Intermediate Catheter Research Articles

Management of internal carotid artery pathology with a covered stent: illustrative cases.

Endovascular treatment of internal carotid artery (ICA) pathology includes reconstructive or deconstructive options. One reconstructive option is covered stent placement, although this is limited by a lack of devices designed specifically for neurointervention. The PK Papyrus is a balloon-mounted covered coronary stent that has a lower profile and is more flexible than other stent grafts, which makes it more suitable for treating ICA lesions. The PK Papyrus was used to treat patients with iatrogenic cavernous ICA injury and symptomatic cervical ICA pseudoaneurysms. In both cases, the stent could be easily delivered without the use of an intermediate catheter or stiff microwire. Stent deployment resulted in immediate angiographic resolution of the pathology, and there were no peri- or postoperative complications. The PK Papyrus covered coronary stent is a good option for treating cervical and cavernous carotid pathology. Its single-layer design makes it more flexible and deliverable than other stent grafts, but additional case series are needed. https://thejns.org/doi/10.3171/CASE24517.

Utility of the turn-back supporting technique using a steerable intermediate catheter: illustrative case.

Selective shunt occlusion (SSO) for intracranial dural arteriovenous fistulas (DAVFs) is a safe and effective method that directly intercepts the shunted pouch from the affected sinus with minimal materials. However, it can be challenging to obliterate the shunted pouch if the microcatheter is not supported adequately. A 68-year-old woman presented with tinnitus and was diagnosed with multiple shunted DAVFs in the right transverse-sigmoid sinus (TSS) and the superior sagittal sinus (SSS). Although the entire sinus packing of the right TSS was performed, a follow-up angiography 7 months later revealed significant cerebral venous reflux due to occlusion of the left TSS and an increasing residual shunt flow in the venous pouch at the confluence of the SSS. A guiding catheter was introduced into the isolated sinus transvenously. Then, a steerable intermediate catheter (SIC) was manually steered into a hairpin shape and hooked on near the pouch prior to navigating a microcatheter into the fistula point. Finally, the fistula pouch was completely obliterated using only two coils under the adequate support of the turned-back intermediate catheter. The turn-back supporting technique using an SIC was useful in achieving SSO for DAVFs, providing both adequate support and guidance for the coaxial microcatheter. https://thejns.org/doi/10.3171/CASE24467.

The Vecta 46 intermediate catheter for mechanical thrombectomy of distal medium vessel occlusions: A single-center experience.

With emerging evidence supporting the clinical efficacy and safety of mechanical thrombectomy (MT) for distal medium vessel occlusions (DMVOs), MT devices specifically designed to navigate through smaller caliber and more delicate tortuous distal cerebrovasculature are required. This study describes our single-center experience using the AXS Vecta 46 intermediate catheter for first-line thromboaspiration of DMVOs. We identified all patients who underwent MT using the Vecta 46 for first-line thromboaspiration for primary or secondary DMVOs. We collected baseline clinical data, angiographic and clinical outcomes, as well as procedural complications. The primary outcome in question was the rate of successful recanalization, which was defined as a modified Thrombolysis in Cerebral Infarction score of ≥2b. We identified 43 patients who underwent MT using the Vecta 46 catheter for thromboaspiration of 54 DMVOs. Intervened vessels included the M2 (23/54), M3 (19/54), and M4 (6/54) branches of the middle cerebral artery, A2 (1/54), A3 (1/54), and A4 (1/54) branches of the anterior cerebral artery, and P1 (1/54), P2 (1/54), and P4 (1/54) branches of the posterior cerebral artery. The median number of passes for primary DMVOs was 2 (IQR: 1-3) and 1 (IQR: 1-1.25) for secondary DMVOs. The rate of successful recanalization was 100% (18/18) for primary DMVOs and 80.6% (29/36) for secondary DMVOs. First-pass effect (FPE) was noted in 55.6% (30/54) of all primary and secondary DMVO cases. Improved short-term clinical outcomes were observed in both the primary (National Institute of Health Stroke Scale [NIHSS] shift: -5 [IQR: -14.25 to -0.25]) and secondary (NIHSS shift: -5 [IQR: -10 to -2]) DMVO groups. A total of six patients died during their hospitalization, though none were deemed procedural-related. Our study demonstrates the safety and efficacy of the Vecta 46 intermediate catheter for thromboaspiration of both primary and secondary DMVOs, achieving high rates of successful recanalization and FPE.

Subacute in-stent thrombosis after carotid artery stenting in a patient with gene polymorphisms associated with aspirin and clopidogrel resistance: a case report

BackgroundCarotid artery stenting (CAS) is a key treatment option for moderate to severe carotid artery stenosis. Carotid stent thrombosis (CST), a rare complication of CAS, has gained significant attention because of its catastrophic nature. More evidences are needed to guide the diagnosis and treatment of CST.Case presentationThis study reports a rare case of sub-acute CST following CAS in a 50-year-old male patient who had experienced repeated cerebrovascular events on the premise of taking antiplatelet drugs. He also suffered an occlusion of the left middle cerebral artery (MCA) in the M2 segment, likely caused by an embolus detached from the stent thrombus. The cause of CST in this patient was presumed to be dual antiplatelet resistance (AR), as indicated by genetic testing. After treated with guide catheter-directed thrombolysis, thrombus aspiration, and a second round of thrombolysis, his in-stent thrombus was basically cleared. His M2 occlusion was resolved by mechanical thrombectomy using the Solitaire FR/Stent with Intermediate Catheter Assisting technique. The patient recovered well after replacement of antiplatelet drugs, and no new thromboembolic event occurred during the 13-month follow-up period.ConclusionsThe occurrence rate of AR-related CST may be underestimated as the cause of majority CST cases remains unclear. Implementation of genetic test for aspirin and clopidogrel resistance may be helpful to find the possible cause of CST and to avoid future repeated cerebrovascular events by replacement of antiplatelet drugs.

Safe Endovascular Recanalization of Internal Carotid Artery Occlusion Using Retrograde Aspiration Angiography

ObjectsCerebral infarction, resulting from acute internal carotid artery (ICA) occlusion, typically manifests with a wide ischemic area and severe symptoms. Mechanical thrombectomy proves effective within 24 hours of disease onset and in less ischemic infarction core. However, in cases with well-developed collateral flow and mild symptoms, conservative treatment is initially selected. If symptoms worsen or ipsilateral hemisphere perfusion decreases, superficial temporal artery (STA) – middle cerebral artery (MCA) anastomosis is considered. Revascularization therapy may also be effective. Contralateral angiography allows for ipsilateral blood flow verification once complete revascularization is achieved, albeit with potential treatment-related complications. Here, we describe retrograde angiography using an intermediate catheter (IMC) and contralateral contrast injection to achieve safer revascularization. MethodsWe present ten acute ICA occlusion cases caused by thromboembolism, arteriosclerosis, carotid artery stent occlusion, or embolic stroke of undetermined source. Employing bilateral femoral artery puncture, one catheter was guided to the occluded ICA, while another was positioned for diagnostic purposes in the contralateral ICA or vertebral artery. The IMC was navigated through the occluded vessel, with contralateral imaging performed during aspiration. The catheter was gradually retracted to confirm the extent of occlusion and recognize recanalization. ResultsRecanalization was successfully achieved in all cases. Symptomatic ischemic complication and hyperperfuison was not seen in all cases. No cases were decreased modified Rankin scale after treatment. ConclusionAdvancements in IMC technology facilitate distal catheter guidance to the ICA, even in proximal occlusion. Combining this technique with contralateral imaging allows us to confirm the extent of occlusion and recanalization status without antegrade imaging, making recanalization therapy safer.

Investigator-initiated clinical trial of stabilizer device: A novel intracranial exchange guidewire for neuroendovascular treatments.

Neuroendovascular procedures, especially those involving significant vessel tortuosity, giant intracranial aneurysms, or distally located lesions, frequently necessitate exchange methods. However, exchange maneuvers pose a risk of inadvertent vessel injury. To address these challenges, a Stabilizer device was developed and evaluated for its efficacy and safety. This clinical trial aimed to assess the efficacy and safety of the Stabilizer device in facilitating the navigation of neuroendovascular devices to target lesions in cases where the exchange technique was necessary. This was a single-arm, prospective, open-label, multicenter clinical trial performed at nine different sites. It focused on investigating the use of the Stabilizer device for treating intracranial aneurysms and atherosclerosis. A total of 31 patients were enrolled across nine centers in Japan from July 21, 2022, to March 10, 2023. The study enrolled 24 (77.4%) patients with intracranial aneurysms and seven (22.6%) patients with intracranial artery stenosis. Majority of the target lesions were in the middle cerebral artery territory (83.9%). The Stabilizer device was used to exchange for 0.027-inch catheters, intermediate catheters, PTA balloons, and Wingspan stent system. The Stabilizer device demonstrated 100% technical success rate. While three complications related to the treatment were noted, there were no complications related to the device, including any vascular damage. This is the first multicenter clinical trial that investigated and demonstrated technical efficacy as well as overall safety profile of the Stabilizer device in neuroendovascular procedures where the use of an exchange method was necessary.

The Era of Radial-Specific Catheters: A Multicenter Comparison of the Armadillo and RIST Catheters in Transradial Procedures.

As the radial approach is gaining popularity in neurointervention, new radial-specific catheters are being manufactured while taking into consideration the smaller size of the radial artery, different trajectories of angles into the great vessels from the arm, and subsequent force vectors. We compared outcomes of transradial procedures performed using the Armadillo catheter (Q'Apel Medical Inc.) and the RIST radial guide catheter (Medtronic). This is a retrospective multicenter study comparing outcomes of transradial neuroendovascular procedures using the Armadillo and RIST catheters at 2 institutions between 2021 and 2024. The study comprised 206 patients, 96 of whom underwent procedures using the Armadillo and 110 using the RIST. Age and sex were comparable across cohorts. In most procedures, 1 target vessel was catheterized (Armadillo: 94.8% vs 89.1%, P = .29) with no significant difference between cohorts. The use of an intermediate catheter was minimal in both cohorts (Armadillo 5.2% vs RIST: 2.7%, P = .36), and the median number of major vessel catheterization did not significantly differ between cohorts (Armadillo: 1 [1-4] vs RIST: 1 [0-6], P = .21). Failure to catheterize the target vessel was encountered in 1 case in each cohort (Armadillo: 1.0% vs RIST: 0.9%, P = .18), and the rate did not significantly differ between cohorts. Similarly, the rate of conversion to femoral access was comparable between cohorts (Armadillo: 2.1% vs RIST: 1.8%, P = .55). There was no significant difference in access site complications (Armadillo: 1% vs RIST: 2.8%, P = .55) or neurological complications (Armadillo: 3.1% vs RIST: 5.5%, P = .42) between cohorts. No significant difference in successful catheterization of target vessels, procedure duration, triaxial system use, complication rates, or the need for transfemoral cross-over was observed between both catheters. Both devices offer high and comparable rates of technical success and low morbidity rates.

Matched-pair analysis of patients with ischemic stroke undergoing thrombectomy using next-generation balloon guide catheters

BackgroundBalloon guide catheters (BGCs) have not been widely adopted, possibly due to the incompatibility of past-generation BGCs with large-bore intermediate catheters. The next-generation BGC is compatible with large-bore catheters. We...

The short-term outcome of intracranial stenosis with distal thrombosis treated with balloon-assisted tracking.

Treating intracranial stenosis with distal thrombosis (IS&DT) using traditional mechanical thrombectomy (MT) techniques has proven challenging. This study aimed to summarize the experience of utilizing the balloon-assisted tracking (BAT) technique for IS&DT. Demographic and morphologic characteristics of patients with IS&DT were collected for this study. The BAT technique, involving a half-deflated balloon outside the intermediate catheter tip, was used in all patients to navigate through the proximal stenosis. Various parameters were recorded, including the sequence of vascular reperfusion, the puncture-to-reperfusion time (PRT), the residual stenosis rate, and the occurrence of re-occlusion. The thrombolysis in cerebral infarction (TICI) scale was used to assess the reperfusion of intracranial vessels, with a TICI score of ≥2b considered as successful perfusion. The clinical status of patients was evaluated at three time points: pre-procedure, post-procedure, and at discharge using the modified Rankin score (mRS). In this study, a total of 10 patients were diagnosed with IS&DT, consisting of 9 male patients (90.0%) and 1 female patient (10.0%). The patients' mean age was 63.10 years (ranging from 29 to 79 years). The mean National Institute of Health Stroke Scale (NIHSS) score before treatment was 24.3 (ranging from 12 to 40), indicating the severity of their condition. Following the procedure, all patients achieved successful reperfusion with a thrombolysis in cerebral infarction (TICI) score of ≥2b. The average puncture-to-reperfusion time (PRT) was 51.8 min (ranging from 25 to 100 min), indicating the time taken for the procedure. During the perioperative period, three patients (30.0%) experienced complications. One patient had hemorrhage, while two patients had contrast extravasation. Among these cases, only the patient with hemorrhage (10%) suffered from a permanent neurological function deficit. At discharge, the patient's condition showed improvement. The mean NIHSS score decreased to 13.2 (ranging from 1 to 34), indicating a positive response to treatment. The mean mRS score at discharge was 3.2 (ranging from 1 to 5), showing some level of functional improvement. In conclusion, the use of the balloon-assisted tracking (BAT) technique for treating intracranial stenosis with distal thrombosis (IS&DT) showed promising results. However, a moderate rate of perioperative complications was observed, warranting further investigation and refinement of the procedure.

TRUST Technique for Neurointervention: A Promising Alternative for Complex Cases.

Neurointervention via Transradial Access (TRA) is becoming increasingly popular as experience with this technique increases. However, approximately 8.6-10.3% of complex TRA cases are converted to femoral access due to a lack of support or radial artery spasm. This study aimed to assess the efficacy and safety of the TRUST (trans-radial coaxial catheter technique using a short sheath, Simmons catheter, and Tethys intermediate catheter) technique in interventional procedures via TRA. This was a single-center retrospective analysis of 16 patients admitted to our institute between January 2023 to May 2023 to undergo endovascular interventions with the TRUST technique via the TRA. The mean age of the study population was 63.8 years, and 62.5% were male (10/16). The most common procedure was intracranial atherosclerotic stenosis (93.75%, 15/16). All procedures were performed successfully, and the most common procedures in our cohort were ballooning (50.0%, 8/16), stenting (18.75%, 3/16), and both procedures combined (31.25%, 1/16). All procedures were performed using the TRA, and the distal and proximal radial arteries were used for access in 31.35% (5/16) and 68.75% (11/16) of the cases, respectively. Technical success was achieved in all patients and most cases demonstrated mTICI ≥2b recanalization (93.75%, 15/16). In this case, no major access-site complications occurred. The TRUST technique is technically safe and feasible and had a high technical success rate and low complication rate in our study. These results demonstrate that the TRUST technique is a promising alternative for patients undergoing complex neurointerventions.

Intermediate catheter use is associated with complete occlusion and dense packing in coil embolization of unruptured cerebral aneurysms: a propensity score matched study

BackgroundAn intermediate catheter (IMC) can improve the maneuverability and stability of the microcatheter.ObjectiveTo investigate the efficacy and safety of using an IMC in triaxial systems for coil embolization of unruptured...

Intermediate catheter use is associated with intraprocedural rupture during coil embolization of ruptured intracranial aneurysms: a retrospective propensity score-matched study.

An intermediate catheter (IMC) may pose a risk of intraprocedural rupture (IPR) during coil embolization of ruptured intracranial aneurysms (RIAs), because the pressure on the microcatheter and coil might be more direct. To verify this hypothesis, this study explored whether use of an IMC might correlate with an increased rate of IPR during coil embolization for RIAs. We retrospectively reviewed 195 consecutive aneurysms in 192 patients who underwent initial coil embolization for saccular RIAs at our institution between January 2007 and December 2023. Patients were divided into two groups with aneurysms treated either with an IMC (IMC group) or without an IMC (non-IMC group). To investigate whether IMC use increased the rate of IPR, a propensity score-matched analysis was employed to control for age, sex, maximal aneurysm size, neck size, bleb formation, aneurysm location, proximal vessel tortuosity, balloon-assisted coiling, type of microcatheter, and type of framing coil. Ultimately, 43 (22%) coil embolization used IMC. In univariate analysis, the incidence of IPR was significantly higher in the IMC group compared with the non-IMC group (14.0 vs. 3.3%, p = 0.016). Propensity score matching was successful for pairs of 26 aneurysms in the IMC group and 52 aneurysms in the non-IMC group. The incidence of IPR was still significantly higher in the IMC group than in the non-IMC group (23.1 vs. 3.8%, p = 0.015). No significant differences in the incidences of ischemic complications and IMC-related parent artery dissection were observed between the two groups. When using IMC for coil embolization of RIAs, the surgeons should be more careful and delicate in manipulating the microcatheter and inserting the coils to avoid IPR.

Custom shaping of distal access catheter for navigation of microcatheter into inferolateral and meningohypophyseal trunk feeders.

Navigating a microcatheter to tiny feeding arteries such as the inferolateral trunk (ILT) and meningohypophyseal trunk (MHT) of the internal carotid artery (ICA) is technically challenging because of the anatomical features of steep angulation, small diameter, and significant caliber difference from the ICA. To guide the microcatheter to these ICA side branch feeders, the authors thought that a custom shaping of the intermediate catheter would be helpful to determine the direction of the microcatheter and strongly back it up. The aim of this study was to report the detailed methodology and clinical outcomes of patients who had undergone the embolization of ILT and MHT feeders using this method. This was a retrospective study of consecutive patients with intracranial tumors and dural arteriovenous fistulas (DAVFs) who had undergone endovascular embolization. The details of the embolization procedures were examined, especially the technique of guiding a low-profile microcatheter supported by the thermoformed intermediate catheter. The authors assessed the patient background, procedural outcomes, and postoperative complications. Between October 2013 and June 2022, 43 patients with intracranial tumors and 45 with DAVFs underwent embolization at the authors' institutions. Among these cases, embolization of the ICA side branch feeder was attempted in 10 intracranial tumors and 2 DAVFs. Of these 12 patients, the microcatheter was guided deep enough for successful embolization in 11 cases (92%). Two asymptomatic arteriovenous fistulas were complicated during guidewire manipulation deep in the feeder. Yet, both disappeared completely after glue injection into the feeding artery. No spasm or dissection of the parent artery occurred during the procedure. Postoperative radiological evaluation showed no intracranial hematoma or symptomatic cerebral infarction. One patient (9%) developed permanent postoperative cranial neuropathy that gradually improved after embolization. This study revealed that custom shaping of distal access catheters is an effective technique that enabled the embolization of ILT and MHT feeders with a success rate of more than 90%.

Mechanical thrombectomy for acute left middle cerebral artery occlusion in a patient with mirror- image dextrocardia

Mirror-image dextrocardia is a physiological variant in which the heart is located in a mirror position to the right of the position of the normal human heart. Mirror-image dextrocardia combined with acute large-artery occlusive stroke is extremely rare in clinical practice. We present here a 67-year- old woman with complete blockage in her left middle cerebral artery. The patient also had a mirror- image dextrocardia. In this report, we share our experience in treating the patient using mechanical thrombectomy. During her visit to the emergency department, we performed various tests to understand the patient’s anatomy. Based on the findings, we decided to approach the femoral artery. Using a combination of stent thrombectomy and intermediate catheter aspiration, we successfully restored blood flow to the patient’s left middle cerebral artery.

Abstract 139: Super Distal Access using the Vecta46 Intermediate Catheter in Embolization of the MMA for cSDH

Introduction There is increasing literature to support the efficacy of middle meningeal artery (MMA) embolization in the treatment of chronic subdural hematomas (cSDH). Techniques for optimal embolization of the MMA are yet to be elucidated. We hypothesized utilization of a novel 046” intermediate catheter within the proximal MMA trunk carry procedural advantages for multiple pedicle embolizations and ease of navigation to distal MMA vasculature. Methods We retrospectively reviewed and analyzed a prospectively maintained IRB‐approved database of the senior authors. Results Twenty‐one (21) consecutive cases of Vecta46 utilization with MMA embolization were identified (2023), in patients 69±13 years (range 49‐83 years), 4 (19%) women. Four (19%) patients were on antiplatelet/anticoagulants. At presentation, recurrent cSDH in 9 patients (43%) were previously managed with burr holes (n=2, 22%), craniotomy (n=3, 33%), or without drainage (n=4, 44%). Average admission cSDH thickness was 8.8±1.6mm, midline shift of 3±0.7mm. Access was performed through a 5‐ or 6‐French arteriotomy. Both anterior and posterior MMA branches were embolized in 16 (76%) cases, and adjunctive coiling of the proximal MMA trunk was performed in all cases. Vecta46 was successfully placed in the proximal MMA trunk in all cases. There were no vessel irregularities, vasospasm, or dissection noted along the course of the MMA Vecta46 placement. No immediate procedural complications were noted and all cases achieved complete distal MMA occlusion. Figure 1: (A) Ophthalmic (black) and petrous (white) collaterals off the anterior and posterior MMA branches, respectively. (B) Contralateral (green) and falx (orange) penetration of the MMA branches. (C) Proximal coiling of the anterior and posterior MMA branches (black). Conclusion The Vecta46 intermediate catheter is a powerful tool for MMA embolization that allows the safe and effective placement of an intermediate catheter in the proximal MMA trunk. This allows for simple catheter exchange for multiple liquid embolic pedicle embolizations and significant support for navigating microcatheters to distal MMA branches.

Abstract 032: Ovine Models for Cerebral Venous Catheter Access: A Single Center Experience

Introduction Large animal models are utilized for preclinical neuroendovascular research, and aid in the characterization and de‐risking of novel therapeutic approaches. To date, only a single prior study has been published providing a detailed account of an ovine model (Corriedale sheep) for cerebral venous access. The generalizability of these experiments has not yet been validated externally. In an effort to replicate these findings and de‐risk a novel, non‐surgical trans‐dural venous sinus approach to the cerebrum, cerebral venous access was attempted in 3 sheep specimens using transcranial and endovascular approaches. We report our experience validating this large animal model for translational and preclinical research. Methods 3 animal experiments were performed at the UCLA TRIC laboratory between 02/2022 and 10/2022. The sheep were anesthesitized and handled under approval of the Animal Research Committee at UCLA (protocol ARC 2020‐19). The neck and groin areas were shaved and aseptically prepped. MRI Brain and MR Brain venogram imaging was performed on a 3T Siemens Magnetom MRI. Femoral artery and external jugular vein access were obtained using the Seldinger technique under ultrasound guidance and did not require a surgical cut down. Two Suffolk and one Rambouillet sheep were used (average weight 60 kg and 40 kg, respectively). The animals were transferred to the catheter laboratory and image guidance was performed with a monoplane Siemens Artis Zeego. A transcranial approach to the dorsal sagittal sinus was attempted in one Suffolk sheep specimen utilizing a Hubly Drill and a micro‐puncture kit. An endovascular approach to the dorsal sagittal sinus was attempted in second Suffolk sheep specimen using a 25 cm, 8 Fr Pinnacle Sheath via the external jugular vein followed by a 132 cm Catalyst 5 catheter, 0.027" Medtronic Marksman, Stryker SL‐10 and Offset microcatheters assembled over 0.014" Synchro Standard and exchange‐length Choice PT microguidewires. In a third experiment, an endovascular approach to the dorsal sagittal sinus was attempted in a Rambouillet sheep specimen using a 95 cm TracStar, 115 cm Catalyst 5 catheter, and 0.027" Medtronic Marksman microcatheter assembled over 0.014" Synchro Standard and exchange‐length Boston Scientific (BS) Choice PT microguidewires. The 0.027" Marksman microcatheter was subsequently exchanged for a 2.7 French BS Stingray LP coronary CTO re‐entry microcatheter in the Rambouillet sheep, which was tracked to the anterior third of the dorsal sagittal sinus over the exchange length wire. Results A transcranial approach to the dorsal sagittal sinus was complicated by misaligned needle trajectories resulting in brain parenchymal damage. The external jugular vein was the conduit for accessing the first and second emissary veins of the retroauricular foramen (figure 2). Access to the temporal and then transverse sinuses was possible from either of the aforementioned emissary veins. Interestingly, the morphology of the dorsal sagittal sinus was bifid and each vessel channel measured between 1.65 – 1.7 mm in diameter (figure 1). Access to the temporal sinus from an endovascular approach was possible with all microcatheters. However, access with a 0.027" microcatheter beyond the torcular herophili and into the dorsal sagittal sinus was only possible in the Rambouillet sheep despite its smaller body size. Intermediate catheters (>4 Fr) could not be advanced beyond the skull base in none of the sheep breeds. Lastly, microcatheter advancement into the cerebral hemispheric space across a transdural venous sinus puncture access point deliberately created by wire perforation was feasible from the Stingray re‐entry system after exchanging for a 0.017" microcatheter. A coil (Stryker Target) was deployed extravascularly from the 0.017" microcatheter for post‐mortem characterization (figure 3). Conclusion One of three experiments met criteria for success. Due to reliance on a monoplane projection, a transcranial approach failed as an access route to the dorsal sagittal sinus resulting in iatrogenic parenchymal damage. Despite the larger body size, the second Suffolk sheep dural venous sinus system could not be catheterized beyond the skull base, likely due to the small caliber or focal stenosis of the temporal or transverse sinuses. The Rambouillet sheep breed proved to be a more adequate specimen for cerebral venous—specifically dorsal sagittal sinus—access with larger bore microcatheters. Based on this experience, careful selection of an appropriate sheep breed is necessary for modeling endovascular cerebral venous access and assessing novel procedures.

Abstract 188: Rescue Left Middle Cerebral Artery Stenting With Xience Skypoint Everolimus‐Eluting Stent: Technical Report

Introduction Drug‐eluting stent (DES) use in symptomatic intracranial atherosclerosis disease (ICAD) has been described in the literature using different guiding and distal access catheters. We describe a case of deployment of a Xience Skypoint everolimus‐eluting stent (EES) (Abbott Vascular, Abbott Park, Illinois) into a symptomatic stenosed left M1 segment using Armadillo catheter (Q'Apel, Fremont, CA) with a successful result. Methods Case report and review of literature Results 67‐year‐old woman with type II diabetes mellitus, hypertension, hyperlipidemia, and recent admission for transient ischemic attack (resolving right hemiparesis and mild dysnomia in the setting of severe left M1 segment stenosis with discharge on Aspirin, Clopidogrel and Atorvastatin), presented with recurrence of symptoms, and MRI brain showing left basal ganglia acute infarction. No tPA was given low NIHSS and resolution of symptoms. Patient’s aphasia and hemiparesis worsened with segmental hypoperfusion which resolved by maintaining high blood pressures with norepinephrine drip. Decision was made to deploy a drug eluting stent into the stenosed M1 segment. Through femoral access, a 7F long destination sheath was inserted to the left common carotid origin. A 7F Armadillo catheter was then inserted into the left internal carotid artery (ICA) terminus. ASAHI Prowater coronary guidewire was inserted over which Xience Skypoint EES deployment was attempted but was unsuccessful given difficulty traversing the ICA ophthalmic segment. Ultimately, Armadillo catheter was advanced over a Phenom catheter (Medtronic) with good access into the distal M1 segment. The Phenom intermediate catheter was then removed, and the 2.25 mm x 12 mm stent was introduced through the Prowater guidewire into the segment and inflated to a pressure of 8 atm, with restoration of blood flow. Postoperatively, SBP was lowered to prevent reperfusion injury. Patient’s exam stabilized with mild dysnomia and right hemiparesis without any elevated blood pressure requirements. At 5‐months follow‐up, patient’s exam was non‐focal with NIHSS 0 and repeat DSA showed no evidence of stent occlusion and patent M1 segment. Conclusion Xience Skypoint EES can be successful in treating symptomatic MCA stenosis refractory to maximal medical therapy with good long term results.

Abstract 138: Use of a 046” Intermediate Guide Catheter for Mini‐Triaxial Access in Flow Diversion: Multi‐institution Experience

Introduction The latest FDA‐approved intermediate guide catheter, Vecta46, allows for a unique, mini‐triaxial access platform. The size of this catheter allows for 058” guide compatibility, intraluminal accommodation of an 027” microcatheter for flow diverter delivery, and angiographic procedural injections in an 070” guide catheter. Methods We retrospectively identified and analyzed patients who underwent Surpass Evolve flow diversion treatment utilizing the Vecta46 across the senior authors’ institutions. Results The use of the Vecta46 was identified for treatment of 9 aneurysms treated with the Surpass Evolve Flow Diverter (March to April 2023), in patient’s aged 61±3.5 years (range 40‐74 years) with 89% (n=8) female. Aneurysm average size of 4.3±0.47mm, aneurysms originating along the internal carotid artery (n=6) and MCA branches (n=4). Preoperative PRU measured 92 ± 21. Radial access was utilized in 2 cases. Mean Surpass Evolve utilized was 4.4±0.17mm (diameter) by 15.7±0.88mm (length). An 071” guide catheter (Armadillo, Q’Appel Medical) was used in 8 cases. Vecta46 was safely navigated to the supraclinoid ICA segment in all cases. Average fluoroscopy time was 24±3.1 minutes, radiation exposure was 756±259mGy, and verapamil was used in all cases. Technical success was achieved in all cases with adequate vessel wall apposition verified. There were no hemorrhagic complications nor parent vessel wall dissection or vasospasm in the region of the Vecta46 catheter on final control angiography in all 9 cases. Conclusion The new low‐profile Vecta46 intermediate catheter can be safely and effectively utilized in a 6‐French mini‐triaxial system for flow diverter delivery without compromising injection quality, support, or trackability.

Mechanical thrombectomy with a new intermediate balloon catheter combining the BGC and DAC features: Initial clinical experience with the iNedit device.

The iNedit balloon distal access catheter is a novel thrombectomy device. It has an inner diameter of 0.058″, proximal outer diameter of 2.13 mm, and distal outer diameter of 1.67mm. It is compatible with a 0.088″ guide catheter and includes a balloon located 5 cm from the catheter tip, enabling proximal flow restriction and combined therapy with stent retrievers. We investigate the appraisal of the use, safety, and efficacy of the iNedit catheter in the first-in-human study. In the preliminary cases that demanded training on the product previous to a multicentric study, prospective data were collected on 22 consecutive patients treated with the iNedit catheter to perform thrombectomy for acute ischemic stroke due to large vessel occlusion within 24 h. The outcome measures consisted of several evaluations of user experience rated on a 5-point scale ranging from 1 (bad) to 5 (excellent), as well as assessments of procedural safety outcomes such as artery perforation and arterial occlusion, procedural efficacy outcomes including first-pass effect (Thrombolysis In Cerebral Infarction [TICI] 2c/3) and final recanalization (TICI 2b/3), and clinical efficacy outcomes such as a 3-month 0-2 modified Rankin Scale (mRS). The mean age was 72 ± 12 years old; median National Institute Health Stroke Scale was 17 (11-19). Sites of primary occlusion were: 2 internal carotid artery, 12 M1-MCA, 7 M2-MCA, and one P1. Median score evaluation of the appraisal of use was 4- IQR [4-5]. The median number of passes was 1 [IQR 1-2]. First pass complete recanalization rate was 50% and the final recanalization rate was 94.45%. No artery perforation and arterial occlusion. Good functional outcome mRS 0-2 was achieved in 50% of patients. In this initial clinical experience, iNedit device achieved a high rate of first-pass effect and final recanalization rate with no safety concerns, thus favoring a high percentage of good clinical outcomes.

Extensive Roles and Technical Advances of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma.

Chronic subdural hematoma (CSDH) is a common pathology that typically affects the elderly in Japan, an aging society. Burr-hole irrigation is the standard treatment, but middle meningeal artery (MMA) embolization is a minimally invasive alternative. MMA embolization for CSDH has frequently been reported in recent years, and many technical innovations to improve clinical outcomes have been described. Embolic materials reaching more distally are found to avoid recurrences after MMA embolization. As a result, various studies have described the superiority of embolizing the anterior and posterior branches of the MMA, the advantages of embolic materials reaching beyond the midline, and a high degree of distal penetration using a "sugar rush technique" in which 5% soluble glucose is injected through an intermediate catheter during MMA embolization. Radiographically, reports have described the importance of a "bright falx" sign obtained by infiltrating embolic material beyond the midline and post-embolization enhancement of the dura, capsular membrane, septations, and subdural hematoma fluid as indicators of the spread of embolic materials. This review provides an overview of the current status and future challenges in MMA embolization for CSDH, focusing on technical aspects to improve clinical outcomes.