Morphological changes in chronic subdural hematomas following upfront middle meningeal artery embolization: sequence, timing, and association with outcomes

Establishment and validation of a CT-based prediction model for the good dissolution of mild chronic subdural hematoma with atorvastatin treatment

PURPOSE

To develop and validate a prediction model based on imaging data for the prognosis of mild chronic subdural hematoma undergoing atorvastatin treatment.

METHODS

We developed the prediction model utilizing data from patients diagnosed with CSDH between February 2019 and November 2021. Demographic characteristics, medical history, and hematoma characteristics in non-contrast computed tomography (NCCT) were extracted upon admission to the hospital. To reduce data dimensionality, a backward stepwise regression model was implemented to build a prognostic prediction model. We calculated the area under the receiver operating characteristic curve (AUC) of the prognostic prediction model by a tenfold cross-validation procedure.

RESULTS

Maximum thickness, volume, mean density, morphology, and kurtosis of the hematoma were identified as the most significant predictors of good hematoma dissolution in mild CSDH patients undergoing atorvastatin treatment. The prediction model exhibited good discrimination, with an area under the curve (AUC) of 0.82 (95% confidence interval [CI], 0.74-0.90) and good calibration (p = 0.613). The validation analysis showed the AUC of the final prognostic prediction model is 0.80 (95% CI 0.71-0.86) and it has good prediction performance.

CONCLUSION

The imaging data-based prediction model has demonstrated great prediction accuracy for good hematoma dissolution in mild CSDH patients undergoing atorvastatin treatment. The study results emphasize the importance of imaging data evaluation in the management of CSDH patients.

Newer treatment paradigm improves outcomes in the most common neurosurgical disease of the elderly: a literature review of middle meningeal artery embolization for chronic subdural hematoma

Chronic subdural hematoma (cSDH) is one of the most prevalent neurosurgical diseases, especially in the elderly. Yet, its incidence is predicted to increase further, paralleling the growth of the geriatric population. While surgical evacuation is technically straightforward, it is associated with significant morbidity and mortality. In fact, 30% of patients are expected to have hematoma recurrence and to need repeat surgical evacuation, and 20% of patients are expected to lose independence and require long-term care. A pathophysiology more complex than originally presumed explains the disappointing results observed for decades. At its core, the formation of microcapillaries and anastomotic channels with the middle meningeal artery (MMA) perpetuates a constant cycle resulting in persistence of hematoma. The rationale behind MMA embolization is simple: to stop cSDH at its source. Over the last few years, this "newer" option has been heavily studied. It has shown tremendous potential in decreasing hematoma recurrence and improving neurological outcomes. Whether combined with surgical evacuation or performed as the only treatment, the scientific evidence to its benefits is unequivocal. Here, we aimed to review cSDH in the elderly and discuss its more recent treatment options with an emphasis on MMA embolization.

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.

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.

Middle Meningeal Artery Embolization in Adjunction to Surgical Evacuation for Treatment of Subdural Hematomas: A Nationwide Comparison of Outcomes With Isolated Surgical Evacuation

BACKGROUND AND OBJECTIVES

Surgical evacuation is the standard treatment for chronic subdural hematomas (CSDHs) but is associated with a high risk of recurrence and readmission. Middle meningeal artery embolization (MMAE) is a novel treatment approach which could be performed upfront or in adjunction to surgical evacuation. MMAE studies are limited by small sample sizes. This study aimed to describe and compare outcomes of MMAE in adjunction to surgery with those of surgery alone on a national level.

METHODS

The national Vizient Clinical Database was queried by use of a specific validated set of International Classification of Diseases, Tenth Revision codes (October 2018-June 2022). Patients with the diagnosis of nontraumatic CSDH who received MMAE and surgical drainage in the same hospitalization were identified, and their outcomes were compared with isolated surgical drainage.

RESULTS

A total of 606 subjects from 156 institutes and 6340 subjects from 369 institutes were included in the MMAE plus surgery (M&S) and surgery groups, respectively. Average length of stay was significantly longer in the M&S group (9.87 vs 7.53 days; P < .01). There was no significant difference in the in-hospital mortality rate (2.8% vs 2.9%), but the complication rate was significantly higher in the M&S group (8.7% vs 5.5%; P < .01). Complications that were significantly more common in the M&S group included aspiration pneumonia, postoperative sepsis, and anesthesia-related. Mean direct costs were significantly higher in the M&S group (28 834 vs 16 292 US dollars; P < .01). The 30-day readmission rate was significantly lower in the M&S group compared with the surgery group (4.2% vs 8.0%; P < .01).

CONCLUSION

This analysis of large-scale national data indicates that MMAE performed in adjunction to surgery for treatment of CSDH is associated with higher direct costs, higher complication rates, and longer length of stay but lower readmission rates compared with surgical evacuation alone.

Extensive Roles and Technical Advances of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a common pathology that typically affects the elderly in Japan, an aging society. Burr-hole irrigation is the standard treatment, but middle meningeal artery (MMA) embolization is a minimally invasive alternative. MMA embolization for CSDH has frequently been reported in recent years, and many technical innovations to improve clinical outcomes have been described. Embolic materials reaching more distally are found to avoid recurrences after MMA embolization. As a result, various studies have described the superiority of embolizing the anterior and posterior branches of the MMA, the advantages of embolic materials reaching beyond the midline, and a high degree of distal penetration using a "sugar rush technique" in which 5% soluble glucose is injected through an intermediate catheter during MMA embolization. Radiographically, reports have described the importance of a "bright falx" sign obtained by infiltrating embolic material beyond the midline and post-embolization enhancement of the dura, capsular membrane, septations, and subdural hematoma fluid as indicators of the spread of embolic materials. This review provides an overview of the current status and future challenges in MMA embolization for CSDH, focusing on technical aspects to improve clinical outcomes.

Middle meningeal artery embolization of septated chronic subdural hematomas

INTRODUCTION

Middle meningeal artery embolization (MMAE) has emerged as a promising new treatment for patients with chronic subdural hematomas (cSDH). Its efficacy, however, upon the subtype with a high rate of recurrence-septated cSDH-remains undetermined.

METHODS

From our prospective registry of patients with cSDH treated with MMAE, we classified patients based on the presence or absence of septations. The primary outcome was the rate of recurrence of cSDH. Secondary outcomes included a reduction in cSDH thickness, midline shift, and rate of reoperation.

RESULTS

Among 80 patients with 99 cSDHs, the median age was 68 years (IQR 59-77) with 20% females. Twenty-eight cSDHs (35%) had septations identified on imaging. Surgical evacuation with burr holes was performed in 45% and craniotomy in 18.8%. Baseline characteristics between no-septations (no-SEP) and septations (SEP) groups were similar except for median age (SEP vs no-SEP, 72.5 vs. 65.5, p = 0.016). The recurrence rate was lower in the SEP group (SEP vs. no-SEP, 3 vs. 16.7%, p = 0.017) with higher odds of response from MMAE for septated lesions even when controlling for evacuation strategy and antithrombotic use (OR = 0.06, CI [0.006-0.536], p = 0.012). MMAE resulted in higher mean absolute thickness reduction (SEP vs. no-SEP, -8.2 vs. -4.8 mm, p = 0.016) with a similar midline shift change. The rate of reoperation did not differ (6.2 vs. 3.1%, p = 0.65).

CONCLUSION

MMAE appears to be equal to potentially more effective in preventing the recurrence of cSDH in septated lesions. These findings may aid in patient selection.

Middle meningeal artery embolization for treatment of chronic subdural hematomas: does selection of embolized branches affect outcomes?

OBJECTIVE

Middle meningeal artery (MMA) embolization (MMAE) is a new therapeutic modality for chronic subdural hematoma (cSDH). There is limited evidence comparing various MMAE procedural techniques, resulting in significant variations in technique and procedural planning. The objective of this study was to compare outcomes of MMAE by the number and location of MMA branches that were embolized.

METHODS

A single-center retrospective study of patients with cSDH treated by MMAE was conducted. Clinical outcomes, need for re-intervention, and changes in hematoma size were compared between different MMAE techniques.

RESULTS

Ninety-four cSDHs in 78 patients were included. Embolization of the proximal trunk only, distal branches only, or proximal trunk plus distal branches resulted in similar rates of need for rescue surgery (7.4%, 13.0%, and 6.8%, respectively; p = 0.66) and rates of reducing the volume of the hematoma by at least 50% (74.1%, 80.0%, and 77.5%, respectively; p = 0.88). Embolization of only one branch had similar outcomes to embolization of more than one branch, as rescue surgery rates were 9.3% and 7.8% (p = 0.80), and rates ≥ 50% volume reduction were 75.6% and 78.3% (p = 0.76), respectively. Selective embolization of the dominant MMA branch was not associated with significantly different outcomes.

CONCLUSIONS

Outcomes of distal, proximal, or combined proximal and distal MMAE in cSDH are not significantly different. Embolization of more than one branch is not associated with improved treatment efficacy. Arguably, targeting any location in the MMA provides sufficient flow restriction to enable spontaneous hematoma resolution. Accordingly, a technical planning algorithm for cSDH MMAE is suggested.

Sequential Middle Meningeal Artery Embolization after Burr Hole Surgery for Recurrent Chronic Subdural Hematoma

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) is a novel, minimally invasive treatment. The indications and treatment practices for MMAE are variable and remain controversial. This study aimed to evaluate a strategy involving sequential MMAE after burr hole surgery for treating recurrent CSDH. We performed a retrospective analysis of data from consecutive patients who had undergone MMAE using liquid embolic agents within approximately 2 weeks after burr hole surgery for recurrent CSDH from September 2020 to March 2022. We analyzed patient characteristics, procedural details, CSDH recurrence after MMAE, surgical rescue, and complications. Six of the nine patients who underwent MMAE for CSDH recurrence were male, and the median age was 85 (range, 70-94) years. Five of the nine patients were being administered antithrombotic agents. The median duration between the burr hole surgery and MMAE procedure was 10 (range, 3-25) days. Anterior and posterior convexity branches were targeted for embolization using low-concentration N-butyl cyanoacrylate (NBCA), and the abnormal vascular networks with a cotton wool appearance disappeared after embolization in all cases. The NBCA distribution was observed by high-resolution computed tomography during the procedure; in three of nine cases, the NBCA penetrated not only the MMA but also the inner membrane. No recurrence, surgical rescue, or complications were observed in any patient during the median follow-up period of 3 months. As a minimally invasive treatment for recurrent CSDH, sequential MMAE after burr hole surgery may be a safe and effective option for preventing recurrence.

Possible mechanism and Atorvastatin-based treatment in cupping therapy-related subdural hematoma: A case report and literature review

Subdural hematoma (SDH) is one of the most lethal types of traumatic brain injury. SDH caused by Intracranial Pressure Reduction (ICPR) is rare, and the mechanism remains unclear. Here, we report three cases of SDH that occurred after substandard cupping therapy and are conjected to be associated with ICPR. All of them had undergone cupping treatments. On the last cupping procedure, they experienced a severe headache after the cup placed on the occipital-neck junction (ONJ) was suddenly removed and were diagnosed with SDH the next day. In standard cupping therapy, the cups are not usually placed on the ONJ. We speculate that removing these cups on the soft tissue over the cisterna magna repeatedly created localized negative pressure, caused temporary but repeated ICPR, and eventually led to SDH development. The Monro-Kellie Doctrine can explain the mechanism behind this - it states that the intracranial pressure is regulated by a fixed system, with any change in one component causing a compensatory change in the other. The repeated ICPR promoted brain displacement, tearing of the bridging veins, and development of SDH. The literature was reviewed to illustrate the common etiologies and therapies of secondary ICPR-associated SDH. Despite the popularity of cupping therapy, its side effects are rarely mentioned. This case is reported to remind professional technicians to fully assess a patient's condition before cupping therapy and ensure that the cups are not placed at the ONJ.