Angiographic Anatomy of the Middle Meningeal Artery in Relation to Chronic Subdural Hematoma Embolization.

PURPOSE: Middle meningeal artery (MMA) embolization is emerging as a potential treatment of chronic subdural hematomas (CSDHs). The purpose of this study is to describe MMA angiographic anatomy in relation to CSDH embolization. METHODS: This retrospective monocentric study was performed on imaging data of MMA embolization procedures for CSDH treatment performed between March 15, 2018 and April 30, 2020. Imaging data, including digital subtraction angiography (DSA) were reviewed independently by two physicians. Discrepancies were resolved by consensus. The MMA bifurcation pattern was analyzed according to an extended Adachi classification. Relations of the MMA with the ophthalmic artery (OA) were also analyzed. RESULTS: In this study, 140 MMAs were analyzed. Dominance of the anterior branch (type I) was observed in only 57/140 (41%) MMAs with a moderate interobserver agreement for classifying MMA into type I against all other (κ = 0.53, 95% confidence interval, CI 0.39-0.67). The posterior branch presented a proximal origin (type A), at the point of emergence of the MMA from the foramen spinosum or its immediate vicinity, in 48/135 (36%) MMAs with a very good interobserver agreement for classifying MMAs into type A against all other (κ = 0.82, 95% CI 0.72-0.92). An angiographic relationship with the OA was observed in 26 MMAs (19%). CONCLUSION: In the majority of CSDH patients both anterior and posterior branches of the MMA should be targeted to achieve extensive convexity devascularization. Frequent anatomical variations of the MMA with respect to emergence of the posterior branch and MMA orbital branches are expected to impact CSDH embolization strategy.

Spinal epidural arteriovenous fistula embolization with ethylene vinyl alcohol (EVOH) copolymer using the Scepter Mini dual-lumen balloon.

Left unattended, spinal epidural arteriovenous fistulas (EAVFs) have a potentially severe clinical course. Embolization using ethylene vinyl alcohol (EVOH) copolymers through regular dual-lumen balloons has emerged as a potential option for the treatment of spinal arteriovenous (AV) fistulas;1-3 the main issue with this technique is the navigability of these balloons. The Scepter Mini is a low-profile, dual-lumen balloon, which may be helpful for EVOH embolization of spinal AV fistulas, as it may help to overcome the navigation drawbacks. In this technical video, we present a case of EVOH embolization of a right T6 spinal EAVF through a Scepter Mini balloon. Of note, particular attention should be paid to radiculomedullary arteries arising at the same level or at adjacent levels to avoid severe neurologic complications related to uncontrolled migration of the liquid embolic agent. Moreover, excessive use of embolic material should be avoided to prevent spinal cord compression (video 1). neurintsurg;13/5/492/V1F1V1Video 1.

Direct puncture of the superficial temporal artery for ethylene vinyl alcohol embolization of a type 3 arteriovenous fistula with a dual lumen balloon.

Intracranial dural arteriovenous fistulas (dAVFs) may be difficult to treat by endovascular means, especially when the arterial feeders to the fistula are tortuous. 1 The usual main feeder to intracranial dAVFs is the middle meningeal artery, which may present very tight loops that are often difficult to cross with a microcatheter. 2 Direct puncture of a subcutaneous artery feeding the fistula indirectly via transosseous branches may be a valuable strategic option to overcome this limitation. 3 4 We report here the successful embolization of a Cognard type 3 parietal dAVF by direct puncture of the superficial temporal artery under roadmap guidance. The dAVF was subsequently embolized with ethylene vinyl alcohol via a dual lumen balloon, under balloon inflation. We highlight in this technical video 1 the potential difficulties and risks of direct puncture of the superficial temporal artery. We also stress the risk of delayed scalp necrosis using this technique. neurintsurg;13/5/493/V1F1V1Video 1.

Larger Middle Meningeal Arteries on Computed Tomography Angiography in Patients with Chronic Subdural Hematomas as Compared with Matched Controls.

Chronic subdural hematomas (CSDHs) are one of the most prevalent head-trauma-related conditions. The middle meningeal artery (MMA) may participate in the pathophysiology of CSDHs. The aim of this study was to determine whether CSDHs are associated with large MMAs. Patients referred for CSDH embolization and having undergone a computed tomography angiography (CTA) before embolization were retrospectively included. For each CSDH patient, two age- and sex-matched controls with a CTA performed during the study period were selected. Size comparisons of the MMA were performed between MMAs ipsilateral to CSDHs, on the contralateral side, and in controls. Comparison was also made with angiographic measurements from CSDH embolization procedures. Seventy-five patients with CSDH with available CTAs prior to embolization were enrolled and 146 MMAs were measured. One hundred fifty controls were included and 288 MMAs were measured. The median diameter of the 94 MMAs ipsilateral to a CSDH (1.5 mm; interquartile range [IQR] 1.3-1.7) was significantly larger than that of control MMAs (1.28 mm; IQR 1.15-1.4) (p < 0.001). The median diameter of 52 MMAs on the side of a unilateral CSDH (1.6 mm; IQR 1.4-1.8) was larger than that of the 52 contralateral MMAs (1.4 mm; IQR 1.25-1.6) (p < 0.001). Among the characteristics of patients with CSDH, multiple surgeries were associated with significantly larger MMAs (>1.7 mm; p = 0.01). MMAs ipsilateral to CSDHs appear to be significantly larger as compared with contralateral MMAs and MMAs in a control population, suggesting the involvement of the MMA in the pathophysiology of CSDH.

Middle meningeal artery embolization reduces the post-operative recurrence rate of at-risk chronic subdural hematoma.

BACKGROUND: Embolization of the middle meningeal artery (MMA) has emerged as a potential treatment of chronic subdural hematomas (CSDHs). OBJECTIVE: To evaluate the impact on recurrence rate of postsurgical embolization of CSDH in patients with a higher than average risk of recurrence. METHODS: A monocentric retrospective study was performed on retrospectively collected data. From March 2018 to December 2019, embolization of the MMA was proposed as an adjunct postoperative treatment after burr-hole surgery in patients operated for a recurrent CSDH or a CSDH with an independent recurrence risk factor, including antiplatelet therapy, full anticoagulation therapy, coagulation disorder, hepatopathy, or chronic alcoholism. Patients who had undergone postoperative embolization were compared with a historic group of patients operated between March 2016 and March 2018, selected based on the same inclusion criteria. RESULTS: During the study period, 89 patients (with 74 unilateral and 15 bilateral CSDHs) were included and underwent an embolization procedure, leading to 91 out of a total of 104 MMA being embolized (88%). These were compared with 174 patients (138 unilateral and 36 bilateral CSDH) in the historic control group. One major procedure-related adverse event was registered. Four of the 89 patients (4%) required surgery for a CSDH recurrence in the embolization group, significantly less than the 24 of 174 patients (14%) in the control group (OR=0.28, 95% CI 0.07 to 0.86, p=0.02). CONCLUSIONS: Postsurgical embolization of the MMA may reduce the recurrence rate of CSDHs with a risk factor of recurrence.