Abstract Number ‐ 178: Optimizing Skin to Device at Occlusion Time Utilizing A Non‐exchange Technique with Novel Steerable Microcatheter

Introduction Vascular tortuosity and difficult access to the target vessel during mechanical thrombectomy is one of the reasons for failed reperfusion. The 021 Bendit adjustable micro catheter is a torqueable microcatheter with an adjustable, 360 rotating, bendable tip. Its unique structure provides it with trackability and support allowing it to be used as a select catheter for the guide and to directly access the target vessel without a guidewire. This feature can result in significant reduction in groin puncture to recanalization time, with possible implications on patient outcomes. It is also designed to fit in a standard sized aspiration catheter and allow delivery of a stentriever device if needed. Herein we describe the first US experience in 021 Bendit adjustable microcatheter in vessel selection and intracranial navigation in patients with large vessel occlusions. Methods We describe our experience with three patients who presented with large vessel occlusions for mechanical thrombectomy in July 2022. The system with guide catheter loaded with aspiration catheter and Bendit adjustable microcatheter was used to directly select the target vessels starting at the arteriotomy site, off the aortic arch and its support was used to advance the guide catheter into the cervical segment. It was then delivered to the intracranial circulation where it was used to deliver the aspiration catheter. Results Patient A is a 73‐year‐old man with a left M1 occlusion. The Bendit microcatheter was advanced through a 071 intermediate catheter and through a 088 guide catheter and was used to select the left common carotid artery. Time between device entering the body to clot touch time of 18 minutes. Patient B is a 57‐year‐old man who presented with a left cavernous internal carotid artery occlusion. The Bendit microcatheter was advanced through a 071 intermediate catheter and a 088 guide catheter was used to successfully select the left common carotid artery.Time between device entering body and bendit being at first lesion is 3 minutes. Patient C is a 60‐year‐old woman with a basilar occlusion. A 088 guide catheter was advanced over 071 intermediate catheter which was advanced over the Bendit microcatheter into the aortic arch. The Bendit microcatheter was maneuvered to select the right subclavian artery and the right vertebral artery, the system was subsequently advanced over the Bendit microcatheter intracranially. Time between groin puncture to aspiration device at the clot was 5 minutes. Conclusions The Bendit steerable microcatheter can be used to maneuver through the aortic arch and successfully select the target vessel without an exchange and without a guidewire. This approach can dramatically reduce access to recanalization time and ultimately neurologic outcomes in patients undergoing mechanical thrombectomy. As more experience is obtained, best practices will be able to achieve consistently lower times

Abstract Number ‐ 197: A Single‐Center, 23‐Year Experience with the MAGIC Catheter for Pediatric AVM

Introduction The MAGIC Catheter (Balt, Montmorency, France) is a commonly used flow‐directed microcatheter for neuro‐interventions. Despite the MAGIC catheter not having FDA approval for use in pediatric and neonatal populations, our institution has used this catheter off‐label for numerous cases of pediatric arteriovenous malformation (AVM), vein of Galen malformation (VOGM), dural arteriovenous fistula (dAVF), and pial AVF (pAVF). Herein, we outline our practice’s experience with the MAGIC catheter for pediatrics. Methods We reviewed our institutional, quality‐control database for all cases of pediatric, vascular malformation that utilized the MAGIC catheter since its original use in pediatrics at our practice (March 1999) and July 2022. We describe the disease and demographic characteristics of this cohort, frequency of MAGIC catheter use, adjunct supplies, complications, smallest vessels catheterized, and clinical outcomes. Results Over the review period, 99 pediatric patients with AVM(45), VOGM(49), dAVF(3), and pAVF(2) were identified for detailed review. This cohort has collectively undergone 194 procedures. The average age at first procedure with the MAGIC catheter was 4.42 years with a wide variation (SD: 4.56; Range: 0–17.64). The majority of cases using the MAGIC catheter were cerebral angiograms with embolization (190 – 97.9%), though occasionally it was employed for angiography alone (4 – 2.1%). A 4‐Fr Berenstein Catheter was the most common adjunct catheter used during the study period (156/194; 80.4%), though the 5‐Fr Envoy appeared often as well (30/194; 15.5%). Every embolization in the series led to interval‐decrease or cure of the malformation, though five intraprocedural complications were noted in the form of transient decrease neuromonitoring evoked potentials, epidural hematoma due to vessel perforation, and three cases of vessel perforation without long‐term consequence. Periprocedural complications occurred in one patient involving an intraventricular hemorrhage requiring a ventriculoperitoneal shunt. The most common liquid embolic agent used with the MAGIC catheter was nBCA (179/190; 94.2%) with occasional use of Onyx 18, Fibered Coils, Surgi‐Flo, STS, and Ethanol. Of the 67 patients who had a follow‐up available for review, 30 (44.8%) are neurologically intact and clinically well, 19(28.4%) are clinically well with mild symptoms (mild autism spectrum disorder, mild hemiparesis, headaches, mild weakness, post‐hemorrhage/stroke excellent recovery), 9 (13.4%)have experienced moderate to severe symptoms (limb weakness, cranial neuropathies, cognitive delay/deficit, inability to ambulate, seizures), 3 (4.5%) have passed away, and 6 (9.0%) have been lost to follow‐up. Selective catheterization of small vessels was performed among the anterior choroidal, thalamoperforator, posterior choroidal, middle meningeal arteries and superior cerebellar, posterior cerebral, and deep external/internal carotid artery branches, and many others by the MAGIC microcatheter for contrast injection or delivery of embolic agents. Conclusions Flow‐directed microcatheters are a quintessential tool used in the endovascular treatment of cerebrovascular diseases, but few have regulatory approval for use in pediatric populations. The off‐label use of the MAGIC microcatheter has been shown to be safe and effective in pediatric embolization procedures. However, there still remains a technology gap in the development of flow‐directed catheters specifically designed and proportioned for use in pediatric patients

Modern Brain Arteriovenous Malformation Models: A Review

Background Research of William Hunter's hypothesized (then discovered) arteriovenous varix (now arteriovenous malformation [AVM]) has developed exponentially over the previous quarter‐millennium. Virchow and Luschka's subsequent contributions (nearly 100 years later) by identifying an AVM of the brain and its congenital nature were 2 of the first significant developments made in the field. AVMs present as an erroneous connection (known as a fistula) between an artery and a vein that bypasses the capillary circulation. The arteries and arterioles contributing to the malformation are known as feeders which connect to the draining veins via a plexiform vascular network known as a nidus. Prior to the design of a synthetic anastomosis coupled with vessel ligation by Spetzler et al, animal models were largely based on embolization or study of the normal anatomy. The animal and early genetic models have been reported on at length and numerous times across the literature, but novel developments spanning the previous decade have ushered in a technological revolution of vascular modeling that warrants discussion and analysis. Methods Parameterization of a PubMed query to include all literature including the words “brain,” “arteriovenous malformation,” and “model” yielded 489 articles. After extraction of relevant literature and full‐text screening, 41 articles were chosen for detailed review. Results Technological innovations outside of neurosurgery have greatly impacted the development of novel AVM models in the form of 3D flow models printed into silicon models and combined with advanced imaging technology such as 4D flow magnetic resonance imagin. Technological developments in preservation solutions, catheterization tools, and imaging technologies have also allowed for advent of the cerebrovascular placental model for testing of treatments such as radiosurgery, glue embolization, coiling, as well as histological assessment of tissue directly after intervention. Conclusion We review the breadth of AVM models in the literature over the last almost 5 decades

Abstract Number ‐ 47: Adult and Pediatric Facial Droop in Facial Lymphatic Malformations: Causes and Resolution

Introduction Facial Lymphatic Malformations (LMs) are low‐flow, infiltrative vascular lesions which are typically treated with sclerotherapeutic agents or, in refractive/aggressive cases, surgical resection. In our practice, we have found a subset of these patients present with or develop a facial droop over the course of their treatment.(1) The development, persistence, or abation of this facial droop is a crucial component of facial LM “cure” considering the long‐term burden patients carry if it persists. The likely causes and frequency of resolution are described. Methods A retrospective review of our institutional, quality‐control database was performed to identify all consecutive cases of facial LMs or LMs with facial components between January 1996 and July 2022. Cases were selected for detailed review if a facial droop was identified in photographs over the course of their treatment and if radiographic imaging was available for review. Results A total of 152 patients with facial LMs or facial components of an LM were selected for initial screening with 110 (72.4%) pediatrics (average age = 5.3+/‐4.6 years) and 42 (27.6%) adults (average age = 34.0+/‐16.0 years) at first treatment for the LM. Among these 152, 36 (23.7%) facial droops were identified of which 31 pediatric patients (86.1% of facial droops; 28% of pediatrics overall) and 5 adults (13.9% of facial droops; 11.9% of adults). 13 (40.6%) patients experiened facial droop abation overall with 10 pediatrics (76.9% of abated, 32% of peds) and 3 adults (23.1% of abated, 60% of adults). Overall, LMs were distributed across 2 (6%) macrocystics, 18 (50%) microcystics, and 16 (44%) mixed lesions. Only 21 cases with facial droops were eligible for the final stage of analysis due to insufficient pre‐operative ragiographic imaging in the excluded 15. Facial nerve involvement alone was identified in 4/21 (19%) cases, muscle damage in 3/21 (14%), 6/21 (29%) with both, and 7/21 (33%) with neither. Resolution was assessed by comparison of pre and post‐treatment imaging with a minimum follow‐up time of 6 months and a maximum of over 11 years.Resolution occurred in 50% of cases involving the facial nerve alone, 100% of cases involving muscle damage alone, and 33% in cases involving both. In cases where facial droop was unattributable to either facial nerve involvement or muscle damage, only 1/7 (14%) facial droops resolved. Conclusions Facial LMs may lead to development of a facial droop as early as initial presentation or during treatment and persist without abation. The majority of LM cases which developed facial droop in this series were microcystic or had a microcystic component (mixed). Facial nerve damage, muscle damage, or both were designated as the cause of the facial droop in 66% of cases. It is unknown what may have led to the droopage in the remaining 33% of cases. Muscle damage alone resulted in the highest rate of resolution across the study period

Abstract Number: LBA4 Platelet Function Testing and Acute Thrombotic Events in Intracranial Aneurysm Patients Undergoing Flow Diversion

Introduction Introduction The role of platelet function testing in patients with intracranial aneurysms undergoing flow diversion remains controversial with limited evidence of its influence on thrombotic outcomes. We report an observational cohort analysis evaluating the association of P2Y12 assay testing with thrombotic events in patients undergoing flow diversion. Methods We performed a retrospective review of our prospectively maintained procedural database to identify patients who underwent flow diversion between January 2020 and July 2022. One physician within our practice never performs P2Y12 assay testing. All other physicians utilize P2Y12 assay testing as part of routine practice. These two different patient cohorts were compared. Acute thrombotic events were our primary outcome. Secondary outcomes included delayed intracerebral hemorrhage, intimal hyperplasia without clinical sequalae, and transient neurologic deficits. Results We identified 150 patients who underwent flow diversion at our institution between January 2020 and July 2022. Median age was 59 years old (Interquartile range (IQR) 49–67), with 113 females (82.5%) and 24 males (17.5%). Out of 150 patients, 93 (62.0%) patients were treated by physicians who performed routine pre and postoperative testing of aspirin and Plavix assays, with subsequent adjustment of antithrombotic dosing accordingly, while 57 patients (38.0%) were treated by the single physician who prescribes aspirin and clopidogrel pre‐operatively without testing. In all, seven out of 150 patients (4.7%) had an acute thrombotic event requiring intraarterial anti‐thrombotic infusion or urgent thrombectomy, or both. Of these, six where from the 93 patient testing cohort (6.5%), and one in 57 patients non‐testing cohort (1.8%) (p = 0.2). Patients who had a thrombotic event were more likely to have underlying atrial fibrillation (28.6% vs 4.9%, p = 0.01) but otherwise had similar demographics, vascular risk factors, maximal aneurysmal diameter, and parent vessel diameter (Table 1). In a multivariable analysis adjusting for age, maximal aneurysm diameter, ruptured aneurysms, and atrial fibrillation, P2Y12 sensitivity assay testing was not significantly associated with acute thrombotic events in aneurysm patients undergoing flow diversion (Odds Ratio (OR) = 0.15, 95% Confidence Interval (CI) = 0.01‐2.67), p = 0.2). Secondary outcomes were also comparable between both groups; transient neurologic deficits were noted in 4/93 in the testing group (4.3%), and 6/57 in the non‐testing group (10%) (p = 0.14), intracranial hemorrhage occurred in only 2 patients, both in the testing group (p = 0.3), and mild intimal hyperplasia was observed in 18.3% in the testing group versus 12.3% in the non‐testing group (p = 0.33). Conclusions Platelet function testing showed no significant correlation with thrombotic events or outcomes in our cohort. The role of platelet function testing remains controversial, albeit widely used in patients undergoing flow diversion of intracranial aneurysms

High rates of conversion of anesthesia modality in agitated thrombectomy patients

Background: Patients with large vessel occlusion acute ischemic stroke (AIS) undergoing thrombectomy can be disruptively agitated. We aimed to determine if procedural and neurological outcomes differ for agitated patients. Methods: We reviewed prospectively collected data of AIS patients undergoing thrombectomy in our tertiary center between January 2014 and July 2017. We divided patients in two cohorts based on the presence of disruptive levels of agitation. We compared the baseline characteristics, procedural details and outcomes between the two cohorts. Results: A total of 156 patients were included, 60 (38.5%) were agitated. The agitated cohort had lower mean ASPECTS (8.3 vs 8.8, p 0.04); but other characteristics were well-matched (age, gender, premorbid mRS, occlusion side, NIHSS and tPA status). There was a trend for longer room arrival-to-recanalization times (87.1 vs 72.9 mins, p 0.09) and higher use of general anesthesia (GA) (35% vs 24%, p 0.14) in the agitated cohort (table 1). In the agitated cohort, pre-planned GA patients had longer arrival to recanalization times when compared with monitored anesthesia care (MAC) only patients (100.5 ± 73.0 vs 75.3 ± 49.8 mins). None of the non-agitated MAC patients required conversion to GA, however 11.6% of the agitated patients were converted to GA intra-procedurally, with the longest arrival-to-recanalization time (125.1 ± 68.7) (p 0.04). Other technical details (method of thrombectomy, number of passes, complications and degree of recanalization) and outcome measures (postoperative NIHSS or good neurological outcome at 90 days) were not different between groups. Conclusions: Agitated patients have a high incidence of conversion from MAC to GA resulting in delay in recanalization compared to pre-planned GA. Our study was limited by a small sample size and larger studies are necessary to elucidate the impact of agitation on outcome and whether there is role for pre-planned GA in agitated thrombectomy patients