The cellular composition of chronic subdural hematoma.

INTRODUCTION: The pathophysiology of chronic subdural hematoma (CSDH) remains to be fully understood. Basic knowledge of the composition and features of cells in the CSDH fluid may contribute to the understanding of the seemingly complex processes involved in CSDH formation and recurrence. This study is the first to examine the composition of cells and of cellular features in both systemic blood and subdural fluid from CSDH patients. We hypothesized that the cellular composition and features in the hematoma fluid may be; 1) different from that in the systemic blood; 2) different between patients with and without recurrence; 3) and different between the first and second operation in patients with recurrent CSDH. METHODS: Systemic blood and subdural hematoma fluid were collected from CSDH patients with and without recurrent CSDH at the time of primary and secondary surgery. Analyses of cells and cellular features included total number of white blood cells, erythroblasts, reticulocytes, platelets, neutrophilocytes, lymphocytes, monocytes, eosinophils, basophils, reticulocytes, immature granulocytes, mean corpuscular cell volume (MCV), mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, hemoglobin and hematocrit. RESULTS: Of the 85 included patients, 20 patients were operated for a recurrent CSDH within 90 days follow-up. All cells found in the systemic blood were present in the CSDH fluid, but the composition was different (p < 0.0001). MCV was higher in the hematoma fluid from the primary operation of patients later developing a recurrent CSDH compared to patients not developing recurrence (p = 0.009). Also, the percentage distribution of inflammatory cells in hematoma fluid from patients with recurrent CSDH was different between the first and second operation (p = 0.0017). CONCLUSION: This study is the first to investigate the cellular composition of CSDH fluid. Compared to systemic blood and to a reference distribution, an increased number of immune cells were present in the hematoma fluid, supporting an inflammatory component of the CSDH pathophysiology. MCV was higher in the subdural fluid at time of the first operation of CSDH patients later developing recurrence. CLINICAL TRIAL REGISTRATION: The study was approved by the Scientific Ethical Committee of the Capital Region of Denmark (Journal no. H-20051073.

Comparative efficacy of dexamethasone versus surgery for chronic subdural hematoma: A systematic review and meta-analysis.

OBJECTIVE: To assess the comparative efficacy of dexamethasone (DXM) as monotherapy in comparison to surgery among the patients of chronic subdural hematoma (CSDH). METHODS: We searched MEDLINE, PUBMED, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception till September 2023. Data was extracted, pooled and analyzed from all the studies that assessed the comparative efficacy of DXM as monotherapy in contrast with surgery as the primary treatment of CSDH. RESULTS: A total of 6 studies involving 704 patients were included in our meta-analysis. Comparison of surgery to DXM revealed there was no statistically significant difference between the two groups regarding mortality [RR=1.09; 95% CI; 0.52-2.28 P = 0.83]. However, a significantly higher incidence of secondary surgical intervention was observed in the DXM group [RR 4.24; 95% CI; 2.06-8.71 P < 0.0001]. No significant difference in performance was observed in terms of poor postoperative outcomes within hospital stay [RR 1.12, 95% CI, 0.40-3.19 P=0.83] and at 6 months [RR 0.92, 95%CI, 0.40-2.13 P=0.85]. CONCLUSION: DXM had a significantly higher incidence of secondary surgical intervention. However, there was no difference regarding mortality and other safety outcomes between surgery and DXM for the patients with CSDH. Observational studies showed that DXM was associated with a lower risk of poor postoperative outcomes within hospital stay and had shorter duration of hospital stay, but the recurrence rate was lower in the surgery group.

Evaluation of Peripheral Blood Inflammatory Markers in Patients with Chronic Subdural Hematoma.

BACKGROUND AND AIM: Chronic subdural hematoma (CSH) refers to intracranial hemorrhages frequently caused by minor head trauma and is mostly seen in middle and advanced age. One of the hypotheses regarding the development of CSH is that the inflammatory cascade plays a pivotal role in this process. MATERIALS AND METHODS: The inclusion criteria covered patients in all ages who were diagnosed as CSH by computed tomography and/or magnetic resonance imaging and treated by surgical intervention in our clinic between 2018 and 2020. Patient files were reviewed retrospectively, and medical records of age, gender, trauma history, unilateral or bilateral lesion, and leukocyte, neutrophil, lymphocyte, monocytes, and platelet counts were obtained. Receiver operating characteristic (ROC) analysis was used for the most appropriate neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and age discrimination in the presence of CSH, and multiple logistic regression analyses were used to determine the effect of independent factors on dependent variables. RESULTS: A total of 68 cases, 57 (83.8%) male and 11 (16.2%) female, aged between 13 and 93, were included in the study. The mean age of the patients included in the study was 72.59 ± 13.13 years. NLR of the cases ranged from 1.37 to 34.18, with a mean of 6.53 ± 6.74 and a median of 3.57. NLR and PLR were found to be statistically significantly higher in CSH patients compared to the healthy control group, and the cut-off values for NLR, PLR, and age were 2.8, 132, and 55, respectively. Age and NLR were found to be independent factors associated with CSH (P < 0.05). CONCLUSION: As seen from the results of this study, peripheral blood values in CSH patients may be significantly higher than in the healthy control group, while they are below the normal laboratory cut-off values.

Risk stratification and predictive modeling of postoperative delirium in chronic subdural hematoma.

Background- Postoperative delirium is a common complication associated with the elderly, causing increased morbidity and prolonged hospital stay. However, its risk factors in chronic subdural hematoma patients have not been well studied. Methods- A total of 202 consecutive patients with chronic subdural hematoma at Peking University Third Hospital between January 2018 and January 2023 were enrolled. Various clinical indicators were analyzed to identify independent risk factors for postoperative delirium using univariate and multivariate regression analyses. Delirium risk prediction models were developed as a nomogram and a Markov chain. Results- Out of the 202 patients (age, 71 (IQR, 18); female-to-male ratio, 1:2.7) studied, 63 (31.2%) experienced postoperative delirium. Univariate analysis identified age (p < 0.001), gender (p = 0.014), restraint belt use (p < 0.001), electrolyte imbalance (p < 0.001), visual analog scale score (p < 0.001), hematoma thickness (p < 0.001), midline shift (p < 0.001), hematoma side (p = 0.013), hematoma location (p = 0.018), and urinal catheterization (p = 0.028) as significant factors. Multivariate regression analysis confirmed the significance of restraint belt use (B = 7.657, p < 0.001), electrolyte imbalance (B = -3.993, p = 0.001), visual analog scale score (B = 2.331, p = 0.016), and midline shift (B = 0.335, p = 0.007). Hematoma thickness and age had no significant impact. Conclusion- Increased midline shift and visual analog scale scores, alongside restraint belt use and electrolyte imbalance elevate delirium risk in chronic subdural hematoma surgery. Our prediction models may offer reference value in this context.

Challenges and patient outcomes in chronic subdural haematoma at the level of a regional care system A multi-centre, mixed-methods study from the East of England.

BACKGROUND: Chronic subdural haematoma (cSDH) is a common neurosurgical pathology affecting older patients with other health conditions. A significant proportion (up-to 90%) of referrals for surgery in neurosciences units (NSU) come from secondary care. However, the organisation of this care and the experience of patients repatriated to non-specialist centres are currently unclear. OBJECTIVES: This study aimed to clarify patient outcome in non-specialist centres following NSU discharge for cSDH surgery and to understand key system challenges. The study was set within a representative neurosurgical care system in the east of England. DESIGN AND METHODS: We performed a retrospective cohort analysis of patients referred for cSDH surgery. Alongside case record review, patient and staff experience were explored using surveys as well as an interactive c-design workshop. Challenges were identified from thematic analysis of survey responses and triangulated by focussed workshop discussions. RESULTS: Data on 381 patients referred for cSDH surgery from six centres was reviewed. One hundred and fifty-six (41%) patients were repatriated following surgery. Sixty-one (39%) of those repatriated suffered an inpatient complication (new infection, troponin rise or renal injury) following NSU discharge, with 58 requiring institutional discharge or new care. Surveys for staff (n = 42) and patients (n = 209) identified that resourcing, communication, and inter-hospital distance posed care challenges. This was corroborated through workshop discussions with stakeholders from two institutions. CONCLUSIONS: A significant amount of perioperative care for cSDH is delivered outside of specialist centres. Future improvement initiatives must recognise the system-wide nature of delivery and the challenges such an arrangement presents.

"Curtain-fall" technique for cerebrospinal fluid leak prevention after removal of intradural drainage. Technical note: application in chronic subdural hematoma surgery.

OBJECTIVE: Chronic subdural hematoma (CSDH) is frequently met in neurosurgical practice and often need urgent surgical treatment in case of neurological deterioration. Different surgical approaches to evacuate CSDH are described in the literature. In our experience, an external drainage system is crucial in order to avoid recurrences. We recently encountered a case of subcutaneous CSF collection after drainage removal. Thus, we developed a simple surgical technique to prevent postoperative CSF leak after subdural drainage system removal. METHOD: We have developed a technique in which the periosteum is harvested during the surgery prior to the evacuation of the hemorrhage and fixed with sutures on the uncut dura mater opposite and laterally to the exit of the catheter exiting the dural hole caused by the passage of the Jackson-Pratt subdural drainage system. When the drainage catheter is removed, the flap, partially held by the sutures, falls over the hole avoiding CSF leakage. By using this technique, the small dural hole will be covered with the periosteum allowing for natural closure and wound healing hence preventing CSF leakage. RESULTS: This technique was successfully employed in 21 patients who didn't develop postoperative CSF leakage following CSDH evacuation and removal of subdural drainage system. CONCLUSION: In this technical note, we describe a safe dura closure technique that we developed to help reduce the risk of postoperative CSF leakage following subdural drainage removal, which can, however, also be applied in all surgeries in which a catheter is placed in the subdural space.

Local anesthesia with sedation and general anesthesia for the treatment of chronic subdural hematoma: a systematic review and meta-analysis.

BACKGROUND: Surgery is the primary treatment for chronic subdural hematoma, and anesthesia significantly impacts the surgery's outcomes. A previous systematic review compared general anesthesia to local anesthesia in 319 patients. Our study builds upon this research, analyzing 4,367 cases to provide updated and rigorous evidence. METHODS: We systematically searched five electronic databases: PubMed, Cochrane Library, Scopus, Ovid Medline, and Web of Science, to identify eligible comparative studies. All studies published until September 2023 were included in our analysis. We compared six primary outcomes between the two groups using Review Manager Software. RESULTS: Eighteen studies involving a total of 4,367 participants were included in the meta-analysis. The analysis revealed no significant difference between the two techniques in terms of 'recurrence rate' (OR = 0.95, 95% CI [0.78 to 1.15], P = 0.59), 'mortality rate' (OR = 1.02, 95% CI [0.55 to 1.88], P = 0.96), and 'reoperation rate' (OR = 0.95, 95% CI [0.5 to 1.79], P = 0.87). Local anesthesia demonstrated superiority with a lower 'complications rate' than general anesthesia, as the latter had almost 2.4 times higher odds of experiencing complications (OR = 2.4, 95% CI [1.81 to 3.17], P < 0.00001). Additionally, local anesthesia was associated with a shorter 'length of hospital stay' (SMD = 1.19, 95% CI [1.06 to 1.32], P < 0.00001) and a reduced 'duration of surgery' (SMD = 0.94, 95% CI [0.67 to 1.2], P < 0.00001). CONCLUSION: Surgery for chronic subdural hematoma under local anesthesia results in fewer complications, a shorter length of hospital stay, and a shorter duration of the operation.

Letter to editor : Local anesthesia with sedation and general anesthesia for the treatment of chronic subdural hematoma: a systematic review and meta­analysis of published cases.

This critique evaluates the systematic review and meta-analysis titled "Local anesthesia with sedation and general anesthesia for the treatment of chronic subdural hematoma." The study provides valuable insights into anesthesia techniques' effectiveness in managing this condition but has limitations, including selection bias, heterogeneity among cases, lack of standardized protocols, and retrospective design. Despite these limitations, the review contributes to understanding chronic subdural hematoma management but underscores the need for future research to address these shortcomings.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma.

BACKGROUND: Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied. METHODS: A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale. RESULTS: Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14 mm and midline shift 3 mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001). CONCLUSION: MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

A randomised, double blind, placebo-controlled trial of a two-week course of dexamethasone for adult patients with a symptomatic Chronic Subdural Haematoma (Dex-CSDH trial).

Background: Chronic subdural haematoma is a collection of 'old blood' and its breakdown products in the subdural space and predominantly affects older people. Surgical evacuation remains the mainstay in the management of symptomatic cases. Objective: The Dex-CSDH (DEXamethasone in Chronic SubDural Haematoma) randomised trial investigated the clinical effectiveness and cost-effectiveness of dexamethasone in patients with a symptomatic chronic subdural haematoma. Design: This was a parallel, superiority, multicentre, pragmatic, randomised controlled trial. Assigned treatment was administered in a double-blind fashion. Outcome assessors were also blinded to treatment allocation. Setting: Neurosurgical units in the UK. Participants: Eligible participants included adults (aged ≥ 18 years) admitted to a neurosurgical unit with a symptomatic chronic subdural haematoma confirmed on cranial imaging. Interventions: Participants were randomly assigned in a 1 : 1 allocation to a 2-week tapering course of dexamethasone or placebo alongside standard care. Main outcome measures: The primary outcome was the Modified Rankin Scale score at 6 months dichotomised to a favourable (score of 0-3) or an unfavourable (score of 4-6) outcome. Secondary outcomes included the Modified Rankin Scale score at discharge and 3 months; number of chronic subdural haematoma-related surgical interventions undertaken during the index and subsequent admissions; Barthel Index and EuroQol 5-Dimension 5-Level utility index score reported at discharge, 3 months and 6 months; Glasgow Coma Scale score reported at discharge and 6 months; mortality at 30 days and 6 months; length of stay; discharge destination; and adverse events. An economic evaluation was also undertaken, during which the net monetary benefit was estimated at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year. Results: A total of 748 patients were included after randomisation: 375 were assigned to dexamethasone and 373 were assigned to placebo. The mean age of the patients was 74 years and 94% underwent evacuation of their chronic subdural haematoma during the trial period. A total of 680 patients (91%) had 6-month primary outcome data available for analysis: 339 in the placebo arm and 341 in the dexamethasone arm. On a modified intention-to-treat analysis of the full study population, there was an absolute reduction in the proportion of favourable outcomes of 6.4% (95% confidence interval 11.4% to 1.4%; p = 0.01) in the dexamethasone arm compared with the control arm at 6 months. At 3 months, the between-group difference was also in favour of placebo (-8.2%, 95% confidence interval -13.3% to -3.1%). Serious adverse events occurred in 60 out of 375 (16.0%) in the dexamethasone arm and 24 out of 373 (6.4%) in the placebo arm. The net monetary benefit of dexamethasone compared with placebo was estimated to be -£97.19. Conclusions: This trial reports a higher rate of unfavourable outcomes at 6 months, and a higher rate of serious adverse events, in the dexamethasone arm than in the placebo arm. Dexamethasone was also not estimated to be cost-effective. Therefore, dexamethasone cannot be recommended for the treatment of chronic subdural haematoma in this population group. Future work and limitations: A total of 94% of individuals underwent surgery, meaning that this trial does not fully define the role of dexamethasone in conservatively managed haematomas, which is a potential area for future study. Trial registration: This trial is registered as ISRCTN80782810. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 13/15/02) and is published in full in Health Technology Assessment; Vol. 28, No. 12. See the NIHR Funding and Awards website for further award information.

Chronic subdural haematoma is one of the most common conditions managed in adult neurosurgery and mainly affects older people. It is an 'old' collection of blood and blood breakdown products found on the surface of the brain. Surgery to drain the liquid collection is effective, with most patients improving. Given that inflammation is involved in the disease process, a commonly used steroid, dexamethasone, has been used alongside surgery or instead of surgery since the 1970s. However, there is no consensus or high-quality studies confirming the effectiveness of dexamethasone for the treatment of chronic subdural haematoma. This study was designed to determine the effectiveness of adding dexamethasone to the normal treatment for patients with a symptomatic chronic subdural haematoma. The benefit of adding dexamethasone was measured using a disability score called the Modified Rankin Scale, which can be divided into favourable and unfavourable outcomes. This was assessed at 6 months after entry into the study. In total, 748 adults with a symptomatic chronic subdural haematoma treated in neurosurgical units in the UK participated. Each participant had an equal chance of receiving either dexamethasone or a placebo because they were assigned randomly. Neither the patients nor the investigators knew who received dexamethasone and who received placebo. Most patients in both groups had an operation to drain the haematoma and experienced significant functional improvement at 6 months compared with their initial admission to hospital. However, patients who received dexamethasone had a lower chance than patients who received placebo of favourable recovery at 6 months. Specifically, 84% of patients who received dexamethasone had recovered well at 6 months, compared with 90% of patients who received placebo. There were more complications in the group that received dexamethasone. This trial demonstrates that adding dexamethasone to standard treatment reduced the chance of a favourable outcome compared with standard treatment alone. Therefore, this study does not support the use of dexamethasone in treating patients with a symptomatic chronic subdural haematoma.

Underwater versus Closed Drainage System for Surgical Treatment of Chronic Subdural Hematoma.

OBJECTIVES: Chronic subdural hematoma (CDH) is a prevalent condition in neurosurgery. Standard care includes surgical evacuation with drainage of residual subdural cavity. We hypothesized that effective and timely drainage of subdural space may improve clinical and radiological outcomes. This study was conducted to compare the effectiveness of standard closed drainage and underwater drainage. METHODS: Medical data of 300 surgically treated chronic subdural hematoma CDH patients were retrospectively collected and analyzed. The patients were divided into two 2 groups: Group I with underwater drainage, and Group II with closed drainage. Groups were compared in terms of gender, age, complication rates, recurrence rates, seizure rates, and length of hospital stay. RESULTS: Underwater drainage was found superior to closed system by all clinical and radiographic parameters. The recurrence rate was significantly lower in Group I (2%) compared to with Group II (10%). Subdural empyema was observed in 10 patients in Group II and none in Group I. The seizure rate was higher in Group II (18%) compared to with Group I (5%). Postoperative pneumocephalus rates was were 20% in Group I and 54% in Group II. The length of hospital stay was 6±2.6 days in Group I and 8.9±6.1 days in Group II. The length of intensive care unit (ICU) stay was 0.6±1.12 days in Group I and 2.7±5 days in Group II. A minority (5%) of the patients in Group II required reoperation due to recurrence. CONCLUSIONS: The use of underwater system significantly the reduces the rates of pneumocephalus, seizures, infection, and recurrence. Additional benefits are shorter intensive care unit ICU and total hospital stays.

Middle meningeal artery embolization reduces recurrence following surgery for septated chronic subdural hematomas.

BACKGROUND: Septated chronic subdural hematomas (cSDH) have high rates of recurrence despite surgical evacuation. Middle meningeal artery embolization (MMAE) has emerged as a promising adjuvant for secondary prevention, yet its efficacy remains ill-defined. METHODS: This is a retrospective review of septated cSDH cases treated at our institution. The surgery-only group was derived from cases performed before 2018, and the surgery+MMAE group was derived from cases performed 2018 or later. The primary outcome was reoperation rate. Secondary outcomes were recurrence, change in hematoma thickness, and midline shift. RESULTS: A total of 34 cSDHs in 28 patients (surgery+MMAE) and 95 cSDHs in 83 patients (surgery-only) met the inclusion criteria. No significant difference in baseline characteristics between groups was identified. The reoperation rate was significantly higher in the surgery-only group (n = 16, 16.8%) compared with the surgery+MMAE cohort (n = 0, 0.0%) (p=0.006). A reduced incidence of recurrence (p=0.011) was also seen in the surgery+MMAE group. CONCLUSIONS: MMAE for septated cSDH was found to be highly effective in preventing recurrence and reoperation. MMAE is an adjunct to surgical evacuation may be of particular benefit in this patient cohort.

Single-cell sequencing analysis of chronic subdural hematoma cell subpopulations and their potential therapeutic mechanisms.

BACKGROUND: Chronic subdural hematoma (CSDH) is a prevalent form of intracranial haemorrhage encountered in neurosurgical practice, and its incidence has notably risen in recent years. Currently, there is a lack of studies that have comprehensively classified the cells present in hematomas removed during surgery, and their correlation with CSDH recurrence remains elusive. This study aims to analyse the subcellular populations and occupancy levels within peripheral blood. METHODS: This study analyses the subcellular populations and occupancy levels within peripheral blood and postoperatively removed hematomas by single-cell sequencing and attempts to analyse the effect of different cell occupancies within peripheral blood and intraoperatively removed hematomas on CSDH. RESULTS: The single-cell sequencing results showed that the cells were classified into 25 clusters by differential gene and UMAP dimensionality reduction clustering analyses and further classified into 17 significant cell populations by cell markers: pDCs, CD8 T cells, CD4 T cells, MigDCs, cDC2s, cDC1s, plasma cells, neutrophils, naive B cells, NK cells, memory B cells, M2 macrophages, CD8 Teffs, CD8 MAIT cells, CD4 Tregs, CD19 B cells, and monocytes. Further research showed that the presence of more cDC2 and M2 macrophages recruited at the focal site in patients with CSDH and the upregulation of the level of T-cell occupancy may be a red flag for further brain damage. ROS, a marker of oxidative stress, was significantly upregulated in cDC2 cells and may mediate the functioning of transcription proteins of inflammatory factors, such as NFκB, which induced T cells' activation. Moreover, cDC2 may regulate M2 macrophage immune infiltration and anti-inflammatory activity by secreting IL1ß and binding to M2 macrophage IL1R protein. CONCLUSION: The detailed classification of cells in the peripheral blood and hematoma site of CSDH patients helps us to understand the mechanism of CSDH generation and the reduction in the probability of recurrence by regulating the ratio of cell subpopulations.

Treatment of chronic subdural haematoma.

A further rise in chronic subdural haematoma (CSDH) prevalence is expected with an ageing population, and evidence-based guidelines are needed to direct treatment, while creating a platform for research. The Danish Chronic Subdural Hematoma Study (DACSUHS) has implemented the first Danish national CSDH guidelines in 2018 and have standardised CSDH management on a national level. Based on CSDH literature published between 2016 and 2022, these guidelines were updated in 2022. The updated guidelines are presented in this review.

Irrigation versus no irrigation in the treatment of chronic subdural hematoma: An updated systematic review and meta-analysis of 1581 patients.

Burr hole craniotomy is a common technique employed in the treatment of chronic subdural hematoma. However, its effectiveness and the occurrence of additional complications with various irrigation techniques utilized during the surgery remain unclear. The paper aims to compare the effectiveness and safety of burr hole craniotomy with and without irrigation in the treatment of chronic subdural hematoma. We conducted a systematic review by searching PubMed, Cochrane Library, Scopus, Ovid, and Web of Science for comparative studies that fit the eligibility criteria. All studies up to January 2023 were included, and the two groups were compared based on five primary outcomes using Review Manager Software. Data reported as odds ratio (OR) or risk ratio (RR) and 95% confidence interval (CI). A p-value of less than 0.05 was considered statistically significant. Our analysis included 12 studies with a total of 1581 patients. There was no significant difference between the two techniques in terms of recurrence rate (OR = 0.94; 95% CI [0.55, 1.06], p-value = 0.81) and mortality rate (RR = 1.05, 95% CI [0.46, 2.40], p-value = 0.91). Similarly, there was no significant difference in postoperative infection (RR = 1.15, 95% CI [0.16, 8.05], p-value = 0.89) or postoperative pneumocephalus (RR = 2.56, 95% CI [0.95, 6.89], p-value = 0.06). The burr hole drainage with irrigation technique was insignificantly associated with a higher risk of postoperative hemorrhagic complication (RR = 2.23, 95% CI [0.94, 5.29], p-value = 0.07); however, sensitivity analysis showed significant association based on the results of two studies (RR = 4.6, 95% CI [1.23, 17.25], p-value = 0.024). The two techniques showed comparable recurrence, mortality rate, postoperative infection, and postoperative pneumocephalus results. However, irrigation in burr hole craniotomy could possibly have a higher risk of postoperative hemorrhage compared with no irrigation, as observed during sensitivity analysis, which requires to be confirmed by other studies. Further research and randomized controlled trials are required to understand these observations better and their applicability in clinical practice.

Middle Meningeal Artery Embolization for Management of Chronic Subdural Hematoma.

Chronic subdural hematoma (CSDH) is a prevalent medical condition with potentially severe consequences if left untreated. While surgical removal has traditionally been the standard approach for treatment, middle meningeal artery (MMA) embolization has emerged as a promising minimally invasive alternative to reduce recurrences. This comprehensive review provides the general radiology community with an overview of MMA embolization as a therapeutic option for managing CSDH. The authors base their insights on existing evidence and their institutional experience. This overview encompasses the pathophysiology of CSDH as well as the potential advantages and limitations, safety profile, and potential complications of MMA embolization as compared with surgical treatment. The imaging findings seen before and after MMA, as well as insights into the procedural techniques used at the authors' institution, are described. On the basis of reports in the current literature, MMA embolization appears to be a safe and effective therapeutic option for managing CSDH, especially in patients who are unsuitable for surgery or at risk for recurrence. Nonetheless, further research is needed to validate these findings. Results from ongoing clinical trials hold promise for future validation and the establishment of scientific evidence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chatterjee in this issue.

Incidence of surgically treated chronic subdural hematoma after head injury with normal initial computed tomography.

PURPOSE: The objective was to determine the incidence of surgically treated chronic subdural hematoma (cSDH) within six months after head trauma in a consecutive series of head injury patients with a normal initial computed tomography (CT). METHODS: A total of 1941 adult patients with head injuries who underwent head CT within 48 h after injury and were treated at the Tampere University Hospital's emergency department were retrospectively evaluated from medical records (median age = 59 years, IQR = 39-79 years, males = 58%, patients using antithrombotic medication = 26%). Patients with no signs of acute traumatic intracranial pathology or any type of subdural collection on initial head CT were regarded as CT negative (n = 1573, 81%). RESULTS: Two (n = 2) of the 1573 CT negative patients received surgical treatment for cSDH. Consequently, the incidence of surgically treated cSDH after a normal initial head CT during a six-month follow-up was 0.13%. Both patients sustained mild traumatic brain injuries initially. One of the two patients was on antithrombotic medication (warfarin) at the time of trauma, hence incidence of surgically treated cSDH among patients with antithrombotic medication in CT negative patients (n = 376, 23.9%) was 0.27%. Additionally, within CT negative patients, one subdural hygroma was operated shortly after trauma. CONCLUSION: The extremely low incidence of surgically treated cSDH after a normal initial head CT, even in patients on antithrombotic medication, supports the notion that routine follow-up imaging after an initial normal head CT is not indicated to exclude the development of cSDH. Additionally, our findings support the concept of cSDH not being a purely head trauma-related disease.