Chronic Subdural Hematoma - SLICE Next Frontiers 2023

Chronic Subdural Hematoma Management

Chronic subdural hematoma (CSDH) is defined as a collection of blood at the surface of the brain between the dura and arachnoid mater. CSDH is a common neurosurgical disease that is increasing in frequency each year. By 2030, CSDH will likely be the most common cranial neurosurgical diagnosis in adults.[1] It is frequently observed in elderly patients with minor head trauma and patient on antiplatelet or anticoagulant treatment. It is not a benign disease. One-year mortality was reported to be up to 32%. It may cause cognitive impairment, gait instability, headaches, hemiparesis, seizures, and aphasia. Once believed that it was venous origin ( torn bridging vein hypothesis), which is more accurate for acute subdural hematoma, now CSDH is considered to arise from oozing from inner dural plexus as a result of arterial injury within this plexus. If this inial injury is unable to be repaired, it stimulates a cycle of chronic inflammation and angiogenesis, and results in the development of a leaky vascular membrane(neomembrane) which incite a positive feedback cycle of continued hemorrhage, inflammation, and angiogenesis (degenerative vascular changes).[2] In the treatment of this disease, surgery is traditionally performed if there are severe symptoms with hematomas larger than 10 mm and 5 mm midline shifts. For other patients with asymptomatic or have minor symptoms conservative management is generally favored. However, 23.5% of patients who manage conservatively ultimately require surgical treatment.

Surgical therapies involve the irrigation and removal of blood products, sometimes with partial resection of neomembranes, but the recurrence rate after surgery is as high as 15% and the requirement of reversal of antiplatelet and anticoagulant agents is also a problem for these elderly patients with numerous comorbidities.

Middle meningeal artery (MMA) embolization is a new indication of the treatment of CSDH. MMA embolization for CSDH was first reported in 2000 as a case report by Mandai et Al.[3] Newly formed vascular membranes are believed to receive blood supply from the MMA. Enhancement of CSDH membranes after MMA embolization supports the idea of a pathological connection between the MMA and subdural membranes in CSDH. The aim of embolization of MMA is to de-vascularize the neomembrane to decrease or prevent recurrent hemorrhages. MMA embolization can be used as a primary treatment modality or as an adjunct to surgery (pre-surgical or post-surgical ). Until now, there is no established guideline for MMA embolization. However, the number of studies on MMA embolization for CSDH has been increasing rapidly in recent years. Currently, according to clinicaltrials. gov, there are 12 randomized clinical trials recruiting patients actively, expected to be completed by the end of this year or next year. Therefore, they will provide an increase in the quality of available data and are expected to help establish its safety and efficacy, as well as identify the most appropriate embolization agents and techniques. It has been reported that the rate of overall treatment success was more than 90%, the embolization-related complication rate was below 5%, and the rate of the need for rescue therapy after embolization was between 5-10%. [4]. It is imperative to be familiar with the anatomy of the MMA and potential anastomosis (MMA-ophthalmic artery, petrous branch, and MMA-ICA).

Most of the existing studies have reported using polyvinyl alcohol microparticles( PVA) as the primary embolizing agent; some used onyx, n-butyl-cyanoacrylate, or coils. The optimal embolic agents remain unknown. If dimethyl sulfoxide(DMSO) is going to be used under conscious sedation, it is reasonable to inject lidocaine (30 mg, If you use 2% lidocaine, it contains 20 mg per ml) intra-arterially at a rate of 0.5mL per minute to prevent discomfort during the procedure [5]. If possible, embolizing both anterior and posterior MMA branches have lower odds of recurrence as opposed to a single branch embolization. It is currently uncertain whether extention of embolization to distal MMA territory may provide additional benefit to patients.

Endovascular neurointervention has continued to be a rapidly evolving field, besides aneurysm, stroke, and AVM treatment, there are various conditions including subdural hematoma embolization, neurooncology, stentrode, CSF field ( CSF-venous fistula, e-shunt) that all coming into neurointervention field, Subdural hematoma management will be part of young neurointeventiolist's job, so young neurointerventionist may be trained how to use simple system (cranial access kit [subdural evacuating port system, SEPS]) to evacuate subdural hematoma and extraventricular drainage placement in anjio-suit regardless of which background they come.

Further reading:

1. Ironside N, Nguyen C, Do Q, et al. Middle meningeal artery embolization for chronic subdural hematoma: a systematic review and meta-analysis. J Neurointerv Surg. 2021 Oct;13(10):951-957.

2. Shapiro M, Walker M, Carroll KT, et al. Neuroanatomy of cranial dural vessels: implications for subdural hematoma embolization. J Neurointerv Surg. 2021 May;13(5):471- 477

3. Mandai S, Sakurai M, Matsumoto Y. Middle meningeal artery embolization for refractory chronic subdural hematoma. Case report. J Neurosurg. 2000;93(4):686-688.

4. Kan P, Maragkos GA, Srivatsan A, et al. Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Multi-Center Experience of 154 Consecutive Embolizations. Neurosurgery. 2021;88(2):268-277. 

5. Rajah GB, Waqas M, Dossani RH, et al. Transradial middle meningeal artery embolization for chronic subdural hematoma using Onyx: case series. J Neurointerv Surg. 2020;12(12):1214-1218.