Inhibitory Mechanism of the Outer Membrane Growth of Chronic Subdural Hematomas

Rapamycin promotes hematoma resorption and enhances endothelial cell function by suppressing the mTOR/STAT3 signaling in chronic subdural hematoma

Chronic subdural hematoma (CSDH) remains a neurosurgical condition and a healthy burden especially in elderly patients. This study focuses on the functions of rapamycin and its related molecular mechanisms in CSDH management. A rat model of CSDH was induced, which developed significant hematoma on day 5 after operation. The rats were treated with rapamycin or atorvastatin, a drug with known effect on hematoma alleviation, or treated with rapamycin and atorvastatin in combination. The atorvastatin or rapamycin treatment reduced the hematoma development, blood-brain barrier permeability, neurological dysfunction in CSDH rats, and the combination treatment showed more pronounced effects. Human brain microvascular endothelial cells hCMEC/D3 were stimulated by hematoma samples to mimic a CSDH condition in vitro. The drug treatments elevated the cell junction-related factors and reduced the pro-inflammatory cytokines both in rat hematoma tissues and in hCMEC/D3 cells. Rapamycin suppressed the mTOR and STAT3 signaling pathways. Overexpression of mTOR or the STAT3 agonist suppressed the alleviating effects of rapamycin on CSDH. In summary, this study demonstrates that rapamycin promotes hematoma resorption and enhances endothelial cell function by suppressing the mTOR/STAT3 signaling.

Risk Factor Analysis of the Conservative Treatment in Chronic Subdural Hematomas: A Substudy of the ATOCH Trial

INTRODUCTION

The objective of the study was to analyze the risk factors for worsening of the disease progression in patients with chronic subdural hematomas (CSDH) during wait-and-observation treatment regimen and conservative treatment with atorvastatin.

METHODS

A total of 196 patients with CSDH were recruited (98 in the atorvastatin group and 98 in the blank placebo group). Receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff for the hematoma volume by testing surgical and nonsurgical outcomes. Other measures, including univariate and multivariate analyses, were performed to identify the potential significant factors indicative of the outcome of therapeutic efficacy of conservative treatment through the characteristics of the baseline indicators at enrollment.

RESULTS

Over a median treatment duration of 2 months, lower total cholesterol, higher hematoma volume, and more midline shift were independent risk factors for worse outcomes of atorvastatin treatment for CSDH, and only a higher hematoma volume was an independent risk factor for spontaneous absorption in the placebo group. ROC analysis of all of the data showed that the optimal threshold of hematoma volume was 68.5 ml (sensitivity 73.5%, specificity 74%) in response to the greatest chance of switching to surgery.

CONCLUSIONS

Critical independent predictors of atorvastatin monotherapy treatment success included higher total cholesterol, lower hematoma volume, and less midline shift in atorvastatin monotherapy, and higher hematoma volume was the only independent risk factor in close follow-up observation patients without any pharmacotherapy. Initial hematoma volume more than 68.5 ml may help clinicians to determine individual risk assessments and to make optimal treatment decisions.

TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov . Identifier NCT02024373.

Atorvastatin combined with dexamethasone in chronic subdural haematoma (ATOCH II): study protocol for a randomized controlled trial

BACKGROUND

Chronic subdural haematoma (CSDH) is a common condition in the elderly that often requires neurosurgical management. For small CSDH, evidence has emerged that statins may reduce haematoma volume and improve outcomes, presumably by reducing local inflammation and promoting vascular repair. We wish to extend this evidence in a study that aims to determine the efficacy and safety of atorvastatin combined with low-dose dexamethasone in patients with CSDH.

METHODS

The second ATorvastatin On Chronic subdural Hematoma (ATOCH-II) study is a multi-centre, randomized, placebo-controlled, double-blind trial which aims to enrol 240 adult patients with a conservative therapeutic indication for CSDH, randomly allocated to standard treatment with atorvastatin 20 mg combined with low-dose dexamethasone (or matching placebos) daily for 28 days, and with 152 days of follow-up. The primary outcome is a composite good outcome defined by any reduction from baseline in haematoma volume and survival free of surgery at 28 days. Secondary outcomes include functional outcome on the modified Rankin scale (mRS) and modified Barthel Index at 28 days, surgical transition and reduction in haematoma volumes at 14, 28 and 90 days.

DISCUSSION

This multi-centre clinical trial aims to provide high-quality evidence on the efficacy and safety of the combined treatment of atorvastatin and low-dose dexamethasone to reduce inflammation and enhance angiogenesis in CSDH.

TRIAL REGISTRATION

ChiCTR, ChiCTR1900021659 . Registered on 3 March 2019, http://www.chictr.org.cn/showproj.aspx?proj=36157 .

Role of Regulatory T cells in Atorvastatin Induced Absorption of Chronic Subdural Hematoma in Rats

Chronic subdural hematoma (CSDH) is a neurological disorder with a substantial recurrence rate. Atorvastatin is an effective drug for treating hyperlipidemia and known to improve neurological outcome after intracerebral hemorrhage. Previous studies have reported that atorvastatin treatment promotes hematoma absorption in CSDH, while the underlying mechanisms remain unclear. In this study, we investigated whether the anti-inflammatory effects of atorvastatin mediate absorption of CSDH. 144 male, Wistar rats (6 months old) were randomly divided into the following groups: 1) sham surgery control, 2) treatment: CSDH + atorvastatin, and 3) vehicle control: CSDH + saline. Atorvastatin or saline was orally administered daily for 19 days after CSDH procedure. A T2WI MRI was used to evaluate CSDH volume changes during the time course of the study. Flow cytometry and immunohistochemical staining were used to measure the number of regulatory T cells (Treg). ELISA was used to measure cytokine level in the hematoma border. Neurological function and cognitive outcome were evaluated using Foot-Fault test and Morris Water Maze test, respectively. When compared to saline treatment, atorvastatin treatment accelerated the absorption of CSDH as indicated by decreased hematoma volume in T2WI MRI data on 14^th and 21^st day after CSDH (P<0.05). Atorvastatin treatment significantly increased the number of Treg in circulation and hematoma border from 3^rd to 21^st day after CSDH. Atorvastatin treatment significantly decreased the levels of interleukins (IL-6 and IL-8) and tumor necrosis factor-α (TNF-α), but increased IL-10 level in the hematoma border. Atorvastatin treatment also improved neurological function and cognitive outcome compared to vehicle treated group. Atorvastatin induced anti-inflammatory responses and increased Treg in circulation and brain which may contribute to the accelerated CSDH absorption in rats.