The Danish chronic subdural hematoma study - risk factors for second recurrence

Immunoprofile of Radiologic Chronic Subdural Hematoma Subtypes

OBJECTIVE

This study aimed to investigate the immunologic profile of chronic subdural hematoma (CSDH) subtypes based on their radiologic appearances, with a focus on comparing the membranous CSDH to other subtypes.

METHODS

We prospectively analyzed 170 CSDH cases from 138 patients, categorizing them into "Membranous" and 'Other' subtypes based on computed tomography scans. Samples were collected from the subdural fluid and systemic blood and analyzed for a panel of inflammatory markers. Demographic data, clinical characteristics, and time since trauma were also assessed.

RESULTS

Time since trauma to diagnostic computed tomography was significantly longer for the "membranous" subtype (P = 0.001). 'Membranous" CSDH exhibited a distinct immunoprofile, including lower hemoglobin levels (P = 0.0002) and higher concentrations of matrix metallopeptidase 9 (P = 0.005) and interleukin-8 (IL-8) (P < 0.0001). Additionally, "Membranous" CSDH showed elevated levels of interferon gamma-induced protein 10, monokine induced by gamma interferon, and uPAR compared to 'Other' subtypes, with significant correlations between interferon gamma-induced protein 10 and monocyte chemoattractant protein-1 (P = 0.013), monokine induced by gamma interferon (P = 0.002), and urokinase-type plasminogen activator receptor (P = 0.006). IL-8 levels also correlated significantly with monocyte chemoattractant protein-1 (P = 0.02), suggesting distinct inflammatory pathways in the "Membranous" subtype.

CONCLUSIONS

This study demonstrates that CSDH subtypes, particularly the "Membranous" subtype, possess a distinct immunologic profile. These findings provide novel insights into CSDH pathophysiology. The unique inflammatory landscape of "Membranous" CSDH, marked by elevated matrix metallopeptidase 9 and IL-8 levels, may contribute to its chronic nature.

Multidisciplinary consensus-based statement on the current role of middle meningeal artery embolization (MMAE) in chronic SubDural hematoma (cSDH)

Introduction

Middle Meningeal Artery Embolization (MMAE) in patients with chronic SubDural Hematoma (cSDH) is a novel treatment approach, albeit the specific role of MMAE in the treatment of cSDH is not yet defined.

Research question

The aim of this work is to provide a consensus-based statement from a multidisciplinary panel on the current role of MMAE in patients with cSDH.

Materials and methods

A literature search was performed using the keywords MMAE and cSDH. Based on the available published data, the panel was asked if a consensus could be reached on the role of MMAE in both de novo as well as in recurrent cSDH.

Results

The panel reached a consensus on the current role of MMAE in both de novo- and recurrent cSDH, as well as in patients on antithrombotics and those with coagulopathy. MMAE should be considered in the following scenarios:1)As "stand-alone" treatment in de novo cSDH requiring intervention but where surgery is prevented due to either coagulopathy or in patients on antithrombotics in whom the risk of suspension is considered unacceptably high,2)as "stand-alone" treatment in recurrent cSDH requiring intervention but where surgery is prevented due to either coagulopathy or in those on antithrombotics in whom the risk of suspension is considered unacceptably high and3)as "adjunct to surgery" in all recurrent cSDH.

Discussion and conclusion

This statement is to be considered an expert consensus opinion of delegates representing key international medical societies of specialists involved in the care of cSDH patients.

Optimal drainage time after evacuation of chronic subdural haematoma (DRAIN TIME 2): a multicentre, randomised, multiarm and multistage non-inferiority trial in Denmark

BACKGROUND

Postoperative drainage after surgical evacuation of chronic subdural haematoma reduces the risk of recurrence, but the optimum drainage time is uncertain. We aimed to investigate the shortest possible drainage time without increasing the haematoma recurrence rate.

METHODS

We conducted a randomised, multi-arm and multistage non-inferiority trial at four neurosurgical centres in Denmark. We enrolled adult patients (aged ≥18 years) with symptomatic chronic subdural haematoma. All patients were treated according to the national standard practice with a burr hole above the maximum width of the haematoma. Patients were randomly assigned in a 1:1:1 ratio via a centralised web server to receive 6 h, 12 h, or 24 h of postoperative passive subdural drainage. Randomisation was done by an independent on-call neurosurgeon and was masked until 6 h after surgery. The primary outcome was symptomatic haematoma recurrence at 3 months after surgery; the rate of recurrence was assessed in a regression model for non-inferiority testing, with no missing data. Personnel assessing the primary outcome were masked to group allocation. Non-inferiority was assessed with a prespecified margin of 7%, in a modified intention-to-treat population-defined as patients with randomly assigned treatment excluding those withdrawing from study participation after randomisation, or experiencing acute rebleedings or accidental drain removal. This trial is registered with ISRCTN (number 15186366); the trial was stopped after the first interim analysis on the advice of an independent safety advisory committee.

FINDINGS

Between March 1, 2021, and June 30, 2022, 347 patients were enrolled and 331 were followed up to 3 months, 105 were assigned to 6 h of drainage, 111 to 12 h of drainage, and 115 to 24 h of drainage. At admission, 83 (25%) participants were women and 248 (75%) were men, mean age was 75·7 years (SD 10·5), median modified Rankin Scale score was 4 (IQR 3-5), and median Glasgow Coma Scale score was 15 (IQR 14-15). At 3 months after surgery, haematoma recurrence was reported in 28 (27%) of 105 patients who were assigned to 6 h drainage (predicted haematoma recurrence rate 27·0%, 95% CI 18·5 to 35·4), 22 (20%) of 111 assigned to 12 h drainage (19·5%, 12·0 to 27·0), and 12 (10%) of 115 assigned to 24 h drainage (10·4%, 4·8 to 16·0). The risk of haematoma recurrence was increased by 16·5 percentage points (95% CI 6·5 to 26·6) in patients drained for 6 h compared with 24 h, and by 9·1 percentage points (-0·4 to 18·5) in patients drained for 12 h compared with 24 h. Therefore, non-inferiority of 6 h and 12 h of drainage to 24 h of drainage was not established. 20 patients had died by 3 months, seven in the 6 h group, eight in the 12 h group, and five in the 24 h group. The most frequent known causes of death were haematoma recurrence (three in 12 h group), comorbidity (three in 12 h group), and pneumonia (one each in 6 h and 12 h groups, two in 24 h group). The most frequent complication was postoperative infection, reported in 20 (20%) patients in the 6 h group, 25 (23%) in the 12 h group, and 19 (17%) in the 24 h group. The most common infection source was the urinary tract.

INTERPRETATION

Patients surgically treated for symptomatic chronic subdural haematoma and postoperatively drained for 6 h or 12 h had higher rates of haematoma recurrence than did patients drained for 24 h. The findings from this non-inferiority trial provide evidence to support 24 h of postoperative drainage as the standard drain time when a fixed drain time approach is used. To provide solid evidence of generalisability of the results to countries other than Denmark, a multinational randomised controlled trial will be needed.

FUNDING

None.

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

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

The Drainage Dysfunction of Meningeal Lymphatic Vessels Is Correlated with the Recurrence of Chronic Subdural Hematoma: a Prospective Study

Meningeal lymphatic vessels (mLVs) were recently discovered to be involved in the waste drainage process in the brain, which has also been associated with a variety of neurological diseases. This research paper hypothesizes that the drainage function of mLVs may be affected after chronic subdural hematoma (CSDH) and the alterations of mLVs' drainage may predict CSDH recurrence. In this prospective observational study, unenhanced 3D T2-fluid-attenuated inversion recovery (3D T2-FLAIR) MRI data were collected from CSDH patients and healthy participants for analysis. Patients with CSDH who underwent surgery received MRI scans before and after surgery, whereas healthy controls and patients with CSDH who received pharmaceutical treatment received only one MRI scan at enrollment. The signal unit ratio (SUR) of mLVs were then measured according to the MRI data and calculated to define mLVs' drainage function. Finally, the relationship between mLVs' drainage function and CSDH recurrence was analyzed accordingly. Thirty-four participants were enrolled in this study, including 27 CSDH patients and 7 controls. The SUR of mLVs in all CSDH patients changed significantly before and after surgery. Moreover, the drainage function of the mLVs ipsilateral to hematoma (mLVs-IH) in CSDH patients was significantly lower than that in the controls (p < 0.05). Last, a higher improvement rate of the drainage function of the mLVs-IH is correlated to a lower risk of recurrence (p < 0.05). This study revealed the mLVs' drainage dysfunction after CSDH through non-invasive MRI. Furthermore, the drainage function of mLVs is an independent predictive factor of CSDH recurrence.