Placement Of Microcatheter Research Articles

Preoperative Simulation of Neuroendovascular Therapy Using a Three-Dimensional Printer Model of a Tailor-Made Hollow Cerebral Aneurysm

Several studies have reported the importance of preoperative simulations. This report describes the methods and utility of neuroendovascular treatment using a three-dimensional(3D)-printed hollow cerebral aneurysm model. This model was created using a stereolithography apparatus-type 3D printer with digital imaging and communications in medicine data from 3D digital subtraction angiograms. The 3D model was used to perform preoperative simulations of microcatheter placement in aneurysms, microguidewire manipulation, and stent deployment. We performed each simulated procedure during surgery. The hollow cerebral aneurysm 3D model can also be used as a training model for surgical trainees. Preoperative simulation using a high-precision hollow cerebral aneurysm model created using 3D printers enables the discussion of specific treatment strategies for each case, including new devices and device sizes, and is expected to develop into "tailor-made medicine" in the future, contributing to safe and reliable treatment implementation.

Angiographic characteristics and treatment approach in patients undergoing intra-arterial chemotherapy for retinoblastoma.

To identify the specific clinical and angiographic variables that determine the success of intra-arterial chemotherapy (IAC) in a patient with retinoblastoma. Medical records from patients undergoing intra-arterial chemotherapy for the treatment of retinoblastoma between January 2015 and June 2020 within a large academic ocular oncology practice were retrospectively reviewed. Demographics were recorded together with clinical, ocular, and angiographic variables such as the diameter of the ophthalmic artery (OA), angle of ophthalmic artery takeoff, and branching pattern of ophthalmic vasculature. Forty-four eyes from 33 patients with retinoblastoma treated with IAC were identified. Over the total 32 mean months of follow-up, these patients received 144 total catheterizations and a mean of 3.2 IAC cycles for each eye. The number of IAC cycles and the chemotherapeutic agent used did not vary significantly with worsening International Classification of Retinoblastoma (ICRB) groups (P > 0.1). Cumulative dose did not vary with the ICRB group for eyes treated with melphalan, topotecan, or carboplatin (P > 0.1). A higher ICRB group was associated with a smaller mean ophthalmic artery diameter across all procedures (P = 0.016), and femoral artery diameter did not vary significantly between ICRB groups (P = 0.906). A higher cumulative dose of IAC was significantly associated with a smaller takeoff angle of the OA (melphalan, P = 0.011; topotecan, P = 0.009; carboplatin, P = 0.031) in patients who underwent successful IAC procedures. Ophthalmic artery diameter and femoral artery diameter did not have a significant association (P > 0.1) with higher IAC doses in successful IACs. Cumulative IAC dose was not significantly associated with ophthalmic vasculature branching pattern, presence of choroidal blush, temporary OA vasospasm reported during the procedure, and OA occlusion upon microcatheter placement. In this study, neurosurgical angioanatomy appeared to influence the cumulative dose of chemotherapy needed during IAC for retinoblastoma. In the future, these anatomic variables may be used to guide the frequency of monitoring, dosing, and estimation of recurrence risk.

Computer-assisted microcatheter shaping for intracranial aneurysm embolization: evaluation of safety and efficacy in a multicenter randomized controlled trial

BackgroundThis study aimed to evaluate the efficacy, stability, and safety of computer-assisted microcatheter shaping (CAMS) in patients with intracranial aneurysms.MethodsA total of 201 patients with intracranial aneurysms receiving endovascular coiling...

Microcatheter-guided compartment packing of acutely ruptured complex intracerebral aneurysms (ARCIAs): Preliminary experience and technical note.

We present our initial experience using the microcatheter-guided compartment packing (MCP) technique for endovascular embolization of acutely ruptured complex intracerebral aneurysms (ARCIAs) and evaluate the safety, feasibility, and efficiency of this technique. This retrospective, single-center study included 28 patients who underwent coil embolization using the MCP technique for ARCIAs at our institution between January 2021 and January 2022. The MCP technique was the placement of microcatheters in different compartments within the aneurysm to deploy the coils simultaneously or sequentially. Patient demographics, aneurysm characteristics, procedural parameters, grade of occlusion, complications, and clinical results were analyzed. The clinical outcomes were evaluated with modified Rankin Scale (mRS) scores. Of the 28 patients successfully treated with the MCP technique, 24 (85.7%) aneurysms were considered as complete occlusions (Raymond I) based on the immediate postembolization angiogram results. Complications occurred in 2/28 treatments, including guidewire perforation with subarachnoid hemorrhage and cerebral vasospasm-related cerebral infarction. An angiography follow-up demonstrated complete occlusion in 25/28 aneurysms. Twenty-six (92.9%) patients had favorable 90-day outcomes (mRS 0-2) after the endovascular coil embolization. The MCP technique is simple, safe, and effective, achieving good packing density and initial occlusion rate when used to treat ARCIAs.

Cone-beam CT-assisted microcatheter tip placement at the shunted pouch entry zone: A technical note for anterior condylar arteriovenous fistula.

Accurate microcatheter placement for anterior condylar arteriovenous fistula (AVF) enables selective transvenous embolization (TVE) and helps to avoid hypoglossal nerve palsy. Anterior condylar AVF has a shunted pouch within the condylar vascular and osseous structures. Detailed anatomical comprehension of the shunted pouch is essential, in addition, we believe that it is important to have a strategy for where in the shunted pouch to start filling with coils. Specifically, we consider that it is important to structurally understand the more upstream location (arterial side) within the shunted pouch (called "shunted pouch entry zone"), guide the microcatheter there, and embolize from that site. Although several studies have discussed the usefulness of intraoperative cone-beam computed tomography (CBCT) for treating anterior condylar AVF, there are no studies which have mentioned the importance of microcatheter position before coil embolization in selective TVE as in this study. Intraoperative localization of the shunted pouch entry zone is often difficult. Herein, the authors report that cone-beam computed tomography (CBCT) can assist accurate microcatheter tip placement at the shunted pouch entry zone before staring embolization. This is the novel application of intraoperative CBCT to treat anterior condylar AVF successfully treated with precise and selective TVE.

Transradial Versus Transfemoral Approach for Endovascular Thrombectomy of Left Anterior Circulation Stroke With Bovine Arch

Transradial Versus Transfemoral Approach for Endovascular Thrombectomy of Left Anterior Circulation Stroke With Bovine Arch

Transradial Access Results in Faster Recanalization in Left Anterior Circulation Stroke with Bovine Arch Anatomy

Background We compared technical and clinical outcomes of transradial (TRA) versus transfemoral (TFA) access for mechanical thrombectomy of acute ischemic stroke due to large vessel occlusion in the left anterior cerebral circulation of bovine origin. Methods A single‐center retrospective review of a prospectively maintained neurointerventional database from a large volume service in a tertiary academic center. Procedural metrics, technical, and clinical outcomes data were collected and analyzed for patients who underwent mechanical thrombectomy presenting with acute ischemic stroke and large vessel occlusion in the left anterior circulation of bovine origin. Clinical and procedural outcomes included the average number of passes, single first effective pass, rate of successful recanalization (thrombolysis in cerebral infarction score≥2b), 3‐month disability modified Rankin scale scores, time from skin puncture to microcatheter placement, and recanalization. Results Between January 2018 and January 2021, 26 patients (TRA=13, TFA=13) underwent mechanical thrombectomy. The TRA cohort had a significantly shorter time in minutes for skin puncture to microcatheter placement (TRA: 17.0±5.8 versus TFA: 35.4±20.5; P =0.0001), shorter skin puncture to recanalization (TRA: 34.0±15.6 versus TFA: 58.1±34.6; P =0.01), and shorter total fluoroscopy time (TRA: 13.8±9.4 versus TFA: 29.5±18.0; P =0.03). The 3‐month modified Rankin scale score of (0–1) was higher in the TRA group (38.5% versus 7.69%; P =0.06). Conclusions In patients with large vessel occlusion in the left anterior cerebral circulation of bovine origin, right TRA access permits more direct navigation and provides a stable platform resulting in shorter procedure times and faster recanalization with potential for improved functional outcomes.

Perioperative Complications of Transvenous Embolization of Ruptured Intracranial Arteriovenous Malformations.

PurposeTo investigate the perioperative complications of transvenous embolization of ruptured intracranial arteriovenous malformations.Materials and MethodsA total of 27 patients with ruptured intracranial arteriovenous malformations underwent transvenous embolization were enrolled from November 2016 to May 2020 in our prospective database. Perioperative complications and angiographic characteristics were analyzed retrospectively.ResultsComplete disappearance of the nidus occured in 22 (88%) of 25 patients with technically feasible AVMs immediately after embolization. Two cases were partially treated by transarterial embolization due to the failure of microcatheter placement into the draining vein. Seven (25.9%, 7/27) patients had perioperative complications, including three cases of intraoperative hemorrhage, three cases of postoperative hemorrhage and one case of ischemic infarction. No significant differences in complication rates between patients with nidus ≥3 cm and <3 cm (P = 0.659), eloquent area and non-eloquent (P = 0.137), deep location and superficial (P = 0.637), deep venous drainage and cortical vein (P = 1.0), the number of venous drainage (P = 0.49), the angle of draining vein entering venous sinus <90° and ≥90° (P = 1.0), aneurysms (P = 0.058) and the time between hemorrhage and TVE (P = 1.0) were found. Three of these patients received ventriculostomy, two of which received lumbar drainage treatments at the same time, and four patients just received conservative management. Good outcomes (mRS ≤ 2) at the 1-month evaluation were achieved in 5 of the patients who had complications, but poor outcome (mRS = 5) at the 1-month evaluation was in 1 patient, and 1 lethal complication occurred.ConclusionThe most common complication of AVMs with transvenous endovascular embolization is cerebral hemorrhage. The prevention of complications may improve the efficacy of AVM embolization, but the current quality of evidence is low and limited in guiding policy development and improving the TVE for AVMs. It is, therefore, necessary to develop clinical research programs in this field.

Abstract 1122‐000096: Transradial Results in Faster Recanalization in Left Anterior Circulation Stroke and Bovine Arch

Introduction : We compared technical and clinical outcomes of transradial (TRA) versus transfemoral (TFA) access for mechanical thrombectomy (MT) of acute ischemic stroke (AIS) due to large vessel occlusion (LVO) in the left anterior cerebral circulation of bovine origin. Methods : A single‐center retrospective review of a prospectively maintained neuro‐interventional database from a large volume service in a tertiary academic center. Procedural metrics, technical, and clinical outcomes data were collected and analyzed for patients who underwent MT presenting with AIS and LVO in the left anterior circulation of bovine origin. Primary outcomes included the average number of passes, single first effective pass, rate of successful recanalization (thrombolysis in cerebral infarction (TICI) score ≥ 2b), 3‐month disability modified Rankin Scale (mRS) score ≤2, time from skin puncture to microcatheter placement and recanalization. Results : Between January 2018 and January 2021, 26 patients (TRA = 13, TFA = 13) underwent MT. The TRA cohort had a significantly shorter time in minutes for skin puncture to microcatheter placement (TRA: 17.0± 5.8 vs TFA: 35.4± 20.5, P = 0.0001), shorter skin puncture to recanalization (TRA: 34.0± 15.6 vs TFA: 58.1± 34.6, P = 0.01), and shorter total fluoroscopy time (TRA: 13.8±9.4 vs TFA: 29.5±18.0, P = 0.03). The 3‐month mRS score of 0–1 was higher in the TRA group (38.5% vs 7.69%, P = 0.06). Conclusions : In patients with LVO in the left anterior cerebral circulation of bovine origin, right TRA access permits more direct navigation and provides a stable platform resulting in shorter procedure times and faster recanalization with the potential to improve functional outcomes.

A novel intelligent microcatheter-shaping method for embolization of intracranial aneurysm

Objective:This study proposed and validated an intelligent microcatheter-shaping algorithm for interventional embolization of intracranial aneurysms.Methods:A stepwise microcatheter simulation algorithm constrained by a vessel center line was developed based on the geometry of aneurysms and parent arteries, and a collision correction factor of vessel walls was introduced to automatically calculate the optimal microcatheter path and tip shape. The efficacy of this intelligent shaping method was verified in an in vitro aneurysm model experiment.Results:The microcatheter path can be automatically generated using the intelligent microcatheter-shaping algorithm. Furthermore, the experiment verified that the delivery performance of an intelligently shaped microcatheter was excellent with 100% placement accuracy, superior to that of three pre-shaped microcatheters: straight (0°), 45°, and 90°. In three typical cases, the microcatheter could not be placed in the aneurysms successfully within 5 min with the aid of a microwire using a manual shaping scheme; however, it can be placed in the aneurysms successfully within 5 min using an intelligent microcatheter- shaping scheme, and the time of microcatheter placement in aneurysms was short.Conclusion:This intelligent microcatheter-shaping algorithm based on three-dimensional image data is effective and reasonable. This approach has advantages over standard pre-shaped microcatheters, with a potential clinical application value.

Usefulness of Adjunctive Technique with a TACTICS Catheter for Coil Embolization of Cerebral Aneurysms.

We report the usefulness of the adjunctive technique using a 3.4-Fr TACTICS catheter, which is a distal access catheter (DAC) for coil embolization. Patients who underwent coil embolization with an adjunctive technique using a TACTICS catheter between October 2018 and May 2019 were retrospectively analyzed. In all, 64 aneurysms in 51 patients were treated. Among them, 18 aneurysms in 15 patients (4 ruptured aneurysms and 14 unruptured aneurysms) required an adjunctive technique using a TACTICS catheter. The methods of embolization were the double catheter technique (DCT) for five aneurysms, stent-assisted coiling (SAT) for seven, DCT + SAC for one, and balloon-assisted technique (BAT) for five aneurysms. Aneurysms were located in the anterior communicating artery (Acom A) in three cases, distal anterior cerebral artery (dACA) in one, middle cerebral artery (MCA) in five, internal carotid artery (ICA) in six, basilar artery (BA) in one, and vertebral artery (VA) in two cases. It was easy to access distal intracranial vessels using the TACTICS catheter. In all cases, guiding of the microcatheter, coiling, and stent placement were improved. There were no complications associated with using the TACTICS catheter. Compared with conventional DACs, distal intracranial vessels were more easily accessed using the TACTICS catheter. A TACTICS catheter is useful because DCT and SAC require sufficient operability of the microcatheter.

Distal Microcatheter Placement Using the ASAHI CHIKAI 008 Microguidewire for Liquid Embolic Material Delivery

Management of vascular malformations requires microcatheter manipulation through distal tortuous arterial feeders <1 mm in diameter to permit safe and effective embolization at the fistula or nidus location. The ASAHI CHIKAI 008 microguidewire (ACM) recently introduced in the United States was used to evaluate microcatheter torque, support, and safety in distal microcatheter navigation. The use of the ACM in conjunction with flow-directed and over-the-wire microcatheters was evaluated in 25 neuroendovascular cases performed by a single operator for endovascular microcatheter embolization of intracranial vascular malformations over a 1-year period. The study evaluated angiographic evidence of distal microcatheter positioning, subsequent obliteration of the fistula at the location, and any complications. The microguidewire was used in microcatheter embolization of 10 vein of Galen malformations, 11 brain and head and neck arteriovenous malformations, 2 spinal dural arteriovenous fistulas, and 2 cranial dural arteriovenous fistulas. Good flow-directed and over-the-wire microcatheter placement using the ACM was possible across the spectrum of cases achieving optimal catheterization and safe embolization in all. There were no microguidewire- or microcatheter-related vessel spasms, dissections, or perforations during combined or individual manipulation and no contrast or embolic extravasation on fluoroscopy or postembolization angiography. The ACM is a safe, sturdy microguidewire that provides good torque in distal arterial anatomy, while providing microcatheter support and maintaining tip configuration on repeated use.

Selective middle cerebral artery occlusion in the rabbit: Technique and characterization with pathologic findings and multimodal MRI

BackgroundA reliable animal model of ischemic stroke is vital for pre-clinical evaluation of stroke therapies. We describe a reproducible middle cerebral artery (MCA) embolic occlusion in the French Lop rabbit characterized with multimodal MRI and histopathologic tissue analysis. New methodFluoroscopic-guided microcatheter placement was performed in five consecutive subjects with angiographic confirmation of MCA occlusion with autologous clot. Multimodal MRI was obtained prior to occlusion and up to six hours post after which repeat angiography confirmed sustained occlusion. The brain was harvested for histopathologic examination. ResultsAngiography confirmed successful MCA catheterization and durable (>6 h) MCA occlusion in all animals. There was increase of ADC volume over time and variable final core volume presumably related to individual variation in collateral flow. FLAIR hyperintensity indicative of cytotoxic edema and parenchymal contrast enhancement reflective of blood brain barrier disruption was observed over time. Tissue staining of the ischemic brain showed edema and structural alterations consistent with infarction. Comparison with existing methodsThis study describes a technique of selective catheterization and embolic occlusion of the MCA in the rabbit with MRI characterization of evolution of ischemia in the model. ConclusionsWe demonstrate the feasibility of a rabbit model of embolic MCA occlusion with angiographic documentation. Serial MR imaging demonstrated changes comparable to those observed in human ischemic stroke, confirmed histopathologically.

Combined aspiration thrombectomy and continuous intrasinus thrombolysis for cerebral venous sinus thrombosis: technical note and case series.

Cerebral venous sinus thrombosis is an uncommon cause of stroke with high morbidity and mortality rates from venous infarction, intracranial hemorrhage, and extensive cerebral edema. Endovascular treatment with various devices has been proposed as a salvage treatment when standard medical treatment with systemic anticoagulation is ineffective, especially in long segment dural sinus thrombosis. We describe our technique of transvenous endovascular aspiration thrombectomy with large bore thrombectomy catheters, followed by placement of microcatheter for local thrombolytic infusion at the site of thrombosis. We report a retrospective study of angiographic and clinical outcome of six consecutive patients treated with this approach. Endovascular aspiration thrombectomy with large bore catheters followed by continuous local thrombolytic infusion appeared to be a safe and effective salvage treatment for selected patients with cerebral dural venous sinus thrombosis refractory to medical treatment.

Cerebral Aneurysmal Coiling in Virtual Reality ‐ An Overview of Novice Skill Development

Introduction and AimsCerebral endovascular aneurysm coiling is an interventional angiography technique which requires the use of fine motor and visuo‐spatial skills in order to guide tools throughout relevant vascular anatomy and deposit coils within the aneurysm. With the help of quantitatively limited fluoroscopy, coils are established through microcatheter placement in the aneurysm neck and electrolytically detached after their appropriate rotation and positioning. This procedure requires, and is currently limited to, extensive clinical training in the AngioSuite, where trainees are closely supervised by a consultant. This approach, although providing the current gold standard in training, limits the pace of skill development, exposes patients to unnecessary risk and wastes valuable monetary and personnel resources. The development of the skills needed for these procedures can be facilitated by 3D simulator‐based training. Simulation‐based medical education has recently started focusing on personalized training in reducing errors and development of specific skills.The ANGIO Mentor visual‐haptic simulator has been regarded as an effective training tool, increasing performance in diagnostic cerebral angiography, however, this simulator has not been tested thoroughly in its ability to train interventional skills. In particular, the details of the aneurysm coiling process during simulation‐based training have not been assessed.MethodsIn this study, 12 novice medical students were given simulation‐based diagnostic cerebral angiography training until a procedural plateau in performance, established in our previous work (Zaika et al., 2016). Subsequently, they were trained using video tutorials and written instructions to identify, measure and intervene with cerebral aneurysms using endovascular coils. Over the span of 6 sessions, participants were assessed on their procedural pace, coiling quantity and quality, and perforation rates. Concurrently, their spatial ability was assessed using a mental rotations test (MRT) and used in the performance analysis.Results and DiscussionWe found that all individuals were able to perform the procedure faster after 6 sessions, reducing their average time from 42 to 24 minutes. Coil success rate improved over from 82% to 88% and coil packing rate remained consistent at 30% throughout testing. High perforation rate seen at the start of the study showed a trend of decreasing over the latter sessions, however, over half of aneurysms were still being perforated by the novice participants. No change in aneurysm coiling quality was found, with a slight decrease in number of parent artery coil protrusions. High MRT individuals were also better able to establish guider catheter and associate tools prior to coiling. This work identifies the utility of simulation‐based cerebral angiography training in identifying the particular difficulties trainees experience in learning procedural skills, including prevention of perforations, proper positioning and success of coils within the aneurysm.Support or Funding InformationThis research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canadian Institutes of Health Research (CIHR).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Endovascular treatment outcomes using the Stroke Triage Education, Procedure Standardization, and Technology (STEPS-T) program.

Background "Door to treatment" time affects outcomes of acute ischemic stroke (AIS) patients undergoing endovascular treatment (EVT). However, the correlation between staff education and accessible technology with stroke outcomes has not been demonstrated. Objective The objective of this paper is to demonstrate the five-year impact of the Stroke Triage Education, Procedure Standardization, and Technology (STEPS-T) program on time-to-treat and clinical outcomes. Methods The study analyzed a prospectively maintained database of AIS patients who benefited from EVT through implementation of STEPS-T. Demographics, clinical characteristics, and modified Rankin Score at three months were analyzed. Thrombolysis in Cerebral Infarction (TICI) scale was used to grade pre- and post-procedure angiographic recanalization. Using electronic hemodynamic recording, stepwise workflow times were collected for door time (TD), entering angiography suite (TA), groin puncture (TG), first DSA (TDSA), microcatheter placement (TM), and final recanalization (TR). Median intervention time (TA to TR) and recanalization time (TG to TR) were compared through Year 1 to Year 5. Results A total of 230 individuals (age 74 ± 12, between 30 to 95) were enrolled. Median intervention and recanalization times were significantly reduced, from 121 minutes to 52 minutes and from 83 minutes to 36 minutes respectively from Year 1 to Year 5, ( p < 0.001). Across the study period, annual recruitment went up from 12 to 66 patients, and modified Rankin Score between 0 and 2 increased from 36% to 59% ( p = 0.024). Conclusions STEPS-T improved time-to-treat in patients undergoing mechanical thrombectomy for AIS. During the observation period, clinical outcomes significantly improved.

Pressure-Directed Embolization of Hepatic Arteries in a Porcine Model Using a Temporary Occlusion Balloon Microcatheter: Proof of Concept

The purpose of this project was to test the hypothesis that temporary hepatic artery balloon occlusion would favorably alter the distribution of particle emboli within the targeted and nontargeted downstream vascular compartments. Five Yorkshire pigs underwent transfemoral placement of balloon microcatheters into selected segmental hepatic arteries. A collection catheter was surgically introduced into a downstream hepatic artery branch. Blood pressures at the femoral artery sheath and the collection catheter were obtained with the microcatheter balloon deflated and inflated. Identical quantities of calibrated 250- and 400-µm microspheres were injected via the balloon microcatheter when inflated, then deflated. Each animal underwent up to four paired microsphere embolizations. Microspheres collected from the intrahepatic collection catheter were counted manually by light microscopy. Inflation of the balloon microcatheter in the segmental hepatic artery resulted in a consistent and significant decrease in blood pressure (mean: 30mmHg; range 23-43mmHg; p<0.05) in the downstream vascular compartment. The number of microspheres selectively delivered to the targeted intrahepatic collection catheter was significantly greater when the balloon microcatheter was inflated rather than deflated in all 20 paired embolic deliveries (by 2.4-fold, mean; p=0.0002), despite delivery of the same total number of microspheres. Balloon occlusion significantly reduces blood pressure in the downstream vascular compartment, resulting in increased delivery of emboli to a targeted intrahepatic arterial collection catheter relative to other portions of the embolized vascular compartment, likely due to blood flowing into this compartment from neighboring hepatic and extrahepatic arteries.

Abstract WMP10: Comparison of 6 mm Diameter and 3-4 mm Diameter Stent Retrievers for Mechanical Thrombectomy in Acute Ischemic Stroke Patients. Is Bigger Better?

Background: There is controversy regarding the optimal size of stent retriever for achieving timely recanalization in acute ischemic stroke patients. Objective: To determine the relationship between stent retriever diameter and procedure time, and rates of recanalization, and functional independence among acute ischemic stroke patients undergoing mechanical thrombectomy. Methods: We analyzed data from consecutive acute ischemic stroke patients treated with mechanical thrombectomy derived from a prospective database. Baseline demographic and clinical characteristics, NIHSS score on admission and discharge, intracranial hemorrhage occurrence, and mRS at discharge were analyzed. Thrombolysis In Cerebral Infarction (TICI) scale was used to grade pre and post procedure angiographic recanalization. Procedural time was defined by the time interval between microcatheter placement and recanalization. We compared the rates of thrombectomy attempts, complete recanalization (TICI grade of 3), and functional independence (defined by mRS 0-2) between patients treated with 6 mm and 3-4 mm diameter stent retrievers. Results: A total of 230 acute ischemic stroke patients (mean age 71.8 ±12.5; 46.6% women) were treated with stent retrievers. Thrombectomy was performed with a 6mm diameter stent retriever in 107 patients and 3 or 4 mm diameter stent retriever in 123 patients. There were no statistically significant differences in demographics or baseline characteristics, or admission NIHSS score between the two groups. There was a trend towards a fewer number of thrombectomy attempts required with a 6mm diameter stent retriever (p=0.06). There was a higher rate of complete recanalization in patients treated with 6mm diameter stent retriever compared with 3 or 4 mm diameter stent retriever (72% vs 57.7% p=0.02). There was no statistically significant difference in rates of functional independence between the two groups (24.3% vs 25.2% p=0.84) at discharge. Conclusion: Among acute ischemic stroke patients undergoing mechanical thrombectomy, use of a 6 mm diameter stent retriever was associated with a higher rate of complete recanalization and a lower number of thrombectomy attempts compared with 3-4 mm diameter stent retrievers.

Numerical investigation of liver radioembolization via computational particle–hemodynamics: The role of the microcatheter distal direction and microsphere injection point and velocity

Liver radioembolization is a treatment option for patients with primary and secondary liver cancer. The procedure consists of injecting radiation-emitting microspheres via an intra-arterially placed microcatheter, enabling the deposition of the microspheres in the tumoral bed. The microcatheter location and the particle injection rate are determined during a pretreatment work-up. The purpose of this study was to numerically study the effects of the injection characteristics during the first stage of microsphere travel through the bloodstream in a patient-specific hepatic artery (i.e., the near-tip particle–hemodynamics and the segment-to-segment particle distribution). Specifically, the influence of the distal direction of an end-hole microcatheter and particle injection point and velocity were analyzed. Results showed that the procedure targeted the right lobe when injecting from two of the three injection points under study and the remaining injection point primarily targeted the left lobe. Changes in microcatheter direction and injection velocity resulted in an absolute difference in exiting particle percentage for a given liver segment of up to 20% and 30%, respectively. It can be concluded that even though microcatheter placement is presumably reproduced in the treatment session relative to the pretreatment angiography, the treatment may result in undesired segment-to-segment particle distribution and therefore undesired treatment outcomes due to modifications of any of the parameters studied, i.e., microcatheter direction and particle injection point and velocity.

Abstract W P86: The Barrel Vascular Reconstruction Device for the Treatment of Wide-Neck Bifurcation Aneurysms

PURPOSE: Complex wide-necked bifurcation aneurysms by using a single-stent and double (X and Y) stenting remain challenging. The purpose of the French Barrel™ Prospective Registry, an intention to treat study, is to evaluate the safety and probable benefit of the Barrel VRD when used to facilitate endovascular coiling of wide-neck bifurcating. METHODS: The Barrel VRD was intended for use with embolic coils for the treatment of wide-neck bifurcating intracranial aneurysms arising from a parent vessel with a diameter of ≥ 2mm and ≤ 4 mm. A wide-neck is defined as having a neck width ≥ 4 mm or a dome-to-neck ratio &lt; 2. Patients (all harboring unruptured aneurysms) were placed on a double anti-platelet protocol (Clopidogrel and ASA) prior to treatment. RESULTS: From December 2013 to June 2014, 18 patients harboring 18 aneurysms (7 MCA, 4 basilar tip, 4 AcoA, 3 ICA termination) were enrolled within the French Barrel Registry thus far. One patient was enrolled, but not treated due to being a low anti-platelet responder. Aneurysm necks ranged from 3.1 to 8.0 mm (mean: 4.8) and dome/neck ratio ranged from 0.6 to 1.7 (mean : 1.2). Trans-cell microcatheter placement was obtained in all cases. Technical success was 88.2% (15/17). In 1 case, 2 coil loops protruded outside the Barrel within the parent vessel, in another case the Barrel moved slightly during coil delivery microcatheter placement into the sac. Discharge mRS was 0 for all but 1 patients (this patient was mRS 2 at admission). Adverse events included 1 groin hematoma, and 1 aneurysm coil perforation, related to the procedure, but not the Barrel VRD. CONCLUSIONS: The initial French Barrel Registry results demonstrate that the Barrel VRD device is new tool for the endovascular treatment of wide neck bifurcation aneurysms.