Chronic subdural hematoma is fundamentally a disorder of the meningeal blood vessels.

Embolization of the middle meningeal artery (MMA) has recently been proposed as a curative treatment for Chronic subdural hematoma (cSDH), but evidencefor the indication and timing is not definitive.

Fiorella and Arthur reviewed the potential role for the endovascular management of cSDH within the context of a discussion of the epidemiology, pathophysiology, and conventional management of this disease¹⁾.

https://clinicaltrials.gov/ct2/show/NCT03307395

Nakagawa et al., retrospectively assessed data from 381 consecutive patients who underwent burr hole irrigation for CSDH between 2009 and 2017. Recurrent symptomatic ipsilateral CSDH in 71 (18%) patients was treated by a second burr-hole irrigation and 20 of them had a further symptomatic CSDH recurrence thereafter. Those with persistent ipsilateral CSDH recurrence were treated by MMA embolization. Before the MMA embolization procedures, the amount of hematoma membrane enhancement determined using superselective MMA angiography-DynaCT imaging was classified into three stages.

Embolization of the MMA proceeded without perioperative complications or further CSDH recurrence. The interval between recurrence and the amount of hematoma membrane enhancement significantly correlated (first to second and second to third treatments: p = 0.012 and p = 0.017, respectively). The frequency of bilateral CSDH was significantly higher and the recurrence interval between the first and second treatments was significantly shorter in repeated recurrences group compared with recurrence group (p = 0.023 and p = 0.006, respectively).

Repeatedly recurrent CSDH can be safely treated and cured by MMA embolization. Hematoma membrane enhancement pattern using DynaCT images can predict repeated recurrences CSDH. ²⁾

Five patients with symptomatic chronic SDHs underwent MMA embolization using PVA microparticles. Size of SDH was recorded in maximum diameter and total volume.

Four patients underwent unilateral and 1 underwent bilateral MMA embolization successfully. All cases had significant reduction in total volume of SDH at longest follow-up scan: 81.4 to 13.8 cc (7 wk), 48.5 to 8.7 cc (3 wk), 31.7 and 88 to 0 and 17 cc (14 wk, bilateral), 79.3 to 24.2 cc (8 wk), and 53.5 to 0 cc (6 wk). All patients had symptomatic relief with no complications. Histologic analysis of the chronic SDH membrane in a separate patient that required surgery revealed rich neovascularization with many capillaries and few small arterioles.

MMA embolization could present a minimally invasive and low-risk initial treatment alternative to surgery for symptomatic chronic SDH when clinically appropriate ³⁾.

MMA embolization was performed using angiography, selective microcatheterization of the MMA, and infusion of polyvinyl alcohol particles. Outcomes were assessed clinically and with interval imaging studies at 1 d, 2 wk, and 6 wk postprocedure, and additional intervals as indicated.

MMA embolization was performed successfully on 60 total SDHs in 49 patients. This includes upfront treatment for new (not previously treated) SDH in 42, for recurrence in 8, and prophylaxis (soon after surgical evacuation) in 10. There were 3 mortalities (unrelated to the procedure), and no procedural complications. Of the 50 nonprophylactic cases, there were 4 (8.9%) cases of recurrence requiring surgical evacuation, and 31 (68.9%) that had resolution or reduction in size >50% of SDH at longest follow-up. Overall, 41 (91.1%) were stable or decreased in size and able to avoid surgery.

MMA embolization may represent a minimally-invasive alternative to surgery for new or recurrent chronic SDH, or as prophylaxis to reduce the risk of recurrence after surgery. Given our encouraging results with a 91% long-term success rate, a large scale clinical trial is warranted ⁴⁾.

Link TW, Schwarz JT, Paine SM, Kamel H, Knopman J. Middle Meningeal Artery Embolization for Recurrent Chronic Subdural Hematoma: A Case Series. World Neurosurg. 2018 Oct;118:e570-e574. doi: 10.1016/j.wneu.2018.06.241. Epub 2018 Jul 6. PubMed PMID: 30257310.

Five patients with symptomatic chronic SDHs underwent MMA embolization using PVA microparticles at our institution. Size of SDH was recorded in maximum diameter and total volume.

Four patients underwent unilateral and 1 underwent bilateral MMA embolization successfully. All cases had significant reduction in total volume of SDH at longest follow-up scan: 81.4 to 13.8 cc (7 wk), 48.5 to 8.7 cc (3 wk), 31.7 and 88 to 0 and 17 cc (14 wk, bilateral), 79.3 to 24.2 cc (8 wk), and 53.5 to 0 cc (6 wk). All patients had symptomatic relief with no complications. Histologic analysis of the chronic SDH membrane in a separate patient that required surgery revealed rich neovascularization with many capillaries and few small arterioles.

MMA embolization could present a minimally invasive and low-risk initial treatment alternative to surgery for symptomatic chronic SDH when clinically appropriate ⁵⁾.

Gobran Taha Alfotih reported 14 cases http://www.roneurosurgery.eu/atdoc/AlfotihGobran_Embolization.pdf

A case of a 74-year-old male on aspirin with a history of recurrent symptomatic chronic right-sided subdural hematoma treated successfully with a SEPS and right middle meningeal artery embolization with poly vinyl alcohol (PVA) microparticles. The patient initially presented to the emergency department with headaches, difficulty walking, and left sided hemiparesis. CT Head showed a large chronic right-sided subdural hematoma measuring 2.7 cm thick with 1 cm of leftward shift. Patient underwent placement of a right-sided SEPS and the subdural hematoma decreased in size to 1.0 cm with 2 mm of leftward shift. The patient had resolution of headaches and neurological symptoms and was discharged home. Three months later, the patient returned to the emergency department with headache and left hand numbness. CT Head showed an acute on chronic right-sided subdural hematoma measuring 1.4 cm with 3 mm of leftward shift. Patient underwent right-sided SEPS placement. Repeat CT Head showed reduction in the subdural hematoma to 1.2 cm. The SEPS was removed and the patient had resolution of neurological symptoms. The patient then had a diagnostic cerebral angiogram with PVA microparticle embolization of the right middle meningeal artery. A SEPS was placed at the time of the angiogram to further reduce the size of the subdural hematoma.

Repeat CT Head after SEPS and middle meningeal artery embolization showed decrease in size of the subdural hematoma. Follow-up CT Head showed stability of the subdural hematoma and patient had no further neurological symptoms. Patient was discharged home.

Middle meningeal artery embolization is a useful endovascular technique for reducing the arterial supply to the membranes in chronic subdural hematomas. Middle meningeal artery embolization can reduce the recurrence rate of subdural hematomas ⁶⁾.