Background: Flow diversion (FD) requires perfect vessel wall apposition to optimize aneurysm occlusion rates and minimize complications. Objective: To elucidate the safety of an off-label technique using the Comaneci device for augmenting vessel wall apposition of distally deployed flow-diverting stents. Methods: Over a 20-month period, all FD cases for the treatment of aneurysms beyond the internal carotid artery terminus performed by the senior author were reviewed. Patient demographics, case characteristics, and procedural outcomes were collected and analyzed for cases involving both distal aneurysms and the use of the Comaneci device to augment vessel wall apposition. Results: Of 58 FD cases of distal aneurysms, the Comaneci device was required for vessel wall apposition in 16 cases (27%). Of these cases, the average patient age was 68.8 ± 8.4 years, and 13 (81%) were female. Average aneurysm size was 3.3 ± 1.1 mm. Comaneci device deployment and retrieval was successful in all (100%) cases. Procedures had an average fluoroscopy time of 38 ± 20.9 minutes, average contrast use of 37.9 ± 9.9 mL, and average radiation exposure of 1182 ± 458.3 mGy. Conclusion: This study demonstrates the safety and feasibility of a previously described technique for augmenting stent stenosis in proximal anterior circulation applied in distal anterior circulation aneurysms. Clinical Impact Incomplete vessel wall apposition of flow-diverting stents increases the risk of thromboembolic complications, in-stent stenosis, and treatment failure. In the distal circulation, techniques for improving apposition are limited due to anatomical tortuosity and vessel size. This series demonstrates the use of the Comaneci device as a safe and effective method for augmenting flow diverter apposition beyond the internal carotid artery terminus. This technique maintains endoluminal flow throughout remodeling, requires no exchange of the existing 0.027” microcatheter, and minimizes device burden, making it an efficient technique for clinicians.

BACKGROUND AND OBJECTIVES:After surgical drainage of a chronic subdural hematoma (cSDH), middle meningeal artery (MMA) embolization aids in preventing the revascularization of the cSDH membranes at the capillary level and, in turn, reaccumulation. With the MMA circulation ipsilateral to the surgical side often being disrupted, there is recruitment of collaterals from the contralateral MMA tree to the ipsilateral cSDH membranes. The aim of this study was to demonstrate the ability of additive contralateral liquid embolic (LE) injection after ipsilateral surgery to augment MMA embolization. We hypothesized that contralateral LE injection may provide additional MMA embolization to the affected ipsilateral side and increase response to treatment. METHODS:Consecutive cases of unilateral cSDH surgery with ipsilateral MMA embolization and additive contralateral LE injection were retrospectively identified from a prospectively maintained database of the senior authors. RESULTS:Over the study period, 26 consecutive cases of recurrent cSDH after unilateral surgery were identified. There was an average age of 73 ± 2.7 years (range 27-90 years), and 14 patients (54%) were female. All 26 patients (100%) had previous burr holes or a craniotomy. The average cSDH thickness after surgery and before embolization was 10 ± 0.3 mm, and the average midline shift was 3.5 ± 0.7 mm. Of the 26 patients who underwent bilateral MMA embolization, 96% had over-the-top contralateral-to-ipsilateral LE injection and penetration, providing additional embolization to membranes of the index ipsilateral cSDH. The average cSDH thickness on follow-up was 4 ± 5 mm and midline shift of 0.2 ± 0.7 mm. Complete cSDH resolution was achieved in 7 patients (39%). Two patients had cSDH recurrence, one of which required reoperation. There were no LE or catheter-related complications. CONCLUSION:Contralateral MMA embolization in patients who have undergone ipsilateral cSDH evacuation and traditional ipsilateral MMA embolization allows for over-the-top LE penetration of cSDH membranes, thereby further augmenting the desired ipsilateral MMA embolization.

BACKGROUND:Endovascular transmural targeting of cervical and cranial perivascular structures is a novel approach for minimally invasive delivery of therapeutics. Components of the autonomic nervous system are in close anatomic proximity to major cervical vasculature and, therefore, represent potential targets for intervention. The superior cervical ganglion (SCG) is a discrete structure of interest for this approach, as sympathetic blockade may have therapeutic effects for various conditions. Variability of SCG location and its relationship to large cervical vessels, and the feasibility of endovascular transmural targeting has not been elucidated. METHODS:In this retrospective study, computed tomography angiography of head and neck from patients with subarachnoid hemorrhage or cerebral aneurysms were reviewed. SCG dimensions and spatial relationship to cervical vessels were measured. Measured anatomic parameters were used to determine endovascular transmural accessibility of the SCG from various cervical vessels. RESULTS:A total of 159 SCGs were identified and measured from 314 unilateral neck images of sufficient quality. SCGs had an average radio-opacity of 49.6 Hounsfield Units, length of 1.91 cm, and width of 0.71 cm. Internal carotid artery (ICA) has the longest contact length with the SCG (mean = 1.80 cm) compared to other major cervical vessels. A total of 95% of SCGs were accessible from ICA using an endovascular transmural approach, with the majority of SCGs located anteromedially to the ICA. CONCLUSIONS:This is the first anatomical study to provide pertinent targeting information for endovascular transmural access to the SCG using computed tomography angiography. In most cases, endovascular transmural access to the SCG is anatomically feasible from the proximal cervical ICA.

Introduction Flow diverting stents (FDS) are routinely used to reconstruct the arteries of the head and neck. When placed into the mobile cervical internal carotid artery (cICA) segment, the FDS runs the risk of post-procedure stent migration and proximal intimal hyperplasia reaction from physiologic movement of the neck. We report our experience using a novel proximal anchoring technique during endovascular flow reconstruction of complex petrocervical dissections to prevent this potentially deleterious result. Methods We reviewed a prospectively maintained IRB-approved institutional database of the senior authors to identify cases of FDS treatment in the mobile petrocervical segments which had the proximal FDS “anchored” with a nitinol stent. Results The proximal anchoring technique was successfully performed in the mobile cervical segment in a total of 31 cases over the study period. Each case involved a complex ICA dissection with 68% (n = 21) having an accompanying pseudoaneurysm. Fifty-two percent (n = 16) were female. Surpass Streamline and Evolve FDS were utilized in all cases. An average of 2.2 ± 0.1 FDS devices were utilized (range 2-4 FDS), with each case utilizing a laser-cut nitinol carotid stent as the proximal anchor. The average stent diameter was 5.64 ± 0.2 mm (range 4-8 mm) and length of 30.1 ± 1.5 mm (range 20-60 mm). On last follow-up angiography, there were no instances of stent migration or proximal neointimal hyperplasia. Conclusion Utilization of the proximal anchoring technique on FDS constructs in the mobile cICA may provide additional protection from post-procedure stent migration and intimal reaction attributed to patient neck movement resulting in augmentation of successful healing.

BackgroundFlow diversion has proven feasible for treating posterior circulation aneurysms. These studies, however, are limited to the utilization of low-mesh density devices. The high-mesh density and mesh geometry of the Surpass Evolve and Streamline flow diverters theoretically allow increased flow diversion while preserving perforators, a critical consideration in posterior circulation flow diversion. We investigate this phenomenon in the largest known series utilizing solely high-mesh density devices for basilar aneurysms.MethodsA prospectively maintained, IRB-approved database of the senior authors was retrospectively reviewed for flow diversion cases involving the upper basilar artery and utilizing Surpass Evolve or Streamline. Technical success was defined as the successful implantation of the device without intraprocedural device removal.ResultsOver a 52-month study period, 23 cases were identified utilizing Surpass Evolve (21 devices) and Surpass Streamline (2 devices) treating aneurysms located along the basilar apex (12 cases, 52%) and superior cerebellar artery (11 cases, 48%). Technical success was achieved in all cases (23 cases, 100%). Patients were placed on antiplatelet therapy consisting of aspirin (22 cases, 95.7%) and ticagrelor (20 cases, 87%) or prasugrel (4 cases, 17.4%). There was one mortality within the 30-day postoperative window due to complications of the presenting high-grade SAH.ConclusionThe treatment of upper basilar and basilar apex aneurysms with high mesh density devices can be performed with acceptable safety standards. Further studies are needed to confirm the safety profile, occlusion rates, and applicability of these findings to lower mesh-density 48-wire flow-diverter implants at the basilar apex.

Background: There is growing need for physician-innovators to address the mounting challenges within the US healthcare system. Despite this, there remains a significant gap in understanding of the efficacy of innovation programs for US MD candidates. We present initial program outcomes of a novel, clinically immersive medical innovation program offered to MD candidates at the David Methods: A novel clinically immersive medical innovation curriculum was developed based on existing and reputable medical innovation frameworks and tailored for medical students. Curricular topics broadly included clinical ethnography, interviewing techniques, mind mapping, needs formulation and prioritization, quality improvement, intellectual property, reimbursement pathways, solution landscaping and prioritization, regulatory processes. The program was trialed during an unscheduled summer with voluntary enrollees from DGSOM Class of 2024. The traditional four-level Kirkpatrick model was employed to assess program outcomes. Results: Program outcomes were positive on all four Kirkpatrick levels. Students rated enjoyment at 9.5/10 for lectures and 9.1/10 for clinical immersion. Student-perceived confidence in key skills increased by 43%, and 75% of faculty directly perceived improvement in ethnographic skills. Students were highly engaged in both didactics and clinical immersion, discovering on average 2.6 faculty-verified needs per week. Faculty largely felt their students discovered important unmet clinical needs and added value to their clinical practice. Conclusion: We developed and trialed a novel clinically immersive medical innovation curriculum tailored for medical students. This program achieved positive outcomes on all four levels of the Kirkpatrick model. Our findings have driven the local adoption of this program into our institution's medical school curriculum. We hope that the program efficacy demonstrated herein catalyzes more institutions to trial similar medical innovation programs.

BACKGROUND:The delivery of neuroendovascular devices requires a robust proximal access platform. This demand has previously been met with a 6Fr long sheath (8Fr guide) that is placed in the proximal internal carotid artery (ICA) or vertebral artery segments. We share our experience with the first 0.088 inch 8Fr guide catheter designed for direct intracranial access. METHODS:We retrospectively reviewed a prospectively maintained IRB-approved institutional database of the senior authors to identify all cases where the TracStar Large Distal Platform (LDP) was positioned within the intracranial vasculature, defined as within or distal to the petrous ICA, vertebral artery (V3) segments, or transverse sinus. Technical success was defined as safe placement of the TracStar LDP within or distal to the described distal vessel segments with subsequent complication-free device implantation. RESULTS:Over the 41-month study period from January 2020 to June 2023, 125 consecutive cases were identified in whom the TracStar LDP was navigated into the intracranial vasculature for triaxial delivery of large devices, 0.027 inch microcatheter and greater, for aneurysm treatment (n=108, 86%), intracranial angioplasty/stenting (n=15, 12%), and venous sinus stenting (n=2, 1.6%). All cases used a direct select catheter technique for initial guide placement (no exchange). Posterior circulation treatments occurred in 14.4% (n=18) of cases. Technical success was achieved in 100% of cases. No vessel dissections occurred in any cases. CONCLUSION:The TracStar LDP is an 0.088 inch 8Fr guide catheter that can establish direct intracranial access with an acceptable safety profile. This can be achieved in a wide range of neurointerventional cases with a high rate of technical success.

Introduction: Ventriculoperitoneal (VP) shunts divert cerebrospinal fluid (CSF) out of cerebral ventricles in patients with hydrocephalus or elevated intracranial pressure (ICP). Despite high failure rates, there exist limited clinically viable solutions for long-term and continuous outpatient monitoring of CSF flow rate through VP shunts. We present a novel, low-power method for sensing analog CSF flow rate through a VP shunt premised on induced spatial electrical charge variation.Methods: Two geometric variants of the proposed sensing mechanism were prototyped: linear wire (P1) and cylindrical (P2) electrodes. Normal saline was gravity-driven through P1 and a commercially available shunt system in series. True flow rates were measured using a high-precision analytical balance. Subsequently, artificial CSF was driven by a programmable syringe pump through P2. Flow rate prediction models were empirically derived and tested. Sensor response was also assessed during simulated obstruction trials. Finally, power consumption per flow measurement was measured.Results: P1 (17 mm long) and P2 (22 mm long) averaged 7.2% and 4.2% error, respectively, in flow rate measurement from 0.01 to 0.90 mL/min. Response curves exhibited an appreciably flattened profile during obstruction trials compared to non-obstructed states. P2 consumed 37.5 µJoules per flow measurement.Conclusion: We propose a novel method for accurately sensing CSF flow rate through a VP shunt and validate this method at the benchtop with normal saline and artificial CSF over a board range of flows (0.01–0.90 mL/min). The sensing element is highly power efficient, compact, insertable into existing shunt and valve assemblies, and does not alter CSF flow mechanics.

Background:Cerebral vasospasm (CV) is a feared complication occurring in 20-40% of patients following subarachnoid hemorrhage (SAH) and is known to contribute to delayed cerebral ischemia. It is standard practice to admit SAH patients to intensive care for an extended period of vigilant, resource-intensive, clinical monitoring. We used machine learning to predict CV requiring verapamil (CVRV) in the largest and only multi-center study to date. Methods:SAH patients admitted to UCLA from 2013-2022 and a validation cohort from VUMC from 2018-2023 were included. For each patient, 172 unique intensive care unit (ICU) variables were extracted through the primary endpoint, namely first verapamil administration or ICU downgrade. At each institution, a light gradient boosting machine (LightGBM) was trained using five- fold cross validation to predict the primary endpoint at various timepoints during hospital admission. Receiver-operator curves (ROC) and precision-recall (PR) curves were generated. Results:A total of 1,750 patients were included from UCLA, 125 receiving verapamil. LightGBM achieved an area under the ROC (AUC) of 0.88 an average of over one week in advance, and successfully ruled out 8% of non-verapamil patients with zero false negatives. Minimum leukocyte count, maximum platelet count, and maximum intracranial pressure were the variables with highest predictive accuracy. Our models predicted "no CVRV" vs "CVRV within three days" vs "CVRV after three days" with AUCs=0.88, 0.83, and 0.88, respectively. For external validation at VUMC, 1,654 patients were included, 75 receiving verapamil. Predictive models at VUMC performed very similarly to those at UCLA, averaging 0.01 AUC points lower. Conclusions:We present an accurate (AUC=0.88) and early (>1 week prior) predictor of CVRV using machine learning over two large cohorts of subarachnoid hemorrhage patients at separate institutions. This represents a significant step towards optimized clinical management and improved resource allocation in the intensive care setting of subarachnoid hemorrhage patients.

Background Endovascular embolization of the middle meningeal artery (MMA) has emerged as an adjunctive and stand-alone modality for the management of chronic subdural hematomas (cSDH). We report our experience utilizing proximal MMA coil embolization to augment cSDH devascularization in MMA embolization. Methods MMA embolization cases with adjunctive proximal MMA coiling were retrospectively identified from a prospectively maintained IRB-approved database of the senior authors. Results Of the 137 cases, all patients (n = 89, 100%) were symptomatic and underwent an MMA embolization procedure for cSDH. 50 of the patients underwent bilateral embolizations, with 53% (n = 72) for left-sided and 47% (n = 65) for right-sided cSDH. The anterior MMA branch was embolized in 19 (14%), posterior in 16 (12%), and both in 102 (74.5%) cases. Penetration of the liquid embolic to the contralateral MMA or into the falx was present in 38 (28%) and 31 (23%) cases, respectively, and 46 (34%) cases had ophthalmic or petrous collateral (n = 41, 30%) branches. MMA branches coiled include the primary trunk (25.5%, n = 35), primary and anterior or posterior MMA trunks (20%, n = 28), or primary with the anterior and posterior trunks (54%, n = 74). A mild ipsilateral facial nerve palsy was reported, which remained stable at discharge and follow-up. Absence of anterograde flow in the MMA occurred in 137 (100%) cases, and no cases required periprocedural rescue surgery for cSDH evacuation. The average follow-up length was 170 ± 17.9 days, cSDH was reduced by 4.24 ± 0.5(mm) and the midline shift by 1.46 ± 0.27(mm). Complete resolution was achieved in 63 (46.0%) cases. Conclusion Proximal MMA coil embolization is a safe technique for providing additional embolization/occlusion of the MMA in cSDH embolization procedures. Further studies are needed to evaluate the potential added efficacy of this technique.

BACKGROUND: Chiari malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, frequently resulting in strain related headaches, and motor/sensory dysfunction. Chiari decompression technique varies significantly, possibly contributing to frequent revisions. We reviewed revision Chiari decompressions at our institution to determine the primary indications for revision and outcomes after revision. METHODS: We retrospectively reviewed patients who underwent revision of Chiari decompression at our institution from 2005 to 2020. Demographics, indications for revision surgery, operative techniques, imaging findings, and preoperative/postoperative symptoms were collected. chi(2 )test was performed to determine statistical significance using a P < 0.05. Independent predictors of operative outcomes were identified. RESULTS: A total of 46 patients (91% females, mean age 38.8 years) were included for analysis. The median time to revision surgery was 69.1 months (range 0-364 months) with headache (n = 37, 80%) being the most commonly recurring symptom. Large craniectomy (n = 28, 61%) was the most frequent indication for revision surgery. Thirty-two (70%) patients underwent cranioplasty, 20 (43%) required duraplasty, 15 (33%) required arachnoid dissection, and 15 (33%) required tonsillar reduction during revision surgery. Postrevision follow-up (at 8.9 +/- 5.2 months average, range 1-18 months), revealed an average reduction in all Chiari-related symptoms relative to symptoms before the revision. CONCLUSIONS: The most common indication for revision Chiari decompression was a large craniectomy resulting in cerebellar ptosis. We found that tonsillar reduction paired with modest craniectomy achieved near-complete resolution of symptoms with minimal complications. For patients with recurrent or persistent sequelae of Chiari malformation after decompression, revision may reduce symptom severity.

Background Sympathetic-mediated vasoconstriction from the superior cervical ganglion (SCG) is a significant contributor to cerebral vasospasm. Inhibition of the SCG has been shown to improve cerebral blood flow and reverse cerebral vasospasm in swine models. We evaluated the efficacy of a novel minimally invasive endovascular approach to target and pharmacologically inhibit the SCG, using a Micro-Infusion Device for transmural drug delivery. Methods Eight SCGs in four Yorkshire swine were surgically identified. After confirming appropriate sympathetic-mediated intracranial vasoconstriction response with SCG stimulation, an endovascular Micro-Infusion Device was used for transmural targeting of the SCG and delivery of 1.5–2 mL of 1% lidocaine-contrast mixture to the perivascular space. Digital subtraction angiography was obtained at: (1) baseline; (2) with SCG stimulation; and (3) after lidocaine delivery to the SCG using the Micro-Infusion Device with concurrent SCG stimulation. Vessel diameters were measured and compared. Results Endovascular transmural delivery of lidocaine to the SCG and carotid perivascular tissue using the Micro-Infusion Device successfully inhibited sympathetic-mediated vasoconstriction response. Measured vessel diameters after lidocaine delivery were comparable to baseline despite SCG stimulation. Conclusion A novel endovascular technique of transmural delivery of lidocaine to the SCG and carotid artery perivascular tissues successfully inhibits the sympathetic input to the cerebral vasculature and modulates sympathetic-mediated cerebral vasospasm. These results suggest promising steps towards translation to potential clinical use for patients suffering from cerebral vasospasm.

BACKGROUND:Flow diversion (FD) embolization of intracranial cerebral aneurysms is an increasingly common modality where treatment success depends on adequate vessel wall apposition of the device. This study aimed to investigate off-label use of the Comaneci device for augmenting vessel wall apposition in post-deployed flow diversion stents (FDS). METHODS:Over a 20- month period, all FD cases for the treatment of internal carotid artery (ICA) aneurysms were reviewed. Cases in which the Comaneci device was used to augment vessel wall apposition were analyzed. Data including patient demographics, case characteristics, and procedural outcomes were collected and analyzed as counts. RESULTS:From a total of 74 ICA FD cases, the Comaneci device was used to improve vessel wall apposition in 22 cases (29.7%) . Of these cases, 91% were female with a mean patient age of 64.9±11.3 years, and an average aneurysm size of 4.5±2.5 mm. Comaneci device deployment and retrieval was successful in all (100%) cases, with an average fluoroscopy time of 27.3±7.8 min, an average contrast usage of 25.8±13.2 mL, and an average radiation exposure of 915.1±320.8 mGy. Only two cases (9%) required subsequent balloon angioplasty after Comaneci deployment to improve vessel wall apposition throughout the FDS. CONCLUSION:Our experience with this technique demonstrates the feasibility of using the Comaneci device for augmentation of FDS vessel wall apposition with 100% success in the deployment and retrieval of the Comaneci device.

Formation of a carotid free-floating thrombus (CFFT) is a rare and life-threatening condition without an optimal management plan. A 78-year-old woman with a history of prior right internal carotid artery (ICA) mechanical thrombectomy and antiplatelet noncompliance presented with transient ischemic attacks secondary to a recurrent CFFT in the right ICA. Given her symptoms and recurrent CFFT, endovascular mechanical thrombectomy was performed. A balloon guide-catheter (BGC) and a Zoom 88 distal access catheter were brought into the right distal common carotid artery and proximal ICA bulb, respectively. Three 0.021-inch microcatheters, each loaded with a unique stentriever, were navigated beyond the thrombus into the upper cervical ICA and deployed in a bouquet fashion. The BGC was inflated to achieve flow arrest, and the Zoom 88 aspiration catheter was tracked over the three bouquet stentrievers to ingest the thrombus. Follow-up angiography demonstrated recanalization of the proximal cervical ICA without evidence of residual thrombus. Twenty-four-hour postoperative computed tomography imaging did not reveal any evidence of new infarction. The patient was discharged home with an intact neurological examination, compliant on aspirin and apixaban. We demonstrate a novel technique utilizing a large-bore catheter with a triple stentriever "bouquet" to thrombectomize a CFFT.

Introduction Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. Methods Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors’ prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. Results The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. Conclusion Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Osteogenesis imperfecta (OI) predisposes individuals to easy bone fracture, vessel fragility, and platelet dysfunction. We report the first known case of neurointerventional treatment with flow diversion of intracranial aneurysms in a patient with OI. A 62 year-old female with known OI Type I, history of >40 lifetime bone fractures and hypertension, underwent workup for transient ischemic attacks revealing a 4-mm right A1 segment aneurysm in 2016. Perioperative dual antiplatelet therapy was aspirin 81 mg and clopidogrel 37.5 mg daily. Tri-axial access was utilized to deploy a 3.5 × 16-mm Pipeline Flex device without complication. Two-month follow-up revealed Raymond I (O’Kelly Marotta I) obliteration of the aneurysm. Five-year follow-up revealed a de novo left-sided 3-mm A1–A2 junction aneurysm. A 4 × 12-mm Surpass Evolve was placed without complication. Six-month follow-up revealed Raymond I (O’Kelly Marotta I) obliteration of the second aneurysm. The patient remained asymptomatic at all follow-up visits.