Meningeal Artery Research Articles

Parasagittal and Superior Sagittal Sinus Dural Arteriovenous Fistulas: Clinical Presentations, Imaging Characteristics, and Treatment Strategies.

Parasagittal and superior sagittal sinus (SSS) dural arteriovenous fistulas (DAVFs) are often inappropriately classified. We explore the clinical presentations, imaging characteristics, and endovascular treatment strategies of these 2 DAVF subtypes. Clinical and imaging data of 19 patients with SSS or parasagittal sinus DAVFs who underwent endovascular treatment in our institution between 2017 and 2022 were retrospectively analyzed. The angiographic findings, endovascular treatment strategies, and angiographic outcomes were evaluated and recorded. Among these 19 patients, 14 had a parasagittal DAVF, 4 had a SSS DAVF, and 1 patient had both parasagittal and SSS DAVF. Only 1 (1/19, 5.26%) patient presented with intracranial hemorrhage. For the parasagittal DAVF group, most of the shunts were located along the middle third of the SSS (12/15, 80%), on the dura in proximity with the junctional zone between the bridging vein and SSS (15/15, 100%), with ipsilateral cortical venous reflux (CVR) (15/15, 100%). For the SSS DAVF group, all 5 patients had shunting zone along the middle third of the SSS, on the sinus or parasinus wall, with bilateral CVR. Transarterial embolization, via the middle meningeal artery as the primary route of access, was the primary treatment approach in 95% of cases (19/20). Reflux of embolization material into the SSS was observed in 1 case (1/5, 20%) of SSS DAVF in which balloon sinus protection was not used during embolization. Our study found that parasagittal DAVFs have shunting point(s) centered on the junctional zone of the bridging vein and the SSS with ipsilateral CVR, while SSS DAVFs have shunting point(s) centered on the sinus or parasinus wall with bilateral CVR. Transarterial embolization via the middle meningeal artery can be used as the primary treatment strategy in most cases. Balloon sinus protection during embolization is not necessary in cases of parasagittal DAVF with occluded or stenosed connection with the SSS but its use should be considered in cases of SSS DAVF with patent sinus.

Vascular microforamina and endocranial surface: Normal variation and distribution in adult humans.

The term craniovascular traits refers to the imprints left by arteries and veins on the skull bones. These features can be used in biological anthropology and archaeology to investigate the morphology of the vascular network in extinct species and past populations. Generally, the term refers to macrovascular features of the endocranial cavity, like those associated with the middle meningeal artery, venous sinuses, emissary foramina, and diploic channels. However, small vascular passages (here called microforamina or microchannels) have been occasionally described on the endocranial surface. The larger ones (generally with a diameter between 0.5 and 2.0 mm) can be detected through medical scanners on osteological collections. In this study, we describe and quantify the number and distribution of these microforamina in adult humans (N = 45) and, preliminarily, in a small sample of children (N = 7). Adults display more microchannels than juvenile skulls. A higher frequency in females is also observed, although this result is not statistically significant and might be associated with allometric cranial variations. The distribution of the microforamina is particularly concentrated on the top of the vault, in particular along the sagittal, metopic, and coronal sutures, matching the course of major venous sinuses and parasagittal bridging veins. Nonetheless, the density is lower in the region posterior to bregma. Beyond oxygenation, these vessels are likely involved in endocranial thermal regulation, infection, inflammation, and immune responses, and their distribution and prevalence can hence be of interest in human biology, evolutionary anthropology, and medicine.

The relationship between the auriculotemporal nerve and middle meningeal artery in a sample of the South African population.

The interaction between the auriculotemporal nerve and the middle meningeal artery within the infratemporal fossa is vital in the spread of perineural tumours. Knowledge of their morphological and morphometric variations is critical to surgeons approaching the infratemporal fossa. There is a paucity of literature on the relationship between the auriculotemporal nerve and middle meningeal artery in a South African population. Hence, the aim of this study was to document the morphology and morphometry of the auriculotemporal nerve and its relationship to the middle meningeal artery within a South African cohort. The infratemporal fossae of 32 cadaveric specimens were dissected and the auriculotemporal nerves and middle meningeal arteries were analysed, together with their variations. Nine out of 32 specimens displayed one-root, 14/32 two-root, 7/32 three-root, and 2/32 four-root auriculotemporal nerves. Eighteen auriculotemporal nerves originated from the mandibular nerve, while the rest had at least one communication to the inferior alveolar nerve. The mean distance between the first and second roots of the auriculotemporal nerve was 4.69 mm. There were V-shaped formations found in 23 auriculotemporal nerves. However, the middle meningeal artery only passed through 13/23 V-shapes. The maxillary artery was of a deep course in relation to the lateral pterygoid muscle in 19/32 and superficial in 13/32 of the sample. There were 15 accessory middle meningeal arteries present in 14/32 specimens. The accessory middle meningeal arteries often arose from the middle meningeal artery (46.67%). The results of this study show a high possibility of variations of the auriculotemporal nerve and middle meningeal artery in the South African population. The variations and interactions should be considered during surgical procedures.

Middle meningeal artery embolization for chronic subdural hematoma- pathophysiology and radiological findings

Middle meningeal artery embolization for chronic subdural hematoma- pathophysiology and radiological findings

Middle meningeal artery embolization for chronic subdural hematoma: An analysis of 45 consecutive patients

ObjectiveThe authors evaluate the outcomes of 45 consecutive patients treated with MMAE in attempt to identify variables which may affect the outcome of patients treated with middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH). MethodsMultivariate analysis was performed on patients who received MMAE for cSDH including age, size of cSDH, adjunct surgical drainage (ASD), presence of unilateral or bilateral collections and use of anti-coagulants. Results20 patients underwent MMAE with planned ASD while 15 patients had MMAE only; these groups had an average reduction of 74 and 69% of cSDH respectively. Of the 15 patients who were initially treated only with MMAE, 3 (20%) required rescue craniotomy. 20 patients (57%) who had initially presented while receiving oral anticoagulants had an average of 71% reduction with ASD compared to 74% reduction in those without ASD. Patients not using anti-coagulants had 84 and 78% average reduction in size respectively. 12 patients presented with bilateral cSDH; patients who received ASD had an average reduction of 58%; those without ASD had 63%. Patients with unilateral cSDH had 85 and 83% respectively. ConclusionsMMAE can be a useful alternative or adjunct to standard surgical treatment for cSDH. Our study found only 3 of 35 patients (9%) treated with this method required any further surgical intervention. No patient who received ASD had a recurrence of their cSDH. Further investigation, including prospective randomized studies would be useful to better identify which patients can benefit and variables which impact the outcome of patients undergoing MMAE.

Middle meningeal artery embolization as standalone treatment versus combined with surgical evacuation for chronic subdural hematomas: systematic review and meta-analysis.

Middle meningeal artery embolization (MMAE) is a novel treatment for chronic subdural hematomas (cSDHs) with high variability of use across practitioners and institutions. This study sought to investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgery for select patients with cSDH. The authors searched the Medline and Embase databases for studies reporting outcomes specific to standalone MMAE and combined MMAE and surgery. The Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess risk of bias in each included study. Patient characteristics were compared between cohorts, and rates of surgical recurrence of standalone MMAE and combined MMAE and surgery were pooled using random-effects models. Four hundred two unique patients (156 with standalone MMAE and 246 with combined MMAE and surgery) were identified across 8 studies. Overall, the subdural thickness for the standalone MMAE group was modestly but statistically significantly smaller (16.8 vs 18.8 mm, estimated p value 0.002), and the mean follow-up time was significantly longer for the standalone MMAE group (5.4 vs 2.3 months, estimated p value < 0.001); there were no significant differences between age, sex, and anticoagulant use. The surgical recurrence rates were not significantly different between the two groups (estimated p value 0.63). Using random-effects models, the surgical recurrence rates were estimated at 6.8% (95% CI 3.5%-11.2%) and 4.6% (95% CI 2.3%-7.7%) for standalone MMAE and combined MMAE and surgery, respectively. Standalone MMAE for cSDH may yield a low rate of surgical recurrence, which may be comparable to that of combined MMAE and surgery. However, studies in this systematic review and meta-analysis were primarily single-arm studies prone to treatment bias. Future studies are needed to further investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgical treatment for cSDH in select patients.

Diagnosis of a Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus: The MMA Sign on Routine 3D-TOF MR Angiography

The main feeding artery of a dural arteriovenous fistula (DAVF) involving the superior sagittal sinus (SSS) is the middle meningeal artery (MMA). MMA extends continuously from the proximal part to SSS in DAVF involving SSS. It is possible to diagnose DAVF involving SSS by evaluating the proximal part of MMA on routine three-dimensional time-of-flight MR angiography (MRA). We termed the finding in an anteroposterior maximum intensity projection (MIP) image of routine MRA in which MMA was continuously visualized at the top of the imaging slab (the upper corpus callosum level) without tapering as the MMA sign. The purpose of the present study was to examine the frequency of the MMA sign on routine MRA in patients with DAVF involving SSS and control patients. Subjects comprised 18 patients with DAVF involving SSS confirmed by angiography and 871 control subjects who underwent routine MRA. The presence of the MMA sign was retrospectively evaluated using an anteroposterior MIP image of routine MRA in patients with DAVF involving SSS and control patients. The MMA sign was observed in 17 of the 18 (94%) patients with DAVF involving SSS. In one patient with DAVF involving the posterior part of SSS without the MMA sign, the main feeding artery was the occipital artery, not MMA. The MMA sign was observed in 13 of the 871 (1.5%) control patients. The MMA sign on routine MRA is useful, suggesting DAVF involving SSS.

Analysis of middle meningeal artery embolization for the treatment of chronic, acute on chronic, and subacute subdural hematomas.

Chronic subdural hematoma (cSDH) is a common sequela of traumatic brain injury. Middle meningeal artery embolization (MMAE) has shown promising results as an emerging minimally invasive alternative treatment. The purpose of this study is to examine the safety and efficacy of MMAE performed in patients with cSDH, acute-on-chronic, and subacute SDH with a traumatic etiology. This retrospective study included cases performed at a Level II Trauma Center between January 2019 and December 2020 for MMAE of cSDHs. Data collected included patient demographic characteristics and comorbidities, SDH characteristics, complications, and efficacy outcomes. The lesion measurements were collected before the procedure, 4-6 weeks and 3-6 months post-procedure. In our patient population, 78% (39) either had lesions improve or completely resolved. The sample included 50 patients with a mean age of 74 years old. Statistically significant reductions in lesion size were found from pre- to post-procedure in the left lesions, right lesions, and midline shifts. The left lesions decreased from 13.88 ± 5.70 mm to 3.19 ± 4.89 mm at 3-6 months with P < 0.001. The right lesions decreased from 13.74 ± 5.28 mm to 4.93 ± 7.46 mm at 3-6 months with P = 0.02. Midline shifts decreased from 3.78 ± 3.98 mm to 0.48 ± 1.31 mm at 3-6 months with P = 0.02. No complications were experienced for bleeding, hematoma, worsening SDH, pseudoaneurysm, or stroke. Our pilot study from a single center utilizing MMAE demonstrates that MMAE is successful without increasing treatment-related complications not only for cSDH but also in acute-on-cSDH and SDH with a subacute component.

Simple coiling of middle meningeal artery embolization for chronic subdural hematoma: An inverse probability of treatment weighting matched cohort study.

Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) has gained much attention in recent years. However, unintended embolization may occur when employing liquid embolic agents or particles. We present our clinical experience in simple coiling of MMAE to manage CSDH. Patients underwent either surgical evacuation or MMAE with simple coiling for CSDH were reviewed. Clinical and radiographic outcomes were assessed at admission, 1-month, and 6-month intervals. Two treatment groups were matched with inverse probability of treatment weighting. One hundred twelve patients were included, with 27 patients in MMAE group and 87 patients in surgery group. In MMAE group, significant reductions were observed in hematoma width (admission vs. 1-month, 2.04 [1.44-2.60] cm vs. 0.62 [0.37-0.95] cm, p < 0.001). The adjusted odds ratio (aOR) of surgical rescue rate (0.77 95%CI 0.13-4.47, p = 0.77), hematoma reduction (>50%) (0.21 95%CI 0.04-1.07, p = 0.06), and midline shift improvement rate (3.22, 95%CI 0.84-12.4, p = 0.09) had no substantial disparities between two groups at 1-month follow-up. In addition, no significant difference was noted between two groups in terms of hematoma reduction (>50%) at 6-month follow-up (aOR 1.09 95%CI 0.32-3.70, p = 0.89). No procedure-related complications were found in MMA embolization group. Simple coiling for MMA had comparable outcomes with surgical evacuation for CSDH. Our findings suggest that simple coiling can be an alternative choice for liquid agents or particles in MMA embolization for CSDH with acceptable safety.

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study.

The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE. Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes. Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations. We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Traumatic middle meningeal artery aneurysm: a case report

IntroductionTraumatic intracranial aneurysms are rare, making up about 1% of all intracranial aneurysms. They can happen due to direct injury or blunt force, with the middle cerebral artery being the most frequent site.The middle meningeal artery (MMA) is the main artery that supplies the cranial dura mater, and, because of its location, is susceptible to damage after trauma. This article reported an unusual case of giant post-traumatic MMA pseudoaneurysm. CaseA 45 year-old man was referred to our department with a history of craniectomy. He complained of non-specific headache, but neurological examination was normal. A follow-up brain CT scan identified a right temporal fossa hyperdense mass. Digital subtraction angiography diagnosed a traumatic MMA aneurysm. The patient was treated with preoperative aneurysm embolization and surgical resection. DiscussionTraumatic MMA aneurysm is a rare presentation after head trauma. It can manifest as epidural hematoma, subdural hematoma or intraparenchymal hematoma, and sometimes resembles the present case, which was discovered incidentally. ConclusionPseudoaneurysm is a rare complication of MMA trauma, with late presentation. It should be considered in patients with history of traumatic brain injury and temporal fossa extra-axial mass lesion with vascular characteristics.

The effect of arterial spin labeling MR angiography (ASL-MRA) in visualizing the branches of external carotid artery

This study aimed to assess the performance of arterial-spin labeling MRA (ASL-MRA) for visualizing the external carotid artery (ECA) branches in comparison with time-of-flight MRA (TOF-MRA) and CT angiography (CTA). We retrospectively selected 31 consecutive patients, who underwent both MRAs and CTA, prior to the intra-arterial chemoradiotherapy (IACRT) for head and neck cancer. Four patients underwent IACRT bilaterally, so we analyzed 35 ECAs. Pseudo-continuous, three-dimensional ASL using a turbo field echo sequence was acquired. For the TOF-MRA and CTA, clinically used parameters were applied. Two observers evaluated each ECA branch with reference to the angiogram at the IACRT, using five-point scale, in consensus. Friedman test for multiple comparisons was applied. ASL-MRA and CTA better visualized the superior thyroid, lingual, facial, submental, transverse facial, and internal maxillary arteries (IMAs) better than TOF-MRA (p < 0.05). In addition, CTA was superior to ASL-MRA in visualizing only submental artery among these arteries (p = 0.0005). Alternatively, the ASL-MRA was superior for visualizing the middle meningeal artery (MMA) and IMA, compared to the CTA (p = 0.0001 and 0.0007, respectively). ASL-MRA was superior to the TOF-MRA and similar to the CTA in visualizing most of ECA branches. Furthermore, ASL-MRA can better visualize the periphery of MMA and IMA than CTA.

A novel swine model of selective middle meningeal artery catheterization and embolization

BackgroundMiddle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models...

The use of Microsurgical Exploration of the External Carotid Artery for Removal of a Retained Microcatheter After Middle Meningeal Artery Embolization Using Live Fluoroscopy: A Technical Note

Fragmentation, disconnection, or entrapment of an in-use microcatheter during neuro-endovascular procedures is a known risk. Often a benign entity, retained catheters are not infrequently observed, but severe complications including thrombus, thromboembolic events, pseudoaneurysm, and limb ischemia have been described, necessitating retrieval. This technical case report demonstrates the safe use of an external carotid artery (ECA) approach for ligation and removal of a retained microcatheter after middle meningeal artery (MMA) embolization. This article also demonstrates the use of live intraoperative fluoroscopy as a surgical adjunct to ensure that the catheter is fully removed without any injury, shearing, or breakage during removal. A 66-year-old male patient presented with bilateral subdural hematomas to an outside hospital. He subsequently underwent evacuation of the hematomas followed by a right-sided MMA embolization, complicated by Onyx (Medtronic, Minneapolis, MN) entrapment of the microcatheter in the MMA. The patient was asymptomatic, but there was significant concern about continuing antiplatelet/anticoagulation therapy in the presence of the subdural hematoma. We proceeded with an open surgical approach for catheter retrieval. As the catheter was withdrawn, intraoperative fluoroscopy demonstrated complete removal without any retained fragments. The patient recovered without event and was discharged on postoperative day 1. On follow-up the patient continued to do well without any complications from the fragment that remained in the external carotid circulation. This case and accompanying video demonstrates the effective use of open ECA surgical approach to retrieve the retained microcatheter after an MMA embolization. This approach allowed for safe and effective removal of the microcatheter while significantly reducing complication risks.

Dolichoectasia of the ophthalmic artery: a case report on the treatment strategy in endovascular therapy and literature review

BackgroundDolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping.Case presentationA 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved.ConclusionsOA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.

Pharmacology of erenumab in human isolated coronary and meningeal arteries: Additional effect of gepants on top of a maximum effect of erenumab.

Multiple drugs targeting the calcitonin gene-related peptide (CGRP) receptor have been developed for migraine treatment. Here, the effect of the monoclonal antibody erenumab on CGRP-induced vasorelaxation was investigated in human isolated blood vessels, as well as the effect of combining erenumab with the small molecule drugs, namely rimegepant, olcegepant, or sumatriptan. Concentration-response curves to CGRP, adrenomedullin or pramlintide were constructed in human coronary artery (HCA) and human middle meningeal artery (HMMA) segments, incubated with or without erenumab and/or olcegepant. pA2 or pKb values were calculated to determine the potency of erenumab in both tissues. To study whether acutely acting antimigraine drugs exerted additional CGRP-blocking effects on top of erenumab, HCA segments were incubated with a maximally effective concentration of erenumab (3μM), precontracted with KCl and exposed to CGRP, followed by rimegepant, olcegepant, or sumatriptan in increasing concentrations. Erenumab shifted the concentration-response curve to CGRP in both vascular tissues. However, in HCA, the Schild plot slope was significantly smaller than unity, whereas this was not the case in HMMA, indicating different CGRP receptor mechanisms in these tissues. In HCA, rimegepant, olcegepant and sumatriptan exerted additional effects on CGRP on top of a maximal effect of erenumab. Gepants have additional effects on top of erenumab for CGRP-induced relaxation and could be effective in treating migraine attacks in patients already using erenumab as prophylaxis.

Embolization of the middle meningeal artery for the prevention of chronic subdural hematoma recurrence in high-risk patients: a randomized controlled trial—the EMPROTECT study protocol

BackgroundMiddle meningeal artery (MMA) embolization has been proposed as a treatment of chronic subdural hematoma (CSDH). The benefit of the procedure has yet to be demonstrated in a randomized controlled...

Endovascular treatment of subdural haematoma in patient under anti-platelet therapy: a case report

Introduction: The incidence of chronic subdural haematoma (cSDH) is relatively high among the elderly population. Other known risk factors for cSDH include male sex, dependency on anti-platelet or anticoagulant medication, and chronic alcoholism. Although, the standard mode of treatment for cSDH is surgery, embolization of the middle meningeal artery (MMA), either upfront or as an adjunct to surgical evacuation can be used for the treatment of cSDH. Case presentation: The authors present a case of a 75-year-old female with prior history of posterior-lateral wall myocardial infarction (MI) eight years back presented to our centre with the chief complaints of a gradual onset of cough and headache for 2 months. The patient had no history of trauma, loss of consciousness, seizures, and vomiting. There was no history of diabetes, hypertension, pulmonary tuberculosis, and other chronic illness. Discussion: The concurrent use of anti- platelet drug during a surgical procedure can make the treatment challenging. Endovascular treatment can be a primary treatment modality in such situation. Conclusion: Elimination of blood supply by middle meningeal artery embolization is emerging as a safe, minimally invasive alternative to treat cSDH.

Abstract WP214: Embolization in Chronic Subdural Hematomas

Introduction: Middle meningeal artery embolization for chronic subdural hematomas is a promising treatment either as an adjuvant to surgical evacuation of the hematoma or as a primary treatment modality. Current randomized trials are ongoing, but there is a lack of clarity as to which embolic agent may be more effective in preventing hematoma expansion. The current study examines if there is a difference between particle and liquid embolic agents for this indication. Methods: This is a single center retrospective study from May 2019- May 2023 where 160 consecutive patients with chronic subdural hematomas were treated with embolization. In August 2021, operators at our institution switched from using NCBA or Onyx to Embospheres. We analyzed if there were differences in complication rates, requirement for surgery after embolization and changes in 90 day CT imaging with regards to resolution. A Fisher’s exact chi square test was used for binary variables and student’s t-test for continuous variables. Results: A total of 160 patients were treated with embolization and the mean age was 71± 11 years with 45 (28%) presenting with bilateral subdural hematomas. The mean maximal diameter of the collection was 16.3 ± 6.6 mm and midline shift of 4.8±4.4 mm. A total of 67 patients (42%) were treated with particles and 93(58%) with liquid embolic agents. There was one patient with facial nerve palsy in the liquid embolic group and one patient with transient vision symptoms and three with post procedural seizures in the particle embolization group. More patients treated with liquid embolic agents were on anti-platelets or anti-coagulants compared to the particle group (34% vs. 16%, p&lt;0.01). There was no difference in requirement of surgery between the two groups (3.2% vs. 1.4%, p&lt;0.49). Both groups had similar reduction of the maximal diameter with no difference noted at 90 days (3.9 vs. 4.4 mm, p&lt;0.59). Conclusions: The current analysis provides preliminary evidence of the safety of both agents and no difference in outcomes noted between the two groups. A well designed future randomized trial would be helpful given the cost differences between the two types of agents.

Balloon-assisted U-turn Technique to Access Cortical Vein for Transvenous Embolization of Mixed Dural-pial Arteriovenous Malformation.

Cerebral arteriovenous malformations can be classified into pure pial, mixed dural-pial, and pure dural types. Mixed pial-dural AVMs (DPAVM) are rare and often receive blood supply from dural meningeal arteries, including branches of the internal carotid, external carotid, and vertebral arteries.1- 6 DPAVMs, which are usually large and complex, require delicate endovascular and surgical treatment methods. The cure rate is low, and recurrence is very common, leading to high morbidity and mortality. In this case video, we present a case of PDAVM that recurred after initial endovascular onyx embolization, requiring additional endovascular coiling which resulted in obliteration of the DPAVM.