Alejandro Berenstein

BACKGROUND AND OBJECTIVES: Hydrocephalus is a comorbid condition in patients with vein of Galen malformations (VOGMs), and its management is complicated by venous hypertension, elevating surgical risk. Endoscopic third ventriculostomy (ETV) is commonly used for cerebrospinal fluid (CSF) diversion in children, but there are limited available data on its efficacy and safety for patients with VOGM. We aimed to review our experiences with ETV across 2 high-volume centers for VOGM patients with hydrocephalus. METHODS: A two-center retrospective review identified all patients with VOGM who underwent ETV. Demographics, clinical presentation, procedural history, and outcomes were reviewed. ETV success scores were calculated. RESULTS: Twelve patients with VOGM underwent ETV; 66.7% was male, with a median age of 6 months. Seven (58.3%) were still undergoing VOGM embolization before ETV, and 4 had a history of hydrocephalus with acute-on-chronic exacerbation. Eight patients (66.7%) presented with obstructive hydrocephalus because of aqueductal stenosis (58.3%) and with intraventricular hemorrhage without CSF pathway stenosis (8.3%). Three (25.0%) required external ventricular drain placement or fontanelle taps pre-ETV, and choroid plexus cauterization was performed in 4 patients (33.3%). Technical success of ETV was achieved in all cases. One patient experienced venous bleeding at the ventriculostomy site. Postoperative complications occurred in 2 patients: one with transient truncal ataxia and the other with seizure activity, all of which resolved by discharge. At most recent follow-up, 10 patients (83.3%) have minimal residual arteriovenous shunting of their VOGM. The mean ETV success score was 60.8, and 11 patients (91.7%) experienced clinical improvement with ETV patency at the 6-month follow-up. One patient required conversion to a ventriculoperitoneal shunt because of lack of improvement at 6 months. CONCLUSION: This largest-to-date series on VOGM-associated hydrocephalus treated with ETV demonstrates high safety and efficacy across 2 independent high-volume centers. In patients with VOGM demonstrating clinical deterioration secondary to hydrocephalus, ETV with possible choroid plexus cauterization is a viable CSF diversion strategy to consider.

BACKGROUND AND OBJECTIVES: Preoperative embolization is used as an endovascular adjunct to surgical resection of meningiomas. However, there is no standardized system to assess the efficacy or extent of embolization during the embolization procedure. We sought to establish a purely angiographic grading system to facilitate consistent reporting of the outcome of meningioma embolization and to characterize the anatomic and other features of meningiomas that predict the degree of devascularization achieved through preoperative embolization. METHODS: We identified patients with meningiomas who underwent preoperative cerebral angiography and subsequent resection between 2015 and 2021. Demographic, clinical, and imaging data were collected in a research registry. We defined an angiographic devascularization grading scale as follows: grade 0 for no embolization, 1 for partial embolization, 2 for majority embolization, 3 for complete external carotid artery embolization, and 4 for complete embolization. RESULTS: Eighty consecutive patients were included, 60 of whom underwent preoperative tumor embolization (20 underwent angiography with an intention to treat but ultimately not embolization). Embolized tumors were larger (59.0 vs 35.9 cc; P = .03). Gross total resection, length of stay, and complication rates did not differ among groups. The distribution of arterial feeders differed significantly across tumors in a location-specific manner. Both the tumor location and the identity of arterial feeders were predictive of the extent of embolization. Anterior midline meningiomas were associated with internal carotid (ophthalmic, ethmoidal) supply and lower devascularization grades (P = .03). Tumors fed by meningeal feeders (convexity, falcine, lateral sphenoid wing) were associated with higher devascularization grades (P < .01). The procedural complication rate for tumor embolization was 2.5%. CONCLUSION: Angiographic outcomes can be graded to indicate the extent of tumor embolization. This system may facilitate consistency of reported angiographic results. In addition, arterial feeders vary in a manner predicted by tumor location, and these patterns correlate with typical degrees of devascularization achieved in those tumor locations.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

Introduction Balloon assistance has been utilized to enhance the efficacy of endovascular embolization of cerebrovascular malformations. Recently, the advent of dual-lumen balloon catheters (DLBC) has allowed for simultaneous flow arrest and the injection of liquid embolic agents (LEA) for embolization without reflux or the creation of a proximal plug. To maximize safety and efficacy in embolization, the balloon should be placed as close as possible to the target pathology. The Scepter Mini is a new dual-lumen microballoon catheter which offers a softer balloon and smaller diameter than previous DLBCs to catheterize small-caliber distal intracranial vasculature. Here, we report on our institution’s experience with the Scepter Mini microcatheter. Methods A single-center retrospective chart review identified all patients with cerebrovascular cerebrovascular pathology (dural arteriovenous fistulas, Vein of Galen Malformations, arteriovenous malformations, intracranial aneurysms, subdural hematomas, and tumor embolizations) treated with the Scepter Mini. Clinical data, structural and hemodynamic characteristics of the pathology, and technical parameters including anatomic approach, LEA used, complications and embolization success were reviewed. Results 110 Scepter Mini microcatheters were used during 80 procedures in the treatment of 13 pediatric and 53 adult patients. The most common pathology treated with the Scepter Mini was dural arteriovenous fistulas (29/80 procedures). 75/80 procedures were performed by transarterial approach, and the Scepter Mini was used for embolization in all but one instance where it was used as balloon assistance for the coiling of a ruptured aneurysm. Technical success was achieved in 96.3% of all cases. Near-tip entrapment of the Scepter Mini occurred in 1/110 (0.9%) uses of the catheter, which was successfully retrieved without further complication. Clinical complications unrelated to the Scepter Mini occurred postoperatively in 8/80 cases and no intraoperative reflux or vessel rupture was noted. Conclusion We report the largest cohort to date of Scepter Mini usage in the treatment of cerebrovascular malformations. The Scepter Mini is an important tool in the treatment of cerebrovascular pathology requiring extremely distal access and allows for the safe utilization of LEAs in high-flow pathology or small-caliber tortuous vasculature. Disclosures A. Devarajan: None. J. Zhang: None. D. Goldman: None. M. Al-Kawaz: None. H. Tabani: None. C. Rossitto: None. R. De Leacy: None. C. Kellner: None. A. Berenstein: 2; C; Microvention. J. Fifi: 2; C; Microvention. T. Shigematsu: None.

Introduction Vein of Galen Malformations (VOGM) are congenital arteriovenous malformations (AVM) which are primarily treated by endovascular embolization. Current treatment involves staged transarterial embolization (TAE) for progressive obliteration of the fistula. However, TAE alone does not always completely close the malformation. To close the malformation and achieve angiographic cure, these staged TAEs can be followed by a final curative transvenous embolization (TVE). The pressure cooker technique (PCT) has gained popularity as a novel and effective TVE technique for the curative embolization of high-flow AVMs. Here, we aim to characterize the angiographic and clinical outcomes of a large cohort of patients who were cured of VOGM with a final curative embolization by PCT. Methods A retrospective chart review at two high-volume endovascular centers identified all patients with VOGM who were cured by TVE using the pressure cooker technique. Initial clinical presentation, presentation at TVE, clinical and angiographic outcomes, and technical parameters were reviewed. Results 15 patients were treated for their VOGM with a final curative TVE by PCT. All patients had a choroidal VOGM (15/15, 100%) which had been previously embolized by staged TAE. Patients initially presented at a median age of 8 months with hydrocephalus, congestive heart failure, and developmental delay. The median age at TVE was 3.614 years and patients presented with hemiplegia, seizures, developmental delay, and persistent hydrocephalus. Technical success was achieved in 100% of PCTs (15/15). Postoperatively, two patients experienced small intraventricular hemorrhage requiring subsequent EVD placement, but recovered without permanent neurologic deficit. All 11 patients who have received follow-up angiograms continue to demonstrate complete obliteration of the malformation. On clinical follow-up, all patients (15/15, 100%) were either asymptomatic or demonstrated notable progression in milestones. Conclusion The pressure cooker technique offers an attractive option to achieve curative embolization of VOGM by TVE. Patients who received curative embolization using PCT demonstrated persistent angiographic cure and excellent clinical outcomes even at long-term clinical follow-up. Disclosures A. Devarajan: None. T. Shigematsu: None. H. Tabani: None. A. Schupper: None. C. Rossitto: None. J. Bonet: None. M. Sorscher: None. P. Morgenstern: None. S. Ghatan: None. A. Berenstein: None. R. Chapot: None. J. Fifi: None.

Introduction Excluding dural arteriovenous fistulas of the transverse-sigmoid sinus junction, posterior fossa dural arteriovenous fistulas (dAVF) are rare and dangerous cerebrovascular lesions to treat. They demonstrate a high risk of hemorrhage and develop in vasculature which supply several eloquent structures. Posterior fossa dAVFs frequently exhibit cortical or subarachnoid venous drainage and are located in technically challenging locations. Here, we review our experience with the management of these complex vascular lesions. Methods A single multi-center health system retrospective chart review identified all patients from January 2015 to December 2022 who presented with posterior fossa dAVFs that did not drain to the transverse-sigmoid junction. Clinical data, structural and hemodynamic characteristics of the dAVF, rate of favorable clinical outcomes defined as a modified Rankin Scale (mRS) of 0-2, and technical parameters including anatomic or surgical approach, embolic agent used, complications, and embolization success were reviewed. Results Out of 208 patients treated for dAVF, 29 patients (13.94%) presented with posterior fossa dAVF that did not drain to the transverse-sigmoid junction. 18/29 (62.07%) of dAVFs were located on the tentorium while 11/29 (37.93%) of dAVFs were located on the skull base. Patients mostly presented with benign symptoms such as posterior headache, but 2 patients (6.9%) presented due to rupture of their dAVF with associated hemorrhage. 67.74% of the dAVFs demonstrated cortical or subarachnoid venous drainage: 11 Cognard type III, 9 Cognard type IV, and one Cognard type V. 17 patients received endovascular embolization (58.62%). 68% of embolizations were transarterial alone, 16% were transvenous alone, and 16% were performed with a combined transarterial and transvenous approach. Ethylene vinyl alcohol copolymer (EVOH) was the most common embolic agent, utilized in 72% of embolizations. Technical success was achieved in 23/25 (92%) embolizations, with both failures occurring due to vessel tortuosity preventing transarterial navigation. 11 patients (37.93%) patients received at least one open surgery for ligation of their fistula: 6 patients received a suboccipital craniotomy, 4 received a middle fossa transtentorial craniotomy, 2 received a retrosigmoid craniotomy, and 1 patient received a decompressive hemicraniectomy due to rupture of their dAVF. On subsequent angiography, 4 patients (13.8%) demonstrated recurrence of a posterior fossa dAVF after surgical obliteration with a change in venous drainage pattern from the venous sinuses to a cortical venous drainage consistent with Cognard type III. This required further open or endovascular intervention with eventual obliteration of the recurrent fistula. On long-term clinical follow-up, 75.86% of patients demonstrated favorable clinical outcomes. Conclusion Surgical intervention was often indicated for posterior fossa dAVFs and a small percentage of fistulas recurred with pathological venous drainage patterns. Careful patient selection and preoperative planning are necessary to ensure favorable clinical outcomes. Disclosures A. Devarajan: None. D. Goldman: None. A. Schupper: None. B. Giovanni: None. R. De Leacy: None. A. Berenstein: None. J. Fifi: None. T. Shigematsu: None.

Introduction Patients with Vein of Galen malformations (VOGM) can develop significant angiogenesis leading to hemodynamic and structural remodeling. This results in an extensive fine angiogenic network with fistulous connections to the vein of Galen. In patients with angiogenic networks, transarterial embolization (TAE) with liquid embolic agents (LEA) is challenging due to poor penetration and access, while transvenous approaches carry a risk of hemorrhage from pathologic vasculature. Dual-lumen balloon microcatheters such as the Scepter Mini (Microvention, Aliso Viejo, CA) improve navigability and distal pedicle access in small vessels. Here, we report on the novel use of the Scepter Mini for TAE of angiogenic VOGM. Methods A single-institution retrospective chart review identified all patients with VOGM treated with Scepter Mini balloon microcatheters. Clinical data, angioarchitecture pre-embolization and post-embolization, and technical parameters including complications and embolization success were reviewed. Results 17 Scepter Mini catheters were used in 12 embolizations of seven patients with VOGM. The median patient age at embolization was 2.10 years old. Patients presented with hydrocephalus (n=7, 100%) and gross motor and speech delays (n=4, 57.14%). Anatomically, fine vascular networks developed extra-axially into the subependymal zone from the posterior choroidal, posterior cerebral, and thalamoperforator arteries. Distal access to the network and VOGM was most commonly achieved within posterior choroidal branches (n=5/17, 29.41%). Successful embolization with Onyx-18 was achieved in 17/17 (100%) uses with all patients angiographically demonstrating significant network penetration. Near tip entrapment of the Scepter Mini with concurrent significant LEA cast displacement on removal occurred in 1/17 uses. One patient experienced postprocedural intraventricular hemorrhage requiring third ventriculostomy without permanent neurologic deficit. Conclusions The Scepter Mini provided excellent distal access with penetration to the fistula and subsequent extra-axial network reduction with few complications. The Scepter Mini provides a means for successful treatment of angiogenic VOGM who present early and symptomatically, facilitating curative embolization. Disclosures A. Devarajan: None. A. Schupper: None. C. Rossitto: None. J. Bonet: None. M. Sorscher: None. P. Morgenstern: None. S. Ghatan: None. T. Shigematsu: None. A. Berenstein: 2; C; Microvention. J. Fifi: 2; C; Microvention.

BACKGROUND AND PURPOSE: A vein of Galen aneurysmal malformation is known to present with recruitment of dural feeders and, in our cohort, a fine, vascular network formation. The vessels we have observed differ from dural vascular recruitment in that they produce a hairlike, collateral network of vessels. We reviewed treatment courses of vein of Galen aneurysmal malformation treatments in a series of 36 cases that displayed a fine, vascular network formation. MATERIALS AND METHODS: We retrospectively analyzed 36 cases of vein of Galen aneurysmal malformation, including tectal/thalamic AVMs, treated at our center from January 2004 to September 2021, and reviewed fine, vascular network formations in the subarachnoid space and subependymal zone alongside the vein of Galen aneurysmal malformation. RESULTS: Patients at first endovascular treatment ranged from neonates to 157 months (median age, 4.3 months). Patients with preinterventional fine, vascular network formations were significantly older at the initial angiogram than patients with postinterventional fine, vascular network formations (P < .05). On average, for 20 control choroidal/mural vein of Galen aneurysmal malformations whose treatment course had been completed and in which no plexiform network was visualized, a mean of 2.63 (SD, 1.64) treatments were required to achieve a radiographic cure. For the 36 choroidal/mural vein of Galen aneurysmal malformations whose treatment course had been completed and in which a fine, vascular network formation was visualized, a mean of 5.94 (SD, 2.73) treatments were required to achieve a radiographic cure (P < .01). CONCLUSIONS: Development of a fine, vascular network formation is an acquired and reversible phenomenon that differs from typical dural vessel recruitment, given the hairlike nature of the network and its rapid onset postinterventionally. It typically resolves after completion of treatment, and this resolution correlates with closure of the vein. We recommend that neurointerventionalists avoid delays in treatment wherever possible to reduce the likelihood of a fine, vascular network formation.

BACKGROUND: Middle meningeal artery (MMA) embolization has been recognized as a promising treatment for patients with subdural hematoma (SDH). OBJECTIVE: To present the technical feasibility and efficacy of n-butyl cyanoacrylate (n-BCA) embolization in the largest consecutive cohort to date. METHODS: We retrospectively reviewed our consecutive cases of recurrent SDH treated with MMA embolization using diluted n-BCA with the “sugar rush” technique. In brief, a 2.1-Fr microcatheter was used to selectively catheterize the frontal and posterior branches of the MMA. 5% dextrose in water (D5W) was injected through an intermediate catheter while injecting n-BCA through the microcatheter. Complete obliteration of MMA and lack of SDH recurrence in a 3–6 months follow-up computed tomography scan were defined as efficacy outcomes. Cranial nerve palsy, vision loss, transient neurological deficit, and stroke were defined as safety outcomes. RESULTS: A total of 61 patients were identified with a mean (±standard deviation) age of 62.5 ± 9 years. In 6 patients (10%), coil embolization of the origin of the frontal or posterior branch was performed because super-selective catheterization of the branch was unsuccessful because of tortuous anatomy. Complete obliteration of frontal and posterior branches was achieved in 100% of the cases. Recurrent SDH was seen in 3 patients (5%). No incidence of cranial nerve palsy, vision loss, or stroke occurred. One patient suffered a transient neurological deficit. CONCLUSION: MMA embolization using diluted n-BCA with concomitant D5W injection is associated with a high degree of distal penetration and complete branch occlusion and minimal risk of cranial nerve palsy or other thromboembolic complications.

BACKGROUND AND PURPOSE: Two-thirds of lymphatic malformations in children are found in the head and neck. Although conventionally managed through surgical resection, percutaneous sclerotherapy has gained popularity. No reproducible grading system has been designed to compare sclerotherapy outcomes on the basis of radiologic findings. We propose an MR imaging–based grading scale to assess the response to sclerotherapy and present an evaluation of its interrater reliability. MATERIALS AND METHODS: A grading system was developed to stratify treatment outcomes on the basis of interval changes observed on MR imaging. By means of this system, 56 consecutive cases from our institution with formally diagnosed head and neck lymphatic malformations treated by sclerotherapy were retrospectively graded. Each patient underwent pre- and posttreatment MR imaging. Each study was evaluated by 3 experienced neuroradiologists. Interrater reliability was assessed using the Krippendorff α statistic, intraclass coefficient, and 2-way Spearman ρ correlation. RESULTS: The overall Krippendorff α statistic was 0.93 (95% CI, 0.89–0.95), denoting excellent agreement among raters. Intraclass coefficients with respect to consistency and absolute agreements were both 0.97 (95% CI, 0.96–0.98), illustrating low variability. Every combination of individual rater pairs demonstrated statistically significant (P < .01) linear Spearman ρ correlations, with values ranging from 0.90 to 0.95. CONCLUSIONS: The proposed radiographic grading scale demonstrates excellent interrater reliability. Adoption of this new scale can standardize reported outcomes following sclerotherapy for head and neck lymphatic malformation and may aid in the investigation of future questions regarding optimal management of these lesions.