Embolization Of Intracranial Aneurysms Research Articles

Excessive platelet inhibition following Pipeline embolization of intracranial aneurysms

BackgroundHigh levels of platelet inhibition have been associated with hemorrhagic complications following Pipeline embolization of intracranial aneurysms. We therefore titrate clopidogrel dosing to maintain a moderate level of platelet inhibition...

Shape Memory Polymer-Based Endovascular Devices: Design Criteria and Future Perspective

Devices for the endovascular embolization of intracranial aneurysms (ICAs) face limitations related to suboptimal rates of lasting complete occlusion. Incomplete occlusion frequently leads to residual flow within the aneurysm sac, which subsequently causes aneurysm recurrence needing surgical re-operation. An emerging method for improving the rates of complete occlusion both immediately after implant and in the longer run can be the fabrication of patient-specific materials for ICA embolization. Shape memory polymers (SMPs) are materials with great potential for this application, owing to their versatile and tunable shape memory properties that can be tailored to a patient’s aneurysm geometry and flow condition. In this review, we first present the state-of-the-art endovascular devices and their limitations in providing long-term complete occlusion. Then, we present methods for the fabrication of SMPs, the most prominent actuation methods for their shape recovery, and the potential of SMPs as endovascular devices for ICA embolization. Although SMPs are a promising alternative for the patient-specific treatment of ICAs, there are still limitations that need to be addressed for their application as an effective coil-free endovascular therapy.

Optimal Duration of Dual Antiplatelet Therapy after Stent- Assisted Coil Embolization of Unruptured Intracranial Aneurysms : A Prospective Randomized Multicenter Trial.

Stent-assisted coil embolization (SAC) has been increasingly used to treat various types of intracranial aneurysms. Delayed thromboembolic complications are major concerns regarding this procedure, so dual antiplatelet therapy with aspirin and clopidogrel is needed. However, clinicians vary the duration of dual antiplatelet therapy after SAC, and no randomized study has been performed. This study aims to compare the safety and efficacy of long-term (12 months) dual antiplatelet therapy and shortterm dual antiplatelet therapy (6 months) after SAC for patients with unruptured intracranial aneurysms (UIAs). This is a prospective, randomized and multicenter trial to investigate the optimal duration of dual antiplatelet therapy after SAC in patients with UIAs. Subjects will receive dual antiplatelet therapy for 6 months (short-term group) or 12 months (longterm group) after SAC. The primary endpoint is the assessment of thromboembolic complications between 1 and 18 months after SAC. We will enroll 528 subjects (264 subjects in each group) and perform 1 : 1 randomization. This study will involve 14 topperforming, high-volume Korean institutions specializing in coil embolization. The trial will begin enrollment in 2022, and clinical data will be available after enrollment and follow-up. This article describes that the aim of this prospective randomized multicenter trial is to compare the effect of short-term (6 months) and long-term (12 months) dual antiplatelet therapy on UIAs in patients undergoing SAC, and to find the optimal duration.

Delayed Rupture of an Anterior Communicating Artery Aneurysm After Elective Woven Endobridge Embolization, Re-Treated With Microsurgical Clipping: Operative Technique and Systematic Review

The Woven EndoBridge (WEB) device is designed for intrasaccular flow disruption for embolization of intracranial aneurysms. In limited experience so far, the rate of rupture after adequate occlusion by embolization has been low. A 58-year-old man initially had an incidental, unruptured 10.4-mm anterior communicating artery aneurysm treated with WEB embolization. Although his 6 months follow-up angiogram showed adequate occlusion of the aneurysm, he presented to our facility with aneurysmal recurrence caused by WEB compaction and rupture. This condition was treated with surgical clipping of the aneurysm. The literature was systematically reviewed for cases of delayed rupture after WEB embolization. Statistical analyses included studies with at least 20 patients and follow-up of 3 months. We identified 36 studies, which were primarily retrospective observational studies. The rate of complete occlusion ranged from 33% to 89%, and the rate of re-treatment ranged from 1.5% to 27%. Across 4 studies, the rate of recanalization ranged from 8.7% to 13%. Two cases of delayed rupture were reported; an additional 4 cases were found in case reports and case series. In only 1 previous case, the aneurysm was reported as previously untreated. Early retrospective data have begun to define the history of WEB-treated aneurysms. Rupture of a previously unruptured, WEB-treated aneurysm with adequate initial occlusion is rare. We describe such a case with techniques for management, showing that aneurysm recurrence and delayed rupture are possible despite good interim angiographic results. This report raises questions about follow-up for WEB-treated aneurysms.

Anterior Circulation Fusiform Aneurysms Have a Lower Occlusion Rate After Pipeline Embolization Device Treatment Than Posterior Circulation Fusiform Aneurysms: A Multicenter Cohort Study.

Objective:Intracranial fusiform aneurysms are uncommon and can occur in vessels of the anterior circulation (AC) or posterior circulation (PC). While flow diversion is one treatment option, research into Pipeline Embolization Device (PED) treatment is lacking. This study explored the efficacy and safety of PED treatment for intracranial fusiform aneurysms, and compared therapeutic effects between AC and PC aneurysms.MethodsIn the post-market multi-center cohort study of embolization of intracranial aneurysms with PED in China (PLUS) registry study, we retrospectively analyzed 71 fusiform aneurysms in 67 patients among 1,171 patients treated with a PED from November 2014 to October 2019. The general characteristics, perioperative status, aneurysm occlusion rate at the last follow-up angiography, and changes in modified Rankin Scale scores were analyzed. Aneurysms were divided into AC and PC groups, and univariate and multivariate analyses were conducted.ResultsThe study included 26 AC (25 patients) and 45 PC (42 patients) aneurysms. A total of 75 PEDs were used, an average of 1.1 PEDs were used, and the median follow-up was 6.7 months. Fifty aneurysms (71.4%) were occluded and twenty (28.5%) were incompletely occluded. There were significantly more occluded aneurysms in the PC group than in the AC group (12 vs. 38; P = 0.001). Risk factors for incomplete occlusion were AC aneurysms (P = 0.001) and a perforating artery originating from the aneurysm (P = 0.006). The mean modified Rankin Scale score was significantly lower at the last follow up than preoperatively (0.58 vs. 0.21; P = 0.0001).ConclusionNon-overlapping PED is a safe and effective treatment for both AC and PC fusiform aneurysms. The occlusion rate of AC fusiform aneurysms is lower than that of PC.

Feasibility and Safety of Transradial Aneurysm Embolization: A Systematic Review and Meta-Analysis

Use of the transradial access (TRA) approach for neuroendovascular procedures has been increasing in recent years. Our aim is to assess the feasibility, success rate, and complications associated with TRA for intracranial aneurysm embolization. PubMed, Scopus, and Embase were systematically searched for studies using TRA for intracranial aneurysm embolization. Random-effects models were used to obtain pooled rates of procedural success and complications. Twenty-four studies comprising 1283 (85.9%) TRA and 122 (8.2%) distal TRA aneurysm embolization procedures were included. The pooled success rate of the 18 studies in the meta-analysis was 93.5% (95% confidence interval [CI], 91.1%-95.8%). The pooled thromboembolic complication rate was 0.5% (95% CI, 0.1%-0.9%), the hemorrhagic complication rate was 0.5% (95% CI, 0.1%-0.9%), and the access site complication rate was 0.8% (95% CI, 0.3%-1.3%). One study (4.3%) used exclusively a 7-French guide catheter, and most used a 6-French guide catheter (22 of 23 studies, 95.7%), which was further incorporated as part of a triaxial configuration through a sheathless 8-French system in 4 studies (17.4%), 7-French guide catheter in 2 studies (8.7%), and 8-French sheath in 1 study (4.3%). The embolization techniques used were flow diverter placement in 451 cases (39.1%), coiling in 376 (32.6%), stent-assisted coiling in 127 (11.0%), balloon-assisted coiling in 104 (9.0%), Woven EndoBridge system in 50 (4.3%), and flow diverter placement plus coiling in 42 (3.6%). Treating intracranial aneurysms using various embolization techniques through TRA is feasible and associated with low access site and intraoperative complications.

Treatment of large and giant posterior communicating artery aneurysms with the Surpass streamline flow diverter: results from the SCENT trial

BackgroundThe Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the...

Artificial Intelligence-Assisted Microcatheter Shaping for Intracranial Aneurysm Coiling: A Preliminary Study

To evaluate the efficacy of artificial intelligence (AI) technology-assisted microcatheter shaping for coil embolization of intracranial aneurysms. From June 2019 to May 2021, 30 aneurysms in 24 patients were treated with coiling embolization using computer software-assisted microcatheter shaping at our institution. All patients underwent digital subtraction angiography (DSA) before coiling embolization. After three-dimensional (3D) rotational angiography, digital imaging and communications in medicine (DICOM) data were extracted and imported into computer software based on an AI algorithm. 3D images of the parent artery and aneurysm were constructed with the software and data including the central axis of the parent artery, aneurysm location, aneurysm size, and 3D structure were automatically obtained. The optimal microcatheter path was calculated and the shape of the mandrel was automatically generated. Surgeons shaped the mandrel and microcatheter following the AI-generated template and completed the endovascular procedure. All patients successfully completed the endovascular procedure without perioperative complications. The microcatheters shaped as per the AI template accurately entered the aneurysm sacs in 1 attempt; 15 aneurysms required no microguidewire assistance in catheterizing the aneurysm sac and 15 did. The stability of the microcatheters during the procedures was satisfactory. No rebound incidence was observed and no reshaping was necessary. The AI-assisted microcatheter shaping technology provides a new method to generate the optimal shape for the mandrel and microcatheter during endovascular procedures. The technology facilitates microcatheter accuracy and stability during coiling embolization and provides technical support for surgeons.

Prospective study on embolization of intracranial aneurysms with the pipeline device (PREMIER study): 3-year results with the application of a flow diverter specific occlusion classification

BackgroundThe pipeline embolization device (PED; Medtronic) has presented as a safe and efficacious treatment for small- and medium-sized intracranial aneurysms. Independently adjudicated long-term results of the device in treating these...

And don't forget your anti in-stent stenosis pill! Commentary on 'Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device' by Flores-Milan et al.

In their INR study, Flores-Milan et al. present a retrospective single-centre study that aimed to investigate and determine some of the factors associated with in-stent stenosis (ISS) after intracranial aneurysm (IA) embolization using a commercially available flow diverter stent (FD). The retrospective analyses included ruptured and unruptured intracranial aneurysms treated with standalone flow diverter stent implantation or initial coil obliteration with the FD device placed subsequently two weeks after initial treatment. The article's methodology was carefully tailored to demystify the unknown pathophysiological mechanism behind the entity of interest called in-stent stenosis. Study outcomes also included angiographic evaluation of aneurysm occlusion thrombotic and hemorrhagic events. The authors reported excellent technical and clinical results altogether. The achieved angiographic occlusion rates resonate with the current obliteration results reported in the literature. Mortality and morbidity are congruent with previously published results and were 5.3% and 1.1%, respectively.

Use of Surpass Streamline Flow Diverter for the Endovascular Treatment of Craniocervical Aneurysms: A Single-Institution Experience

Flow diversion has revolutionized endovascular treatment for cerebral aneurysms. The Surpass Streamline flow diverter (SSFD) has shown promise for expanding flow diversion device options for aneurysm treatment. SSFD differs from earlier stents by maintaining high porosity with increased pore density to ensure appropriate flow disruption. Given the delivery system's increased dimension options and potential greater flow-diverting properties, SSFD is poised to extend the anatomic and pathologic reaches of flow diversion therapy. Data pertaining to SSFD-treated aneurysms were gathered retrospectively between 2019 and 2020, including aneurysm location, size, symptoms, complications, and occlusions rates at follow-up. Size was categorized as small (<10 mm), large (10-25 mm), and giant (>25 mm) according to SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms) criteria. Aneurysm occlusion on follow-up imaging was characterized by Simple Measurement of Aneurysm Residual after Treatment (SMART) grading with adequate occlusion defined as grades 3 and 4. Imaging was performed at time of treatment and 6-month and 1-year follow-up. There were 42 aneurysms treated with SSFD throughout the cerebrovascular system: 3 cervical, 4posterior, and 35 intracranial anterior circulation. Complete occlusion rates at 6 months and 1 year were 48% and 57% with adequate occlusion achieved in 89.6% and 85.7%, respectively. Rates of complete occlusion were higher for small (69%) compared with large (38%) aneurysms. Our data suggest comparable complete occlusion rates compared with SCENT (66.1% vs. 57% in our center) and adequate occlusion rates. Similar occlusion rates to prior studies despite broadened inclusion criteria and diversity of treated aneurysms demonstrate favorable generalizability of flow-diverting technology to a wide array of aneurysmal pathology.

Predisposing factors for the deformation of parent artery of anterior circulation saccular aneurysm after stent-assisted embolization: A retrospective cohort study.

It has been previously reported in several studies that deformation of parent artery (DPA) occurs after stent-assisted coil embolization (SACE) for intracranial aneurysms (IAs). To investigate the predisposing factors of stent-induced DPA, as well as its effect on the follow-up of aneurysm embolization. Clinical and imaging data were collected from 198 patients (201 aneurysms). Angles of the stent-covered parental artery were measured before treatment and during follow-up. Cases in which the angle had changed more than 5 degrees, were defined as DPA. The related factors of DPA were analyzed. The relation between DPA and follow-up results was also studied. Univariate analysis revealed that sex (p = 0.014), age (p = 0.017), aneurysm location (p < 0.001), stent type (p < 0.001), aneurysm size (p = 0.019), and pretreatment angle (p = 0.002) correlated with DPA. On the other hand, multivariate analysis revealed that aneurysms located in the anterior communicating artery (ACOA) (OR = 4.559, p = 0.013) and middle cerebral artery (MCA) (OR = 9.474, p < 0.001) were independent predisposing factors for DPA after stent implantation, whereas a braided stent (OR = 0.221, p = 0.030), flow diverter (FD) device (OR = 0.100, p = 0.028) were negative factors to develop DPA. The complete occlusion rate in the DPA group was higher (p = 0.035) than in the non-DPA group. Aneurysms located in ACOA and MCA are more prone to DPA after SACE than aneurysms at other locations in the anterior circulation, braided stents and FD devices do not predispose to induce vascular deformation. DPA may be beneficial for the long-term cure of IAs after SACE.

166 Predictors of Incomplete Aneurysm Occlusion After Treatment with Pipeline Embolization Device: PREMIER Trial 1-year Analysis

INTRODUCTION: Failure of treatment with Pipeline Embolization Device (PED) occurs in 16.1% to 24.6% of aneurysms. Studies investigating mechanisms behind PED failure are mostly retrospective series with conflicting findings. We performed an analysis of aneurysms that failed to achieve complete occlusion in the Prospective Study on Embolization of Intracranial Aneurysms with the Pipeline Device (PREMIER) trial. METHODS: PREMIER was a prospective, multicenter and single-arm interventional. Assessment images was done by independent core laboratory. We retrospectively analyzed patients who failed the primary efficacy endpoint. Aneurysms with incomplete occlusion (RR &gt; 1) were further analyzed and compared to completely occluded aneurysms. RESULTS: Twenty-five (18.1%) aneurysms were incompletely occluded at 1-year. Twenty-two patients had RR-3 and 3 had RR-2. There was a median reduction of 0.9 mm (IQR 0.41-2.43) in maximum-diameter between pre-procedure and 1-year follow-up. Mean age of patients with incomplete occlusion was significantly higher than in those with complete occlusion (mean ±SD; 59.9 ± 10.4 vs 53.6 ± 11.2, P = 0.011). Smoking (P = 0.045) and C6 segment location (P = 0.005) were significantly associated with complete occlusion, while location at V4 (P = 0.01) and C7 (P = 0.007) segments and involvement of a side branch (&lt;0.001) were significantly associated with incomplete occlusion. There was no difference in the rate of inadequate wall apposition between complete and incomplete occlusion groups (12% vs 12.4%, P = 1). In multivariable logistic regression, significant predictors of incomplete occlusion were non-smoker status (adjusted OR, 4.49; 95% CI, 1.11-18.09; p = 0.03), and side branch involvement (adjusted OR, 11.68; 95% CI, 3.84-35.50; P &lt; 0.0001), while the C6 location had reduced odds of incomplete occlusion versus those at other segment locations (adjusted OR, 0.29; 95% CI, 0.10-0.84; p = 0.02). CONCLUSION: In the PREMIER cohort, non-smoking status and vessel branch involvement were the strongest predictors of incomplete occlusion at 1-year. Although the presence of side branches can lead to incomplete occlusion, we observed decrease in aneurysm size and stable remodeling. The efficacy of protecting against rupture remains to be confirmed in longer follow-up. The results from our prospective study is consistent with previous retrospective series and warrants considerations for technique adaptations to achieve higher occlusion rates.

Long-Term Characteristics of De Novo Bleb Formation at the Aneurysm Neck After Coil Embolization in Unruptured Cerebral Aneurysms

De novo bleb formation at the aneurysm neck after coil embolization of unruptured intracranial aneurysms is a rarely observed type of recurrence. The aim of this study was to elucidate the clinical characteristics of recurrent aneurysms in the long-term period. Between January 2002 and December 2015, 290 unruptured intracranial aneurysms were treated with coil embolization at our institution. Patients who underwent retreatment due to aneurysm recurrence were divided into 2 patterns of recanalization: de novo bleb formation at the neck of a coiled sac (type DNV) and an enlarged residual cavity without de novo bleb formation (type non-DNV). Twenty-seven patients with aneurysms (9.3%) underwent retreatment (type DNV, 7; type non-DNV, 20). The initial aneurysm size of type DNV aneurysms was significantly smaller than that of type non-DNV (6.1 ± 2.2 mm vs. 10.1 ± 3.6 mm; P < 0.01), and time to retreatment in type DNV was significantly longer than that in type non-DNV (9.4 ± 5.3 years vs. 2.0 ± 2.0 years; P < 0.01). Two type DNV basilar artery (BA) aneurysms ruptured after a few years; however, the other type DNV aneurysms, including 4 anterior circulation aneurysms (including the internal carotid artery), were observed to grow gradually without rupture for >10 years until retreatment. De novo bleb formation at the neck of a coiled sac emerges with insidious growth during long-term follow-up. Constant caution should be exercised, even in cases of small- and medium-sized anterior circulation aneurysms. A risk of rupture risk may be anticipated, especially in BA lesions.

Initial Experience with Left Transradial Neurointerventions for Cerebral Aneurysms Using the 6-French Simmons Guiding Sheath

ObjectiveThe use of a transradial approach utilizing a Simmons-shaped catheter for neurointervention has been steadily increasing. Although the right radial artery is commonly used, in interventional cardiology, the left transradial approach offers clear clinical benefits for right-handed patients. To the best of our knowledge, no previous studies have examined intracranial aneurysm embolization with the routine use of the left transradial approach. The aim of this study was to evaluate the technical feasibility of left transradial intracranial aneurysm embolization. MethodsWe conducted a retrospective review of a prospective database of consecutive patients who had undergone left transradial intracranial aneurysm coiling using a 6-French Simmons guiding sheath between January and August 2021. The following outcome variables were then analyzed: whether the catheterization was successful, the angiographical results, and the presence of any procedure-related complications. ResultsIn total, 25 patients underwent left transradial coiling for 15 anterior and 10 posterior circulation aneurysms. The Simmons guiding sheath could be successfully shaped and cannulated into the targeted vessel in all patients. All aneurysms were completely embolized without any complications. Immediate postoperative angiograms showed Raymond 1 in 10 aneurysms (40.0%), Raymond 2 in 12 (48.0%), and Raymond 3a in 3 (12.0%). None of the patients required crossover to the right radial or femoral arteries, and no radial artery spasms or occlusions were observed. ConclusionThe results of this study suggest that the left transradial approach for intracranial aneurysm coiling is not only safe, effective, and technically feasible, but also provides improved comfort to right-handed patients.

Abstract TMP61: Telerobotic Neurovascular Interventions With Magnetic Manipulation

Background: Advances in robotic technology have been adopted in various subspecialties of both open and minimally invasive surgery, offering benefits such as enhanced surgical precision and accuracy with reduced efforts and fatigue. Despite the advantages, robotic applications to endovascular neurosurgery have remained largely unexplored due to technical challenges such as the miniaturization of robotic devices that can navigate the complex and tortuous cerebral vasculature. Although some commercial robotic systems enable precise manipulation of conventional guidewires for coronary and peripheral vascular interventions, they remain unsuited for neurovascular applications due to the considerably smaller and more tortuous anatomy of cerebral arteries. Methods: We present a teleoperated robotic system designed for neurovascular interventions based on magnetic steering and navigation. Our system consists of a magnetically controlled guidewire, a robot arm with a permanent magnet attached to its end-effector for steering control of the guidewire, a set of motorized linear drives to advance or retract the guidewire and a microcatheter, and a remote-control console to operate the system under feedback from real-time fluoroscopic imaging and visualization. Results: With a life-sized neurovascular phantom, we demonstrate the navigational capability to reach several branches of circle of Willis and distal cerebral vasculature with the magnetic guidewire under teleoperation of the system. We further demonstrate telerobotically-assisted therapeutic procedures including coil embolization and clot retrieval thrombectomy for intracranial aneurysms and ischemic stroke, respectively. Conclusion: Our telerobotic neurointerventional platform could enable safer and quicker access to hard-to-reach lesions, significantly reduce operative time and perioperative risk by reducing intravascular manipulation, minimize the radiation exposure to interventionalists, and open the possibility of remote procedural services to address challenges in current stroke systems of care. Note: Animal testing will be performed in Q3 2021 and the results will be presented at ISC.

Abstract TP161: Embolization Of Intracranial Aneurysms Using WAVE Extra Soft Coils, A Part Of The Penumbra SMART COIL System: An Interim Analysis Of The SURF Study

Introduction: Initial clinical evidence has shown that coiling with the SMART COIL System (Penumbra, Inc.) is a safe and durable treatment option for intracranial aneurysms. The SURF study is a post-market, prospective, multicenter, single-arm, observational study to assess the utility of the WAVE Extra Soft Coil (WAVE) as fill and finishing coil to support adequate occlusion of intracranial aneurysms. Methods: Enrollment began November 5, 2019; this analysis includes data as of July 20, 2021. Patients undergoing embolization of intracranial aneurysms with WAVE as the final finishing coil and Penumbra SMART COIL System accounting for at least 75% of the total number of coils implanted were enrolled consecutively at 34 centers globally. Post-procedure Raymond Roy Occlusion Classification (RROC) was assessed by a core lab. The estimated enrollment will be 800 patients. Results: This analysis includes 346 patients, mean age 60.1 (SD 13.03), 73.1% female. Of the target aneurysms, 39.8% (135/339) were ruptured, and 80.5% (269/334) were saccular, and 11.5% (39/338) were previously treated. Post-procedure, 89.2% (206/231, 95% CI 85.2%, 93.2%) of aneurysms were RROC I or II. Device-related SAEs occurred in 1.5% (5/346, 95% CI 0.2%, 2.7%) of patients up to 7 days or discharge. The rate of major ipsilateral stroke was 0.6% (2/346), and the intra-procedural rupture rate was 0.6% (2/346). Conclusions: We report interim outcomes from the SURF study. This post-market registry evaluates the safety and performance of the Penumbra SMART COIL System, including WAVE as fill and finishing coil, in the treatment of intracranial aneurysms.

Thromboembolic events during endovascular coiling for unruptured intracranial aneurysms: Clinical significance of platelet reactivity unit and adjunctive cilostazol

ObjectiveThis study aimed to reveal the clinical significance of the platelet reactivity unit (PRU) and the efficacy of adjunctive cilostazol and its association with thromboembolic and microembolic events after coil embolization for unruptured intracranial aneurysms (UIAs). MethodsWe retrospectively analyzed the data of 427 patients with UIAs who underwent endovascular treatment between July 2011 and June 2014. When clopidogrel resistance was confirmed via PRU assay after dual antiplatelet medication (aspirin plus clopidogrel) administration for 5 days, triple antiplatelet therapy with cilostazol was administered (Group I, 274 patients). The other group was placed on standard dual antiplatelet therapy (Group II, 153 patients). All patients underwent magnetic resonance diffusion-weighted imaging within 2 days after endovascular coiling. ResultsNo significant associations with the occurrence of thromboembolic and microembolic events were found between the groups. The occurrence of thromboembolic and microembolic events showed no statistical difference between groups I and II (p = 0.725 for thromboembolic events and p = 0.109 for microembolic events). Also, the PRU value and the occurrence of microembolic events, using a PRU cutoff value of 240, showed no statistical difference (p = 0.114 in group I and 0.064 in group II). There was significant increase in microembolic events after the use of a stent-assisted endovascular procedure. As the PRU value increased, there was a trend toward an increase in the mean number of microembolic lesions without statistical significance. ConclusionEven though there is a presumed anti-thromboembolic effect for clopidogrel resistance in other literature, the clinical efficacy of adjustment of additional cilostazol for endovascular coiling of unruptured aneurysms may be limited due to the unspecified cutoff value of the PRU assay for evaluating the resistance.

Three-dimensional printing-assisted precision microcatheter shaping in intracranial aneurysm coiling.

Optimal microcatheter shaping is essential for successful endovascular coiling procedures which is sometimes challenging. Our aim was not only to introduce a new shaping method using three-dimensional (3D) printed vessel models but also to prove its feasibility, efficiency and superiority. This was a retrospective cohort study. From September 2019 to March 2021, 32 paraclinoid aneurysms managed with endovascular coiling were retrospectively included and identified. Sixteen aneurysms were coiled using 3D microcatheter shaping method (3D shaping group), and traditional manual shaping method using shaping mandrels was adopted for another 16 patients (control group). The cost and angiographical and clinical outcomes between the two groups were compared, and the feasibility and effectiveness of the new 3D shaping method were evaluated and described in detail. With technical success achieved in 93.75%, most of the 16 shaped microcatheters using new shaping method could be automatically navigated into the target aneurysms without the assistance of microguidewires and could be assessed with favorable accessibility, positioning and stability. Twenty-seven out of 32 aneurysms (84.38%) were completely occluded with the rate of perioperative complications being 12.50%. Although there was no significant difference between the occlusion rates and complication rates of the two groups, the new shaping method could dramatically decrease the number of coils deployed and reduce the overall procedure time. Patient specific shaping of microcatheters using 3D printing may facilitate easier and safer procedures in coil embolization of intracranial aneurysms with shorter surgery time and less coils deployed.

Cerebral Aneurysm Coil Embolization with a Coil-Assisted Technique Using a Small-Diameter Helical Coil.

We introduce a coil-assisted technique using a small diameter helical coil to preserve a branch artery in the aneurysm neck or dome during coil embolization of a cerebral aneurysm. We report three cases that were treated with the coil-assisted technique. Using this method, the branch artery was preserved with a small diameter helical coil that was placed to support another frame coil. The first case was a ruptured internal carotid artery-posterior communicating artery (IC-Pcom) aneurysm, the second case was a ruptured anterior communicating artery aneurysm, and the third case was an unruptured IC-Pcom aneurysm, with branching of the Pcom, A2, and Pcom, respectively, from the neck or dome of the aneurysm. We were able to preserve the branch artery in all cases. This technique is feasible and safe for coil embolization of intracranial branch-incorporated aneurysms. The technique is especially useful for preserving branch arteries that are difficult to preserve by conventional techniques.