Safety and Effectiveness of Embolization for Chronic Subdural Hematoma: Systematic Review and Case Series

To drill or not to drill, that is the question: nonsurgical treatment of chronic subdural hematoma in the elderly. A systematic review

OBJECTIVE

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical pathologies, typically affecting the elderly. Its incidence is expected to grow along with the aging population. Surgical drainage represents the treatment of choice; however, postoperative complications and the rate of recurrence are not negligible. For this reason, nonsurgical alternatives (such as middle meningeal artery embolization, steroids, or tranexamic acid administration) are gaining popularity worldwide and need to be carefully evaluated, especially in the elderly population.

METHODS

The authors performed a systematic review according to PRISMA criteria of the studies analyzing the nonsurgical strategies for CSDHs. They collected all papers in the English language published between 1990 and 2019 by searching different medical databases. The chosen keywords were "chronic subdural hematoma," "conservative treatment/management," "pharmacological treatment," "non-surgical," "tranexamic acid," "dexamethasone," "corticosteroid," "glucocorticoid," "middle meningeal artery," "endovascular treatment," and "embolization."

RESULTS

The authors ultimately collected 15 articles regarding the pharmacological management of CSDHs matching the criteria, and 14 papers included the endovascular treatment.

CONCLUSIONS

The results showed that surgery still represents the mainstay in cases of symptomatic patients with large CSDHs; however, adjuvant and alternative therapies can be effective and safe in a carefully selected population. Their inclusion in new guidelines is advisable.

Endovascular Treatment of Chronic Subdural Hematomas through Embolization: A Pilot Study with a Non-Adhesive Liquid Embolic Agent of Minimal Viscosity (Squid)

OBJECTIVE

Endovascular embolization using non-adhesive agents (e.g., ethylene vinyl alcohol copolymer with suspended micronized tantalum dissolved in dimethyl sulfoxide; Squid, Balt Extrusion) is an established treatment of brain arteriovenous malformations, dural arteriovenous fistulas, and hypervascular neoplasms. Middle meningeal artery (MMA) embolization is a relatively new concept for treating chronic subdural hematomas (CSDH). This study aimed to evaluate the safety and effectiveness of the use of Squid in the endovascular treatment of CSDH.

METHODS

Embolization was offered to patients with CSDH with minimal or moderate neurological deficits and patients who had previously undergone open surgery to evacuate their CSDH without a significant effect. Distal catheterization of the MMA was followed by embolization of the hematoma capsule with Squid 12 or Squid 18. Safety endpoints were ischemic or hemorrhagic stroke and any other adverse event of the endovascular procedure. Efficacy endpoints were the feasibility of the intended procedure and a ≥ 50% reduction of the maximum depth of the CSDH confirmed by follow-up computed tomography (CT) after >3 months.

RESULTS

Between November 2019 and July 2021, 10 patients (3 female and 7 male, age range 42-89 years) were enrolled. Five patients had bilateral hematomas, and five patients had previously been operated on with no significant effect and recurrent hematoma formation. The attempted embolization was technically possible in all patients. No technical or clinical complication was encountered. During a post-procedural follow-up (median 90 days), 10 patients improved clinically. A complete resolution of the CSDH was observed in 10 patients. The clinical condition of all enrolled patients during the so-far last contact was rated mRS 0 or 1.

CONCLUSION

A distal catheterization of the MMA for the endovascular embolization of CSDH with Squid allowed for the devascularization of the MMA and the dependent vessels of the hematoma capsule. This procedure resulted in a partial or complete resolution of the CSDH. Procedural complications were not encountered.

Hematoma subdural crónico: Una patología común de manejo complejo

Antecedentes:

El hematoma subdural crónico (HSDC) es una patología ampliamente estudiada, muy frecuente, sobre todo en adultos mayores; su cuadro clínico tiene una apariencia benigna y suele ir acompañado de múltiples comorbilidades asociadas a la edad, lo que resulta en un aumento de las complicaciones e incluso la muerte. Con el incremento de la expectativa de vida a nivel mundial, el uso de medicamentos antitrombóticos es cada vez más frecuente. El papel de estos fármacos en la evolución de la enfermedad como en la recurrencia, sigue siendo motivo de discusión.

Métodos:

Los autores revisaron la fisiopatología y características clínicas del HSDC. El presente artículo discute acerca de las terapéuticas actuales y las nuevas opciones de tratamiento que podrían mejorar los resultados. Este manuscrito es susceptible de cambios en el tiempo, con el desarrollo científico y tecnológico.

Resultados:

El HSDC puede ser abordado por vía quirúrgica y farmacológica; no obstante, un manejo individualizado requiere la consideracion cuidadosa de diversos factores. A pesar de los avances en el campo de la neurocirugía, la clásica trepanación craneal sigue siendo el Gold estándar en el HSDC y sobre todo en pacientes con síntomas graves. Se debe resaltar que aún hay aspectos de este procedimiento (como la localización del dren, número de drenajes, el efecto de la irrigación, la temperatura de la solución con que se irriga, etc.) que siguen siendo materia de estudio.

Conclusiones:

Entender el mecanismo de la enfermedad ha permitido explicar su historia natural y a su vez proponer nuevas alternativas de tratamiento. El manejo médico (atorvastatina, corticoides) ha generado gran interés por sus alentadores resultados preliminares. Recientemente, se ha reportado la terapia endovascular como una alternativa segura y existe gran expectativa por confirmar su efecto en estudios más grandes.

Middle meningeal artery embolization for chronic subdural hematoma: a systematic review and meta-analysis

Middle meningeal artery (MMA) embolization has been proposed as a minimally invasive treatment for chronic subdural hematoma (cSDH). The aim of this systematic review and meta-analysis is to compare outcomes after MMA embolization versus conventional management for cSDH. We performed a systematic review of PubMed, Embase, Oxford Journal, Cochrane, and Google Scholar databases from April 1987 to October 2020 in accordance with PRISMA guidelines. Studies reporting outcomes after MMA embolization for ≥3 patients with cSDH were included. A meta-analysis comparing MMA embolization with conventional management was performed. The analysis comprised 20 studies with 1416 patients, including 718 and 698 patients in the MMA embolization and conventional management cohorts, respectively. The pooled recurrence, surgical rescue, and in-hospital complication rates in the MMA embolization cohort were 4.8% (95% CI 3.2% to 6.5%), 4.4% (2.8% to 5.9%), and 1.7% (0.8% to 2.6%), respectively. The pooled recurrence, surgical rescue, and in-hospital complication rates in the conventional management cohort were 21.5% (0.6% to 42.4%), 16.4% (5.9% to 27.0%), and 4.9% (2.8% to 7.1%), respectively. Compared with conservative management, MMA embolization was associated with lower rates of cSDH recurrence (OR=0.15 (95% CI 0.03 to 0.75), p=0.02) and surgical rescue (OR=0.21 (0.07 to 0.58), p=0.003). In-hospital complication rates were comparable between the two cohorts (OR=0.78 (0.34 to 1.76), p=0.55). MMA embolization is a promising minimally invasive therapy that may reduce the need for surgical intervention in appropriately selected patients with cSDH. Additional prospective studies are warranted to determine the long-term durability of MMA embolization, refine eligibility criteria, and establish this endovascular approach as a viable definitive treatment for cSDH.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A National Database Study of 191 Patients in the United States

BACKGROUND

Middle meningeal artery embolization (MMAE) has been used as an effective minimally invasive treatment for chronic subdural hematoma (cSDH). The demographics and clinical outcomes after MMAE treatment for cSDH have not yet been studied using a national database.

METHODS

We queried all MMAE cases up to October 7, 2020, from the TriNetX Analytics Network. We identified patients >18 years old who underwent MMAE for treatment of cSDH. Patient demographics, baseline characteristics, comorbidities, and clinical outcomes were evaluated within 180 days after MMAE. Analyses of 180-day mortality and recurrence were performed after propensity score matching to control for baseline characteristics and comorbidities.

RESULTS

The study included 191 patients (mean age 71.2 ± 13.5 years, 73.3% male, 69.6% White, 13.6% Black/African American, and 16.8% other race). Essential hypertension (71.3%), heart disease (62.8%), type 2 diabetes mellitus (27.2%), nicotine dependence (23.6%), chronic kidney disease (19.4%), and overweight/obesity (19.4%) were among the most prevalent comorbidities. At presentation, 20.4% and 40.3% of patients were on antiplatelet and anticoagulation therapy, respectively. Outcomes within 180-day follow-up were 6.3% (1.0%-5.8% when propensity matched) for mortality (12 patients), 7.3% for craniotomy/craniectomy after MMAE (14 patients), 0.52%-5.2% for burr hole procedures (1-10 patients), and no patients with low vision/blindness.

CONCLUSIONS

MMAE is a safe and effective minimally invasive procedure for treatment of cSDH. This is the first analysis of patients undergoing MMAE for cSDH using a national database.

Preoperative embolization of jugular paraganglioma tumors using particles is safe and effective

BACKGROUND

Jugular paragangliomas represent a surgical challenge due to their vascularity and proximity to vital neurovascular structures. Preoperative embolization aids in reducing intraoperative blood loss, transfusion requirements, and improves surgical visualization. Several embolization agents have been used.

OBJECTIVE

The aim of this study is to evaluate the safety and efficacy of PVA in pre-operative embolization of jugular paragangliomas.

METHODS

A retrospective review of all patients who underwent jugular paraganglioma resection with pre-operative embolization between 2000 and 2020 was performed. Pre-operative data including baseline patient and tumor characteristics were documented. Outcomes of preoperative embolization including extent of devascularization and post-embolization complications were recorded. Early and long-term postoperative outcomes were reported.

RESULTS

Twenty-nine patients met study criteria with a median age of 38 years. Average tumor size was 3.4±1.8 cm. The most commonly encountered arterial feeder was the ascending pharyngeal artery followed by the posterior auricular artery. More than 50% reduction in tumor blush was achieved in 25 patients (86.2%). None of the patients experienced new or worsening cranial neuropathy following embolization. Gross total or Near total resection was achieved in 13 patients (44.8%). A STR or NTR was chosen in these patients to preserve cranial nerve function or large vessel integrity. Average intraoperative estimated blood loss was 888 ml, 9 patients (31%) required intra-operative transfusion of blood products. Extent of resection and post-operative complications did not correlate with extent of devascularization.

CONCLUSION

Pre-operative embolization of jugular paraganglioma tumors with PVA particles is an effective strategy with a high safety profile.

Perioperative prophylactic middle meningeal artery embolization for chronic subdural hematoma: a series of 44 cases

OBJECTIVE

Chronic subdural hematoma (cSDH) is a common and challenging pathology to treat due to both the historically high recurrence rate following surgical evacuation and the medical comorbidities inherent in the aging patient population that it primarily affects. Middle meningeal artery (MMA) embolization has shown promise in the treatment of cSDHs, most convincingly to avoid surgical evacuation in relatively asymptomatic patients. Symptomatic patients requiring surgical evacuation may also benefit from perioperative MMA embolization to prevent cSDH recurrence. The goal of this study was to determine the utility of perioperative MMA embolization for symptomatic cSDH requiring surgical evacuation and to assess if there is a decrease in the cSDH recurrence rate compared to historical recurrence rates following surgical evacuation alone.

METHODS

Symptomatic cSDHs were evacuated using a subdural evacuating port system (SEPS) with 5-mm twist-drill craniostomy in an intensive care unit or by performing a craniotomy in the operating room, using either a small (silver dollar, < 4 cm) or large (≥ 4 cm) craniotomy. MMA embolization was performed perioperatively using angiography, selective catheterization of the MMA, and infusion of polyvinyl particles. Outcomes were assessed clinically and radiographically with interval head CT imaging.

RESULTS

There were 44 symptomatic cSDHs in 41 patients, with 3 patients presenting with bilateral symptomatic cSDH. All cSDHs were evacuated using an SEPS (n = 18), a silver-dollar craniotomy (n = 16), or a large craniotomy (n = 10). Prophylactic MMA embolization was performed successfully in all cSDHs soon after surgical evacuation. There were no deaths and no procedural complications. There was an overall reduction of greater than 50% or resolution of cSDH in 40/44 (90.9%) cases, regardless of the evacuation procedure used. Of the 44 prophylactic cases, there were 2 (4.5%) cases of cSDH recurrence that required repeat surgical evacuation at the 1-year follow-up. These 2 cSDHs were initially evacuated using an SEPS and subsequently required a craniotomy, thereby representing an overall 4.5% recurrence rate of treated cSDH requiring repeat evacuation. Most notably, of the 26 patients who underwent surgical evacuation with a craniotomy followed by MMA embolization, none had cSDH recurrence requiring repeat intervention.

CONCLUSIONS

Perioperative prophylactic MMA embolization in the setting of surgical evacuation, via either craniotomy or SEPS, may help to lower the recurrence rate of cSDH.

Middle meningeal artery embolization with subdural evacuating port system for primary management of chronic subdural hematomas

Optimal treatment for chronic subdural hematomas remains controversial and perioperative risks and comorbidities may affect management strategies. Minimally invasive procedures are emerging as alternatives to the standard operative treatments. We evaluate our experience with middle meningeal artery (MMA) embolization combined with Subdural Evacuating Port System (SEPS) placement as a first-line treatment for patients with cSDH. A single institution retrospective review was performed of all patients undergoing intervention. Patients were stratified by treatment with MMA embolization and SEPS placement, MMA embolization and surgery, SEPS placement only, and surgery only for cSDH from 2017 to 2020, and cohorts were compared against each other. Patients treated with MMA/SEPS were more likely to be older, be on anticoagulation, have significant comorbidities, have shorter length of stay, and less likely to have symptomatic recurrence compared to SEPS only cohort. Thus, MMA/SEPS appears to be a safe and equally effective minimally invasive treatment for cSDH patients with significant comorbidities who are poor surgical candidates.

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.

Middle Meningeal Artery Embolization Using Combined Particle Embolization and n-BCA with the Dextrose 5% in Water Push Technique for Chronic Subdural Hematomas: A Prospective Safety and Feasibility Study

BACKGROUND AND PURPOSE

Embolization of the middle meningeal artery for treatment of refractory or recurrent chronic subdural hematomas has gained momentum during the past few years. Little has been reported on the use of the n-BCA liquid embolic system for middle meningeal artery embolization. We present the technical feasibility of using diluted n-BCA for middle meningeal artery embolization.

MATERIALS AND METHODS

We sought to examine the safety and technical feasibility of the diluted n-BCA liquid embolic system for middle meningeal artery embolization. Patients with chronic refractory or recurrent subdural hematomas were prospectively enrolled from September 2019 to June 2020. The primary outcome was the safety and technical feasibility of the use of diluted n-BCA for embolization of the middle meningeal artery. The secondary end point was the efficacy in reducing hematoma volume.

RESULTS

A total of 16 patients were prospectively enrolled. Concomitant burr-hole craniotomies were performed in 12 of the 16 patients. Two patients required an operation following middle meningeal artery embolization for persistent symptoms. The primary end point was met in 100% of cases in which there were no intra- or postprocedural complications. Distal penetration of the middle meningeal artery branches was achieved in all the enrolled cases. A 7-day post-middle meningeal artery embolization follow-up head CT demonstrated improvement (>50% reduction in subdural hematoma volume) in 9/15 (60%) patients, with 6/15 (40%) showing an unchanged or stable subdural hematoma. At day 21, available CT scans demonstrated substantial further improvement (>75% reduction in subdural hematoma volume).

CONCLUSIONS

Embolization of the middle meningeal artery using diluted n-BCA and ethiodized oil (1:6) is safe and feasible from a technical standpoint. The use of a dextrose 5% bolus improves distal penetration of the glue.

A propensity-adjusted comparison of middle meningeal artery embolization versus conventional therapy for chronic subdural hematomas

OBJECTIVE

Middle meningeal artery (MMA) embolization is a promising treatment strategy for chronic subdural hematomas (cSDHs). However, studies comparing MMA embolization and conventional therapy (surgical intervention and conservative management) are limited. The authors aimed to compare MMA embolization versus conventional therapy for cSDHs using a propensity-adjusted analysis.

METHODS

A retrospective study of all patients with cSDH who presented to a large tertiary center over a 2-year period was performed. MMA embolization was compared with surgical intervention and conservative management. Neurological outcome was assessed using the modified Rankin Scale (mRS). A propensity-adjusted analysis compared MMA embolization versus surgery and conservative management for all individual cSDHs. Primary outcomes included change in hematoma diameter, treatment failure, and complete resolution at last follow-up.

RESULTS

A total of 231 patients with cSDH met the inclusion criteria. Of these, 35 (15%) were treated using MMA embolization, and 196 (85%) were treated with conventional treatment. On the latest follow-up, there were no statistically significant differences between groups in the percentage of patients with worsening mRS scores. Of the 323 total cSDHs found in 231 patients, 41 (13%) were treated with MMA embolization, 159 (49%) were treated conservatively, and 123 (38%) were treated with surgical evacuation. After propensity adjustment, both surgery (OR 12, 95% CI 1.5-90; p = 0.02) and conservative therapy (OR 13, 95% CI 1.7-99; p = 0.01) were predictors of treatment failure and incomplete resolution on follow-up imaging (OR 6.1, 95% CI 2.8-13; p < 0.001 and OR 5.4, 95% CI 2.5-12; p < 0.001, respectively) when compared with MMA embolization. Additionally, MMA embolization was associated with a significant decrease in cSDH diameter on follow-up relative to conservative management (mean -8.3 mm, 95% CI -10.4 to -6.3 mm, p < 0.001).

CONCLUSIONS

This propensity-adjusted analysis suggests that MMA embolization for cSDH is associated with a greater extent of hematoma volume reduction with fewer treatment failures than conventional therapy.

Neuroanatomy of cranial dural vessels: implications for subdural hematoma embolization

Adoption of middle meningeal artery embolization in the management of chronic subdural hematomas has led to a renewed interest in dural vascular anatomy. The readily identifiable major dural arteries and potential hazards associated with their embolization are well described. Less emphasized are several levels of intrinsic dural angioarchitecture, despite their more direct relationship to dural based diseases, such as subdural hematoma and dural fistula. Fortunately, microvascular aspects of dural anatomy, previously limited to ex vivo investigations, are becoming increasingly accessible to in vivo visualization, setting the stage for synthesis of the old and the new, and providing a rationale for the endovascular approach to subdural collections in particular. In contrast with traditional anatomical didactics, where descriptions advance from larger trunks to smaller pedicles, we present a strategic approach that proceeds from a fundamental understanding of the dural microvasculature and its relationship to larger vessels.

Management of chronic subdural hematoma with the subdural evacuating port system: Systematic review and meta-analysis

The subdural evacuating port system (SEPS) is a minimally invasive option for treating chronic subdural hematoma (cSDH). Individual case series have shown it to be safe and effective, but outcomes have not been systematically reviewed. We sought to review the literature in order to determine the safety and efficacy of SEPS as a first line treatment for cSDH. A comprehensive literature search for outcomes following SEPS placement as a primary treatment for cSDH was performed. The primary outcome was treatment success, which was defined as a composite of improvement in presenting symptoms and no need for further treatment in the operating room. Additional outcomes included discharge disposition, length of stay (LOS), hematoma recurrence, and complications. A total of 12 studies comprising 953 patients who underwent SEPS placement met the inclusion criteria. The pooled rate of a successful outcome was 0.79 (95% CI 0.75-0.83). Frequency of delayed hematoma recurrence was 0.15 (95% CI 0.10-0.21). The pooled inpatient mortality rate was 0.02 (95% CI 0.01-0.03). Complications rates included 0.02 (95% CI 0.00-0.03) for any acute hemorrhage, 0.01 (95% CI 0.00-0.01) for acute hemorrhage requiring surgery, and 0.02 (95% CI 0.01-0.03) for seizure. SEPS placement is associated with a success rate of 79% and very low rates of acute hemorrhage and seizure. This data supports its use as a first-line management strategy, although prospective randomized studies are needed.

Chronic Subdural Hematoma (cSDH): A review of the current state of the art

Introduction

Incidence of Chronic Subdural Hematoma (cSDH) is rising worldwide, partly due to an aging population, but also due to increased use of antithrombotic medication. Many recent studies have emerged to address current cSDH management strategies.

Research question

What is the state of the art of cSDH management.

Material and methods

Review.

Results

Head trauma, antithrombotic use and craniocerebral disproportion increase the risk of cSDH development. Most patients present with disorientation, GCS 13–15, and symptoms arising from cortical irritation and increased intracranial pressure. cSDH occurs bilaterally in 9–22%. CT allows assessment of cerebral compression (herniation, hematoma thickness, ventricle collapse, midline shift), hematoma age and presence of membranes, factors that ultimately determine treatment urgency and surgical approach. Recurrence remains the principle complication (9–33%), occurring more commonly with older age and bilateral cSDHs.

Discussion and conclusion

While incompletely understood, it is generally believed that injury in the dural cell layer results in bleeding from bridging veins, resulting in a hematoma formation, with or without a preceding hygroma, in a potential space approximating the junction between the dura and arachnoid. Neovascularization and leaking from the outer membrane are thought to propagate this process. Evidence that MMA embolization may reduce recurrence rates is a potentially exciting new treatment option, but also supports the theory that the MMA is implicated in the cSDH pathophysiology. The use of steroids remains a controversial topic without clear treatment guidelines. cSDH represents a common neurosurgical problem with burr-hole treatment remaining the gold standard, often in conjunction with subgaleal drains. MMA embolization to stop recurrence may represent an important evolution in understanding the pathophysiology of cSDH and improving treatment.

•

Incidence of cSDH is rising, partly due to the aging population and increased antithrombotic use.

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cSDH occurs bilaterally in 9–22% of cases.

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Recurrence remains the principle complication and has been estimated at 9–33%.

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Risk factors for recurrence include old age and bilateral cSDHs.

•

MMA embolization may reduce recurrence, but its efficacy and target population remain unclear.

Endovascular embolisation of the middle meningeal artery to treat chronic subdural haematomas: effectiveness, safety, and the current controversy. A systematic review

INTRODUCTION

Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established.

DEVELOPMENT

This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients.

CONCLUSIONS

eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

Segmentation of Chronic Subdural Hematomas Using 3D Convolutional Neural Networks

OBJECTIVE

Chronic subdural hematomas (cSDHs) are an increasingly prevalent neurologic disease that often requires surgical intervention to alleviate compression of the brain. Management of cSDHs relies heavily on computed tomography (CT) imaging, and serial imaging is frequently obtained to help direct management. The volume of hematoma provides critical information in guiding therapy and evaluating new methods of management. We set out to develop an automated program to compute the volume of hematoma on CT scans for both pre- and postoperative images.

METHODS

A total of 21,710 images (128 CT scans) were manually segmented and used to train a convolutional neural network to automatically segment cSDHs. We included both pre- and postoperative coronal head CTs from patients undergoing surgical management of cSDHs.

RESULTS

Our best model achieved a DICE score of 0.8351 on the testing dataset, and an average DICE score of 0.806 ± 0.06 on the validation set. This model was trained on the full dataset with reduced volumes, a network depth of 4, and postactivation residual blocks within the context modules of the encoder pathway. Patch trained models did not perform as well and decreasing the network depth from 5 to 4 did not appear to significantly improve performance.

CONCLUSIONS

We successfully trained a convolutional neural network on a dataset of pre- and postoperative head CTs containing cSDH. This tool could assist with automated, accurate measurements for evaluating treatment efficacy.

The IDEAL framework in neurosurgery: a bibliometric analysis

BACKGROUND

The Idea, Development, Exploration, Assessment and Long-term study (IDEAL) framework was created to provide a structured way for assessing and evaluating novel surgical techniques and devices.

OBJECTIVES

The aim of this paper was to investigate the utilization of the IDEAL framework within neurosurgery, and to identify factors influencing implementation.

METHODS

A bibliometric analysis of the 7 key IDEAL papers on Scopus, PubMed, Embase, Web of Science, and Google Scholar databases (2009-2019) was performed. A second journal-specific search then identified additional papers citing the IDEAL framework. Publications identified were screened by two independent reviewers to select neurosurgery-specific articles.

RESULTS

The citation search identified 1336 articles. The journal search identified another 16 articles. Following deduplication and review, 51 relevant articles remained; 14 primary papers (27%) and 37 secondary papers (73%). Of the primary papers, 5 (36%) papers applied the IDEAL framework to their research correctly; two were aligned to the pre-IDEAL stage, one to the Idea and Development stages, and two to the Exploration stage. Of the secondary papers, 21 (57%) explicitly discussed the IDEAL framework. Eighteen (86%) of these were supportive of implementing the framework, while one was not, and two were neutral.

CONCLUSION

The adoption of the IDEAL framework in neurosurgery has been slow, particularly for early-stage neurosurgical techniques and inventions. However, the largely positive reviews in secondary literature suggest potential for increased use that may be achieved with education and publicity.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Chronic subdural hematoma (cSDH) is a common disease process associated with significant morbidity that occurs most often in elderly patients. Asymptomatic patients are typically treated conservatively, with surgical intervention reserved for patients with symptomatic and/or large hematomas that cause brain compression. However, conservatively managed cSDH cases frequently progress, and surgical evacuation of cSDH is associated with high rates of complication and recurrence. Recently, successful treatment of cSDH via middle meningeal artery (MMA) embolization has been reported in small case series and case reports. This article reviews the existing literature on MMA embolization for cSDH and discusses the need for randomized control trials and/or large prospective studies to establish the efficacy of MMA embolization for this disease.

Middle meningeal artery embolization for chronic subdural hematoma: an institutional technical analysis

BACKGROUND

Recently, middle meningeal artery (MMA) embolization has emerged as a potentially safe and effective method of treating chronic subdural hematoma (cSDH).

OBJECTIVE

To report a single-center experience with MMA embolization and examines the type of embolic material used, the extent of penetration, and the number of MMA branches embolized.

METHODS

A retrospective analysis of all patients with MMA embolization from 2018 through 2019 was performed. A failed outcome was defined as either surgical rescue and/or greater than 10 mm of hematoma residual or reaccumulation following embolization.

RESULTS

Of 35 patients, surgery had failed for 9 (26%) and initial conservative treatment had failed for 6 (17%). Of 41 MMA embolizations, including those in six patients with bilateral cSDH who underwent bilateral MMA embolization, 29 (72%) were performed using ethylene vinyl alcohol copolymer (Onyx), 7 (17%) using particles, and 5 (12%) using n-butyl cyanoacrylate. Both the anterior and posterior MMA divisions were embolized in 29 cases (71%); distal penetration of these branches was achieved in 25 embolizations (61%). Twenty-six (63%) cSDHs completely resolved. Complete resolution was seen in 22 of 29 hematomas (76%) in which both anterior and posterior MMA branches were occluded versus 4 of 12 (33%) following single-branch embolization (p=0.014). Embolization of one cSDH (2%) failed.

CONCLUSION

MMA embolization of cSDHs appears to be both safe and efficacious. Furthermore, embolization of both the anterior and posterior MMA branches may be associated with increased odds of complete resolution.

Middle meningeal artery embolization treatment of nonacute subdural hematomas in the elderly: a multiinstitutional experience of 151 cases

OBJECTIVE

The incidence of already common chronic subdural hematomas (CSDHs) and other nonacute subdural hematomas (NASHs) in the elderly is expected to rise as the population ages over the coming decades. Surgical management is associated with recurrence and exposes elderly patients to perioperative and operative risks. Middle meningeal artery (MMA) embolization offers the potential for a minimally invasive, less morbid treatment in this age group. The clinical and radiographic outcomes after MMA embolization treatment for NASHs have not been adequately described in elderly patients. In this paper, the authors describe the clinical and radiographic outcomes after 151 cases of MMA embolization for NASHs among 121 elderly patients.

METHODS

In a retrospective review of a prospectively maintained database across 15 US academic centers, the authors identified patients aged ≥ 65 years who underwent MMA embolization for the treatment of NASHs between November 2017 and February 2020. Patient demographics, comorbidities, clinical and radiographic factors, treatment factors, and clinical outcomes were abstracted. Subgroup analysis was performed comparing elderly (age 65–79 years) and advanced elderly (age > 80 years) patients.

RESULTS

MMA embolization was successfully performed in 98% of NASHs (in 148 of 151 cases) in 121 patients. Seventy elderly patients underwent 87 embolization procedures, and 51 advanced elderly patients underwent 64 embolization procedures. Elderly and advanced elderly patients had similar rates of embolization for upfront (46% vs 61%), recurrent (39% vs 33%), and prophylactic (i.e., with concomitant surgical intervention; 15% vs 6%) NASH treatment. Transfemoral access was used in most patients, and the procedure time was approximately 1 hour in both groups. Particle embolization with supplemental coils was most common, used in 51% (44/87) and 44% (28/64) of attempts for the elderly and advanced elderly groups, respectively. NASH thickness decreased significantly from initial thickness to 6 weeks, with additional decrease in thickness observed in both groups at 90 days. At longest follow-up, the treated NASHs had stabilized or improved in 91% and 98% of the elderly and advanced elderly groups, respectively, with > 50% improvement seen in > 60% of patients for each group. Surgical rescue was necessary in 4.6% and 7.8% of cases, and the overall mortality was 8.6% and 3.9% for elderly and advanced elderly patients, respectively.

CONCLUSIONS

MMA embolization can be used safely and effectively as an alternative or adjunctive minimally invasive treatment for NASHs in elderly and advanced elderly patients.

Organized Chronic Subdural Hematoma Treated with Middle Meningeal Artery Embolization and Small Craniotomy: Two Case Reports

The most preferred treatment for organized chronic subdural hematoma (OSDH) remains controversial. Although a large craniotomy has been reported to be necessary and effective for the treatment of an OSDH, a craniotomy is associated with postoperative hemorrhagic complications and recurrence. Although middle meningeal artery (MMA) embolization has been reported to be effective for a refractory chronic subdural hematoma (CSDH), its efficacy for an OSDH remains unclear. We report two cases of OSDH treated with MMA embolization followed by hematoma removal via a small craniotomy under local anesthesia with good progress. Case 1: A 71-year-old man underwent a single burr hole irrigation for a CSDH, which failed due to a solid hematoma. He underwent a small craniotomy under local anesthesia after an MMA embolization. During the craniotomy, a small hemorrhage from the hematoma and its outer membrane was observed. Postoperatively, the symptoms disappeared immediately, and the hematoma did not recur. Case 2: A 77-year-old man underwent a burr hole irrigation, but the hematoma was not evacuated because of an OSDH, and he remained in motor aphasia. After an MMA embolization, a craniotomy was performed under local anesthesia. Intraoperative hemorrhage was minimal, and after the craniotomy, his neurological symptoms improved without any recurrence. MMA embolization and hematoma removal with a small craniotomy could be a treatment option for an OSDH.

Endovascular embolisation of the middle meningeal artery to treat chronic subdural haematomas: Effectiveness, safety, and the current controversy. A systematic review

INTRODUCTION

Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established.

DEVELOPMENT

This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients.

CONCLUSIONS

eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

Transradial middle meningeal artery embolization for chronic subdural hematoma using Onyx: case series

Background

Middle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation.

Methods

Data for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018–2019) were analyzed from a single-center, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed.

Results

Forty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) TRA embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of TRA conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity Index (>5). Symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. At mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009).

Conclusion

Transradial Onyx MMA embolization under conscious sedation is safe and effective for CSDH treatment. TRA may be especially useful in elderly patients with numerous comorbidities.

Systematic review of current randomised control trials in chronic subdural haematoma and proposal for an international collaborative approach

BACKGROUND

Chronic subdural haematoma (CSDH) is a pathology that is frequently encountered by neurosurgeons. Nevertheless, there is a lack of guidelines based on solid evidence. There has been a recent and considerable increase in the interest on management and outcomes for CSDH. Therefore, we systematically reviewed all currently running randomised controlled trials (RCTs) in chronic subdural haematoma to understand the areas under investigation and plan future collaborative trials.

METHODS

Clinical trials databases (Cochrane Controlled Register of Trials, WHO ICTRP and clinical trials.gov) were searched for trials relevant to chronic subdural haematoma. It was then established which trials were currently running and fulfilled robust research methodology for a RCT.

RESULTS

There are 26 currently running RCTs in CSDH, with the most common topics covering application of steroids (7), surgical techniques (5) and tranexamic acid (5). Further to this, there are trials running on other pharmacological agents (4), middle meningeal artery (MMA) embolisation (2) and peri-operative management (3).

CONCLUSIONS

Pharmacological agents are a particular focus of CSDH management currently, and a wealth of studies on steroids will hopefully lead to more harmonised, evidence-based practice regarding this in the near future. Surgical techniques and new procedures such as MMA embolisation are also important focuses for improving patient outcomes. There is an on-going need for future RCTs and evidence-based guidelines in CSDH, particularly including low- and middle-income countries, and it is hoped that the establishment of the iCORIC (International COllaborative Research Initiative on Chronic Subdural Haematoma) will help address this.

Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis

INTRODUCTION

Refractory or chronic subdural hematomas (cSDH) constitute a challenging entity that neurosurgeons face frequently nowadays. Middle meningeal artery embolization (MMAE) has emerged in the recent years as a promising treatment option. However, solid evidence that can dictate management guidelines is still lacking.

METHODS

We conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of MMAE compared with conventional treatments for refractory or cSDH. Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk difference were conducted recurrence, need for surgical rescue, and complications.

RESULTS

Eleven studies (177 patients) were included. Majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. Meta-analysis of proportions showed treatment failure to be 2.8%, need for surgical rescue 2.7%, and embolization-related complications 1.2%. Meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I² = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I² = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I² = 0) compared to conventional groups.

CONCLUSIONS

Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH.

Recurrent Acute Subdural Hematoma Due to Middle Meningeal Artery Bleeding Treated by Embolization

BACKGROUND

Recurrent acute subdural hematomas (ASDHs) are a common complication of neurosurgical operations. However, ASDHs associated with middle meningeal artery (MMA) injury are extremely rare. We encountered a rare case of recurrent ASDH due to MMA bleeding after craniotomy for a nontraumatic ASDH and successfully performed MMA embolization for treatment of it.

CASE DESCRIPTION

A 56-year-old woman was admitted to our department with progressively worsening headache and vomiting approximately 1 week. She had no history of head trauma and illness. A head computed tomography (CT) scan revealed an ASDH on the right hemisphere. The patient underwent a right-sided craniotomy for evacuation of the hematoma. Two days later, she exhibited impaired consciousness and a repeat CT scan showed a recurrent ASDH. To clarify the cause, we performed cerebral digital subtraction angiography for the patient. Obvious contrast extravasation from the anterior branch of the right MMA was noticed. It was considered to be related to the recurrent ASDH. Embolization of the MMA was performed using Onyx 18 (Micro Therapeutics, Inc., Irvine, California, USA). Follow-up CT scans showed progressive resolution of the ASDH and no recurrence. The patient was discharged without any neurologic deficits.

CONCLUSIONS

In our case, the relationship between the recurrent ASDH and MMA was observed via angiography and MMA embolization was successfully performed to avoid surgery for reevacuation, suggesting that active bleeding of MMA may be a cause of recurrent ASDH after neurosurgical operations and endovascular exploration, and possible treatment is necessary for an unexplained ASDH.

Treatment Outcomes of Burr-Hole Surgery for Chronic Subdural Hematoma in the Elderly Living Beyond Life Expectancy: A Study Comparing Cure, Recurrence, and Complications in Patients Aged ≥80 Years versus ≤79 Years

BACKGROUND

Few reports have focused on chronic subdural hematoma (CSDH) in the very elderly, who have lived beyond average life expectancy. Our aim is to appraise treatment outcomes of burr-hole craniotomy for CSDH in the elderly, focusing on cure, recurrence, and complications.

METHODS

Fifty patients ≤79 years of age (group A) and 73 patients ≥80 years of age (group B) were studied. Recurrence was defined as requiring reoperation for hematoma regrowth or symptomatic failure. A cure was regarded as having been achieved in the absence of hematoma on postoperative computed tomography. Complications were defined as any harmful event related to the treatment procedure for CSDH.

RESULTS

Cure was documented in 31 patients in group A (63%) and 24 patients in group B (33%) (P = 0.0017). Median intervals to cure were 2.76 and 3.73 months, respectively (P = 0.06). Cumulative cure rates were 51%/76% and 36%/59%, respectively, at the sixth/twelfth postoperative months. Recurrence was documented in 2 patients (4%) and 11 patients (15%), respectively (P = 0.07). Median intervals to recurrence were 0.81 and 1.25 months, respectively (P = 0.049). Cumulative recurrence-free rates were 96%/92% and 87%/75%, respectively, at the third/sixth postoperative months. Complications were observed in 2 patients (4%) and 4 patients (5%), respectively (P = 1.00).

CONCLUSIONS

With advancing age, CSDH might show a greater tendency to recur and a longer time is required to achieve a cure. However, complications developed only in high-risk patients. Thus, surgical treatment for CSDH in elderly patients, even those who have lived beyond life expectancy, might provide acceptably effective results.