

The mean age of patients was 71 years (range, 66 to 79). The patients were all male. In two cases, the ISH was not identified on CT, but was clearly seen on MRI in all patients. The inner membrane of the CSDH was tense and bulging after draining of the CSDH in endoscopic view due to the high pressure of the ISH. After fenestration of the inner membrane of the CSDH and aspiration of the ISH, the membrane was sunken down due to the decreasing pressure of the ISH. There was one recurrence in post-operative 2-month follow up. The symptoms improved in all patients after surgery, and there were no surgery-related complications.

CONCLUSION

CSDH combined with ISH can be diagnosed on imaging, and endoscopic surgery facilitates safe and effective treatment.

Surgical treatment of chronic subdural hematoma by twist drill craniotomy: A 9-year, single-center experience of 219 cases

OBJECTIVE

This study aims to assess the safety and efficiency of twist drill craniotomy (TDC) for surgical treatment of chronic subdural hematoma (CSDH) based on a single-center experience of 219 cases performed over nine years.

METHODS

We performed a retrospective analysis of CSDH patients who underwent TDC treatment in our hospital between January 2013 and December 2021. Clinical and radiological characteristics, as well as surgical outcomes of the included patients, were reviewed and analyzed. Factors that may affect hematoma recurrence and outcomes were also investigated.

RESULTS

A total of 219 patients (186 males and 33 females) were included. Eighteen (8.2%) patients experienced postoperative complications. The in-hospital mortality and recurrence rates in our series were 0.5% (1/219) and 4.1% (9/217), respectively. 91.7% (199/217) of patients achieved favorable outcomes six months after the operation. Duration of drainage catheter (odds ratio [OR] 0.135, 95% confidence interval [CI] 0.017-1.099; P = 0.030) was the only factor significantly related to the recurrence of CSDH. Moreover, brain infarction (OR 5.175, 95% CI 1.417-18.896; P = 0.013), Alzheimer's disease (OR 20.515, 95% CI 1.950-215.840; P = 0.012), and preoperative dysfunction of coagulation (OR 6.509, 95% CI 1.501-28.217; P = 0.012) were markedly associated with unfavorable functional outcomes.

CONCLUSION

TDC with irrigation and closed-system drainage is a minimally invasive, simple, safe, and effective surgical technique that can serve as the first-choice for the treatment of CSDH with a low recurrence rate.

Comparison of craniotomy and limited membranectomy with conventional techniques in the treatment of chronic subdural hematoma

Background/aim

Chronic subdural hematoma is the most frequently operated on intracranial hemorrhage worldwide. Although surgical results are satisfactory, recurrence remains an important problem. In this study, it was aimed to evaluate patients who underwent craniotomy with limited membranectomy (CwLM) in terms of recurrence rate and other complications.

Materials and methods

Electronic records of 291 consecutive patients who were operated on at our clinic (Atatürk University Yakutiye Research Hospital) between 2015 and 2020 were retrospectively reviewed. Their radiological images at the time of admission, clinical status, any early postoperative complications, and clinical status at the 6-month follow-up were all evaluated.

Results

According to the results of the study, postoperative mortality and morbidity of patients who underwent CwLM were similar to those with minimally invasive methods, and it reduced recurrence, especially in laminar and separated subtypes.

Conclusion

It is our belief that CwLM will be an appropriate treatment approach in suitable patients (radiologically detected) in chronic subdural hematoma, where recurrence is an important problem.

Anti-Inflammatory Drug Therapy in Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis of Prospective Randomized, Double-Blind and Placebo-Controlled Trials

Althoughanti-inflammatory drug therapy has been identified as potentially beneficial for patients suffering from chronic subdural hematoma (cSDH), contemporary literature presents contradictory results. In this meta-analysis, we aimed to investigate the impact of anti-inflammatory drug therapy on mortality and outcome. We searched for eligible randomized, placebo-controlled prospective trials (RTCs) on PubMed, Embase and Medline until July 2022. From 97 initially identified articles, five RTCs met the criteria and were included in our meta-analysis. Our results illustrate significantly lower rates of recurrent cSDH (OR: 0.35; 95% CI: 0.21-0.58, p = 0.0001) in patients undergoing anti-inflammatory therapy. In the subgroup of patients undergoing primary conservative treatment, anti-inflammatory therapy was associated with lower rates of "switch to surgery" cases (OR: 0.30; 95% CI: 0.14-0.63, p = 0.002). Despite these findings, anti-inflammatory drugs seemed to be associated with higher mortality rates in patients undergoing surgery (OR: 1.76; 95% CI: 1.03-3.01, p = 0.04), although in the case of primary conservative treatment, no effect on mortality has been observed (OR: 2.45; 95% CI: 0.35-17.15, p = 0.37). Further multicentric prospective randomized trials are needed to evaluate anti-inflammatory drugs as potentially suitable therapy for asymptomatic patients with cSDH to avoid the necessity of surgical hematoma evacuation on what are predominantly elderly, vulnerable, patients.

Dexamethasone reduces vascular endothelial growth factor in comparison to placebo in post-operative chronic subdural hematoma samples: A target for future drug therapy?

Background

Chronic subdural hematoma (CSDH) is a collection of blood and fluid that arises on the brain surface due to a combination of trauma and/or inflammation. The mainstay of treatment is surgical drainage, but CSDH can recur. Dexamethasone has been shown to reduce CSDH recurrence, but its mechanism of action has not been fully elucidated. Understanding the inflammatory mediators driving CSDH formation and recurrence and how dexamethasone alters this can help develop new therapeutic strategies.

Methods

A subgroup of adult patients recruited to the Dex-CSDH trial, randomized to dexamethasone or placebo, who had surgery for their CSDH, were included. CSDH fluid and peripheral blood were collected intraoperatively, from post-operative drains and operated recurrences. Samples were analyzed using a 12-plex panel of inflammatory mediators. Clinical patient data were also reviewed.

Results

A total of 52 patients, with a mean age of 76 years, were included. Five recurrent CSDHs occurred. Vascular endothelial growth factor (VEGF) had the highest concentration across all CSDHs, and only matrix metalloproteinase (MMP)-9 had lower concentrations in CSDH compared to plasma but was increased in recurrent CSDHs. The interleukin (IL)-10 concentration was significantly lower in primary CSDHs that recurred. Most inflammatory mediators increased post-operatively, and dexamethasone significantly reduced the post-operative peak in VEGF on day 2, compared to placebo.

Conclusion

It is evident that VEGF plays a critical role in the inflammatory response in CSDH. The post-operative reduction with dexamethasone could signal the mechanism by which it reduces recurrence. Novel therapies with a better side-effect profile than dexamethasone should be targeted at VEGF or potential alternatives such as IL-10 supplementation.

Peripheral Monocyte Percentage as a Potential Indicator of Prognosis in Patients with Chronic Subdural Hematoma Receiving Conservative Therapy

BACKGROUND

Studies have confirmed active and abnormal inflammation in the hematoma cavity of chronic subdural hematoma (CSDH). However, a relationship between the peripheral blood status and the prognosis of CSDH patients has not been demonstrated.

METHODS

We retrospectively analyzed 245 CSDH patients who received conservative therapy (67 under close follow-up observation, 103 treated with atorvastatin, and 75 treated with atorvastatin combined with dexamethasone) from 2014 to 2021 to evaluate the role of major inflammation-associated cells in the prognostic assessment of patients. Univariate and multivariate analyses were performed to assess the potential factors that could indicate the prognosis among the 103 patients who underwent observation only or atorvastatin therapy. Changes in peripheral blood inflammation-associated cells at different time points were compared between patients with good and poor outcomes. Furthermore, the changes in inflammatory cells in 75 patients who received atorvastatin combined with dexamethasone were analyzed.

RESULTS

The monocyte percentage was the only independent influencing factor in subsequent follow-up assessments. Patients with good outcomes had obviously lower circulating monocyte percentages in their peripheral blood counts throughout the treatment period. The monocyte percentage was also significantly decreased in the patients who responded well to atorvastatin combined with dexamethasone. The peripheral monocyte percentage was significantly higher in patients who transitioned to surgery because of a poor response to pharmacotherapy.

CONCLUSIONS

The peripheral monocyte percentage may be a convenient and effective indicator for predicting the outcome of CSDH for patients receiving conservative treatment. A higher percentage of monocytes could be a risk factor for a poor response.

Effectiveness Comparisons of Drug Therapy on Chronic Subdural Hematoma Recurrence: A Bayesian Network Meta-Analysis and Systematic Review

Objectives: We aim to compare the effectiveness of different drug treatments in improving recurrence in patients with chronic subdural hematoma (CSDH). Methods: Eligible randomized controlled trials (RCTs) and prospective trials were searched in PubMed, Cochrane Library, and Embase, from database inception to December 2021. After the available studies following inclusion and exclusion criteria were screened, the main outcome measures were strictly extracted. Taking the random-effects model, dichotomous data were determined and extracted by odds ratio (OR) with 95% credible interval (CrI), and a surface under the cumulative ranking curve (SUCRA) was generated to calculate the ranking probability of comparative effectiveness among each drug intervention. Moreover, we used the node-splitting model to evaluate inconsistency between direct and indirect comparisons of our network meta-analysis (NMA). Funnel plots were used to evaluate publication bias. Results: From the 318 articles found during initial citation screening, 11 RCTs and 3 prospective trials (n = 3,456 participants) were ultimately included in our study. Our NMA results illustrated that atorvastatin + dexamethasone (ATO+DXM) (OR = 0.06, 95% CrI 0.01, 0.89) was the most effective intervention to improve recurrence in patients with CSDH (SUCRA = 89.40%, 95% CrI 0.29, 1.00). Four drug interventions [ATO+DXM (OR = 0.06, 95% CrI 0.01, 0.89), DXM (OR = 0.18, 95% CrI 0.07, 0.41), tranexamic acid (TXA) (OR = 0.26, 95% CrI 0.07, 0.41), and ATO (OR = 0.41, 95% CrI 0.12, 0.90)] achieved statistical significance in improving recurrence in CSDH patients compared with the placebo (PLB) or standard neurosurgical treatment (SNT) group. Conclusion: Our NMA showed that ATO+DXM, DXM, ATO, and TXA had definite efficacy in improving recurrence in CSDH patients. Among them, ATO+DXM is the best intervention for improving recurrence in patients with CSDH in this particular population. Multicenter rigorous designed prospective randomized trials are still needed to evaluate the role of various drug interventions in improving neurological function or outcome. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=299491), identifier (CRD 42022299491).

Dehydration Status at Admission Predicts Recurrence in Patients with Traumatic Chronic Subdural Hematoma

Objective: There remains a significant risk of chronic subdural hematoma (CSDH) recurring after treatment. Patient-related predictors and surgical procedures have been investigated in many studies. In contrast, the literature remains scant on reports of the potential impact of dehydration on the admission of affected patients and on the CSDH recurrence rate. Methods: All consecutively admitted patients with CSDH and surgical treatment at the authors’ institution between 2015 and 2019 were retrospectively identified. Dehydration was assessed as a blood urea/creatinine (U/Cr) ratio > 80. The association between dehydration on admission and postoperative complication rates, in-hospital mortality, and recurrence of CSDH, with the need for additional surgical treatment, was further analyzed. Results: A total of 265 patients with CSDH requiring surgery were identified. In 32 patients (12%), further surgery was necessary due to the recurrence of CSDH. It was found that 9 of the 265 patients with CSDH (3%) suffered from dehydration at the time of admission. Multivariate analysis revealed diabetes mellitus (p = 0.02, OR 2.7, 95% CI 1.2−6.5), a preoperative midline shift > 5 mm (p = 0.003, OR 3.3, 95% CI 1.5−7.5) and dehydration on admission (p = 0.002, OR 10.3, 95% CI 2.4−44.1) as significant and independent predictors for the development of CSDH recurrence that requires surgery. Conclusion: the present findings indicate that dehydration on admission appears to be an independent predictor for CSDH recurrence that requires surgery.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Cerebrospinal fluid leak as a driving factor in chronic subdural hematoma formation: A histological study

Background:

Chronic subdural hematoma (CSDH) represents the most common neurosurgical disease. Given the demographic shift toward an aging population, the overall incidence of this condition is increasing. Nevertheless, clarity in the pathophysiological process is yet to be made. Several etiological mechanisms have been proposed to initiate and consequently promote fluid collection in the subdural space. Traumatic injury of the bridging veins has long been considered the primum movens of the pathology but increasing evidence shows that trauma is not the only factor involved. Along with recent advances we sought to understand the role of the cerebrospinal fluid (CSF) in the buildup of the intense inflammatory reaction that characterizes CSDH.

Methods:

In the present study, we examined histological features of reactive membranes secondary to extracranial CSF leakage with CSDH-related membranes. Similarity and differences between the specimens were examined by means of light microscopy.

Results:

Histological similarities were consistently found between CSDH membranes and reactive membranes secondary to CSF leakage in the extracranial space. Activated histiocytes were highlighted in all specimens along with an intense inflammatory reaction.

Conclusion:

CSDH is most likely the result of a complex interaction among different pathophysiological events resulting from both traumatic and inflammatory etiologies. In the present work, we highlight how CSF leakage could be an early factor that leads to a cascade of events that culminates in CSDH formation.

Paradigms in chronic subdural hematoma pathophysiology: Current treatments and new directions

ABSTRACT

Chronic subdural hematomas (CSDHs) are an increasingly common pathology encountered in a neurosurgical trauma practice. Although the operative and nonoperative management of CSDH has been studied extensively, the recurrence rate of CSDH remains high, with no significant decrease in recent years. We undertook a detailed assessment of the known pathophysiological mechanisms by which CSDHs recur to improve our ability to treat patients with this disease successfully. In this review of the literature from the PubMed and Scopus databases, we used the search terms "(pathophysiology) AND chronic subdural hematoma [tiab]" to identify pertinent reviews and articles in English. The results demonstrated a complex inflammatory response to subdural blood, which begins with the formation of a collagen neomembrane around the clot itself. Proinflammatory mediators, such as vascular endothelial growth factor, interleukin-6, interleukin-8, tissue necrosis factor α, matrix metalloproteinases, and basic fibroblast growth factor, then contribute to chronic microbleeding by promoting the formation of fragile, leaky blood vessels, and widening of gap junctions of existing vessels. It is evident that the lack of improvement in recurrence rate is due to pathological factors that are not entirely alleviated by simple subdural evacuation. Targeted approaches, such as middle meningeal artery embolization and anti-inflammatory therapies, have become increasingly common and require further prospective analysis to aid in the determination of their efficacy.

Atorvastatin combined with dexamethasone promote hematoma absorption in an optimized rat model of chronic subdural hematoma

Previous studies found that atorvastatin and dexamethasone were effective in promoting the absorption of chronic subdural hematoma. In this study, we aimed to investigate the effect of pharmacotherapy in an optimized rat model of chronic subdural hematoma. Rat model of chronic subdural hematoma via a bEnd.3 cell and Matrigel mix was established and dynamic changes in different drug treatment groups were tested. The hematoma gradually increased, peaked on the fifth day (263.8±52.85 μl), and was completely absorbed in two weeks. Notably, Kruppelle-like factor 2 expression was significantly decreased with increasing hematoma volume, and then increased in the repair period. The expression of IL-10 was increased and peaked on 7 days, and then decreased at 14 days. The dynamic trends of IL-6, IL-8, MMP-9, and VEGF were also increased first and then decreased. Both monotherapy and the combined treatment by atorvastatin and dexamethasone could counteract the inflammatory activities, decrease hematoma permeability, and improve hematoma absorption, however, most prominent in combined group. The combined treatment could more effectively increase Kruppelle-like factor 2 and ZO-1 expression, attenuate the expression of NF-κb. Most importantly, the combined treatment enhanced the neural functional prognosis and reduced the mortality of chronic subdural hematoma rats. According to our results, the combined treatment could more effectively attenuate inflammatory. And it could also enhance angiogenic activities which could promote the stability of local function and structure of the hematoma cavity, reduce the hematoma volume and improve the outcomes of rats with chronic subdural hematoma than single treatments in the optimized chronic subdural hematoma model.

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.

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.

Pathogenesis of Chronic Subdural Hematoma: A Cohort Evidencing De Novo and Transformational Origins

Chronic subdural hematoma (CSDH) is a common neurosurgical pathology, yet conflicting opinions exist concerning the pathophysiological processes involved. Many consider CSDH a product of an aged acute subdural hematoma (ASDH) secondary to trauma. Serial imaging, however, has demonstrated CSDH formation in patients without any initial ASDH. To understand the relevance of acute hemorrhage in a cohort of patients with CSDH, transformation from an ASDH were categorized as CSDH-acute transformed (CSDH-AT) and those without any acute hemorrhage at the outset as CSDH-de-novo (CSDH-DN). A cohort of 41 eligible patients with CSDH were included, with baseline imaging after trauma (or spontaneous ASDH) available for assessment of acute hemorrhage. Volumetric analysis of all subdural collections and measurements of baseline atrophy were performed. In 37% of cases, there was an ASDH present on baseline imaging (CSDH-AT), whereas 63% had no acute hemorrhage at baseline (CSDH-DN). The CSDH-ATs developed more rapidly (mean 16 days from baseline to diagnosis) and were smaller in volume than the CSDH-DNs, which developed at a mean delay of 57 days. In 54% of the CSDH-DNs, a subdural hygroma was present on baseline imaging, and there was a wide range of baseline cerebral atrophy. This study provides radiological evidence for two distinct pathways in the formation of CSDH, with CSDH-DN occurring more commonly and often involving subdural hygroma. Further work is needed to understand whether the pathological origin has implications for patient outcome.

Efficacy of endoscopic treatment for chronic subdural hematoma surgery

Endoscopic treatment is a potential therapeutic addition to chronic subdural hematoma (CSDH) surgery. However, the effect of endoscopic treatment remains controversial. Herein, we examined the optimal indication for endoscopic treatment in CSDH surgery. We retrospectively analyzed 380 consecutive patients with CSDH who underwent single burr-hole craniostomy. We defined postoperative rebleeding as radiological re-accumulation or increased computed tomography value of the hematoma. Reoperation was performed following further hematoma accumulation and/or neurological deterioration. Complicated CSDH was radiologically defined as a hematoma with a clot and/or fibrous septum. There were no differences in baseline characteristics or postoperative mortality and morbidity between the endoscope (97 patients) and control (283 patients) groups. The incidence of postoperative rebleeding (9.3% vs 25.1%, respectively; P = 0.001) and reoperation (0% vs 9.2%, respectively; P = 0.004) were significantly lower in the endoscope group versus controls. Multivariate analysis showed that males (odds ratio 2.14, 95% confidence interval 1.19-3.81; P = 0.012) and endoscopy (odds ratio 0.29, 95% confidence interval 0.13-0.59; P = 0.001) were independently associated with postoperative rebleeding. When CSDHs were divided into two types based on hematoma component, 175 patients exhibited complicated CSDH. There was a significant reduction in postoperative rebleeding (6.5% vs 23.0%, respectively; P = 0.010) and reoperation (0% vs 9.7%, respectively; P = 0.027) in complicated CSDH patients. Endoscopic treatment in CSDH surgery does not increase the risk of surgical complications. Complicated CSDH with a clot and/or septum may be an optimal indication for endoscopic treatment in CSDH surgery to reduce postoperative recurrence.

A novel rat model of chronic subdural hematoma: Induction of inflammation and angiogenesis in the subdural space mimicking human-like features of progressively expanding hematoma

Pathophysiological mechanisms of chronic subdural hematoma (CSDH) involve localized inflammation, angiogenesis, and dysregulated coagulation and fibrinolysis. The scarcity of reproducible and clinically relevant animal models of CSDH hinders further understanding the underlying pathophysiology and improving new treatment strategies. Here, we developed a novel rat model of CSDH using extracellular matrices (Matrigel) and brain microvascular endothelial cell line (bEnd.3 cells). One hundred-microliter of Matrigel-bEnd.3 cell (10⁶ cells per milliliter) mixtures were injected into the virtual subdural space of elderly male Sprague-Dawley rats. This approach for the first time led to a spontaneous and expanding subdural hematoma, encapsulated by internal and external neomembranes, formed as early as 3 d, reached its peak at 7 d, and lasted for more than 14 d, mimicking the progressive hemorrhage observed in patients with CSDH. The external neomembrane and hematoma fluid involved numerous inflammatory cells, fibroblasts, and highly fragile neovessels. Furthermore, a localized pathophysiological process was validated as evidenced by the increased expressions of inflammatory and angiogenic mediators in external neomembrane and hematoma fluid rather than in peripheral blood. Notably, the specific expression profiles of these mediators were closely associated with the dynamic changes in hematoma volume and neurological outcome. In summary, the CSDH model described here replicated the characteristics of human CSDH, and might serve as an ideal translational platform for preclinical studies. Meanwhile, the crucial roles of angiogenesis and inflammation in CSDH formation were reaffirmed.

Impact of inflammatory cell ratio, biomarkers, activated partial thromboplastin time and prothrombin time on chronic subdural haematoma severity and outcome

INTRODUCTION

Chronic subdural haematoma (CSH) has multifactorial mechanisms involved in its development and progression. Identifying readily available inflammatory and coagulation indices that can predict the prognosis of CSH will help in clinical care, prognosis, generating objective criteria for assessing efficacy of treatment strategies and comparisons of treatment efficacy between clinical studies. We conducted a study in which we evaluated the impact value of neutrophil to lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), inflammatory biomarkers (erythrocyte sedimentation rate and C-reactive protein), activated partial thromboplastin time (APTT), prothrombin time (PT) and international normalized ratio (INR) at presentation on CSH severity and outcome using Glasgow outcome scale (GOS), Markwalder grading scale (MGS) and Lagos brain disability examination scale (LABDES).

METHODS

We prospectively studied patients in a single healthcare system with clinical and radiological features of chronic subdural haematoma. Only patients who were managed surgically were recruited. The primary outcome was predictors of severe form CSH (using admission Glasgow coma scale score, MGS grade, inflammatory cells and biomarkers, APTT, PT, and INR) and outcome (using GOS, MGS and LABDES grades 3 months) with secondary outcome being mortality rate, 3 months following surgery. Good outcome was defined as GOS score > 3, LABDES score ≥ 40 at three months and MGS score < 2. Differences in categorical and continuous variables between groups were compared using Fisher's exact test or Chi-square test (χ2) analysis, one-way ANOVA or Kruskal-Wallis test (in case of non-normal distribution).

RESULTS

We included 61 patients with a male-to-female ratio of 2.6:1 and mean age of 57.5 ± 13.3 years (median 58 years; 27-83 years). The pre-op MGS grade was significantly associated with the LABDES (p = 0.034), GOS (p = 0.011) and post-op MGS (p = 0.007) grade. All the patients that died had elevated APTT and PT with low PLR. A low admission PLR was significantly associated with a poor outcome using the GOS (p = 0.001), MGS (p = 0.011) and LABDES grade (p = 0.006) (Table 3). A high APTT was also significantly associated with a worse outcome using GOS (p = 0.007), MGS (p = 0.007) and LABDES grade (p = 0.003). There were three (4.9%) deaths with post-mortem diagnosis of pulmonary embolism, chronic renal failure and irreversible craniocaudal herniation syndrome. All the patients that died had elevated APTT and PT with low PLR.

CONCLUSION

Patients' admission APTT, PT, INR and PLR are good predictors of outcome using the GOS. A high admission INR is also associated with a worse outcome using MGS and LABDES grade.

An association of low high-density lipoprotein levels with recurrence of chronic subdural hematoma

BACKGROUND

Chronic subdural hematoma (CSDH) is a common illness in neurosurgical practice with a substantial recurrence rate. Previous studies found that serum lipids were associated with the risk of stroke and subarachnoid hemorrhage. In the current study, we aimed to identify the relationship between serum lipids and CSDH recurrence.

METHODS

The medical records of 274 consecutive surgical patients with CSDH in our department were reviewed and analyzed. Patients were separated into recurrence and non-recurrence groups. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify serum lipids (triglycerides, total cholesterol, LDL, HDL) and other potential predictors associated with CSDH recurrence, and the performance of predictors was assessed with receiver operating characteristic (ROC) curve.

RESULTS

Of the 274 patients included in the study, 42 (15.3%) experienced at least 1 recurrence of CSDH. Univariate analysis showed that age, hypertension, diabetes mellitus, anticoagulant use, triglycerides, HDL, and midline shift were all significantly associated with CSDH recurrence. Multivariable Cox regression analysis found that only age, diabetes mellitus, midline shift, and HDL level were independent risk factors for CSDH recurrence. A higher HDL level (HR = 0.929, 95% CI 0.905-0.953) was significantly associated with a lower risk of recurrence, and ROC curve analysis revealed that the optimal HDL cut-off value as a predictor was 37.45 mg/dl.

CONCLUSIONS

Low level of high-density lipoprotein is significantly associated with recurrence of chronic subdural hematoma.

Statins as a Medical Adjunct in the Surgical Management of Chronic Subdural Hematomas

BACKGROUND

By stabilizing immature leaky vessel formation in neomembranes, statin drugs have been suggested as a nonsurgical treatment option for chronic subdural hematomas (cSDH). Statin therapy seems to reduce conservatively managed cSDH volume. However, the usefulness of these medications in supplementing surgical treatment is unknown.

OBJECTIVE

To investigate the effect of concurrent statin therapy on outcomes after surgical treatment of cSDH.

METHODS

A retrospective single-institution cohort study of surgically managed patients with convexity cSDH between 2009 and 2019 was conducted. Patients receiving this diagnosis who underwent surgical decompression were included, and those without follow-up scans were excluded. Demographic, clinical, and radiographic variables were collected. cSDH size was defined as maximum radial thickness in millimeters on axial computed tomography of the head. Multivariable linear regression was performed to identify factors (including statin use) that were associated with preoperative to follow-up cSDH size change.

RESULTS

Overall, 111 patients, including 36 patients taking statins on admission, were evaluated. Median time to follow-up postoperative imaging was 30 days (interquartile range, 17-42 days). Patients on statins were older (median, 75 years, range, 68-78.25 years vs. 69 years, range, 59-7 years; P = 0.006) and reported more antiplatelet use (67% vs. 28%; P < 0.001). Median change in follow-up size was 13 mm in both statin and nonstatin groups. Adjusting for other clinical covariates, statin use was associated with greater reduction in cSDH size (CE = -6.72 mm, 95% confidence interval, -13.18 to -0.26 mm; P = 0.042).

CONCLUSIONS

Statin use is associated with improved cSDH size postoperatively. Statin drugs might represent a low-cost and low-risk supplement to the surgical management for patients with cSDH.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Atorvastatin Combined with Low-Dose Dexamethasone Treatment Protects Endothelial Function Impaired by Chronic Subdural Hematoma via the Transcription Factor KLF-2

Objective

Our previous study showed that the combination therapy with atorvastatin and low-dose dexamethasone protected endothelial cell function in chronic subdural hematoma (CSDH) injury. In this study, we aimed to investigate the mechanism underlying the effects of this combination therapy on CSDH-induced cell dysfunction.

Methods

Monocytes and endothelial cells were cocultured with CSDH patient hematoma samples to mimic the pathological microenvironment of CSDH. Monocytes (THP-1 cells) and endothelial cells (hCMEC/D3 cells) were cocultured in a transwell system for 24 h before stimulation with hematoma samples diluted in endothelial cell medium (ECM) at a 1:1 ratio. Tight junction markers were detected by Western blotting, PCR and immunofluorescence. hCMEC/D3 cells were collected for Western blot and PCR analyses to detect changes in the expression levels of vascular cell adhesion molecule (VCAM-1), intercellular adhesion molecule (ICAM-1), and Kruppel-like factor 2 (KLF-2). The IL-6, IL-10 and VEGF levels in the supernatant were measured by enzyme-linked immunosorbent assay (ELISA).

Results

KLF-2 expression in endothelial cells was decreased after stimulation with CSDH patient hematoma samples, but combination therapy with atorvastatin and low-dose dexamethasone reversed this trend. KLF-2 protected injured cells by increasing the expression of VE-cadherin and ZO-1; attenuating the expression of VCAM-1, ICAM-1, IL-6 and VEGF; and enhancing the expression of IL-10, all of which play pivotal roles in endothelial inflammation. Moreover, the effect of combination therapy with atorvastatin and low-dose dexamethasone was obviously reduced in endothelial cells with KLF-2 knockdown compared with normal cells.

Conclusion

Coculture with hematoma samples decreased KLF-2 expression in human cerebral endothelial cells. Combination therapy with atorvastatin and low-dose dexamethasone counteracted hematoma-induced KLF-2 suppression in human cerebral endothelial cells to attenuate robust endothelial inflammation and permeability. KLF-2 plays an important role in drug therapy for CSDH and may become the key factor in treatment and prognosis.

Late complications of radiosurgery for cerebral arteriovenous malformations: report of 5 cases of chronic encapsulated intracerebral hematomas and review of the literature

Background

Chronic encapsulated intracerebral hematomas (CEIHs) are a rare, late complication of radiosurgery for intracranial AVM. We present 5 cases treated mostly by surgical excision and review the literature.

Methods

Patients (age 39, 42, 36, 31, 62) presented with headache, paresthesia, hemiparesis or were asymptomatic. CEIHs presented 10 to 13 years (median 12 years) post radiosurgery. Three patients had demonstrated early radiation induced changes post radiosurgery. Angiographic cure, assessed with DSA, was present in all cases except 1 case with a small nidus remnant. MRI demonstrated mixed lesions with a solid enhancing part, organized hematoma and extensive surrounding edema while three cases had also a cystic component.

Results

Excision of the CEIHs with complete or partial removal of the capsule was performed in 4 patients and resulted in marked clinical improvement. One patient was managed conservatively with administration of steroids as surgery was judged excessively hazardous with eventual stabilization of his symptoms.

Conclusions

CEIHs are rare, late complications of radiosurgery for cranial AVM. They may be asymptomatic or provoke symptoms and may be preceded by early radiation induced changes. Complete removal of CEIHS is an effective treatment. Because of the long latency period of CEIHs, patients who had radiosurgery for brain AVMs should be followed by MRI at least 10 years even after complete obliteration.

Updates in Chronic Subdural Hematoma: Epidemiology, Etiology, Pathogenesis, Treatment, and Outcome

Chronic subdural hematoma (CSDH) is a complex disease with an overall incidence of 1.7-20.6 per 100,000 persons per year and is more commonly encountered in the elderly population. The pathophysiologic cycle of CSDH formation and expansion involves traumatic and inflammatory components that promote the formation of membranes with permeable neovessels. Many drugs targeting different elements of this cycle are being actively investigated as potential therapeutic agents in CSDH. Burr hole craniostomy appears to be the most commonly used procedure for surgical evacuation, and outcomes are generally favorable. Recurrence can occur in 10%-20% of patients and is associated with several clinical and radiographic predictors. Middle meningeal artery embolization represents one of the latest additions to the therapeutic arsenal of cerebrovascular specialists in treating CSDH and is being critically evaluated in numerous ongoing clinical trials.

Assessment of peripheral blood cell inflammatory markers in patients with chronic subdural hematoma

OBJECTIVES

We aimed to study the role of peripheral blood cell inflammatory markers in patients with chronic subdural hematoma (CSDH).

PATIENTS AND METHODS

We enrolled 466 patients with CSDH and 150 healthy controls and retrospectively analyzed peripheral blood cell inflammatory markers, including neutrophils, platelets, lymphocytes, neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR). Subsequently, we performed a subgroup analysis of the patients with CSDH based on gender, age, trauma history, and unilateral or bilateral hematoma.

RESULTS

The CSDH group had higher numbers of neutrophils and platelets, as well as a higher NLR and PLR, than those in the healthy control group. Further, compared with the healthy control group, the CSDH group had lower lymphocyte counts. Subgroup analysis indicated trauma history as the only significant factor.

CONCLUSION

Peripheral blood cell inflammatory markers could serve as indexes for evaluating the inflammatory state in patients with CSDH. There is a need for further studies on the prognostic role of this index in patients with CSDH.

Hematoma-derived exosomes of chronic subdural hematoma promote abnormal angiogenesis and inhibit hematoma absorption through miR-144-5p

Exosomes are small (30-150 nm diameter) lipid bilayer-enclosed vesicles found in all bodily fluids. We investigated whether exosomes play a role in chronic subdural hematoma (CSDH). Exosomes were identified and characterized using transmission electron microscopy and NanoSight particle tracking. The functions of hematoma-derived exosomes were evaluated in a rat model of acute subdural hematoma (SDH). The hematoma-derived exosomes inhibited hematoma absorption and exacerbated neurological deficits in SDH rats. We examined the effects of the exosomes on angiogenesis and cell permeability in human umbilical vein endothelial cells (HUVECs). Co-culture of exosomes with HUVECs revealed that the hematoma-derived exosomes were taken-in by the HUVECs, resulting in enhanced tube formation and vascular permeability. Additionally, there was a concomitant increase in ANG-2 expression and decrease in ANG-1 expression. Exosomes were enriched with microRNAs including miR-144-5p, which they could deliver to HUVECs to promote angiogenesis and increase membrane permeability. Overexpression of miR-144-5p in HUVECs and in SDH rats promoted abnormal angiogenesis and reduced hematoma absorption, which mimicked the effects of the hematoma-derived exosomes both in vitro and in vivo. Thus, hematoma-derived exosomes promote abnormal angiogenesis with high permeability and inhibit hematoma absorption through miR-144-5p in CSDH.

Safety and Efficacy of Atorvastatin for Chronic Subdural Hematoma in Chinese Patients: A Randomized ClinicalTrial

Importance

Chronic subdural hematoma (CSDH) is a trauma-associated condition commonly found in elderly patients. Surgery is currently the treatment of choice, but it carries a significant risk of recurrence and death. Nonsurgical treatments remain limited and ineffective. Our recent studies suggest that atorvastatin reduces hematomas and improves the clinical outcomes of patients with CSDH.

Objective

To investigate the safety and therapeutic efficacy of atorvastatin to nonsurgically treat patients with CSDH.

Design, Setting, and Participants

The Effect of Atorvastatin on Chronic Subdural Hematoma (ATOCH) randomized, placebo-controlled, double-blind phase II clinical trial was conducted in multiple centers in China from February 2014 to November 2015. For this trial, we approached 254 patients with CSDH who received a diagnosis via a computed tomography scan; of these, 200 (78.7%) were enrolled because 23 patients (9.1%) refused to participate and 31 (12.2%) were disqualified.

Interventions

Patients were randomly assigned to receive either 20 mg of atorvastatin or placebo daily for 8 weeks and were followed up for an additional 16 weeks.

Main Outcomes and Measures

The primary outcome was change in hematoma volume (HV) by computed tomography after 8 weeks of treatment. The secondary outcomes included HV measured at the 4th, 12th, and 24th weeks and neurological function that was evaluated using the Markwalder grading scale/Glasgow Coma Scale and the Barthel Index at the 8th week.

Results

One hundred ninety-six patients received treatment (169 men [86.2%]; median [SD] age, 63.6 [14.2] years). The baseline HV and clinical presentations were similar between patients who were taking atorvastatin (98 [50%]) and the placebo (98 [50%]). After 8 weeks, the HV reduction in patients who were taking atorvastatin was 12.55 mL more than those taking the placebo (95% CI, 0.9-23.9 mL; P = .003). Forty-five patients (45.9%) who were taking atorvastatin significantly improved their neurological function, but only 28 (28.6%) who were taking the placebo did, resulting in an adjusted odds ratio of 1.957 for clinical improvements (95% CI, 1.07-3.58; P = .03). Eleven patients (11.2%) who were taking atorvastatin and 23 (23.5%) who were taking the placebo underwent surgery during the trial for an enlarging hematoma and/or a deteriorating clinical condition (hazard ratio, 0.47; 95% CI, 0.24-0.92; P = .03). No significant adverse events were reported.

Conclusions and Relevance

Atorvastatin may be a safe and efficacious nonsurgical alternative for treating patients with CSDH.

Trial Registration

ClinicalTrials.gov Identifier: NCT02024373.

Treatment of Relapsed Chronic Subdural Hematoma in Four Young Children with Atorvastatin and Low-dose Dexamethasone

Chronic subdural hematoma (CSDH) can develop in children in rare cases. Burr-hole drainage (BHD) is the treatment of choice, but it is associated with a high rate of recurrence. This report describes four cases of pediatric patients (1-7 yrs of age) with post-BHD relapsed CSDH who were successfully treated with a drug regimen that included 2.5-5 mg atorvastatin daily combined with dexamethasone with stepwise-decreasing dosing for a total of 4 weeks. After 4 weeks of treatment, the hematoma was completely resolved in three patients and significantly reduced in one patient. During the treatment, no patient reported clinically significant adverse events. No patient experienced hematoma relapse during the follow-up period that lasted for up to 4 years. This case report suggests the need for a randomized placebo-controlled trial to evaluate this drug regimen for nonsurgical treatment of patients with relapsed CSDH.

Expressions of Eotaxin-3, Interleukin-5, and Eosinophil-Derived Neurotoxin in Chronic Subdural Hematoma Fluids

Eosinophils induce inflammation by releasing cytokines and cytotoxic granule proteins. Infiltration of eosinophilic granulocytes occurs in the outer membrane of chronic subdural hematomas (CSDHs). Eosinophils play an important role in the growth of CSDHs. However, the manner in which eosinophils accumulate within CSDH fluid remains undetermined. In the current study, we assessed the expression of eosinophil chemoattractants in CSDH fluids according to growth stage of CSDHs and examined the correlation between the two. CSDH fluids were obtained from 38 patients during trepanation surgery. Ecalectin, eotaxin-3, interleukin-5 (IL-5), and eosinophil-derived neurotoxin (EDN) concentrations were measured using enzyme-linked immunosorbent assay kits. For use as controls, serum samples were collected from 5 healthy adults, and cerebrospinal fluid (CSF) samples were collected from 5 adults with unruptured aneurysms. The percentage of eosinophils (%eosinophil) in CSDH fluids was calculated using Giemsa staining. Concentrations of ecalectin, eotaxin-3, IL-5, and EDN were nearly equivalent in serum and CSF samples; however, their concentrations were high in CSDH fluids. In particular, ecalectin and EDN levels in CSDH fluids were significantly higher than those in serum and CSF. Levels of eotaxin-3, IL-5, EDN, and %eosinophil were significantly higher in laminar type of CSDH, whereas that of ecalectin was not. The correlations between eotaxin-3 and IL-5, IL-5 and EDN, and EDN and %eosinophil were statistically significant (p < 0.01). Our data suggest that eotaxin-3 is a chemoattractant of eosinophils. IL-5 induces the activation of eosinophils subsequent to degranulation of EDN into CSDH fluids. These factors may serve as novel therapeutic targets for managing CSDH.

Pathophysiology and Nonsurgical Treatment of Chronic Subdural Hematoma: From Past to Present to Future

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the more frequent pathologic entities in daily neurosurgical practice. Historically, CSDH was considered progressive recurrent bleeding with a traumatic cause. However, recent evidence has suggested a complex intertwined pathway of inflammation, angiogenesis, local coagulopathy, recurrent microbleeds, and exudates. The aim of the present review is to collect existing data on pathophysiology of CSDH to direct further research questions aiming to optimize treatment for the individual patient.

METHODS

We performed a thorough literature search in PubMed, Ovid, EMBASE, CINAHL, and Google scholar, focusing on any aspect of the pathophysiology and nonsurgical treatment of CSDH.

RESULTS

After a (minor) traumatic event, the dural border cell layer tears, which leads to the extravasation of cerebrospinal fluid and blood in the subdural space. A cascade of inflammation, impaired coagulation, fibrinolysis, and angiogenesis is set in motion. The most commonly used treatment is surgical drainage. However, because of the pathophysiologic mechanisms, the mortality and high morbidity associated with surgical drainage, drug therapy (dexamethasone, atorvastatin, tranexamic acid, or angiotensin-converting enzyme inhibitors) might be a beneficial alternative in many patients with CSDH.

CONCLUSIONS

Based on pathophysiologic mechanisms, animal experiments, and small patient studies, medical treatment may play a role in the treatment of CSDH. There is a lack of level I evidence in the nonsurgical treatment of CSDH. Therefore, randomized controlled trials, currently lacking, are needed to assess which treatment is most effective in each individual patient.

Statins in conditions other than hypocholesterolemic effects for chronic subdural hematoma therapy, old drug, new tricks?

Chronic subdural hematoma (CSDH) is one of the most common intracranial hematomas worldwide with a high incidence in the general population. However, the optimum treatment for CSDH is Burr-hole drainage with or without rinse Considering the poor outcomes of CSDH in aged patients, and ambiguous prediction of recurrence in many sides of recurrent CSDHs who have been analyzed, new effective therapies are needed for those CSDHs who are predicated to have poor prognosis for surgery and/or have a higher risk of recurrence. Statins, which is the first-line treatment for patients with high cholesterol and coronary heart disease. However, statins are still not solely limited in the treatment of these diseases. It has been demonstrated that statins could improve CSDH due to its effect of regulation of angiogenesis and inflammation. In this review, in order to provide potential new treatment for CSDH we summarize the recent findings of statins in CSDH in order to try to clarify the mechanisms of this effect.

Subdural Abnormal Communicating Vessel in Chronic Subdural Hematoma

Traditionally, lacerations of bridging vessels were surmised to cause chronic subdural hematoma (CSDH), although neither observation studies nor medical research was able to testify this. Nowadays, an inflammatory process is known to take place in the development of CSDH. Of note, post-traumatic angiogenesis at its early stage also features inflammation with immune cell infiltration. The authors found a patient suffering from CSDH with unusual angiogenesis between dura and pia matters. The observation of dura-and-pia angiogenesis may be a piece of evidence to underline compensatory reaction of central nervous system to offset the negative effects produced by CSDH, and points out to a possible approach of bolstering angiogenesis to manage ischemic diseases in cerebral hemispheres.

Chronic Subdural Hematoma: A Perspective on Subdural Membranes and Dementia

OBJECTIVE

To review the complex pathogenesis of the subdural membrane and the link between head trauma, dementia, and dural lymphatics.

METHODS

A thorough literature search of published English-language articles was performed using PubMed, Ovid, and Cochrane databases.

RESULTS

Chronic subdural hematoma (cSDH) is a common intracranial pathology and a leading cause of reversible dementia. cSDH is projected to affect at least 60,000 new individuals in the United States annually by 2030. This condition can result from mild to moderate head trauma that leads to hemorrhaging in the dura-arachnoid interface. The short-term and long-term effects of cSDH and the subdural membrane on the pathogenesis of dementia and the newly discovered dural lymphatics is a topic of increasing importance.

CONCLUSIONS

Further research into the possible link between traumatic brain injury and cSDH in particular and dural lymphatics and intracranial fluid dynamics is warranted.