Vascular endothelial growth-permeability factor in granulation tissue of chronic subdural haematomas

Does a negative correlation of heme oxygenase-1 with hematoma thickness in chronic subdural hematomas affect neovascularization and microvascular leakage? A retrospective study with preliminary validation

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common neurological disease among elderly adults. The progression of CSDH is an angiogenic process, involving inflammatory mediators that affect vascular permeability, microvascular leakage, and hematoma thickness. The authors aimed to identify biomarkers associated with angiogenesis and vascular permeability that might influence midline shift and hematoma thickness.

METHODS

Medical records and laboratory data of consecutive patients who underwent surgery for CSDH were analyzed. Collected data were basic demographic data, CSDH classification, CSDH thickness, midline shift, heme oxygenase-1 (HO-1) levels in hematomas, and common laboratory markers. Linear regression analysis was used to evaluate the relationship of CSDH thickness with characteristic variables. The chick chorioallantoic membrane (CAM) assay was used to test the angiogenic potency of identified variables in ex ovo culture of chick embryos.

RESULTS

In total, 93 patients with CSDH (71.0% male) with a mean age of 71.0 years were included. The mean CSDH thickness and midline shift were 19.7 and 9.8 mm, respectively. The mean levels of HO-1, ferritin, total bilirubin, white blood cells, segmented neutrophils, lymphocytes, platelets, international normalized ratio, and partial thromboplastin time were 36 ng/mL, 14.8 μg/mL, 10.5 mg/dL, 10.3 × 103 cells/μL, 69%, 21.7%, 221.1 × 109 cells/μL, 1.0, and 27.8 seconds, respectively. Pearson correlation analysis revealed that CSDH thickness was positively correlated with midline shift distance (r = 0.218, p < 0.05) but negatively correlated with HO-1 concentration (r = -0.364, p < 0.01) and ferritin level (r = -0.222, p < 0.05). Multivariate linear regression analysis revealed that HO-1 was an independent predictor of CSDH thickness (β = -0.084, p = 0.006). The angiogenic potency of HO-1 in hematoma fluid was tested with the chick CAM assay; topical addition of CSDH fluid with low HO-1 levels promoted neovascularization and microvascular leakage. Addition of HO-1 in a rescue experiment inhibited CSDH fluid-mediated angiogenesis and microvascular leakage.

CONCLUSIONS

HO-1 is an independent risk factor in CSDH hematomas and is negatively correlated with CSDH thickness. HO-1 may play a role in the pathophysiology and development of CSDH, possibly by preventing neovascularization and reducing capillary fragility and hyperpermeability.

Pilot Biomarker Analysis and Decision Tree Algorithm Modeling of Patients with Chronic Subdural Hematomas

The elderly population are at high risk for developing chronic subdural hematoma (cSDH). Surgical evacuation of cSDH is one of the most common procedures performed in neurosurgery. The present study aims to identify potential inflammatory biomarkers associated with its development and recurrence. Patients (>65 years of age) who presented with symptomatic cSDH (≥1 cm thickness or ≥5 mm midline shift [MLS]), requiring surgical intervention, were prospectively enrolled. The collected cSDH fluid was analyzed for inflammatory markers. Computed tomography (CT) scan data included pre-operative cSDH thickness and MLS. Outcome data included Glasgow Outcome Scale-Extended (GOS-E) score at 3, 6, and 12 months post-surgery, as well as cSDH recurrence. A decision tree model was used to determine the predictive power of extracted analytes for MLS, cSDH thickness, and recurrence. This pilot study includes 20 enrolled patients (mean age 77.9 ± 7.4 years and 85% falls). Rate of cSDH recurrence was 42%, with 21% requiring reoperation. Chemokine (C-X-C motif) ligand 9 (CXCL9) concentrations correlated with cSDH thickness (r = 0.975, p = 0.040). Interleukin (IL)-6 and vascular endothelial growth factor (VEGF)-A concentrations correlated with MLS (r = 0.974, p = 0.005; r = 0.472, p = 0.036, respectively). IL-5 concentrations correlated with more favorable GOS-E scores at 3, 6, and 12 months (r = 0.639, p = 0.006; r = 0.727, p = 0.003; r = 0.693, p = 0.026, respectively). Regulated on activation, normal T-cell expressed and secreted (RANTES) concentrations correlated with complete cSDH resolution (r = 0.514, p = 0.021). The decision tree model identified that higher concentrations of CXCL9 were predictive of MLS (risk ratio [RR] = 12.0), higher concentrations of IL-5 were predictive of cSDH thickness (RR = 4.5), and lower concentrations of RANTES were predictive of cSDH recurrence (RR = 2.2). CXCL9, IL-6, VEGF, IL-5, and RANTES are associated with recurrence after surgery and may be potential biomarkers for predicting cSDH recurrence and neurological outcomes.

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.

Change in Hematoma Size after Dexamethasone Therapy in Chronic Subdural Hematoma Subtypes: A Prospective Study in Symptomatic Patients

The main treatment strategy for chronic subdural hematoma is surgical intervention. When a conservative pharmacological approach is considered in symptomatic patients, mainly dexamethasone therapy is applied. Recent trials revealed dexamethasone therapy to be an ineffective treatment in symptomatic patients with chronic subdural hematoma. Whether the efficacy of dexamethasone therapy differs in radiological hematoma subtypes is unknown. The aim of this substudy was to identify which hematoma subtype might be favorable for dexamethasone therapy. As part of a randomized controlled trial, symptomatic chronic subdural hematoma patients received 19-days dexamethasone therapy. The primary outcome measure was the change in hematoma size as measured on follow-up computed tomography (CT) after 2 weeks of dexamethasone in six hematoma (architectural and density) subtypes: homogeneous total, laminar, separated and trabecular architecture types, and hematoma without hyperdense components (homogeneous hypodense, isodense) and with hyperdense components (homogeneous hyperdense, mixed density). We analyzed hematoma thickness, midline shift, and volume using multi-variable linear regression adjusting for age, sex and baseline value of the specific radiological parameter. From September 2016 until February 2021, 85 patients were included with a total of 114 chronic subdural hematoma. The mean age was 76 years and 25% were women. Larger decrease in hematoma thickness and midline shift was revealed in hematoma without hyperdense components compared with hematoma with hyperdense components (adjusted [adj.] b -2.2 mm, 95% confidence interval [CI] -4.1 to -0.3 and adj. b -1.3 mm, 95% CI -2.7 to 0.0 respectively). Additional surgery was performed in 57% of patients with the highest observed rate (81%) in separated hematoma. Largest hematoma reduction and better clinical improvement was observed in chronic subdural hematoma without hyperdense components after dexamethasone therapy. Evaluation of these parameters can be part of an individualized treatment strategy.

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.

Dexamethasone enhances the efficacy of atorvastatin in inhibiting excessively inflammation-induced abnormal angiogenesis by regulating macrophages

BACKGROUND

We have recently showed that atorvastatin (ATO) combined with low dose of dexamethasone (DEX) was more efficacious in treating patients with chronic subdural haematoma (CSDH) than ATO monotherapy. This study was designed to investigate the underlying mechanisms of the improved efficacy of this combined therapy.

METHODS

Mass spectrometry was performed to quantitatively detect drugs in haematoma fluids and serum samples from CSDH patients and also in cultured macrophages after treatment with either ATO alone or in combination with DEX. The differentiation and apoptosis of macrophages were evaluated using flow cytometry. The expression of cytokines, chemokines and angiogenesis-related proteins was evaluated using proteome profile arrays, immunoblots and ELISA, respectively.

RESULTS

ATO was detected in haematoma fluids and serum samples, whose levels were increased significantly in samples collected from patients treated with both ATO and DEX. ATO was also increased in cultured macrophages treated with ATO and DEX. The numbers of M1-polarized macrophages were higher than the M2 phenotype in the haematoma fluids of patients. Cultured macrophages treated with ATO and DEX had reduced numbers of M1-polarized macrophages, increased numbers of M2-polarized macrophages as compared to monotherapies, and decreased rate of apoptosis induced by high-dose DEX. DEX enhanced the anti-inflammatory and anti-angiogenic activity of ATO by suppressing VEGFA and other inflammatory angiogenic factors. Consistent with the finding, patients responded well to the drug treatments had lower serum levels of VEGFA.

CONCLUSIONS

We have shown for the first time that ATO given orally was detected in CSDH haematoma fluids. DEX enhances the anti-inflammatory and anti-angiogenic effects of ATO, primarily by increasing the presence of ATO in haematoma and macrophages and by regulating the functions of macrophages.

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.

Corticosteroids as an Adjuvant Treatment to Surgery in Chronic Subdural Hematomas: A Multi-Center Double-Blind Randomized Placebo-Controlled Trial

Chronic subdural hematoma (CSDH) is a common condition necessitating surgery; however, recurrence occurs in 15-25% of cases despite surgical management. The HEMACORT trial was a prospective randomized, double-blind, placebo-controlled, multi-centric study (NCT01380028). The aim of this trial was to determine the effect of corticosteroids as an adjuvant treatment to surgery on CSDH recurrence at 6 months. After surgery, participants were assigned by block-randomization to receive either placebo or oral prednisone at a dose of 1 mg/kg/day followed by weekly stepwise tapering in steps of 10 mg/day. The primary outcome was CSDH recurrence, defined by the need for reoperation and/or radiological progression of CSDH. Secondary outcomes were one-year death, radiological changes, safety, neurological status, and quality of life. The trial was discontinued at midpoint of expected inclusions: 78 participants received prednisone and 77 received placebo controls. In an intention-to-treat analysis, CSDH clinicoradiological recurrence was not different between prednisone and placebo groups (21.8% vs. 35.1%, respectively; hazard ratio 0.56; 95% confidence interval 0.30-1.02; p = 0.06), although post hoc analyses concluded to statistical significance (p = 0.02). Earlier radiological resolution was observed after prednisone administration, but reoperation rates (reaching 5.8% overall) and functional outcomes were not different at 6 months. Among adverse events, sleep disorders occurred more often in the prednisone group (26.1% vs. 9.1%, p = 0.02). The HEMACORT trial data suggest that prednisone, as an adjuvant treatment to surgery, may reduce early radiological recurrence of CSDH, although clinical benefits are unclear. In view of these findings, the authors suggest that shorter treatment duration should be assessed for safety and efficacy in future trials.

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.

Significantly high concentrations of vascular endothelial growth factor in chronic subdural hematoma with trabecular formation

The underlying mechanism of chronic subdural hematoma (CSDH) after minor head injury is complex, probably due to mechanical injury of the arachnoid membrane, hematological coagulopathy, and pathological angiogenesis in the dura caused by inflammatory cytokines including vascular endothelial growth factor (VEGF). To confirm whether VEGF might be a reliable predictive biomarker for the natural history of CSDH, including progression and recurrence, we analyzed the correlation of VEGF concentration in the subdural fluid with CT findings and clinical features, including interval from minor head injury. Based on CT classification by hematoma density, the mean concentration of VEGF in hematoma fluid was found to be highest in the trabecular group, whereas the recurrence of CSDH was most frequent in the separated group in which VEGF concentration was low. There was a significant correlation between VEGF concentration and the CT classification. Furthermore, only in the trabecular group, a significant negative correlation between the VEGF concentration and interval from minor head injury to surgery was observed. These results suggest that VEGF concentration in the hematoma alone could not be a reliable predictive biomarker for the natural history of CSDH including its recurrence. Amongst the classified groups of CSDH, the trabecular group is likely to follow a different time course of VEGF concentration in the hematoma fluid compared to the other three groups.

The Effect of Goreisan on the Prevention of Chronic Subdural Hematoma Recurrence: Multi-Center Randomized Controlled Study

The relatively high rate of post-operative recurrence in the treatment of chronic subdural hematoma (CSDH) is a significant problem. Goreisan is an herbal medicine that exhibits a hydragogue effect by inhibiting the expression of aquaporins, and its efficacy in preventing post-operative CSDH recurrence has been suggested by several case trials. This multi-center prospective randomized controlled trial was performed to investigate the preventative effect of goreisan on post-operative CSDH recurrence. Patients with symptomatic CSDH over 60 years old undergoing burr hole surgery were enrolled in this study. The patients were randomly allocated to the control group or the goreisan group, in which oral administration of goreisan (7.5 g daily) was continued for 12 weeks. The primary end-point was the post-operative recurrence rate at 12 weeks and the secondary end-point was hematoma volume reduction rates on computed tomography scan at 12 weeks. The analyses were performed not only on patients of all ages older than 60 years, but also on patients divided into those over or under 75 years old. One hundred and eighty patients were followed and analyzed (the control group, n = 88; the goreisan group, n = 92). The recurrence rates considering patients of all ages and patients under 75 years old were relatively low in the goreisan group but without a significant difference. The hematoma volume reduction rates showed no significant difference. Based on the results of the present study, a larger-scale study including more cases is necessary in future to confirm the efficacy of goreisan.

Embolization of the Middle meningeal artery in chronic subdural hematoma - A systematic review

Chronic subdural hematomas (cSDH) are one of the most frequent reasons for consultation in neurosurgery. Multiple authors have proposed middle meningeal artery embolization (MMAE) as an option in cSDH patients to manage recurrence or avoid surgery altogether. Although many articles have been published on the matter, the current body of evidence still has to be evaluated before MMAE is integrated into clinical practice. The goal of this study was to review the evidence on MMAE in cSDH to assess its safety, feasibility, indications and efficacy. We performed a systematic review of the literature according to PRISMA guidelines using multiple electronic databases. Our search yielded a total of 18 original articles from which data were extracted. A total of 190 patients underwent MMAE from which 81.3% were symptomatic cSDH. Over half (52.3%) of the described population were undergoing antithrombotic therapy. Most (83%) procedures used polyvinyl alcohol (PVA) particles and no complications were reported regarding the embolization procedures. Although the definition of resolution varied among authors, cSDH resolution was reported in 96.8% of cases. MMAE is a feasible technique for cSDH, but the current body of evidence does not yet support its use as a standard treatment. Further studies with a higher level of evidence are necessary before MMAE can be formally recommended.

Recurrent Chronic Subdural Hematoma: Report of 13 Cases

Chronic subdural hematoma is a frequent type of hemorrhage, which terminates with mortality if not diagnosed and treated early. The aim of this clinical study is to evaluate the patients with unilateral and bilateral recurrent chronic subdural hematoma. The study group consisted of 13 cases with unilateral and bilateral recurrent chronic subdural hematomas who underwent aggressive wide craniotomy, duraectomy, inner and outer membranectomy, dural border coagulation, incision through cortical vein trace and hang up of dural edge, between 2009 - 2016. All of our patients were diagnosed by preoperative Magnetic Resonance Imaging. We evaluated the age, gender, complaints and neurologic signs, localization and thickness of the hematoma. We can estimate that wide craniotomy, duraectomy and membranectomy is a good option in preventing recurrent chronic subdural hematoma and complications.

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.

Steroids in chronic subdural hematomas (SUCRE trial): study protocol for a randomized controlled trial

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurological pathology, especially in older patients. The actual "gold standard" of treatment is surgical evacuation, with various techniques used across neurosurgical teams. Over the years, there has been growing evidence that inflammatory processes play a major role in the pathogenesis of CSDH. In that context, the use of corticosteroids has been proposed alone or as an adjuvant treatment to surgery. However, this practice remains very empirical and there is a need for high-quality-of-evidence studies to clarify the role of corticosteroids in the management of CSDH.

METHODS/DESIGN

We propose a double-blind, randomized controlled trial comparing methylprednisolone versus placebo in the treatment of CSDH without clinical and/or radiological signs of severity. The treatment will be administered daily for a duration of 3 weeks, at a dose of 1 mg/kg. The primary endpoint will be the delay of occurrence of surgical treatment at 1 month following the introduction of the treatment. Secondary endpoints will include the rate of recourse to surgery, survival rate, quality of life and functional assessments, occurrence of systemic secondary effects and radiological assessment of the response to treatment. This multimodal assessment will be done at 1, 3 and 6 months. Two hundred and two patients (101 per arm) are expected to be included considering our primary hypotheses.

DISCUSSION

This trial started in June 2016; its results may open interesting alternatives to surgery in the management of patients harboring a CSDH, and may provide insights into the natural history of this common pathology.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02650609 . Registered on 4 January 2016. Graphical output of the OBF boundaries.

Pathophysiology of chronic subdural haematoma: inflammation, angiogenesis and implications for pharmacotherapy

Chronic subdural haematoma (CSDH) is an encapsulated collection of blood and fluid on the surface of the brain. Historically considered a result of head trauma, recent evidence suggests there are more complex processes involved. Trauma may be absent or very minor and does not explain the progressive, chronic course of the condition. This review focuses on several key processes involved in CSDH development: angiogenesis, fibrinolysis and inflammation. The characteristic membrane surrounding the CSDH has been identified as a source of fluid exudation and haemorrhage. Angiogenic stimuli lead to the creation of fragile blood vessels within membrane walls, whilst fibrinolytic processes prevent clot formation resulting in continued haemorrhage. An abundance of inflammatory cells and markers have been identified within the membranes and subdural fluid and are likely to contribute to propagating an inflammatory response which stimulates ongoing membrane growth and fluid accumulation. Currently, the mainstay of treatment for CSDH is surgical drainage, which has associated risks of recurrence requiring repeat surgery. Understanding of the underlying pathophysiological processes has been applied to developing potential drug treatments. Ongoing research is needed to identify if these therapies are successful in controlling the inflammatory and angiogenic disease processes leading to control and resolution of CSDH.

COXIBRAIN: results of the prospective, randomised, phase II/III study for the selective COX-2 inhibition in chronic subdural haematoma patients

BACKGROUND

Chronic subdural haematomas (cSDHs) have shown an increasing incidence in an ageing population over the last 20 years, while unacceptable recurrence rates of up to 30 % persist. The recurrence rate of cSDH seems to be related to the excessive neoangiogenesis in the parietal membrane, which is mediated via vascular endothelial growth factor (VEGF). This is found to be elevated in the haematoma fluid and is dependent on eicosanoid/prostaglandin and thromboxane synthesis via cyclo-oxygenase-2 (COX-2). With this investigator-initiated trial (IIT) it was thought to diminish the recurrence rate of operated-on cSDHs by administering a selective COX-2 inhibitor (Celecoxib) over 4 weeks' time postoperatively in comparison to a control group.

METHOD

The thesis of risk reduction of cSDH recurrence in COX-2-inhibited patients was to be determined in a prospective, randomised, two-armed, open phase-II/III study with inclusion of 180 patients over a 2-year time period in four German university hospitals. The treated- and untreated-patient data were to be analysed by Fisher's exact test (significance level of alpha, 0.05 [two-sided]).

RESULTS

After screening of 246 patients from January 2009 to April 2010, the study had to be terminated prematurely as only 23 patients (9.3 %) could be enrolled because of on-going non-steroid anti-rheumatic (NSAR) drug treatment or contraindication to Celecoxib medication. In the study population, 13 patients were treated in the control group (six women, seven men; average age 66.8 years; one adverse event (AE)/serious adverse event (SAE) needing one re-operation because of progressive cSDH (7.7 %); ten patients were treated in the treatment group (one woman, nine men; average age 64.7 years; five AEs/SAEs needing two re-operations because of one progressive cSDH and one wound infection [20 %]). Significance levels are obsolete because of insufficient patient numbers.

CONCLUSIONS

The theoretical advantage of COX-2 inhibition in the recurrent cSDH could not be transferred into the treatment of German cSDH patients as 66.6 % of the patients showed strict contraindications for Celecoxib. Furthermore, 55 % of the patients were already treated with some kind of COX-2 inhibition and, nevertheless, developed cSDH. Thus, although conceptually appealing, an anti-angiogenic therapy with COX-2 inhibitors for cSDH could not be realised in this patient population due to the high prevalence of comorbidities excluding the administration of COX2 inhibitors.

Impact of Time Interval between Trauma Onset and Burr Hole Surgery on Recurrence of Late Subacute or Chronic Subdural Hematoma

Objective

Although subdural hematoma (SDH) is commonly treatable by burr hole surgery in the late subacute or chronic stage, there is no clear consensus regarding appropriate management and exact predictive factors for postoperative recurrence also remain unclear. The aim of this study was to evaluate risk factors associated with recurrence of SDH that requires burr hole surgery in the late subacute or chronic stage. We also identified the appropriate timing of surgery for reducing the recurrence.

Methods

We retrospectively reviewed 274 patients with SDH in the late subacute or chronic stage treated with burr hole surgery in our hospital between January 2007 and December 2014. Excluding patients with acute intracranial complications or unknown time of trauma onset left 216 patients included in the study.

Results

Of 216 patients with SDH in the late subacute or chronic stage, recurrence was observed in 36 patients (16.7%). The timing of the operation in patients with late subacute stage (15–28 days) resulted in a significant decrease in recurrence (RR, 0.33; 95% CI, 0.17–0.65; p=0.001) compared to chronic stage (>28 days). Otherwise, no significant risk factors were associated with recurrences including comorbidities and surgical details.

Conclusion

The results indicated that time from trauma onset to burr hole surgery may be important for decreasing the risk of recurrence. Therefore, unless patients can be treated conservatively without surgery, prompt surgical management is recommended in patients diagnosed as having late subacute or chronic subdural hematoma treatable by burr hole surgery, even when neurological deficits are unclear.

Postural stability in patients with chronic subdural hematoma

BACKGROUND

Gait disturbances and falls are common in patients with chronic subdural hematoma (cSDH). Postural stability is mainly visually assessed and has not been described using an objective and quantitative measurement tool. The objective of this prospective study was to evaluate postural stability in cSDH patients by measuring trunk sway during stance and gait compared to healthy elderly (HE). It was also to evaluate the relationships among postural stability and age, hematoma size, brain midline shift and hematoma location.

METHODS

Using a gyroscopic method, trunk sway was measured in 22 cSDH patients preoperatively, 5 postoperatively and 58 HE during seven standing and walking tasks. Trunk sway amplitude and velocity in the anterior-posterior and medial-lateral directions were assessed.

RESULTS

Postural stability was reduced in the cSDH group compared to HE for all standing tasks. During gait, the sway angle was increased while velocity was decreased in the cSDH group. Only 18 % of the patients could perform all tasks without losing their balance. Postoperatively, postural stability was normalized in the medial-lateral direction during standing. There were no correlations among age, hematoma size, brain midline shift or location of the hematoma and trunk sway.

CONCLUSIONS

The majority of cSDH patients had reduced postural stability that was partly reversed soon after surgery. It was not correlated to hematoma characteristics, indicating that an increased risk to fall is present regardless of hematoma size and midline shift. This must be accounted for when handling these patients and measures taken to prevent further fall accidents during hospital stays.

Chronic Encapsulated Expanding Thalamic Hematoma Associated with Obstructive Hydrocephalus following Radiosurgery for a Cerebral Arteriovenous Malformation: A Case Report and Literature Review

Chronic encapsulated intracerebral hematoma is a unique type of intracerebral hematoma accompanied by a capsule that is abundant in fragile microvasculature occasionally causing delayed regrowth. A 37-year-old man who had undergone radiosurgery for an arteriovenous malformation (AVM) causing intracerebral hematoma in the left parietal lobe presented with headache, vomiting, and progressive truncal ataxia due to a cystic lesion that had been noted in the left thalamus, leading to progressive obstructive hydrocephalus. He underwent left frontal craniotomy via a transsylvian fissure approach, and the serous hematoma was aspirated. The hematoma capsule was easy to drain and was partially removed. Pathological findings demonstrated angiomatous fibroblastic granulation tissue with extensive macrophage invasion. The concentration of vascular endothelial growth factor (VEGF) was high in the hematoma (12012 pg/mL). The etiology and pathogenesis of encapsulated hematoma are unclear, but the gross appearance and pathological findings are similar to those of chronic subdural hematoma. Based on the high concentration of VEGF in the hematoma, expansion of the encapsulated hematoma might have been caused by the promotion of vascular permeability of newly formed microvasculature in the capsule.

Clinical Features According to the Histological Types of the Outer Membrane of Chronic Subdural Hematoma

Objective

The aim of our study was to classify the outer membrane of chronic subdural hematoma (CSDH) histologically and to determine the clinical and radiological meaning of the classified membranes.

Methods

The outer membrane specimen of 31 patients who underwent surgery for CSDH were acquired in this study. The specimen was classified into four types and each were analyzed of the symptoms on the admission day and during the period from trauma to surgery. The radiological features such as subdural fluid density, Hounsfield number, thickness of the hematoma, and midline shift were analyzed.

Results

There were 6% of type I, 29% of type II, 39% of type III, and 26% of type IV neomembranes. The cases of CSDH accompanied by neurologic deficit were highest from type IV of 63%, followed by type II with 56%. On the radiological findings such as Hounsfield unit, hematoma thickness and midline shift, only hematoma thickness between type II and III were statistically significant (p=0.021). The hematoma thickness and midline shift were greatest in type II. On computed tomography scans, the isodense, hyperdense and laminar type that shows the high recurrence rate formed 75% of type II and 67% of type IV while type III had the low possibility of recurrence rate (33%).

Conclusion

We have identified that the outer membrane have the tendency to develop from type I to IV in time while type II and type IV may have more risk of neurologic deficit and the high possibility of recurrence.

Correlation of the Beta-trace protein and inflammatory cytokines with magnetic resonance imaging in chronic subdural hematomas : a prospective study

Objective

Magnetic resonance imaging (MRI) of chronic subdural hematoma (CSDH) detects various patterns, which can be attributed to many factors. The purpose of this study was to measure the level of interleukin-6 (IL-6), interleukin-8 (IL-8), and highly specific protein [beta-trace protein (βTP)] for cerebrospinal fluid (CSF) in CSDHs, and correlate the levels of these markers with the MRI findings.

Methods

Thirty one patients, treated surgically for CSDH, were divided on the basis of MRI findings into hyperintense and non-hyperintense groups. The concentrations of IL-6, IL-8, and βTP in the subdural fluid and serum were measured. The βTP was considered to indicate an admixture of CSF to the subdural fluid if βTP in the subdural fluid (βTP_SF)/βTP in the serum (βTP_SER)>2.

Results

The mean concentrations of IL-6 and IL-8 of the hyperintense group (n=17) of T1-WI MRI were 3975.1±1040.8 pg/mL and 6873.2±6365.4 pg/mL, whereas them of the non-hyperintense group (n=14) were 2173.5±1042.1 pg/mL and 2851.2±6267.5 pg/mL (p<0.001 and p=0.004). The mean concentrations of βTP_SF and the ratio of βTP_SF/βTP_SER of the hyperintense group (n=13) of T2-WI MRI were 7.3±2.9 mg/L and 12.6±5.4, whereas them of the non-hyperintense group (n=18) were 4.3±2.3 mg/L and 7.5±3.9 (p=0.011 and p=0.011).

Conclusion

The hyperintense group on T1-WI MRI of CSDHs exhibited higher concentrations of IL-6 and IL-8 than non-hyperintense group. And, the hyperintese group on T2-WI MRI exhibited higher concentrations of βTP_SF and the ratio of βTP_SF/βTP_SER than non-hyperintense group. These findings appear to be associated with rebleeding and CSF admixture in the CSDHs.

Perindopril and residual chronic subdural hematoma volumes six weeks after burr hole surgery: a randomized trial

OBJECTIVE

Recurrence rates of between 5% and 25% have been reported following surgery for chronic subdural hematoma (CSH). A previous study showed that the treatment with angiotensin converting enzyme (ACE) inhibitors decreases the risk of recurrence. To test the effects of ACE inhibitors on the recurrence CSH and CSH remnant six weeks after surgery, we conducted a prospective double-blinded randomized controlled clinical trial on patients with CSHs from July 2009 until October 2012.

PATIENTS AND METHODS

Patients eligible for burr hole surgery for CSH were randomized into either an ACE inhibitor perindopril 5mg or placebo treatment daily for three months prior to surgery. Cerebral CT scans were performed after six weeks, and clinical follow-ups were performed three months after surgery. Additionally, a retrospective analysis of the data and CT scans from all nonrandomized patients from the same time period was performed.

RESULTS

Forty-seven patients were included in the randomized study. The patients' preoperative Glasgow Coma Scale scores were 15. None of the patients in the randomized group developed a recurrence after surgery. Measurements of the sizes of the CSH before and six weeks after surgery revealed no difference between the placebo and perindopril-treated groups. In the retrospective group (245 patients), there was no correlation between the risk of recurrence and ACE inhibitor treatment.

CONCLUSION

Our data suggest that perindopril does not diminish the size of residual CSHs six weeks after burr hole surgery and that ACE inhibitors do not decrease the risk of CSH recurrence.

The correlation between pro- and anti-inflammatory cytokines in chronic subdural hematoma patients assessed with factor analysis

Chronic subdural hematoma (CSDH) is a relatively common disorder in neurosurgery on elderly patients, though the mechanism that causes the disease remains unclear. Studies have suggested that local anticoagulation and inflammatory changes may be important in its pathogenesis. Most studies have used a basic bivariate statistical analysis to assess complex immunological responses in patients with this disorder, hence a more sophisticated multivariate statistical approach might be warranted. Our objective was to assess the association and correlation between the pro- and anti-inflammatory responses in a cohort of patients with chronic subdural hematoma (n=57) using an exploratory and confirmatory factor analysis. Thirteen assigned pro-inflammatory (TNF-α, IL-1β, IL-2, IL-2R, IL-6, IL-7, IL-12, IL-15, IL-17, CCL2, CXCL8, CXCL9 and CXCL10) and five assigned anti-inflammatory (IL-1RA, IL-4, IL-5, IL-10 and IL-13) cytokines from blood and hematoma fluid samples were examined. Exploratory factor analysis indicated two major underlying immunological processes expressed by the cytokines in both blood and hematoma fluid, but with a different pattern and particularly regarding the cytokines IL-13, IL-6, IL-4 and TNF-α. Scores from confirmatory factor analysis models exhibited a higher correlation between pro- and anti-inflammatory activities in blood (r=0.98) than in hematoma fluid samples (r=0.92). However, correlations of inflammatory processes between blood and hematoma fluid samples were lower and non-significant. A structural equation model showed a significant association between increased anti-inflammatory activity in hematoma fluid samples and a lower risk of recurrence, but this relationship was not statistically significant in venous blood samples. Moreover, these findings indicate that anti-inflammatory activities in the hematoma may play a role in the risk of a recurrence of CSDH.

Expression of the TGF-β-ALK-1 pathway in dura and the outer membrane of chronic subdural hematomas

Neovascularization of the outer membrane plays a critical role in the development and enlargement of chronic subdural hematomas (CSHs) and vascular endothelial growth factor (VEGF) may promote their progression. However, the precise mechanisms remain to be determined. We focused on the signaling pathway upstream of VEGF, transforming growth factor β (TGF-β), and activin receptor-like kinase 1 (ALK-1) to identify the mechanisms underlying the neovascularization of the outer membrane of CSH. Retrospective comparative study was conducted on 15 consecutive patients diagnosed as CSH with burr-hole drainage. Dura and the outer membrane were collected. We immunohistochemically examined the expression of VEGF, integrin-α, TGF-β, and ALK-1 on the outer membrane and dura of CSH and compared our findings with control samples and the signal intensity of hematomas on computed tomography (CT) scans. VEGF and integrin-α expression was markedly up-regulated in both the dura and outer membrane of CSH, the expression of TGF-β and ALK-1 in the dura was slightly increased in the dura and markedly up-regulated in the outer membrane. There was no significant correlation between their expression and CT density. Here we first report the expression of TGF-β and ALK-1 in the outer membrane and dura mater of CSH. We suggest that the TGF-β–ALK-1 pathway and VEGF affect neovascularization and the progression of CSH.

Measurement of inflammatory cytokines and thrombomodulin in chronic subdural hematoma

Inflammation and the coagulation system may influence the genesis of chronic subdural hematoma (CSDH). The appearance of CSDH on computed tomography (CT) varies with the stage of the hematoma. This study investigated the pathogenesis and the recurrence of CSDH by comparing cytokine levels with the CT features of CSDH in 26 patients with 34 CSDHs who underwent single burr-hole surgery at our hospital between October 2004 and November 2006. The hematoma components removed during the procedure were examined, and the hematoma serum levels of cytokines measured such as thrombomodulin (TM), interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and interleukin-10 (IL-10). Using CT, mixed density hematomas were distinguished from other homogeneous hematomas, and found that the TM level was significantly higher in mixed density hematomas than in homogeneous hematomas (p = 0.043). Mixed density hematomas were classified into three subtypes (laminar, separated, and trabecular hematomas). The TM level was significantly higher in laminar and separated hematomas than in other hematomas (p = 0.01). The levels of IL-6, TNFα, and IL-10 were extremely high, but showed no significant differences in relation to the CT features. Mixed density hematomas had high recurrence rate, as reported previously, and TM level was high in mixed density hematomas such as laminar and separated mixed density hematomas. The present findings suggest that the types of CSDH associated with high TM levels tend to have higher recurrence rate.

Chemokines as markers of local inflammation and angiogenesis in patients with chronic subdural hematoma: a prospective study

OBJECTIVE

The goal of this study was to investigate the chemokines CCL2, CXCL8, CXCL9 and CXCL10 as markers of the inflammatory responses in chronic subdural hematoma (CSDH).

METHODS

Samples of peripheral venous blood and CSDH fluid (obtained during surgery) in 76 adult patients were prospectively analyzed. Chemokine values were assessed by a Multiplex antibody bead kit.

RESULTS

We found significantly higher levels of chemokines CCL2, CXCL8, CXCL9 and CXCL10 in hematoma fluid compared with serum.

CONCLUSIONS

Chemokines are elevated in the hematoma cavity of patients with CSDH. It is likely that these signaling modulators play an important role in promoting local inflammation. Furthermore, biological activity of CCL2 and CXCL8 may promote neovascularization within the outer CSDH membrane, and a compensatory angiostatic activity of CXCL9 and CXCL10 may contribute to repairing this disorder. This phenomenon was restricted to the hematoma site, and the systemic chemokine levels might not reflect local immune responses.

A preliminary study of aquaporin 1 immunolocalization in chronic subdural hematoma membranes

Aquaporin 1 (AQP1) is a molecular water channel expressed in many anatomical locations, particularly in epithelial barriers specialized in water transport. The aim of this study was to investigate AQP1 expression in chronic subdural hematoma (CSDH) membranes. In this preliminary study, 11 patients with CSDH underwent burr hole craniectomy and drainage. Membrane specimens were stained with a monoclonal antibody targeting AQP1 for immunohistochemical analysis. The endothelial cells of the sinusoid capillaries of the outer membranes exhibited an elevated immunoreactivity to AQP1 antibody compared to the staining intensity of specimens from the inner membrane and normal dura. These findings suggest that the outer membrane might be the source of the increased fluid accumulation responsible for chronic hematoma enlargement.

Dexamethasone treatment in chronic subdural haematoma

INTRODUCTION

Neurosurgeons are familiar with chronic subdural haematoma (CSH), a well-known clinical entity, which is usually treated by some modality of trepanation. Despite the excellent outcomes obtained by surgery, complications may occur, some of which may be potentially severe or fatal. Furthermore, up to 25% recurrence rate is reported. The authors present a novel approach to the management of CSH based on the use of dexamethasone as the treatment of choice in the majority of cases.

PATIENTS AND METHODS

Medical records of 122 CSH patients were retrospectively reviewed. At admission, symptomatic patients were classified according to the Markwalder Grading Score (MGS). Those scoring MGS 1-2 were assigned to the Dexamethasone protocol (4 mg every 8h, re-evaluation after 48-72 h, slow tapering), and those scoring MGS 3-4 were, in general, assigned to the Surgical protocol (single frontal twistdrill drainage to a closed system, without irrigation). Patients were followed in the Outpatient Office with neurological assessment and serial CT scans. RESULTS. Between March 2001 and May 2006, 122 consecutive CSH patients (69% male, median aged of 78, range 25-97) were treated. Seventy-three percent of the patients exhibited some kind of neurological defect (MGS 2-3-4). Asymptomatic patients (MGS 0) were left untreated. Initial treatment assignment was: 101 dexamethasone, 15 subdural drain, 4 craneotomy and 2 untreated. Twenty-two patients on dexamethasone ultimately required surgical drain (21.8%). Favourable outcome (MGS 0-1-2) was obtained in 96% and 93.9% of those treated with dexamethasone and surgical drain, respectively. Median hospital stay was 6 days (range 1- 41) for the dexamethasone group and the whole series, and 8 days (range 5-48) for the surgical group. Overall mortality rate was 0.8% and re-admissions related to the haematoma reached 14.7% (all maintained or improved their MGS). Medical complications occurred in 34 patients (27.8%), mainly mild hyperglycemic impairments. Median outpatient follow up was 25 weeks (range 8-90), and two patients were lost.

DISCUSSION

The rationale for the use of dexamethasone in CSH lies in its anti-angiogenic properties over the subdural clot membrane, as it is derived from experimental studies and the very few clinical observations published. Surgical evacuation of CSH is known to achieve excellent results but no well-designed trials compare medical versus surgical therapies. The experience obtained from this series lets us formulate some clinical considerations: dexamethasone is a feasible treatment that positively compares to surgical drain (and avoided two thirds of operations); the natural history of CSH allows a 48-72 h dexamethasone trial without putting the patient at risk of irreversible deterioration; eliminates all morbidity related to surgery and recurrences; does not provoke significant morbidity itself; reduces hospital stay; does not preclude ulterior surgical procedures; it is well tolerated and understood by the patient and relatives and it probably reduces costs. The authors propose a protocol that does not intend to substitute surgery but to offer a safe and effective alternative.

CONCLUSION

Data obtained from this large retrospective series suggests that dexamethasone is a feasible and safe option in the management of CSH. In the author's experience dexamethasone was able to cure or improve two thirds of the patients. This fact should be confirmed by others in the future. The true effectiveness of the therapy as compared to surgical treatment could be ideally tested in a prospective randomized trial.

Cerebrospinal fluid leakage into the subdural space: possible influence on the pathogenesis and recurrence frequency of chronic subdural hematoma and subdural hygroma

OBJECT

The purpose of this study was to clarify whether cerebrospinal fluid (CSF) leakage into the subdural space is involved in the genesis of chronic subdural hematoma (CSDH) and subdural hygroma (SH) and to clarify whether this leakage of CSF into the subdural space influences the postoperative recurrence rate of CSDH and SH.

METHODS

In this prospective observational study, 75 cases involving patients treated surgically for CSDH (67 patients) or SH (8 patients) were evaluated with respect to clinical and radiological findings at presentation, the content of beta -trace protein (beta TP) in the subdural fluid (betaTPSF) and serum (betaTPSER), and the CSDH/SH recurrence rate. The betaTPSF was considered to indicate an admixture of CSF to the subdural fluid if betaTPSF/betaTPSER>2.

RESULTS

The median beta TPSF level for the whole patient group was 4.29 mg/L (range 0.33-51 mg/L). Cerebrospinal fluid leakage, as indicated by betaTPSF/betaTPSER>2, was found to be present in 93% of the patients with CSDH and in 100% of the patients with SH (p=0.724). In patients who later had to undergo repeated surgery for recurrence of CSDH/SH, the betaTPSF concentrations (median 6.69 mg/L, range 0.59-51 mg/L) were significantly higher (p=0.04) than in patients not requiring reoperation (median 4.12 mg/L, range 0.33-26.8 mg/L).

CONCLUSIONS

As indicated by the presence of betaTP in the subdural fluid, CSF leakage into the subdural space is present in the vast majority of patients with CSDH and SH. This leakage could be involved in the pathogenesis of CSDH and SH. Patients who experience recurrences of CSDH and SH have significantly higher concentrations of betaTPSF at initial presentation than patients not requiring reoperation for recurrence. These findings are presented in the literature for the first time and have to be confirmed and expanded upon by further studies.

Morphological aspects of the traumatic chronic subdural hematoma capsule: SEM studies

The morphology of the outer and inner membranes of traumatic chronic subdural hematomas (CSDHs) surgically removed from eight patients was investigated by scanning electron microscopy (SEM). Hematomas were divided into three groups based on time that had passed from the initiation of trauma to surgery. Structure of the CSDHs showed gradual morphological changes of the developing hematoma capsule. They initially included angiogenic and aseptic inflammatory reactions followed by progressive involvement of fibroblasts-proliferating and producing collagen fibrils. Numerous capillaries suggesting formation of new blood vessels were observed mainly in young hematomas removed between 15 and 21 days after trauma. In "older" hematomas (40 days after trauma), more numerous capillaries and thin-walled sinusoids were accompanied by patent, larger diameter blood vessels. Within the fibrotic outer membrane of the "oldest" hematoma capsules (60 or more days after trauma), especially in the area over the hematoma cavity, blood vessels were frequently occluded by clots. The results suggest dynamic changes in cellular and vascular organization of traumatic CSDH capsules paralleling the progression in hematoma age.

Tissue plasminogen activator in chronic subdural hematomas as a predictor of recurrence

Object

Chronic subdural hematomas (CSDHs) recur in 7 to 18% of cases. The present study was conducted to determine whether serum or lesion concentrations of coagulofibrinolytic and angiogenic factors, which have been reported to be potential markers of CSDH development, might predict such recurrences.

Methods

Sixty consecutive patients (mean age 71.5 years) with CSDHs (74 affected sides) were studied. Samples of serum in preoperative peripheral venous blood and of hematomas (obtained during surgery) were collected and analyzed. The CSDH recurred in six (8.1%) of the 74 affected sides in six patients. None of the values of the coagulative factors or tests in serum showed significant variation between cases with and those without recurrence. Among coagulofibrinolytic factors, tissue plasminogen activator (TPA) in hematomas demonstrated significantly greater levels in recurrent than in nonrecurrent cases; a similar tendency was noted for α2-plasmin inhibitor–plasmin complex in hematomas. Both factors were greater in the lesions than in the serum. Among the angiogenic factors, levels of hepatic growth factor (HGF) and vascular endothelial growth factor (VEGF) in hematomas were significantly greater than in serum, whereas those of basic fibroblast growth factor were rather lower. Note that comparisons between recurrent and nonrecurrent cases revealed no significant difference.

Conclusions

Patients harboring CSDHs with high TPA concentrations on sampling at the initial surgery have a relatively high probability of recurrence and require follow up with computerized tomography scanning. Angiogenic factors, such as HGF and VEGF, might be candidate markers of CSDH enlargement but are not useful as predictors of recurrence.

Treatment of chronic subdural hematoma by burr-hole craniostomy in adults: influence of some factors on postoperative recurrence

BACKGROUND

The study was conducted to determine the causative factors in the postoperative recurrence (PR) of chronic subdural haematomas (CSDHs) and to evaluate the efficacy of surgery in adults enrolled in this trial.

METHODS

99 patients with 121 CSDHs, who were operated on between January 1999 and December 2001, were studied. We evaluated the PR rate related to anamnestic, clinical, surgical and neuroradiological imaging variables. In addition, we reviewed the number and the type of repeated operations, complications of surgery and the outcomes at one, three and 12 months.

FINDINGS

82.6% of lesions were successfully treated following the initial evacuation, and 95.9% of lesions following a second procedure. The PR rate was 14.9%. A significantly high PR rate was found to be associated with separated type, frontal base type, a midline displacement >5 mm and the presence of acute subdural clots in cranial base type on CT scans obtained within four days postsurgery. The interval from head trauma to initial surgery <60 days, the maximum width of subdural space >10 mm and massive collection of air in the subdural space tended to give a high PR rate. The PR rate associated with the homogeneous type of CSDHs was significantly low.Age, sex, cause of CSDH, anticoagulant therapy, preoperative neurological presentation, concomitant disease, variables on preoperative CT scans, and surgical factors such as the extent of the surgical procedure, use of drainage, duration and volume of drainage were not significantly associated with PR rate.

CONCLUSIONS

It is important to identify factors leading to a high or a low PR rate in the treatment of CSDHs because this may help to select appropriate surgical procedures and postoperative management to treat this condition efficiently.

A reassessment of vascular endothelial growth factor in central nervous system pathology

✓ Overexpression of vascular endothelial growth factor (VEGF) is associated with several central nervous system (CNS) diseases and abnormalities, and is often postulated as a causative factor and promising therapeutic target in these settings. The authors' goal was to reassess the contribution of VEGF to the biology and pathology of the CNS.

The authors review the literature relating to the following aspects of VEGF: 1) the biology of VEGF in normal brain; 2) the involvement of VEGF in CNS disorders other than tumors (traumatic and ischemic injuries, arteriovenous malformations, inflammation); and 3) the role of VEGF in brain tumor biology (gliomas and the associated vasogenic edema, and hemangioblastomas).

The authors conclude the following: first, that VEGF overexpression contributes to the phenotype associated with many CNS disorders, but VEGF is a reactive rather than a causative factor in many cases; and second, that use of VEGF as a therapeutic agent or target is complicated by the effects of VEGF not only on the cerebral vasculature, but also on astrocytes, neurons, and inflammatory cells. In many cases, therapeutic interventions targeting the VEGF/VEGF receptor axis are likely to be ineffective or even detrimental. Clinical manipulation of VEGF levels in the CNS must be approached with caution.

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

The aim of the study was to determine the source of vascular endothelial growth factor (VEGF) in hematoma fluid of patients suffering from chronic subdural hematoma (CSH) and to identify the level of gene expression of the pro-angiogenic factors angiopoietin 1 (ANG-1) and ANG-2 in hematoma membranes. Samples of venous blood, hematoma fluid, and outer membrane were obtained during surgery for CSH. The numbers of mononuclear cells were determined in hematoma fluid and in venous blood samples taken from 11 patients. The concentration of VEGF was measured by ELISA technique in hematoma fluid and in plasma. RT-PCR methodology was used to study the expression of different mRNA species in 11 patients. The mRNA species analyzed include VEGF and its receptors, VEGFR-1 and VEGFR-2, and ANG-1, ANG-2 and their receptor, Tie-2. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) served as housekeeping gene and was used for semiquantitative analysis. The VEGF concentration was several hundred fold higher in the hematoma fluid than in corresponding plasma samples. A significant correlation was found between the number of neutrophils and the VEGF content in the hematoma fluid. The expression levels of VEGF, mainly VEGF165 and VEGF121 mRNA were highest in cells obtained from the hematoma fluid. In membrane samples, mRNA encoding for VEGF and its receptors was only inconsistently detected while the mRNA species encoding for ANG-1, ANG-2, and Tie-2 were found throughout all samples. The mean ratio of ANG-1/ANG-2 mRNA expression was 0.48 as opposed to 1.9 in a normal human brain tissue sample. The results suggest that the hematoma cells are the primary source of VEGF. A marked increase in the expression of ANG-2 mRNA over ANG-1 mRNA demonstrates a pro-angiogenic pattern in the hematoma membranes. Persistent activation of the ANG/Tie-2 system in addition to high levels of VEGF may keep the vasculature in a destabilized condition and may account for the continuous formation of new and immature blood vessels resulting in massive plasma extravasation and repeated bleeding episodes. Thus, the present study provides new evidence in favor of pro-angiogenic mechanisms playing an important role in the pathophysiology of CSH.

Chronic subdural haematoma: surgical treatment and outcome in 1000 cases

Chronic subdural haematoma (CSDH) is one of the most common clinical entities in daily neurosurgical practice. To evaluate the clinical features, computed tomography findings, surgical results, and complications our series was statistically analysed to elucidate the factors affecting the post-operative outcome. A retrospective study (1980-2002) of the records of 1000 patients harbouring 1097 chronic subdural haematoma treated with burr-hole craniotomy with closed-system drainage was carried out. The series included 628 males and 372 females, age range 12-100 years, mean age 72.7+/-11.4 years. The mean interval from trauma to appearance of clinical symptoms was 49.1+/-7.4 days (15-751). The principal symptom was headache (29.7%) in the over 70s, and behavioural disturbance (33.8%) in the under 70s. The CSDH was right sided in 432 patients, left sided in 471, and bilateral in the remaining 97 cases. Post-operative complications occurred in 196 patients and 21 patients died in hospital. Poor prognosis was related to patient's age (>70) and clinical grade on admission (grades 0-2 versus grades 3-4).